Editor:
Dr. Tom Overton
Assistant Professor of Dairy Management/Nutrition
Department of Animal Science
Cornell University
272 Morrison Hall
Phone:  (607) 255-2878
FAX:  (607) 255-1335
Email:  tro2@cornell.edu

Researchers at the University of Wisconsin recently explored the possibility that induction of calving may help prevent occurrence of metabolic disorders in dairy cows during early lactation. The rationale is straightforward; induction of calving may circumvent the depression in feed intake and associated endocrine changes that occur at the time of calving that seem to initiate the process of nonesterified fatty acid (NEFA) mobilization from body fat and triglyceride accumulation in liver. The treatments were:

1. placebo
2. 1 mg of fenprostalene (PGF_2a analog) (FP)
3. 50 mg of estradiol-17b benzoate (EB)
4. 1 mg of fenprostalene + 50 mg of estradiol-17b

All treatments were administered on day 276 of gestation. Fenprostalene was used to induce parturition and estradiol-17b was used to determine whether estradiol has a role in reducing retained placenta in cows induced to calve or in metabolic processes related to liver metabolism in transition cows.

Cows induced to calve using FP had greater dry matter intakes during the last 8 days before calving. Similar to controls, however, their feed intake decreased during the final day prior to calving. Dry matter intakes from calving until 10 DIM were lower for the induced cows compared with controls (24 vs. 29 lb/day). Milk yield from calving until 10 DIM was decreased for the induced cows compared with controls, although differences between treatments were not significant from 10 to 31 DIM. These transient decreases in performance probably were due to a significantly increased occurrence of retained placenta in cows induced to calve (86 versus 35% at 24 hours postcalving).

Peak concentration of nonesterified fatty acids (NEFA) was delayed until 2 d after calving in the cows induced to calve. Concentrations of triglyceride in liver were not affected by treatment, although liver triglyeride concentrations measured in this experiment were relatively low.

For more information:

Bremmer, D. R., J. O. Christensen, R. R. Grummer, F. E. Rasmussen, and M. C. Wiltbank. 1999. Effects of induced parturition and estradiol on feed intake, liver triglyceride concentration, and plasma metabolites of transition dairy cows. J. Dairy Sci. 82:1440-1448.

Rasmussen, F. E., M. C. Wiltbank, J. O. Christensen, and R. R. Grummer. 1996. Effects of fenprostalene and estradiol-17b benzoate on parturition and retained placenta in dairy cattle. J. Dairy Sci. 79:227-234.

Feed Dealer Seminar Series

It’s time again for the annual Feed Dealer Seminars. Larry Chase and Tom Overton will be discussing what’s new in forage analyses, amino acid nutrition of dairy cows, ionophores in relation to transition dairy cows, and choline for transition cows. Locations, times, and contacts follow:

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