Evaluation of some environmental and genetic factors csn3 and agpat6 gene on milk yield and composition in saanen goats

Abstract

This study was designed to determine the effect of some environmental factors on milk yield and composition in Saanen goats and the effect of CSN3 and AGPAT6 gene polymorphisms on milk production traits. Saanen goats were genotyped for milk traits, and the samples were collected during the lactation, and the milk yield/compositions of each goat were specified. In terms of the CSN3 and AGPAT6 genes, the genotypes were defined by PCR-RFLP. The milk yield (MY), lactation length (LL), protein, fat, total solid (TS), solid not fat (SNF), casein, lactose rates and yields were as follows; 388.9 +/- 17.5 kg, 243 +/- 5.81 days, 3.29 +/- 0.05%, 3.59 +/- 0.07%, 11.60 +/- 0.13%, 8.43 +/- 0.06%, 2.57 +/- 0.04%, 4.31 +/- 0.03%, 11.21 +/- 0.47 kg, 12.79 +/- 0.64 kg, 40.95 +/- 1.82 kg, 29.53 +/- 1.31 kg, 8.82 +/- 0.37 kg, 15.40 +/- 0.74 kg respectively. The determined genotype and allele frequencies of CSN3 and AGPAT6 gene were as follows; FF (%99.20), MF (%0.80), F (0.996), M (0.004); GG (%12), GC (%43.20), CC (%44.80), G (0.336), C (0.664). The impacts of lactation length on all milk yield parameters (protein, fat, TS, SNF, casein, lactose. MY) (P<0.001); the age on all milk yield parameters (P<0.001) and the protein, fat, SNF, casein rates (P<0.05), the TS rate and LL (P<0.01) were found to be significant. The birth type was not found to significantly affect any milk yield parameters. Although Saanen goats showed the variation for the AGPAT6 gene (g.9263C>G), the herd was found to be monomorphic (FF) for the CSN3 gene. The effect of the AGPAT6 gene on milk traits in Saanen goats was determined not to be statistically significant. Environmental factors, such as maternal age and lactation length, were found to significantly affect some milk traits in Saanen goats. So consideration of factors such as maternal age or lactation length could be useful for improving breeding strategies for dairy goats.