Academic literature on the topic 'Ruminant production'

Methane gas is produced in the rumen by methanogenic bacteria as a metabolic end product. The energy released by bacteria in the process of methane formation can be used for bacterial cell formation. Methane formation acts as an electron sink into which the hydrogen from all ruminal microorganisms drains, allowing a higher yield of adenosine triphosphate. Factors such as the type of carbohydrate in the diet, level of feed intake, digesta passage rate presence of ionophores or lipids in the diet, and ambient temperature influence the emission of methane from ruminants. Methanobrevibacter spp. appear to be the major methanogens in the rumen, but it is likely that phytogenetic analyses will identify new species. The biochemical reduction of carbon dioxide to methane is well defined, and it has been shown that interspecies hydrogen transfer between methanogens and ruminal bacteria prevents the accumulation of reduced nucleotides and the inhibition of feed digestion. The development of strategies to mitigate methane production in ruminants, without causing a negative impact on ruminant production, continues to be a major challenge for ruminant nutritionists and microbiologists. Enhancement of the reduction of carbon dioxide to acetate and direct genetic manipulation of methanogens are two interventions that may further reduce methane losses of ruminants. Key words: Methane, diet, ruminant, microbiology, methanogen

Maximizing the production of ruminants requires high intakes of feeds that are energy dense, therefore feeds that are usually high in starch. Under these conditions there can be significant passage of partially digested feed starch and fibre to the small intestine. These digesta components interact in a manner that can diminish post-ruminal digestion and absorption. However, in ruminants, the effects of digesta composition on causing physical constraints to digestion and absorption, via increased digesta viscosity have not been given adequate consideration. While elevation of digesta viscosity as a means of reducing rate of nutrient absorption and re-absorption of compounds detrimental to health is a valid approach in humans, digesta viscosity may reduce the production potential of livestock. Thus, there is merit in reviewing the feeding strategies that lead to increased viscosity and how its mitigation can be managed through inclusion of oil in ruminant diets. The interactions between digesta composition and the resultant viscosity with digestive physiology and production factors are examined. This review also highlights the associated benefits of dietary oil for ruminants, such as enhancement of bio-active lipids in ruminant products, health benefits directly to the animal, through decreasing incidence of liver abscesses and effects on production and possibly on the environment (reduction of enteropathogenic bacterial shedding and methane emissions). Key words: Ruminant, starch, digesta characteristics, viscosity, cholecystokinin

Whereas the contribution of ruminants to human civilization remains unequivocal, there are concerns regarding the unintended negative consequences of rearing these animals for food. These concerns range from the ruminant’s contribution to greenhouse gas emissions to negative impacts of its products on the health of consumers. Rearing ruminants for food is thus seen as the root cause of ills such as climate change, species extinction, deforestation, food insecurity, cardiovascular disease, obesity, cancer and diabetes. Indeed, critics of ruminant production envision a future where humanity does not have to rely on animal products for food. They are convinced that this would be the panacea to food and nutrition insecurity, environmental pollution and meat-induced nutritional disorders and diseases in humans. The critics seem to be unaware of the wide diversity of ruminant production systems in use as well as the array of benefits that can be derived from these enterprises. For instance, there are large human communities that inhabit climatically hostile areas, which have no food crop production potential. Food and nutrition needs of these communities are largely dependent on nourishment provided by products and income derived from ruminants and other herbivores. The aim of this review article is to interrogate the validity of the concerns around the use of ruminants for food and highlight appropriate strategies and technologies that may be applied to mitigate some of these challenges. We conclude that solutions already exist that have the potential to deliver efficient, environmentally friendly and consumer-conscious ruminant production systems based on high standards of animal welfare. Such sustainable production systems will ensure that ruminants continue to play a crucial role in food and nutrition security of humans as they have done for millennia.

The ruminal microbiota allows ruminants to utilize fibrous feeds and is in the limelight of ruminant nutrition research for many years. However, the overwhelming majority of investigations have focused on bacteria, whereas anaerobic fungi (AF) have been widely neglected by ruminant nutritionists. Anaerobic fungi are not only crucial fiber degraders but also important nutrient sources for the host. This review summarizes the current findings on AF and, most importantly, discusses their new application potentials in modern ruminant nutrition. Available data suggest AF can be applied as direct-fed microbials to enhance ruminal fiber degradation, which is indeed of interest for high-yielding dairy cows that often show depressed ruminal fibrolysis in response to high-grain feeding. Moreover, these microorganisms have relevance for the nutrient supply and reduction of methane emissions. However, to reach AF-related improvements in ruminal fiber breakdown and animal performance, obstacles in large-scale AF cultivation and applicable administration options need to be overcome. At feedstuff level, silage production may benefit from the application of fungal enzymes that cleave lignocellulosic structures and consequently enable higher energy exploitation from forages in the rumen. Concluding, AF hold several potentials in improving ruminant feeding and future research efforts are called for to harness these potentials.

Productivity is at a maximum when the principles of chemistry and genetics allow it to proceed no further, even under ideal environmental conditions. It is often limited by current knowledge, which could be improved through research, by the antagonism between selection criteria, or by economic considerations that make additional productivity unrealistic. Emphasis on increased productivity per se should give way to or at least accommodate improved efficiency of production. Some of the areas of constraint and potential improvement as they relate to the nutritional and reproductive physiology and genetics of ruminants are discussed. For the most part, advances in the level of production will continue to be made in small increments. Radical changes in performance brought about by new technology must be tested thoroughly under practical conditions to assure that long-term deleterious effects on the ruminant population do not exceed the apparent productivity benefits in the short term. Key words: Biological constraints, ruminants, nutrition, physiology, metabolism, reproduction

This review presents the latest advances in and main obstacles to the application of invitro embryo production (IVEP) systems in small ruminants. This biotechnology is an extremely important tool for genetic improvement for livestock and is essential for the establishment of other biotechnologies, such as cloning and transgenesis. At present, the IVEP market is almost non-existent for small ruminants, in contrast with the trends observed in cattle. This is probably related to the lower added value of small ruminants, lower commercial demand and fewer qualified professionals interested in this area. Moreover, there are fewer research groups working on small ruminant IVEP than those working with cattle and pigs. The heterogeneity of oocytes collected from growing follicles in live females or from ovaries collected from abattoirs remains a challenge for IVEP dissemination in goats and sheep. Of note, although the logistics of oocyte collection from live small ruminant females are more complex than in the bovine, in general the IVEP outcomes, in terms of blastocyst production, are similar. We anticipate that after appropriate training and repeatable results, the commercial demand for small ruminant invitro-produced embryos may increase.

