Effects of dietary and abomasally infused choline on milk production responses of lactating dairy cows
1989
Sharma, B.K. | Erdman, R.A.
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 inceased 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 switch-back 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.
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