Effects of dietary and abomasally infused choline on milk production responses of lactating dairy cows.
Three experiments investigated the effects of exogenous choline on milk production responses of dairy cows. Ruminally fistulated Holstein cows were fed total mixed diets containing 30% corn silage and 70% corn/soybean meal-based concentrate in experiment 1, or 40% corn silage and 60% concentrate in experiments 2 and 3. In experiment 1, the effects of unsupplemented (control), dietary supplemented choline (50 g/d) and abomasally infused choline (50 g/d) were examined using three first-lactation cows in a 3 X 3 Latin square design. While dietary added choline had no effect, abomasally infused choline increased daily milk and 4% fat-corrected milk yield 3.2 and 3.8 kg/d respectively. In experiment 2, effect of daily abomasal infusion of 0, 30, 60 and 90 g choline were studied using four mature cows in a 4 X 4 Latin square design. Fat-corrected milk and milk fat percent were 2.6 kg/d and 0.59 percentage units higher for cows infused with 30 g/d choline than for unsupplemented controls, with 60 and 90 g/d choline infusions showing smaller effects. In experiment 3, daily abomasal infusion of 0 or 40 g choline were studied using four mature cows in a switchback design. Choline infusion (40 g/d) increased daily milk 1.6 kg/d over control while having no effect on milk composition or feed intake. Results of these experiments suggest a possible requirement for supplementing choline in lactating dairy cows.
Sharma
B K
BK
Animal Sciences Department, University of Maryland, College Park 20742.
Erdman
R A
RA
D000018:Abomasum; D000818:Animals; D002417:Cattle; D002794:Choline / Q000008:administration & dosage / Q000494:pharmacology*; D004032:Diet; D004041:Dietary Fats / Q000032:analysis; D004435:Eating / Q000187:drug effects; D005260:Female; D007441:Intubation, Gastrointestinal / Q000662:veterinary; D007774:Lactation / Q000187:drug effects*; D008892:Milk / Q000032:analysis; D008894:Milk Proteins / Q000032:analysis; D011247:Pregnancy
D004041:Dietary Fats; D008894:Milk Proteins; D002794:Choline