ASSESS MILK PRODUCTION OF CATTLE BREEDS IN DIFFERENT AGRO-ECOLOGICAL ZONES OF WESTERN BHUTAN

Abstract

The study was conducted in seven functional Dairy Farmers Groups (DFGs) of Thimphu and Chukha Dzongkhags from June 2017 to May 2018, to assess milk production level of dairy cattle breeds with varying exotic inheritance level, lactation no, age and herd type in three Agro-Ecological Zones (AEZ) of western Bhutan. The study also compared milk yield in different seasons and AM-PM milking. Prevalent dairy cattle breeds in the study area were Jersey Cross (JX), pure Holstein Friesian (HF) and HF cross. The overall mean daily milk yield (DMY) was 7.72 ±3.75 litres and days in milk (DIM) was 266.51±81.03 days. Mean DMY recorded in Cool temperate, Warm temperate and Dry sub-tropical AEZs were 5.63±2.14, 6.30±1.94 and 9.07±4.28 litres respectively. Mean DMY of HF pure, HF cross and JX cows were 12.41±3.7, 10.74±5.79 and 6.92±3.07 litres respectively. Cows of exotic inheritance level of 50-75% produced higher mean DMY of 8.44±3.89 l/day than exotic inheritance level of above 75% (7.58±3.66 l/day) and below 50% (5.57±2.2 l/day). Similarly among different herd size, mean DMY of medium herd size (6-10 cows) was highest (11.81±4.79 l/day) as compared to very small (1-2), small (3-5),and large (>10 milking dairy cows) herd sizes which yielded 6.58±2.94, 6.96±2.98, and 10.2±2.47 l/day, respectively. The aspects that determined productivity were breed, exotic inheritance level and herd type which showed significant differences (p<0.05) in DMY. The DMY increased from 1^st (6.57±3.67) to 2^nd (8.68±3.38) and highest was observed in 3^rd lactation (8.77±4.67). Thus, the findings suggest that cows above 11 years of age, are not advisable to retain in farmers’ field because of its decreasing productivity with age. Significant difference in milk yield between AM (4.74±2.19) and PM (3.16±1.59) milking was observed. However, no significant difference was observed in DMY across seasons although yield in winter (7.42±4.16) and autumn (7.60 ±3.93) were lower than summer (8.07 ±4.51) and spring (7.86±4.49) seasons. As the study found higher productivity of cows in the lower altitudes, it can be deduced that dairy farming is more suitable in such warmer areas. Nonetheless, further studies are needed to establish whether altitude or other management practices affect milk production.