Effect of prepartum compensatory nutrition regimen on metabolism and performance of dairy cows

摘要

The impact of closely controlled energy management during the dry period upon general peripartum metabolism and the subsequent lactation was evaluated in multiparous dairy cows. Eight lactating, pregnant Holstein cows were paired according to currentmilk production and body condition score and assigned to either the control or the stair-step compensatory nutrition (SSCN) regimen 16 weeks prior to expected calving date. Control cows were fed according to National Research Council [National Research Council., 2001. Nutrient Requirements of Dairy Cattle. 7th rev. ed. Natl. Acad. Sci., Washington, DC.] recommendations and for ad libitum intake during late lactation and the far-off dry period. The SSCN cows were subjected to dietary energy restriction [80% of net energy for lactation requirements (NE_L)] during late lactation in order to maintain body weight, followed by realimentation (130% of NE_L) during the far-off dry period to induce a compensatory response. A common diet was fed thereafter. TheSSCN cows gained less body condition during late lactation and tended to gain more body condition during the far-off dry and transition periods than control cows. There was no difference in dry matter intake during the prepartum transition period and early lactation. Milk yield was not affected by treatment. Serum nonesterified fatty acids (NEFA) were not altered by dietary treatment during late lactation and the dry period; however NEFA were lower in SSCN cows at week 4 of the subsequent lactation. Serum insulin was higher in SSCN cows 8 weeks prior to parturition (end of restriction), tended to be higher at 4 weeks (end of realimentation) before calving, and was also higher at week 12 of early lactation. An SSCN regimen stimulated body condition gainof mature dairy cows during the dry period, did not affect periparturient nutrient metabolism, and led to modest improvements in metabolic parameters later in the subsequent lactation.