This review presents the latest advances in and main obstacles to the application of invitro embryo production (IVEP) systems in small ruminants. This biotechnology is an extremely important tool for genetic improvement for livestock and is essential for the establishment of other biotechnologies, such as cloning and transgenesis. At present, the IVEP market is almost non-existent for small ruminants, in contrast with the trends observed in cattle. This is probably related to the lower added value of small ruminants, lower commercial demand and fewer qualified professionals interested in this area. Moreover, there are fewer research groups working on small ruminant IVEP than those working with cattle and pigs. The heterogeneity of oocytes collected from growing follicles in live females or from ovaries collected from abattoirs remains a challenge for IVEP dissemination in goats and sheep. Of note, although the logistics of oocyte collection from live small ruminant females are more complex than in the bovine, in general the IVEP outcomes, in terms of blastocyst production, are similar. We anticipate that after appropriate training and repeatable results, the commercial demand for small ruminant invitro-produced embryos may increase.

The agricultural industry is the main emitter of methane (CH4) and nitrous oxide (N2O), gases that each have a global warming potential that is greater than that of CO2 by 23 and 298 times, respectively. On a global scale, enteric fermentation from ruminant animal production (especially of cattle and sheep) is responsible for between 21% and 25% of total anthropogenic CH4 emissions. The search for effective, simple, and fast methods to measure the production of CH4 and other products from ruminal fermentation has been the objective of several studies on ruminant nutrition. Thus, techniques have been developed under experimental conditions of Brazil and other international countries to quantify CH4 emissions of ruminants. The objective of this literature review is to discuss and compare the existing techniques of measuring enteric CH4 from ruminants. Each technique has a shortcoming or disadvantage in its characterization of ruminal fermentation. The ex-situ technique of measuring CH4 from ruminal fermentation has been quite promising, because it facilitates the measurement of CH4 and other fermentation products, such as short chain fatty acids (SOFA). CH4 detection by a portable laser is effective in monitoring fluctuations in emission and is recommended especially for short-term measurements of respiring and eructating animals reared in a feedlot system. Other methods are being improved and better adapted for practical use in the ongoing quest for more efficient uses of ruminal fermentation products.

Since 1986 the RAMR project (Recherche Appliquee en Milieu Reel) has conducted on-farm research on the Adja Plateau in Mono Province (South Benin). In this article, technical and socio-economic aspects of small ruminant production systems on the Adja Plateau are described. Monitoring of small ruminant flocks showed that about 25% of the small ruminants were sold annually. Export of nutrients as a result of the sale of animals (85 g N. 23 g P. 12 g K and 46 g Ca per hectare) was low compared with export through crop production. In-depth studies at village level showed that farmers mainly collected oil palm leaves, constituting 75% of the small ruminant rations, to feed their animals. Nutrients in collected oil palm leaves represented a substantial fraction (about 10%) of available nutrients in fields under oil palm. Proposals for future research on small ruminant production systems have to contribute to the sustainability of farming systems. Emphasis will be put on animal feeding and feed production integrating small ruminant and crop production.

Background Ruminal methane (CH4) emissions from ruminants not only pollute the environment and exacerbate the greenhouse effect, but also cause animal energy losses and low production efficiency. Consequently, it is necessary to find ways of reducing methane emissions in ruminants. Studies have reported that feed additives such as nitrogen-containing compounds, probiotics, prebiotics, and plant extracts significantly reduce ruminant methane; however, systematic reviews of such studies are lacking. The present article summarizes research over the past five years on the effects of nitrogen-containing compounds, probiotics, probiotics, and plant extracts on methane emissions in ruminants. The paper could provide theoretical support and guide future research in animal production and global warming mitigation. Methods This review uses the Web of Science database to search keywords related to ruminants and methane reduction in the past five years, and uses Sci-Hub, PubMed, etc. as auxiliary searchers. Read, filter, list, and summarize all the retrieved documents, and finally complete this article. Results Most of the extracts can not only significantly reduce CH4 greenhouse gas emissions, but they will not cause negative effects on animal and human health either. Therefore, this article reviews the mechanisms of CH4 production in ruminants and the application and effects of N-containing compounds, probiotics, prebiotics, and plant extracts on CH4 emission reduction in ruminants based on published studies over the past 5 years. Conclusion Our review provides a theoretical basis for future research and the application of feed additives in ruminant CH4 emission reduction activities.

