TY - JOUR
T1 - Effect of increasing digestible undegraded protein supply to dairy cows in late gestation on the yield and composition of milk during the subsequent lactation
AU - Moorby, Jon
AU - Dewhurst, Richard J.
AU - Stuart, Marsden
PY - 1996/10
Y1 - 1996/10
N2 - Effects of feeding a protein supplement to dairy cows during the dry period on performance during the following lactation were investigated in two experiments. Holstein-Friesian cows were paired towards the end of lactation, and, after drying off, one of each pair received a typical dry cow management regime of ad libitum grass silage (experiment 1), or a mix of grass silage and distillers' grains or pressed beet pulp (experiment 2). The other cows were offered restricted access to the same basal diet, together with ad libitum access to barley straw and 0.5 kg/day high protein maize gluten meal. During the following lactation, animals from both groups were treated without reference to dry period treatment, and were offered equal access to the same lactation diet. Data were analysed by analysis of variance of experiment means and by parallel curve analysis using sample means. In experiment 1, milk yields were similar (27.2 v. 27.9 (s.e.d. 2.12) kg/day for control and supplemented animals respectively) but milk protein yields, and hence concentrations, were significantly higher (P < 0.001) from supplemented animals (28.9 v. 31.8 (s.e.d. 0.58) g/kg). In experiment 2, milk yields were significantly higher (P < 0.001) from supplemented animals (mean 33.3 v. 35.4 (s.e.d. 1-66) kg/day; however, milk protein yields were also significantly increased (P < 0.001) and the change in milk protein concentration was small. No difference in dry-matter intake was recorded in a subset of animals during early lactation in experiment 2. It is hypothesized that the maternal labile body protein pool was maintained or replenished during the dry period by the provision of the protein supplement, and that this had a significant effect on subsequent lactation performance.
AB - Effects of feeding a protein supplement to dairy cows during the dry period on performance during the following lactation were investigated in two experiments. Holstein-Friesian cows were paired towards the end of lactation, and, after drying off, one of each pair received a typical dry cow management regime of ad libitum grass silage (experiment 1), or a mix of grass silage and distillers' grains or pressed beet pulp (experiment 2). The other cows were offered restricted access to the same basal diet, together with ad libitum access to barley straw and 0.5 kg/day high protein maize gluten meal. During the following lactation, animals from both groups were treated without reference to dry period treatment, and were offered equal access to the same lactation diet. Data were analysed by analysis of variance of experiment means and by parallel curve analysis using sample means. In experiment 1, milk yields were similar (27.2 v. 27.9 (s.e.d. 2.12) kg/day for control and supplemented animals respectively) but milk protein yields, and hence concentrations, were significantly higher (P < 0.001) from supplemented animals (28.9 v. 31.8 (s.e.d. 0.58) g/kg). In experiment 2, milk yields were significantly higher (P < 0.001) from supplemented animals (mean 33.3 v. 35.4 (s.e.d. 1-66) kg/day; however, milk protein yields were also significantly increased (P < 0.001) and the change in milk protein concentration was small. No difference in dry-matter intake was recorded in a subset of animals during early lactation in experiment 2. It is hypothesized that the maternal labile body protein pool was maintained or replenished during the dry period by the provision of the protein supplement, and that this had a significant effect on subsequent lactation performance.
KW - Dairy cows
KW - Dry period
KW - Milk production
KW - Milk protein
UR - http://www.scopus.com/inward/record.url?scp=0011606667&partnerID=8YFLogxK
U2 - 10.1017/S1357729800014752
DO - 10.1017/S1357729800014752
M3 - Article
SN - 1357-7298
VL - 63
SP - 201
EP - 213
JO - Animal Science
JF - Animal Science
IS - 2
ER -