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Background: The most frequently observed forms of beta casein (β-Cn) in dairy cattle are A1 and A2. A2 β-Cn is recognized as the original β-Cn protein because it existed before a mutation caused the appearance of A1 β-Cn in European cattle (Bos taurus) a few thousand years ago. In cattle, beta-casein (CSN2) gene is highly polymorphic with at least 13 genetic variants known until now. Methods: Research work was carried out on 50 Malvi and 50 Nimari, 50 Sahiwal and 50 H F Cross bred cow. In present research work the PCR amplicons of 121bp were digested by restriction endonuclease enzyme DdeI, which recognizes G^AATTC sites. Present association study of polymorphic variants’ showed that the presence of no restriction sites for the enzyme DdeI in both Malvi and Nimari. So one band of 121bp was observed on the gel and such genotype was designated as A2A2 type. Whereas in Sahiwal and H F Crossbred showed two type of genotypes A1A2 and A2A2. Result: The result of RFLP revealed that the gene and genotypic frequencies of β-casein (CSN2) gene for A2A2 was 1.00 for both Malvi and Nimari breed of cattle but 0.00, 0.30 and 0.70 in Sahiwal and 0.00, 0.64 and 0.36 in HF crossbred cattle, respectively. Association study showed that the lactose per cent was significantly higher in Nimari as compared to Malvi and Sahiwal. Among all the four breeds of cattle, significantly lower SNF (%) and density was noticed in Malvi breed of cattle for A2A2 genotype compared to remaining three breeds.

Present research work was carried out on 50 Sahiwal and 50 HF Crossbred cattle in the Department of Animal Genetics and Breeding of College of Veterinary Science and A H Jabalpur. During the research work the PCR amplified products of 121bp was digested by restriction endonuclease enzyme DdeI, which recognizes G^AATTC sites. The patterns evolved in the present study showed that the presence of one restriction site on one alleles and absence of restriction site on other alleles resulted in the appearance of three bands of 121, 86 and 35bp.This genotype was referred to as A1A2. When both strand had no restriction sites for the enzyme, only one band of 121bp was observed on the gel such genotype was designated as A2A2 type. The â- casein gene showed A2A2 and A1A2 genotypes were observed in Sahiwal and HF crossbred cattle. The genotypic frequencies of â-casein (CSN2)/ DdeI gene for A1A1, A1A2 and A2A2 are 0.00, 0.30, and 0.70 in Sahiwal and 0.00, 0.64 and 0.36 in HF crossbred cattle, respectively and the gene frequency A1 and A2 is 0.15 and 0.85 in Sahiwal and 0.32 and 0.68 in HF crossbred cattle. High frequency of A2 allele was observed in both the breeds of cattle under the study.

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A Gross morphologic and biometric study was conducted on ovaries of a total 72 female chicks/ growers, 36 each of Kadaknath and White Leghorn (WLH) breeds. The birds were grouped according to age into 6 (I-VI) groups, viz., 1, 4, 8, 12, 16 and 20 weeks old. The gross observations revealed that the left ovary was elongated triangular with base directed rostrally and conical apex caudally in all the groups of Kadaknath and WLH, except in age group V and VI of WLH. The mean weight of the ovary in age group I was 0.08±0.01g and 0.08±0.18 g, which increased to 0.31±0.04 g and 21.17±2.29 g in Kadaknath and WLH, respectively. The mean length of ovary in Kadaknath was 0.68±0.03 cm in age group I, which increased to 2.02±0.09 cm in age group VI. The mean length of ovary was slightly more in WLH than Kadaknath group I, which became more than twice in age group VI.