Effects of rumen-inert fat on lactation, reproduction, and health of high producing Holstein herds.
Two hundred twenty of 443 cows freshening between June 1989 and March 1990 in five commercial Holstein herds were fed .45 kg/d of rumen-inert fat from calving until 200 DIM. Control diets were fed as TMR and contained, on average, 3.7 to 4.8% supplemental fat (DM basis). Test herds had rolling herd averages of 9300 to 13,250 kg of milk. Production of 4% FCM and milk increased 1.01 (3.3%) and 1.50 kg/d (4.6%), respectively, for primiparous cows fed additional fat. Multiparous cows from four herds demonstrated no response; multiparous cows in one herd increased production of 4% FCM by 2.88 kg/d (8.2%), milk by 2.45 kg/d (6.4%), and milk fat by .14kg/d (10.6%) in response to additional fat. An explanation of response differences among herd for multiparous cows was not possible. For primiparous and multiparous cows, increased genetic potential increased treatment response. Increased body condition score at calving influenced treatment response of multiparous cows. Thinner cows produced more milk and less milk fat in response to additional dietary fat than did fatter cows. Most reproductive indices were unaffected by treatment. Cows receiving additional fat had lower, but nonsignificantly lower, incidences of most health disorders. Responses to rumen-inert fat by cows receiving high concentrations of dietary fat were marginal and were affected by body condition score at calving and by genetic potential.
Scott
T A
TA
Department of Dairy Science, University of Wisconsin, Madison 53706, USA.
Shaver
R D
RD
Zepeda
L
L
Yandell
B
B
Smith
T R
TR
D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002118:Calcium; D002417:Cattle / Q000502:physiology*; D004041:Dietary Fats / Q000494:pharmacology*; D005227:Fatty Acids / Q000008:administration & dosage; D005260:Female; D006304:Health Status; D007774:Lactation; D000073878:Palm Oil; D010298:Parity; D010938:Plant Oils / Q000008:administration & dosage; D012098:Reproduction; D012417:Rumen / Q000378:metabolism*
D004041:Dietary Fats; D005227:Fatty Acids; D010938:Plant Oils; D000073878:Palm Oil; D002118:Calcium