Library Open Repository

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

Downloads

Downloads per month over past year

Roche, JR (2007) 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

[img] PDF
4522.pdf | Request a copy
Full text restricted
Available under University of Tasmania Standard License.

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.

Item Type: Article
Keywords: Transition cow; Pasture; Dry matter intake
Journal or Publication Title: Livestock Science
Publisher: Elsevier BV
Page Range: pp. 12-24
ISSN: 1871-1413
Identification Number - DOI: 10.1016/j.livsci.2006.08.016
Additional Information:

The definitive version is available at http://www.sciencedirect.com

Date Deposited: 07 Apr 2008 14:43
Last Modified: 18 Nov 2014 03:36
Item Statistics: View statistics for this item

Actions (login required)

Item Control Page Item Control Page