Perfromance of Lactating Dairy Cows in Response to Supplementation of Rumen-Protected Choline

Effects of rumen-protected choline supplementation on milk production and milk fatty acids in crossbred Holstein Friesian dairy cows were studied. Twenty four Holstein Friesian crossbred lactating dairy cows, averaging 32 +/- 8 days in milk, 16.0 +/- 1.6 kg of milk and 426 +/- 27 kg body weight were blocked by milking days first and then stratified balanced milk yield and body weight into three groups of 8 cows. The first group (Control) received approximately 9 kg of concentrate. The second group was fed the same basal diet as the control group and supplemented with 20 g day(-1) of Rumen-Protected Choline (RPC) and the third group was fed the same basal diet as the control group and supplemented with 40 g day of RPC. All cows also received ad libitum grass silage (Brachiuriu ruziziensis, 55 days cutting interval) had free access to clean water and were individually housed in a free-stall unit and individually fed according to treatments. The experiment lasted for 10 weeks with the 1st 2 weeks being considered as adaptation period and measurements were made during the last 8 weeks. Daily milk yields were recorded. Milk sample and dry matter intake were collected in 2 consecutive days weekly. Live weights were recorded at the start and at the end of the experiment. Milk choline and blood parameters were also analyzed. The results showed no statistical significant differences in intakes, live weight change, milk compositions and blood parameters (p>0.05) however, milk yield, 3.5% fat-corrected-milk yield and milk choline were increased by rumen-protected chorine supplementation. It is recommended in the present study that the addition of 20 g day(-1) rumen-protected chorine could be beneficial to lactating dairy cows in early lactation.