Abstract:The present study assessed the semen characteristics of bulls used for Artificial Insemination (AI) programme in Bangladesh with regard to season, ambient temperature and relative humidity. A total of 3720 semen samples from 71 bulls were collected from Central Cattle Breeding Station and Dairy Farm (CCBSDF), Savar, Dhaka, Rajshahi Dairy and Cattle Improvement Farm (RDCIF), Rajabarihat, Rajshahi and District Artificial Insemination Centre (DAIC), Rajshahi during 1995Rajshahi during -2002. Semen was collected by artificial vaginal method once a week. Different seasons viz. spring, summer, autumn and winter had significant effect (P<0.05) on colour, density, mass activity, sperm concentration, sperm motility, total sperm cells/ejaculate, total number of motile sperm cells/ejaculate, number of semen doses per collection and postfreezing motility of sperm. The maximum values of these semen characteristics were found in summer. Ambient temperature groups of <21°C, 21-25°C, 25-29°C and >29°C had significant (P<0.05) effect on all the semen characteristics except for volume of semen. The highest volume of semen was found at >29°C and the lowest at 25-29°C. The total number of sperm cells/ejaculate, total number of motile sperm cells/ejaculate and number of semen doses per collection were found in >29 °C temperature groups. Relative humidity groups of <65%, 65-75%, 75-85% and >85% had significant effect on all the semen characteristics excluding for volume of semen and number of semen doses per collection. The largest volume of semen, colour, mass activity, total sperm cells/ejaculate, total motile sperm cells/ejaculate and number of semen doses/collection were found in >85% relative humidity and the smallest in 65%-75% relative humidity. Finally, this study recommended that, summer season, ambient temperature groups of >29°C and Relative humidity groups of >85% are suitable for excellent semen characteristics.

Impacts of age, body weight, body conditions, and scrotal circumference on sperm abnormalities of bulls used for artificial insemination (AI) in Bangladesh have been studied. During 1997During -2002During , 1390 ejaculates of semen from 71 bulls from Central Cattle Breeding Station and Dairy Farm, Savar, Dhaka, Rajshahi Dairy and Cattle Improvement Farm, Rajabarihat, and District Artificial Insemination Centre, Rajshahi, were collected and examined. Total head abnormalities, free loose head, mid-piece, tail abnormalities, proximal and distal cytoplamic droplets, total tail abnormalities and total sperm abnormalities were recorded. Age of the bulls had significant effect on sperm abnormalities (P<0.01) except for proximal cytoplasmic droplet. Similarly, body weight had significant effect (P<0.05) except for the total head abnormalities, while body conditions had no significant effect on mid-piece, total tail abnormalities and total sperm abnormalities except for the total head abnormalities. Scrotal circumference had significant effect (P<0.05) on all the sperm abnormalities. The present results demonstrate that the middle (8 to <10 yrs) and older (>10 yrs) bulls having body weight of <450 kg, very good body condition and 36 to <38 cm scrotal circumference had the lowest sperm abnormalities. The need for semen examination for morphological abnormalities of spermatozoa in bulls to be used for AI programme is strongly implicated by this study.

Abstract:A survey was conducted to study clinical signs, gross and histopathological lesions in pigeons with naturally occurring Newcastle disease (ND). For this purpose, 45 pigeon farms of the Rajshahi, Natore and Pabna districts were conducted during from July 2015 to June 2016. Among these, 17(37.78%) farms showed clinical signs of Newcastle disease, including mainly greenish white mucoid diarrhoea and nervous signs with high morbidity and mortality. Morbidity was 90% and mortality was 100%. Diarrhoea, the most common clinical sign observed, was present in 48.28% of the affected pigeons, followed by nervous signs (27.59%), shivering (24.14%). Postmortem examination of affected birds showed lesions mainly in proventriculus, liver, lungs and kidneys. Histopathological changes were also observed in lungs, liver, and proventriculus. The results showed that the Newcastle disease virus was widespread in pigeons locally and caused high mortality rate. It is concluded that pigeon fanciers of northern Bangladesh do not maintain the regular preventive measures or vaccination against ND is being adopted to control the disease.

Pigeon farming, like chicken and duck farming, is getting popularity nowadays in Bangladesh. The present study was conducted on the postnatal development and morphometry of egg of different breeds of pigeon available at northern Barind tract of Bangladesh. The study was conducted at thirty selected pigeon farms of three districts (Rajshahi, Natore and Pabna) of northern Barind tract of Bangladesh. The postnatal development (weight gain of squabs) of five groups (D0, D7, D14, D21, D28; D=day), and morphometry of eggs (egg weight, egg width (short axis), and length (long axis)) of breeds of pigeon (n=20, each breed) available at northern Barind tract in Bangladesh were collected and analyses with Duncan's Multiple Range test (DMRT). Considerable differences in the postnatal weight gain and egg morphometry were found among breeds of pigeon. The mature body weight of Giribaz, Kormona, Nun and Owl breeds of pigeon were below 300 gm; Satinette, Mookee, Suachandan, Lakkha, Jacobin, Bokhara, Shirajee, Homer and Pouter were 300-500 gm, and King and Strasser were below 800 gm. The postnatal weight of an age group was significantly different (p<0.05) from other age groups of all studied breeds. The highest egg length was 4.37±0.02 cm in Strasser, and the lowest was 3.68±0.01 cm in Giribaz pigeon. The highest egg width was 3.24±0.19 cm in Mookee, and the lowest was 2.73±0.02 cm in Giribug pigeon. The highest egg weight was 21.20±0.49 gm in Strasser, and the lowest was 14.00±0.23 gm in Owl pigeon. Moreover, a relationship between the body weight and egg length, width and weight of pigeons was observed in pigeons of all studied breeds. Asian J. Med. Biol. Res. September 2020, 6(3): 594-598