Methane is a potent greenhouse gas with a global warming potential 21 times that of carbon dioxide. Globally, ruminants are the main anthropogenic contributors to methane release to the atmosphere. Methane is produced in the gastrointestinal tract of ruminants, mostly within the rumen by methanogenic archaea. However, methane production represents a loss of 2 to 12% of dietary gross energy for the animal, which could otherwise be available for growth or milk production. Therefore, mitigation of methane production by ruminants could produce both economic and environmental benefits, with more sustainable and energy efficient livestock, and offering a promising way of slowing global warming. Despite extensive research undertaken to find ways of reducing methane emissions from ruminants, progress has been relatively limited. Furthermore, there is still a lack of studies linking rumen microbiology and ruminant nutrition and production. The central purpose of this research was to investigate feed additives to reduce methane emissions and to understand associated changes that occur in the rumen microbiota. For the first experiment (Chapter 2), biochar was evaluated as an antimethanogenic compound for beef cattle. The in vitro gas production technique was used to study the effects of biochar on rumen fermentation and methane production. Overall, methane production was reduced by 5% by the addition of biochar compounds (10 g/kg of substrate). The observed reduction in methane produced was not associated with a change in volatile fatty acid profile suggesting biochar primarily inhibited fermentation. Ammonia concentration was significantly reduced with biochar inclusion. Because different biochars had different effects on methane production, further investigation of relationships between the physicochemical properties of biochars and antimethanogenic effects are necessary. However, due to the small reduction in methane production recorded, research with biochar was discontinued. Encapsulated nitrate was then explored as an antimethanogenic additive and as an alternative non-protein nitrogen source to urea (Chapter 3). The effect of using encapsulated nitrate as a replacement for urea or dietary protein, plus the addition of inorganic sulphur, on enteric methane emissions, nutrient digestibility, nitrogen utilization and microbial protein synthesis from crossbred beef steers were studied. In addition, nitrate toxicity and eating behaviour were investigated. The inclusion of encapsulated nitrate reduced methane production compared to urea and a true protein source, with no adverse effects on rumen fermentation or nitrogen metabolism and no effects with the inclusion of elemental sulphur. The level of addition of encapsulated nitrate (14.3 g nitrate /kg DM) and the time of adaptation chosen for this study (14 days) were adequate to avoid nitrate toxicity. Finally, the effects of adding nitrate inclusion to different basal diets on rumen microbial populations and relationships of these populations with methane production were investigated (Chapter 4). The V4 hypervariable regions of the bacterial and archaea 16S rRNA genes were amplified and sequenced. Effects on microbial population induced by nitrate were dependant on the basal diet but nitrate altered specific archaeal and bacterial OTUs consistently between studies. A direct and strong correlation between some archaea taxonomic groups and OTUs with methane production was observed.

Dans le domaine de l'alimentation des ruminants, les huiles essentielles, en raison de leur pouvoir antibactérien, sont considérées de plus en plus comme une des solutions alternatives aux antibiotiques tels que les ionophores. Cette étude a pour but de caractériser les effets de deux composés aromatiques issus des huiles essentielles (CHE), l'aldéhyde cinnamique (Ac) et le carvacrol (Cv). Quatre expérimentations sont menées, avec des méthodologies différentes : in vitro en culture batch, avec des doses de 10, 100 et 1000 ppm dans le milieu, un substrat reproduisant une ration simplifiée et des durées d'incubation de 4 et 16h ; in situ où deux types de ration, l'une riche en amidon (RA), l'autre riche en fibre (RF) sont utilisées avec deux temps d'adaptation aux CHE (3 et 21 jours), et où les effets des deux CHE administrés oralement à raison de 1 g/jour/vache en période de tarissement sont mesurés sur la disparition ruminale in sacco de l'amidon de maïs, des matières azotées de différentes sources protéiques, ainsi que des glucides pariétaux de la luzerne ; un bilan nutritionnel conduit sur vaches taries recevant les deux CHE séparément (à la dose quotidienne de 1 g/vache) et en association ; et enfin, de façon contemporaine au bilan, la mesure de l'effet de l’association des deux CHE sur la production laitière et la qualité du lait. Ln vitro, il existe un seuil compris entre 100 et 1000 ppm dans le milieu qui conduit à une inhibition pratiquement totale des activités fermentaires et traduit l'effet antimicrobien des CHE. Les réponses aux doses de 10 et 100 ppm ne sont globalement pas différentes. La dose de 10 ppm, correspondant approximativement à 1 g/j/vache, a donc été retenue dans les expérimentations in vivo. Certaines réponses aux CHE témoignent d'une amélioration potentielle de l'utilisation de l'énergie. Ils diminuent in vitro la production de méthane calculée à partir des AGV après 16h de fermentation. L'Ac augmente la proportion de propionate in vitro comme in sacco après 21 jours d'adaptation; cependant ces effets ne sont pas répétés lors de la réalisation des bilans nutritionnels ; ils seraient donc observés uniquement dans le cadre de rations particulièrement riches en glucides pariétaux ou concentrées en amidon. Le Cv augmente la digestion ruminale de l'ADF mesurée par la méthode des bilans ainsi que la disparition de l’ADF de luzerne in sacco avec la ration riche en amidon, ce qui conduit, d'après les caractéristiques des rations, à associer préférentiellement ce CHE aux rations contenant un minimum de 34 % d'amidon. L'effet des CHE sur les glucides de réserve semble par contre limité, puisque l'Ac diminue la disparition de l'amidon de maïs mesurée in sacco mais de façon numériquement plus marquée à court terme, et que cet effet n'apparaît pas avec ce CHE dans le bilan de l'utilisation digestive de l'amidon. D'autres résultats traduisent une amélioration probable de l'utilisation de l'azote. Les deux CHE diminuent la concentration du N-NH3 dans le milieu de culture après 16 heures d’incubation in vitro ainsi qu'in situ avec la ration riche en amidon. Le Cv augmente l’efficacité de la synthèse microbienne mesurée dans le cadre du bilan nutritionnel, avec une ration moyenne en terme d'apports en amidon et glucides pariétaux, et plus pauvre en MAT, comparativement aux rations RF et RA utilisées in sacco. L'association de l'Ac et du Cv administrée oralement à des vaches en lactation n'a cependant pas entraîné d'effet sur la production laitière; il semble toutefois que l'utilisation métabolique de l'azote soit légèrement améliorée, comme en témoigne la diminution significative de la teneur en urée du lait. A l'instar des antibiotiques ionophores, le Cv et l'Ac semblent donc pouvoir être utilisés pour modifier la digestion ruminale, afin d'orienter le métabolisme fermentaire vers une utilisation plus efficace de l'énergie et de l'azote chez le ruminant. Les conditions dans lesquelles ils expriment les réponses les plus favorables restent toutefois à préciser, ainsi que leur effet exact sur la microflore ruminale<br>Ln the area of ruminant feed, essential oils are increasingly being considered, on account of their antibacterial property, as one alternative solution to antibiotics such as ionophores. This study sets out to characterize the effects of two aromatic essential oil compounds (EOC), cinnamaldehyde (Ca) and carvacrol (Cv). Four experiments were conducted using different methodologies: in vitro batch culture with doses of 10, 100 and 1000 ppm in the medium, a substrate reproducing a simplified ration and incubation times of 4 and 16h; in situ in which two types of ration are used, one high starch (HS), the other high fibre (HF) with two adaptation times to EOCs (3 and 21 days), and in which the effects of the two EOCs administered orally at the rate of 1 g/day/cow during the dry period are measured on in sacco rumen disappearance of maize starch, nitrogen matter from different protein sources, and parietal carbohydrates of alfalfa; a nutrient intake analysis on dried off cows receiving both EOCs separately (daily dose of 1 g/cow) and in association; and finally, contemporary with nutrient intake analysis, measurement of the effect of the association of both EOCs on milk production and milk quality. Ln vitro, there exists a threshold of between 100 and 1000 ppm in the medium which leads to almost total inhibition of fermenting activities, translating the antimicrobial effects of the EOC. Responses to doses of 10 and 100 ppm do not differ globally. The dose of 10 ppm, approximately corresponding to 1 g/d/cow, was therefore chosen for the in vivo experiments. Some responses to the EOCs evidence a potential improvement in utilization of energy. They reduce in vitro production of methane calculated on VFA levels after 16 h fermentation. Ca increases the proportion of propionate both in vitro and in sacco after 21 days’adaptation; however these effects are not repeated in nutrient intake analysis; they are apparently therefore only seen when rations are particularly high in parietal carbohydrates or starch concentration. Cv increases rumen digestion of ADF measured using the nutrient analysis method, and the in sacco disappearance of alfalfa ADF with the high starch ration which, according to ration characteristics, leads to associating this EOC preferably with rations containing at least 34% starch. On the other hand, the effects of EOCs on reserve carbohydrates appear to be limited, since Ca reduces the disappearance of maize starch measured in sacco but with higher counts over the short term, while this effect is not seen with this EOC in the results on the digestive utilization of starch. Other results translate a probable improvement in the utilization of nitrogen. Both reduce the EOCs concentration of N-NH3 in the culture medium after 16 hours' in vitro and in situ incubation with the high starch ration. Cv increases the efficacy of microbial synthesis, as measured by the nutrient analysis method, with a ration providing average starch and parietal carbohydrate content but lower total nitrogen content, with respect to the HF and HS rations used in sacco. The association of Ca and Cv administered orally to lactating cows did not however evidence any effect on milk production; it would appear however that the metabolic utilization of nitrogen is slightly improved, as indicated by the significant reduction in the urea content of the milk. Similar to ionophore antibiotics, Cv and Ac therefore appear to have use in modifying ruminant digestion, to orient fermenting metabolism towards more efficient energy and nitrogen utilization in ruminants. However, the conditions under which they express the most favourable response remain to be specified, and also their exact effect on ruminant microflora

