EFFECTS OF MET HYDROXY ANALOG (MHA (R)) SUPPLEMENTATION OF DAIRY COW'S DIETS ON MILK YIELD AND MILK COMPOSITION

Twenty one Holstein Friesian crossbred (>87.5% Holstein Friesian) lactating dairy cows, averaging 103 +/- 53 days in milk, 12.5 +/- 3.0 kg of milk, 58 +/- 19 mo old and 412 +/- 56 kg body weight (BW), were blocked by parity first and then stratified random balanced for milking days, milk yield, age and body weight into three groups of 7 cows. The first group (control) received approximately 17.4 kgDM of total mixed ration (TMR) which comprised approximately 7, 6, and 30 kg of commercial concentrate, corn silage and fresh cut grass, respectively. The second group was fed with the basal diet as the control group and supplemented with 11 g/d of Met hydroxy analog (MHA (R)). The third group was fed the same way as the control group with 22 g/d of Met hydroxy analog (MHA (R)). Performance parameters showed that DM, CP, and NEL intakes, final body weight and live weight change were similar in all treatments. Milk yield and milk composition were unaffected, however, UFA was increased while SFA was reduced by MHA (R) supplementation.