Effect of supplementing methionine to physical condition, milk productivity and quality of milk cows

Abstract

The study was carried out to evaluate the effect of supplementing methionine to the physical condition, milk productivity and quality of the milk cows. The experiment was arranged with 40 Holstein Friesian dairy cows, divided into 2 treatments (control and RPM treatment) with
the same parity, body condition score and milk yield. The cows in control group were fed with the basic diet and the cows in RPM group were fed with basic diet and supplementing RPM at 7 g/cow/day from 30 days before calving to postpartum and at 10 g/cow/day from lactation
day 1 to 100. The studied results showed that the average milk yield in 100 days postpartum (liters/head/day): 29.20±0.81/26.86±0.98; dry matter ratio (%): 12.67±0.26/11.97±0.30; milk fat percentage (%): 3.86±0.24/3.33±3.30; proportion of protein in milk (%): 3.56±0.15/3.28±0.14;
proportion of lactose in milk (%): 4.47±0.14/4.41±0.16; quantity milk somatic cells (cells/ml): 447,586±415,328/703,150±498,381 and serum ketones (mmol/L): 0.72±0.35/1.20±0.56.
Supplementing RPM into the diet did not affect the body condition during 100 days postpartum. However, this supplement improved milk production, especially during the peak milk period, increase the percentage of dry matter, fat and protein, but did not affect colostrum quality, percentage lactose and somatic cell concentration in milk. In addition, this supplement
helps to reduce the incidence of ketosis.