Les légumineuses permettent de réduire les intrants en élevage (engrais, concentrés) en raison notamment de leurs niveaux élevés en protéines. Cependant, à la fois pendant le processus d'ensilage et celui de fermentation dans le rumen, les protéines peuvent subir une importante dégradation, ce qui affecte la valeur nutritive des fourrages et induit des rejets d'azote (N) importants, notamment dans l'urine. Certaines légumineuses peuvent alors être d'un intérêt particulier car elles produisent des composés secondaires qui peuvent modifier positivement les processus fermentaires et digestifs. Ainsi, les tannins condensés (CT) présents dans le sainfoin (SF, Onobrychis viciifolia) sont capables de se lier aux protéines, réduisant leur dégradation dans le silo et le rumen et se traduisant par un transfert de l'excrétion d'azote de l'urine vers les fèces. Le trèfle violet (RC, Trifolium pratense) contient la polyphénoloxydase (PPO), une enzyme qui catalyse l'oxydation de différents composés phénoliques en quinones. Comme les CTs, les quinones sont capables de former des complexes avec les protéines permettant de réduire leur dégradation dans le silo et le rumen. L'objectif de cette thèse était alors d'étudier et de quantifier les bénéfices potentiels de l'utilisation de ces deux espèces de légumineuses bioactives sur i) la qualité et la conservation des ensilages, ii) la fermentation ruminale, l'efficacité digestive et les performances des ovins, et iii) l'empreinte environnementale (excrétion d'N et de CH4). Nous avons effectué deux essais in vitro et deux essais in vivo, basés sur des ensilages composés de ces deux légumineuses, seules ou en mélange avec une graminée (la fléole- T, Phleum pratense L.) qui nous a servie de contrôle. Les essais in vitro nous ont permis de nous focaliser sur la qualité et la conservation des ensilages ainsi que sur la fermentation ruminale, tandis que les essais in vivo se sont concentrés sur la performance et l'efficacité digestive des agneaux, ainsi que sur leur bilan azoté et leurs émissions de CH4. L'inclusion de légumineuses bioactives dans les ensilages d'herbe a amélioré la qualité du fourrage, la fermentation pendant le processus d'ensilage ainsi que la protection des protéines contre une dégradation au sein du silo et du rumen. Globalement, l'alimentation des agneaux avec des mélanges comportant ces légumineuses s'est traduite par une augmentation de l'ingestion de matière sèche, en comparaison des agneaux alimentés avec la graminée pure. Néanmoins, en raison de la digestibilité nettement plus faible de T-SF, probablement due à une composition et une nature des fibres différentes ainsi qu'à la présence de CT, les agneaux ayant reçu T-SF ont montré une ingestion et des performances plus faibles que ceux ayant reçu les ensilages contenant RC. Dans le rumen, il semble que les protéines de RC aient été plus protégées de la dégradation que celles de SF, tandis que dans la suite du tractus digestif, les complexes formés entre protéines et CT (avec SF) se seraient moins dissociés que ceux formés entre protéines et quinones (avec RC), ce qui pourrait en partie expliquer le transfert d'excrétion de l'N de l'urine vers les fèces, observé chez les agneaux alimentés avec T-SF et bénéfique pour l'environnement. SF a également permis de réduire légèrement les émissions de CH4. Ainsi, utiliser des légumineuses bioactives dans les pratiques d'alimentation des ruminants apparaît une stratégie prometteuse pour fournir des produits animaux de façon plus durable. Nos résultats montrent que chaque espèce apporte des avantages différents, plutôt orientés vers la qualité de l'aliment et les performances animales pour RC mais plutôt orientés vers la réduction des rejets pour SF. Des recherches complémentaires sont donc nécessaires pour mieux caractériser ces avantages et élargir les investigations à d'autres espèces, d'autres mélanges et d'autres bénéfices potentiels. (...)<br>Fodder legume species allow to reduce inputs in livestock breeding systems (fertilizer, concentrates) notably because they contain high levels of crude proteins which are of primary importance in ruminant nutrition. However, during both silage and rumen fermentation processes, proteins are submitted to degradation which affects forage nutritive value and leads to nitrogen (N) losses notably via urine. Some specific legumes can then be of particular interest as they produce plant secondary compounds that can positively affect silage and digestive processes. Condensed tannins (CTs) present in sainfoin (SF, Onobrychis viciifolia) are able to bind with proteins thereby reducing their degradation in the silo and the rumen, resulting in a shift in N excretion from urine to faeces. Red clover (RC, Trifolium pratense) contains polyphenol oxidase (PPO), an enzyme that catalyses the oxidation of different phenolics into quinones. As CTs, quinones are able to form complexes with proteins that will similarly reduce their degradation in the silo and the rumen. The aim of this thesis was to investigate and quantify the potential benefits of using these two bioactive legume species on i) quality and conservation of silages, ii) rumen fermentation, digestive efficiency and sheep performance, and iii) environmental footprint (N excretion and CH4 emissions). We conducted two in vitro and two in vivo trials which were based on silages of pure legumes or of different mixtures with the grass species (timothy T, Phleum pratense L.), which served as control. In the in vitro trials, we focussed on silage quality, silage conservation and rumen fermentation, while in the in vivo trials, we focussed on lambs' performance, digestion efficiency, N balance and CH4 emissions. Including bioactive legumes in mixtures with grass improved, compared to pure grass, forage quality and fermentation during the silage making process, as well as proteins' protection from degradation within both the silos and the rumen. Lambs fed with the mixtures involving legumes responded with an increase in DM intake compared to their counterparts fed with T. Nevertheless, due to a possibly different fibre composition and to the presence of CT which impaired SF digestibility, lambs that consumed T-SF showed lower intake and performance than those that received RC-containing silages. In the rumen, RC proteins appeared more protected from degradation than SF ones, while in the subsequent parts of the digestive tract, the proteins-CT complexes (from SF) might less dissociate than the proteins-quinones ones (from RC). This could partly explain the environment-friendly shift in N excretion from urine to faeces when animals are fed with T-SF. SF also allowed to slightly reduce CH4 emissions. Thus, utilizing bioactive legumes in livestock feeding practices is a promising strategy to produce animal products more sustainably. Our results show different benefits relative to the bioactive legume species involved, directed towards boosted forage quality and animals' performance for RC but towards lowered wastes for SF. Further research is thus needed to better characterize these benefits and enlarging investigations to other plant species, mixtures and potential benefits (e.g. health). This will help to determine the appropriate choice of plant species according to the objectives

