Academic literature on the topic 'Milking frequency; Milk yield'

Mastitis in dairy animals is the primary concern of dairy farmers, which is the most common disease that causes huge economic losses in the dairy industry. The economic losses due to mastitis are from a reduction in milk yield, condemnation of milk with antibiotic residues, veterinary treatment costs, and death. In addition, some mastitis pathogens also cause serious human diseases associated with the contamination of milk or milk products with bacteria or their toxins. Bovine mastitis is mainly caused by a wide range of environmental and contagious bacterial mastitis pathogens. Contagious pathogens are those whose main reservoir is the infected udder. Contagious pathogens mainly spread among animals during milking process whereas environmental pathogens spread from environment to udder at any time. The source of the environmental pathogens is the surrounding environment of an animal. The major contagious pathogens include Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma spp. and the minor contagious pathogens include Corynebacterium bovis and others. Major environmental pathogens include coliform bacteria (Escherichia coli, Klebsiella spp., Enterobacter spp. and Citrobacter spp.), environmental streptococci (Strep. dysgalactiae, Strep. uberis). This chapter covers detailed review of published data on contagious and environmental pathogens responsible for bovine mastitis.

The aim of the research was to evaluate the influence of the type of the nervous system on the productive and reproductive qualities of animals. The type of nervous system (strong, weak) of cows of the Ukrainian red dairy breed was determined by the index of the nervous system, which is based on the variability of the fat content in the morning milk yield after changing the conditions of cows keeping. Under the new conditions of keeping cows with a strong type of nervous activity, the coefficients of variability of the morning milk yield and the fat content in milk practically remained at the same level (their slight increase was noted at the level of 4.5 and 3.1%). In cows of a weak type under similar conditions of keeping, a significant increase in the variability of milk yield (by 53.6%) and fat content in milk (by 266.7%) was found. In animals of both types, in the first days of summer-camp keeping, in comparison with winter-stall keeping, there was an increase in milk yield and a decrease in fat content in milk. In cows of the strong type, the fat content decreased by 0.08% and of the weak type by 0.12%. The average index of the nervous system type in animals of the strong type is 1.18, and in cows of the weak type 2.71 (P> 0.999). Before and during milking, the pulse rate in the cows of weak type was higher by 8.0 and 10.8 beats / min. (P> 0.999), compared with the strong type. The animals of strong type of the nervous system, in comparison with the weak type, had a smaller thickness of the concha and skin, a higher pulse and respiratory rate, and a lower rectal body temperature. In cows of a strong type of the nervous system in postnatal ontogenesis, the formation of productive traits took place more rapidly and they better adapted to the conditions of the external environment. This is evidenced by their high coefficient of relative decline in the growth at the age of one (85.0) than in animals with a weak type of nervous system (78.5). The advantage of cows with a strong type of nervous activity over a weak one in milk yield was 348 kg (P>0.95) and in milk fat 8.0 kg. The service period in animals with a strong type of nervous activity was 6.3 days shorter. The animals with a strong type of nervous activity during the first lactation had a higher adaptation index compared with animals of a weak type. The difference for this indicator is 0.49 (or 3.7%). They also had a higher productivity index for the first (3.1%) and second (4.0%) lactation. Thus, the typological features of the nervous activity of cows affect the formation of the most important functions of the body, which can be used in breeding work to improve the herd.