Fifty-four high producing Holstein cows in early lactation were used in a complete randomized block design to determine the effects of calcium salts of palm fatty acids and protected methionine supplementation on Dry Matter Intake (DMI), milk yield and composition and on selected reproductive parameters starting week 2 post partum through week 17 of lactation. Cows were blocked by body weight, milk production and lactation number and randomly allocated from blocks to 3 treatments. Treatments were: (1) concentrate only (Control, C) (2) control+added calcium salt (700 g/cow/day, CSFA) and (3) control+added calcium salt+protected methionine (700 g of calcium salt per cow per day containing 6% (40 g) of protected methionine, CSFAM). Cows were fed for ad libitum intake a basal diet consisting of tritical silage, rye-grass and oat hay. DMI and milk production were measured. Milk composition was determined and 4% Fat Corrected Milk (FCM) was calculated. Body condition scores were monitored every three weeks. Reproduction data were recorded and major reproductive parameters were computed. Results showed that calcium salt supplementation decreased DMI and milk protein content, but increased milk yield, FCM, milk fat content and yields of milk fat and protein. DMI decreased (p<0.05) by 1 to 1.5 kg/cow. FCM was 34.2 kg day- for the control and increased an average of 3 to 4 kg day-, respectively with fat and fat plus protected methionine supplementation. Feed efficiency was higher for cows fed the calcium salt and methionine added calcium salt diets (1.84 and 1.77 versus 1.56 kg milk kg- DM for the CSFAM, CSFA and C treatments, respectively). Percentages of milk fat were significantly higher (p<0.05) for cows fed fat added diets (36.3 and 36.1 versus 35.1 g kg- for the CSFA, CSFAM and C treatments, respectively). However, the protein content of milk was lower (p<0.05) for the calcium salt supplemented cows (30.4 versus 31.2 g kg-), but the addition of protected methionine to calcium salt did prevent the decrease in milk protein that was induced by supplemental fat alone. Yields of milk fat and protein were lower for the control cows. Body condition scores were higher for cows fed diets supplemented with fat and fat plus methionine (2.81 and 2.73 vs. 2.48 for the CSFAM, CSFA and C treatments, respectively). Supplemental fat significantly increased (p<0.05) the first service and overall 150 day conception rates and reduced the number of services per conception. The addition of methionine to calcium salts further improved these indices. Overall results suggest that the use of 700 g of calcium salts of palm fatty acids/cow/day in the concentrate supplement improves major reproductive indices and milk yield of high producing dairy cows during early lactation and that adding ruminally protected methionine to calcium salt not only helps alleviate the milk protein depression commonly observed with added fat, but further improves the performances of cows.
M. Ben Salem and R. Bouraoui, 2008. Effects of Calcium Salts of Palm Fatty Acids and Protected Methionine Supplementation on Milk Production and Composition and Reproductive Performances of Early Lactation Dairy Cows. International Journal of Dairy Science, 3: 187-193.