Thesis (PhD (Forest and Wood Science))—University of Stellenbosch, 2007.<br>Sustainable livestock production in semi-arid Botswana could be improved through tree planting on-farm to provide much needed protein and shade. Such action can be encouraged if the growth, productivity, nutritional value of trees and their contribution to mass gain of livestock are known.. A study at Malotwana investigated two indigenous species, Acacia galpinii and Faidherbia albida, and two exotic species, Leucaena diversifolia and L. leucocephala, at three spacings in a randomised complete block design replicated five times. The three spacings represented 400, 317 and 241 trees per hectare. The study was conducted over 6.5 years. Indigenous trees were sampled biennially and exotics annually to evaluate crown width, height, stem diameter, stem number and stem volume index. Complete plant harvesting of exotic trees at 2.5, 4.5 and 6.5 years evaluated agroforestry production. Leaves from all four species and pods of exotic species were analysed for chemical composition. Two groups of eight lambs were balanced for mass at selection for an on-farm feeding trial. Browse from exotic trees, comprising a 2:1 ratio of pods to leaves, was fed at 30% as supplement to hay to one group whose mean mass was contrasted with that of the control group fed sorghum bran at 30%. A. galpinii was a promising species, adaptable to planting away from its origin. Its crown width ranged from 5.86 m in high density plots to 6.08 m at low density and was significantly different among stands (p = 0.0406) at 6.5 years. Diameter at breast height (dbh) was significantly different among stands aged 6.5 years (p = 0.0003) and ranged between 10.38 cm at high density to 12.48 cm in low density plots, demonstrating a capacity to provide both shade and poles on-farm. At 4.5 years, F. albida attained a mean height of 4.5 m and 4.5 cm in dbh but suffered 67% mortality during a severe drought. Annual fodder production of 0.647 and 0.996 metric tonnes ha-1 for leaves and pods of L. diversifolia and 1.237 and 1.431 for L. leucocephala was recorded in years of average rainfall. Yields of 0.3 and 0.59 metric tonnes ha-1 were recorded for both species in the driest year. Equally good agroforestry production was obtained from both low and high density stands suggesting that low density plantings, which foster higher plant survival and reduce disease incidence, are best suited to the semi-arid conditions of Botswana. The crude protein of leaves ranged between 16.26 (L. diversifolia) and 25.25% (F. albida). They were highly digestible with more than twice the calcium content livestock require. Crude protein and digestibility measures were significantly different among leaves and varied significantly at different spacings (p<0.0001). Pods of the exotic species contained significantly more protein than the leaves (p<0.0001). Lambs supplemented with browse gained 102.33 g per animal per day while the control group gained 83.95 g. There were significant differences between groups during growth (p<0.05). Growing of A. galpinii, complemented with L. diversifolia and L. leucocephala, can supply short and long term feed, and greatly enhance livestock production while diversifying farm feed sources

