This study was conducted to ascertain anatomical variation in different body parts of Desi, Fayoumi, Cross (Rhode Island Red x Fayoumi) and Nick Chick laying hens. A total 16 laying hens of average body weight were selected using random numbers out of 2600 laying hens, slaughtered and eviscerated. It was observed that proportion of neck, ribs, breast, back, wings, thigh and legs out of aggregate weight was highest (51.74 plus minus 2.85) in Fayoumi hens. The proportion of liver, gizzard, heart and spleen combined weight was highest (6.05 plus minus 1.81) in desi hens. The proportion of non edible offals including trachea, lungs, kidneys, blood, feathers, head, crop, proventriculus, intestines, shanks, gizzard waste, skin, tail, testes, ova, oviduct and fat was estimated to be highest i.e. 46.60 plus minus 1.16 in Nick Chick laying hens. The anatomical variation in Desi and Fayoumi chicks was attributable to scavenging habit of these birds. The high proportion of edible offal in commercial Nick Chick hens may be ascribable to higher productive and reproductive traits.

The distribution of bovine immunodeficiency virus (BIV) in the organs of experimentally infected cows was investigated by use of nested polymerase chain reaction (PCR). Two cows (Nos. 1 and 2) experimentally infected with BIV were alive without any clinical symptoms of BIV infection for 28 months. Viral and proviral genomes of BIV were continuously detected from peripheral blood leukocytes in those cows by nested PCR. Proviral genome of BIV were also detected in liver, lung, and spleen cells in the two cows, and in the brain in cow No.1. Viral genomes were detected in liver, lung and spleen cells in cow No.1, and detected only in spleen cells in cow No.2. These results suggest that BIV tended to the persistent in some organs, especially in the spleen

In the conditions of the Republic of Belarus there was presented a characteristic of breeding stock of mares of Trakensky breed in accordance with body conformation and exterior. In course of the study there were taken measurements of height at the shoulder, heart-girth, metacarpus circumference at 1 year old and two year old age stages. There was calculated an index of massiveness which characterize the development of chest, index of bone which provided insight into skeleton development. Research results showed that in accordance with an exterior the breeding stock mares had a deep and massive barrel, good skeleton and developed muscle. The index of massivness was 118,4-120,5, bone index – 20,8-21,6, that corresponded to a type of riding horses. In accordance with the exterior, measurements and quality of posterity the mares of the bred lines obtained high grades and 93,5% were graded as elite class.

Determination of regular variations of macromorphological and topographical characteristics of thymus gland, spleen, thyroid gland, and atrabiliary capsules of swamp beavers (Myocastor coypus) at the postnatal ontogenesis was realized in the conditions of the Republic of Belarus. Taking into consideration active participation of immune and endocrine system organs in metabolic processes and vicarious and adaptive reactions there were revealed species and age-specific anatomical peculiar features of thymus gland, spleen, thyroid gland, and atrabiliary capsules of swamp beavers that made it possible to broader knowledge in the sphere of species, age-specific, breed and topographic anatomy