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Milk production responses to pre- and postcalving dry matter Intake in grazing dairy cows

Citation

Roche, JR, Milk production responses to pre- and postcalving dry matter Intake in grazing dairy cows, Livestock Science, 110, (1-2) pp. 12-24. ISSN 1871-1413 (2007) [Refereed Article]

DOI: doi:10.1016/j.livsci.2006.08.016

Abstract

Sixty-eight multiparous grazing dairy cows were randomly allocated to two precalving pasture allowances to achieve differential dry matter intakes (DMI) for 29 ± 7.7 d precalving (Low or High DMI; 4.8 or 11.9 kg DM). At calving, cows within each precalving treatment were randomly allocated to one of two levels of feeding (Low or High DMI; 8.6 or 13.5 kg DM) for 35 d postcalving in a completely randomized design and a 2 × 2 factorial arrangement of treatments. Following treatments all cows grazed together and were fed pasture and pasture silage. Daily milk yields were recorded, and fat, protein and lactose concentrations determined weekly for 15 weeks. Blood was sampled weekly pre- and postcalving and analysed for indicators of energy status, growth hormone (GH) and insulin-like growth factor-1 (IGF-1). Body condition score (BCS) at calving was reduced by precalving restriction (P < 0.001; 2.8 and 3.0 for precalving Low and High treatment groups, respectively). Precalving restriction reduced milk fat production by 8.4% during the first 5 weeks postcalving, but differences were not significant subsequently. Postcalving feed restriction reduced yield of fat corrected milk (FCM), fat and protein by 23, 21 and 28%, respectively, during the first 5 weeks postcalving. Decreased (P < 0.05) yields of FCM, fat and protein (11, 10 and 9%, respectively) were also evident for 10 weeks after the feed restriction finished. There was a tendency (P < 0.1) for a precalving × postcalving DMI interaction in milk protein yield during the first 5 weeks of lactation with no effect of precalving level of feeding in cows that were restricted postcalving. The plasma concentrations of non-esterified fatty acids (NEFA), β-hydroxybutyrate (BOH) and GH were elevated in restricted cows precalving, and IGF-1 concentration was reduced. Plasma NEFA and BOH concentrations were elevated postcalving in restricted cows, but no effect of postcalving DMI on GH or IGF-1 concentration was evident. Results suggest that under grazing systems milk production responses to precalving DMI are small, but energy restrictions in early lactations result in significant carryover effects in milk production. © 2006 Elsevier B.V. All rights reserved.

Item Details

Item Type:Refereed Article
Research Division:Agricultural and Veterinary Sciences
Research Group:Animal Production
Research Field:Animal Nutrition
Objective Division:Animal Production and Animal Primary Products
Objective Group:Livestock Raising
Objective Field:Dairy Cattle
Author:Roche, JR (Dr John Roche)
ID Code:41280
Year Published:2007
Web of Science® Times Cited:39
Deposited By:Agricultural Science
Deposited On:2007-08-01
Last Modified:2011-11-18
Downloads:0

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