-Twenty-four multiparous cows were divided into 4 groups immediately after calving according to a 2 × 2 factorial design: 2 milking frequencies (1 daily [morning only] milking for the first three weeks of lactation, then 2 daily milkings vs. 2 daily milkings throughout) under two diet energy concentrations (normal or low). The trial lasted 30 weeks, on average, and ended in the pasture on 28 May 2000. During the winter period, the cows were housed together in a free-stall barn, and were given complete rations ad libitum. The cows that were not milked were significantly more vocal than the controls, close to the omitted milking, and in a large number of them, milk leaked from the udder. Once-daily milking gradually reduced the amount of milk secreted in relation to that produced by cows milked twice a day, with differences of 8.5 kg·d -1 (P < 0.01) at week 3. As early as the first week of resumption of twice-daily milking, that difference ceased to be statistically significant but amounted to 1.3 kg·d -1 (P > 0.10) throughout the rest of the trial. Once-daily milking did not affect the contents of milk fat, true protein, serum albumin and lactose contents or somatic cell count, plasmin activity and plasminogen-derived activity. That treatment also increased the G1 immunoglobulin concentration (P = 0.02; measured at week 3) and reduced milk lipoprotein lipase activity. Once-daily milking improved the nutritional status at the beginning of lactation (reduced live weight and body condition losses, and increased the computed energy balance) and had no effect on the ration intake. The normal-energy diet produced expected results, in relation to the low-energy diet: a significant increase in intake (1.2 kg DM·d -1 ), milk yield (3.1 kg·d -1 ), milk protein content (2.0 g·kg -1 ), and nutritional indices, in particular. The decrease in milk yield induced by once-daily milking during the (0)4 73 98 13 80; e-mail: remond@gentiane.enitac.fr first three weeks of lactation was 5.5 kg·d -1 in the low-energy group and 8.5 kg·d -1 for the normal energy group (non-significant interaction; P > 0.10). once-daily milking / level of feeding / milk production / enzyme activities / nutritional status Résumé -Effets de la traite une fois par jour combinée au niveau d'alimentation pendant les trois premières semaines de la lactation sur la production et les activités enzymatiques du lait, et l'état nutritionnel, chez des vaches Holstein. Vingt-quatre vaches multipares ont été réparties dès le vêlage en 4 lots, selon un schéma factoriel 2 × 2 : 2 fréquences de traite (1 traite par jour pendant les 3 premières semaines de lactation, puis 2 traites par jour vs. 2 traites par jour en permanence) × 2 concentrations énergétiques de la ration (normale ou basse). L'essai a duré en moyenne 30 semaines et s'est terminé au pâturage, le 28 mai 2000. Pendant la période hivernale, les vaches étaient logées ensemble dans une stabulation libre à logettes et recevaient à volonté une ration complète. La traite omise était celle du soir. Les vac...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.