Peripartum responses of dairy cows fed energy-dense diets for 3 or 6 weeks prepartum.
Pregnant cows (n = 189) in two commercial dairy farms were assigned randomly to be fed energy-dense diets for either 3 or 6 wk before expected calving. Cows fed diets for less than or equal to 26 d were designated the short (S) treatment group, and those fed greater than 26 d were the long (L) treatment group. Cows in L tended to have improved energy status during the first 2 wk postpartum, as indicated by higher insulin concentrations and a tendency for lower nonesterified fatty acid concentrations. Treatment did not affect plasma beta-hydroxybutyrate concentrations. Cows in L tended to gain more body condition during the late dry period. Total body condition loss from parturition through 6 wk postpartum was not different between treatments, but the rate of change varied over this period. Cows in S lost more body condition during the first 3 wk postpartum than cows in L. In farm 1 only, cows in L lost more body condition from 3 to 6 wk postpartum and had a higher incidence of metritis and a longer interval to first service than cows in S. Cows in L had higher milk protein content through 60 d in milk compared with cows in S. Additionally, cows in L in farm 1 produced 4.4 kg/d less milk, tended to have lower milk fat content and yields, and higher somatic cell counts through 150 d in milk than cows in S. Overall, increasing the length of time cows were fed the energy-dense diet prepartum elicited significant changes in farm 1, but had little effect in farm 2. Based on these results, L treatment may improve energy status immediately postpartum, but long-term effects varied between farms, perhaps due to other unmeasured management differences.
Mashek
D G
DG
Department of Animal Science, Michigan State University, East Lansing 48824-1225, USA.
Beede
D K
DK
D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004032:Diet; D002149:Energy Intake; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D006885:Hydroxybutyrates / Q000097:blood; D007328:Insulin / Q000097:blood; D007774:Lactation / Q000502:physiology*; D049590:Postpartum Period; D011247:Pregnancy; D013997:Time Factors
D005230:Fatty Acids, Nonesterified; D006885:Hydroxybutyrates; D007328:Insulin