Suitability of Temperate and Tropical Crossbred Dairy Cattle under Peri-Urban Production System in Bangladesh

Suitability of temperate and tropical crossbred dairy cattle under peri-urban production system was investigated.The study was conducted during a period from April, 2010 to March, 2013 in peri-urban dairy production system of Mymensingh district. The available dairy crossbred genotypes were 50% Holstein Friesian(HF) , 62.5% HF (5/8HF), 75% HF (3/4HF).A total of 103 households, possessing 358 lactating cows were selected where two different management environments were applied: (i) Intervention (E1) group and (ii) Non-intervention (E2) group. There were a total of 158 cows registered from 58 households in E1 and a total of 200 non-registered cows from 145 households in E2. Average daily milk yield was 8.11±0.24 kg, it is higher in 62.5% HF genotype (8.60±0.41 kg) compared to 50% HF(8.32±0.42 kg) and 75% HF (7.42±0.42 kg). However, the intervention group (E1) was more efficient with an average of 9.85 ±0.39 than non intervention group (E2) with6.38±0.28 kg. The highest milk yield in 180 days was found (1550±74 kg) at 62.5 % HF and lowest (1339±76) at 75% HF genotype. Against, G×E interaction effects were not significant on total milk yield (TMY) and daily milk yield though effect of environment was highly significant (P<0.001). The shortest dry period was found in 50% (89±2.53 days) and highest in 75% HF cross cows (102±2.72 days). The shortest age at first heat was found in 50 % (28±0.28) and highest in 75% (36±0.29) months. The shortest age at fist calving was found in 50% HF (37±0.30) and highest was in 75% HF (45±0.32) month. The shortest calving interval was found in 50% HF (378±8.63) and highest was in 75% HF (438±10.53) days. The shortest post-partum heat period found in 62.5% (91±3.31) days and highest in 75% HF (109±3.72) days. The lowest number of services per conception found in 62.5% (1.42±0.07) and highest in75% (1.64±0.08) HF cross genotype. Conception rate was found shortest in 50% (71±2.66) and highest in 75% 80±2.52Holstein Friesian cross cows. In case of reproductive performances (number of services per conception, conception rate, age at first heat, age at first calving, dry period, calving interval), genotype, environment and G x E interaction had highly significant effects (P<0.001). Therefore, it can be concluded that for reproduction 50% HF crossbred cows and for production both 50% and 62.5% HF crossbred cows are suitable in small holder peri-urban dairying system.