FACTORS AFFECTING ON THE CONCEPTION RATE OF DAIRY CATTLE AT FIRST SERVICE IN CHAR AREAS OF NORTHERN BANGLADESH

Abstract

The study was conducted on the char areas of eight districts in namely Bogra, Sirajgonj, Pabna, Jamalpur, Kurigram, Nilphamari, Rangpur, Gaibandha, respectively. However, data was collected from January, 2012 to December, 2013 by the structured questionnaires, informal interview and group discussion. A total of 800 local, 800 Holstein-Frisian (L×HF) and 800 Red Chittagong (L×RC) crossbred cows were selected for this study. Feeding and management of the experimental animals were uniform throughout the year. Animals were vaccinated and dewormed regularly. Cows generally were grazed in the field and supplied 5−6 kg straw daily at evening. In improved feeding system cows were grazed in the field and supplied ready feed (a mixture of rice polish, wheat bran, broken rice and oil cake; @ 2–3.5 kg/d/head) with 5−6 kg straw. The cows accessed ad libitum fresh drinking water with iodized salt. The results revealed that though first service conception rate was not significantly influenced by cows genotypes, but it was significantly influenced by bull genotypes when the RC crossbred cows inseminated naturally by local bull (73%) than the cows inseminated (AI) by the semen of L×HF crossbred bull (61%). The cows showed moderate conception rate inseminated naturally by L×RC crossbred bull (66%). The conception rate of cows is influenced by the quality and quantity of semen, it was higher in the cows inseminated by using the semen supplied by Department of Livestock Services as compared to the semen supplied by the Ejab, even though the semen of BRAC. The variations in conception rate were actually due to the ultimate variability of semen quality which were depends on bull genotype, semen collection technique, processing, preservation, heat detection, experience of AI technicians, etc. Farmers who use professional Al technicians from reputable Al organizations usually have fewer concerns about semen quality being a major cause of low conception rates. It was higher in the cows inseminated in spring season than the cows were inseminated specially in summer season. It was significantly varied on the experience of AI technicians. The conception rate was significantly higher in the cows were 2.5−3.0 years old (68 %) than the cows were 4.5−5.0 years old (54%). Conception rates were significantly higher in the cows provided improved diet, and managed under regular vaccination and deworming practices. Therefore, it may be suggested that to achieve the satisfactory conception rate in char areas, the farmers should inseminate their cows during spring season with experience AI technician by using good quality semen. They may choose to rear Red Chittagong cows or their crossbreds. They should provide concentrate feed at least a minimum amount and have to practice of regular vaccination and deworming to their cattle.