[EN] The main objective of this Thesis was to study the energy metabolism in small ruminants under different nutrition sceneries. As methodology we utilized indirect calorimetry instead of direct calorimetry or feeding trials. Within indirect calorimetry we worked with a portable open circuit gas exchange system with a head hood. This open circuit respiration system permitted completed the whole energy balance and evaluate the efficiency of utilization of the energy of the diet for different physiological circumstances as milk production in dairy goats or maintenance in sheep. Besides, we could quantify in each trial some of the wastes related to environmental pollution as CH4 emissions and excretion of nitrogen in feces and urine. In this thesis three experiments were designed, two in dairy goats and other in sheep as we described below. In the first experiment, digestibility, energy balance, carbon and nitrogen balance, milk performance, rumen parameters and milk fatty acids and metabolites were obtained. Metabolic cages and open circuit indirect calorimetry system were the methods applied. Treatments consist in two mixed diets with alfalfa as forage. Within the concentrate, oat grain was replaced with rice bran. No significant differences were found for metabolizable energy intake (MEI), 1254kJ/kg of BW0.75 on average, and heat production (HP); 640 kJ/kg of BW0.75 on average. No differences were obtained for milk production (2.2 kg/d on average) and milk fat was greater in the rice bran diet (6.9% vs. 5.3% for rice bran and oat diets, respectively). Energy balance was positive and milk metabolites correlated these found. Regards to CH4 emissions, determined in vivo by gas exchange indirect calorimetry, goats fed the rice bran significantly reduced methane production (23.2 g/d vs 30.1 g/d). In the second experiment, we also used two types of diets, but in this case we substituted the forage and maintained the same concentrate; in one of the diets a grass (Maralfafa [Pennisetum sp.]- M diet) was used as forage and in the other an extensively used leguminous (Alfalfa [Medicago sativa]- A diet). Methods and analysis were the same that in Experiment 1, and here we include metabolites in urine and blood plasma. The dry matter intake was higher for diet A (1.8 vs 1.6 kg/d, respectively) and digestibility coefficients were higher for diet M. However, no significant differences were shown in MEI (1089 kJ/kg of BW0.75, on average) and HP (639 kJ/kg of BW0.75on average). Higher milk yield was observed in A diet than M diet (1.8 vs. 1.7 kg/d, respectively) and metabolites in urine, plasma and milk indicated better use of diet A than M, while no differences in milk composition were found (5% of fat and 4.3% of protein). Methane production was higher for A diet (28.5 g/d) than M diet (25.9 g/d), although these differences were not statistically significant. In the third experiment, energy partition was compared in two sheep breeds (Manchega vs. Guirra) fed above maintenance. We fed again with mixed diets and metabolic cages, indirect calorimetry, nitrogen balance and integral calculus were the tools used for these energy partitioning approach. An approximation of division of heat production was done. ME for maintenence was estimated at 354 kJ/kg of BW0.75and day, on average for the two breeds. Basal metabolic rate was different between breeds; 270 vs. 247 kJ/kg of BW0.75for Guirra and Manchega, respectively.<br>[ES] El objetivo principal de esta tesis fue estudiar el metabolismo energético en pequeños rumiantes bajo diferentes escenarios de nutrición. Como metodología se utilizó la calorimetría indirecta en vez de calorimetría directa o pruebas de alimentación. Dentro de la calorimetría indirecta trabajamos con un sistema portátil de circuito abierto de intercambio de gases con una "urna" (Heat hood). Este sistema de circuito abierto de respiración nos permitió completar todo el balance energético y evaluar la eficiencia de la utilización de la energía de la dieta para diferentes estados fisiológicos como producción de leche en cabras u oveja en mantenimiento. Además fue posible cuantificar en cada ensayo algunas perdidas relacionadas con la contaminación ambiental como emisiones de CH4 y la excreción de nitrógeno en heces y orina. En esta tesis se diseñaron tres experimentos, dos en cabras en lactación y otro en ovejas como describimos a continuación. En el primer experimento se han determinado, digestibilidad, balance energético, balance carbono nitrógeno, producción de leche, parámetros ruminales, ácidos grasos y metabolitos en leche. Jaulas metabólicas y un sistema de circuito abierto de calorimetría indirecta fue el método aplicado. Los tratamientos consistieron en dos dietas mixtas con alfalfa como forraje y dentro del concentrado el grano de avena fue reemplazado por cilindro de arroz. No se encontraron diferencias significativas en la energía metabolizable ingerida (MEI) de 1254 kJ/kg PV0.75 en promedio y una producción de calor (HP) de 640 kJ/kg PV0.75 en promedio. La producción de leche no presentó diferencias significativas entre las dos dietas, (2,2 kg/den promedio), la grasa de la leche fue mayor en la dieta de cilindro de arroz (6,9% vs. 5,3% para cilindro de arroz y avena respectivamente). El balance energético fue positivo y correlacionado a los metabolitos en leche determinados. En cuanto a las emisiones de CH4, determinadas en vivo mediante el intercambio de gases por calorimetría indirecta, las cabras alimentadas con el subproducto redujeron significativamente la producción de metano (23,2 g / d vs 30,1 g / d.). En el segundo experimento, también utilizamos dos tipos de dietas, pero en este caso sustituimos los forrajes y mantuvimos el mismo pienso; en una de las