| dc.description.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. | en_US |
