[Relation between the cell concentration of individual cow's milk, milk production and the cow's susceptibility to mammary infection].
The relations between the cell concentration in the milk from individual cows, their susceptibility to mastitis and milk production capacity were studied for 30 months on the 62 black-and-white French Frisian X Holstein cows of an experimental herd. During this period, the cows were regularly submitted to bacteriological tests for intramammary infections, individual cell counts and controls of the milk production. The cell concentrations in the milk before infection were not different for two groups of cows that showed more or less susceptibility to mastitis. The corrected milk production fell linearly with the logarithmic mean of the lactation cell concentration, leading to a decrease of the yield that was as great as between 100 000 and 200 000 as between 200 000 and 400 000 cells/ml. The reduction in yield was particularly large in cows that presented brief clinical infections followed by persistent inflammatory sequelae. The biological significance of these results and their implications for the control of mastitis were discussed.
D000818:Animals; D002417:Cattle; D002452:Cell Count; D004198:Disease Susceptibility / Q000662:veterinary; D005260:Female; D007774:Lactation; D008414:Mastitis, Bovine / Q000276:immunology*; D008892:Milk / Q000166:cytology* / Q000378:metabolism; D011247:Pregnancy
Relation entre concentration cellulaire du lait individuel, production laitière, et sensibilité des vaches aux infections mammaires.