dietas se utilizó como forraje una gramínea (Maralfafa [Pennisetum sp.] - dieta M) y en el otro una leguminosa de uso extendido (Alfalfa [Medicago sativa] - dieta A). Los métodos de análisis y análisis fueron los mismos que los utilizados en el Experimento 1, y se incluyeron además análisis de metabolitos en orina y plasma. La materia seca ingerida fue mayor para dieta A (1,8 vs 1,6 kg/d, respectivamente), los coeficientes de digestibilidad fueron mayores para la dieta M. Sin embargo, no se encontraron diferencias significativas en MEI (1089 kJ/kg PV0.75, en promedio) y HP 639 kJ/kg PV0.75, en promedio). La producción de leche fue mayor en la dieta A que la dieta M, (1,8 vs. 1,7 kg/d, respectively) y los metabolitos en orina, plasma y leche indican un mejor aprovechamiento de la dieta A. No se presentaron diferencias en la composición de la leche (5% de grasa and 4.3% de proteína). La producción de metano fue mayor para la dieta A (28,5 g/d) que para la dieta M (25,9 g/d), aunque estas diferencias no fueron estadísticamente significativas. En el tercer experimento se compararon la partición energética en dos razas de ovejas (Manchega vs. Guirra) en mantenimiento. Fueron alimentadas con dietas mixtas en jaulas metabólicas, calorimetría indirecta, balance carbono nitrógeno y cálculos integrales fueron las herramientas utilizadas para un aproximación de la partición energética. Se realizó una aproximación de división de producción de calor. El ME para mantenimiento se estimó en 354 kJ/kg PV0.75/ día, en promedio para las dos razas. Las diferencias en la tasa metabólica basal entre las razas fu<br>[CAT] El principal objectiu d'aquesta tesi va ser estudiar el metabolism energètic en xicotets ruminants baix diferents escenaris de nutrició. Com a metodologia es va utilitzar la calorimetria indirecta en compte de calorimetria directa o proves d'alimentació. Dins de la calorimetria indirecta treballarem amb un sistema portatil de circuit obert d'intercanvi de gasos amb "urna" (Heat hood). Aquest sistema de respiració de circuit obert ens va permetre completar tot el balanç energètic i avaluar l'eficiència de la utilització de l'energia de la dieta per a diferents circumstàncies fisiològiques com produccion de llet en cabres o manteniment en ovelles. A més va ser possible quantificar en cada assaig algunes perdues relacionades amb la contaminacion ambiental com a emissions de CH4 i l'excreció de nitrogen en femta i orina. En aquesta tesi es van dissenyar tres experiments, dos en cabres en lactación i un altre en ovelles com vam descriure a continuació. En el primer experiment s'han determinat,digestibilidad, balanç energètic, balanç carboni nitrogen, producció de llet, paràmetres ruminales, àcids grassos i metabòlits en llet. Gàbies metabòliques i un sistema de circuit obert de calorimetria indirecta va ser el mètode aplicat. Els tractaments van consistir en dues dietes mixtes amb alfals com a farratge i dins del concentrat el gra de civada va ser reemplaçat per cilindre d'arròs. No es van trobar diferències significatives en l'energia metabolizable ingerida (MEI) de 1254 kJ/kg PV0.75 en mitjana i una producció de calor (HP) de 640 kJ/kg PV0.75 en mitjana. La producció de llet no va presentar diferències significatives entre les dues dietes, (2.2 kg/donen mitjana), el greix de la llet va ser major en la dieta de cilindre d'arròs (6.9% vs. 5.3% per a cilindre d'arròs i civada respectivament). El balanç energètic va ser positiu i correlacionat als metabòlits en llet determinats. Quant a les emissions de CH4, determinades en viu mitjançant l'intercanvi de gasos per calorimetria indirecta, les cabres alimentades amb el subproducte van reduir significativament la producció de metà (23.2 g / d vs 30.1 g / d.).En el segon experiment, també utilitzem dos tipus de dietes, però en aquest cas substituïm els farratges i vam mantenir el mateix pinso; en una de les dietes es va utilitzar com a farratge una gramínea (Maralfafa [Pennisetum sp.] - dieta M) i en l'altre una **leguminosa d'ús estès (Alfals [Medicago sativa] - dieta A). Els mètodes d'anàlisis i anàlisis van ser els mateixos que els utilitzats en l'Experiment 1, i es van incloure a més anàlisi de metabòlits en orina i plasma. La matèria seca ingerida va ser major per a dieta A (1,8 vs 1,6 kg/d, respectivament), els coeficients de digestibilidad van ser majors per a la dieta M. No obstant açò no es van trobar diferències significatives en MEI (1089 kJ/kg PV0.75, en mitjana) i HP 639 kJ/kg PV0.75, en mitjana). La producció de llet va ser major en la dieta Al fet que la dieta M, (1,8 vs. 1,7 kg/d, respectively) i els metabòlits en orina, plasma i llet indiquen un millor aprofitament de la dieta A. No es van presentar diferències en la composició de la llet (5% de greix i 4.3% de proteïna). La producció de metà va ser major per a la dieta A (28,5 g/d) que per a la dieta M (25,9 g/d), encara que aquestes diferències no van anar estadísticament significatives. En el tercer experiment es van comparar la partició energètica en dues races d'ovelles (Manxega vs. Guirra) en manteniment. Van ser alimentades amb dietes mixtes en gàbies metabòliques, calorimetria indirecta, balanç carboni nitrogen i càlculs integrals van ser les eines utilitzades per a un aproximació de la partició energètica. Es va realitzar una aproximació de divisió de producció de calor. L'EM para manteniment es va estimar en 354 kJ/kg PV0.75 / dia, en mitjana per a les dues races. Les diferències en la taxa metabòlica basal entre les races va ser de 2<br>Criscioni Ferreira, PF. (2016). Application of an open circuit indirect calorimetry system for gaseous exchange measurements in small ruminant nutrition [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/64069<br>TESIS

AbstractAgriculture is a significant source of GHGsglobally and ruminant livestock animals are one of the largest contributors to these emissions, responsible for an estimated 14% of GHGs (CH4and N2O combined) worldwide. A large portion of GHG fluxes from agricultural activities is related to CH4 emissions from ruminants. Both direct and indirect methods are available. Direct methods include enclosure techniques, artificial (e.g. SF6) or natural (e.g. CO2) tracer techniques, and micrometeorological methods using open-path lasers. Under the indirect methods, emission mechanisms are understood, where the CH4 emission potential is estimated based on the substrate characteristics and the digestibility (i.e. from volatile fatty acids). These approximate methods are useful if no direct measurement is possible. The different systems used to quantify these emission potentials are presented in this chapter. Also, CH4 from animal waste (slurry, urine, dung) is an important source: methods pertaining to measuring GHG potential from these sources are included.

Abstract This chapter describes the livestock production systems and resource use (land, water quantity and quality, air and ecosystem services), climate change impacts on ruminant livestock, adaptation of livestock systems to climate change, knowledge gaps on adaptation and mitigation of greenhouse gas emissions from livestock.

A number of studies on digestion of the ruminants have shown the process of synthesis of all the essential amino acids in the rumen (Abu Fadel, 2004; Trukhachev, V., Zlidnev, N. 2008). However, according to some researches, microbial protein is deficient in methionine and lysine. This assumption also proves the need for further study of the influence of balanced amino acids to these diets on the growth, development and productive performance of the ruminants. Scientific approbation of the issues related to establishing the requirements of young sheep in lysine and methionine with cystine and development of recommendations for their proper balance in animal rations have been conducted along with a series of physiological, scientific and practical experiments. For this purpose, we used the following research methods: preparative, analytical, measuring and calculating. Zootechnical evaluation of young sheep’s diet with different levels of lysine and methionine with cysteine has been conducted, and influence of these components on growth, development, metabolism, the use of amino acids and wool productivity have been studied. The importance of studying the content of amino acids in plasma is evident because they are the indicators of protein metabolism in the animals’ organism and represent themselves the exchange fund when used in the biochemical transformations in the process of updating the protein of the body tissues and the synthesis of animal products. Increase in young sheep’s diet of lysine and methionine can improve their productivity, reduce the cost of feed energy and improve biochemical indexes of meat, taking into account the optimization of its amino acid composition. Efficiency increase of young sheep during the process of the individual development is linked to conditions of feeding and in particular the usefulness of a protein food, which is primarily determined by sufficient intake of essential amino acids - lysine and methionine with cystine. Thus, the inclusion in the diet of growing young sheep some amount of synthetic amino acids – 6–8 grams of lysine and 3–4 g of methionine per 1 fodder unit, enhances oxidation-reduction processes, increase productivity, i.e. wool yield and other indicators. The content of free amino acids in plasma directly depends on their availability in feed. The use of synthetic amino acids (lysine, methionine and cystine) contributed to the increase of their content in a free state in the blood serum, indicating their increased demand in sheep. With the use of different doses of synthetic amino acids (lysine, methionine, cystine) in the diets of young sheep it has been found that the organization of optimum conditions of feeding, care and management of sheep in winter season help to avoid abrupt changes in the structure of the skin, to ensure the normal development of the histological structure and morphogenetic processes.)

Abstract Puissant field planning is increasingly becoming a sophisticated quandary with less emphasis on parametric synergy with reservoir spasmodic acuity. This conundrum leads to inaccurate harbinger of the required number of wells to be drilled for future field development programs from existing production and reservoir data particularly at pressures above the bubble point which is a major sobriety as orchestrated in most recent simulators. The aim of this erudition is to compendiously carry out astute predictive heterodox principles of wellbore aggregates from critical recovery factor parameters for savvy field planning. The main objectives are to glean and develop new propinquities for differential pressures (ΔP), rock compressibilities (Co) and oil formation volume factors (Bo) for predicting the number of wells to be drilled and recovery factors (RF) by equating the simulated results and the theoretical model (Ezekwe, 2010). To elucidate, metaphorize and ruminate new models. Reservoir and economic data was carefully simulated using FAST-FEKETE Evolution software for initial 40 future oil wells. Average results were mathematically correlated with recovery factor model to produce new correlations to quickly re-jig field planning efficiency. Results of matched and validated compressibility factors, differential reservoir pressures and oil formation volume factors were correlated with field data from Ezekwe (2011) model. Results of compressibility factor showed increasing similar 3rd order polynomial converging correlation for both models but gave slight divergence with increasing number of wells and RF. Results of differential pressures gave linearly increasing correlation with number of wells and RF while the new model had a cross-over point at 6435.64 psi for 2 wells but slightly increased divergently with number of wells and RF. Results of oil FVF gave a good similar regression (R2) of 0.999 while both models showed decreasing 3rd order polynomial correlation comparison with number of wells but with slight divergent disparity with increased RF. To further validate the potency of this study, detailed comprehensive paired sample test gave standard deviation, standard error of mean and degree of freedom of 0.00356, 0.0012 and 8 for compressibility factors; 324.7, 102.68 and 9 for differential pressure while the oil formation volume factor gave 0.0067, 0.0021 and 9. The predictions obtained by the new model showed appreciable degree of consistency and accuracy with number of wells and RF. This is perhaps largely hinged on the capacity to cogently infuse field data with theoretical and simulated models effectively. This study has clearly shown that no special technique or rigorous computational procedures is required to plan future number of wells to be drilled in a field or perhaps estimate the required RF. Sequel to this, further research is encouraged to inculcate more correlations based on comprehensive field validation studies to improve the efficacy of this model.