EFFECT OF MATING METHOD, SEX AND BIRTH TYPE ON GROWTH OF LAMBS

Estrus synchronization methods was use to control the reproductive traits of sheep, as well as bringing more females at the same stage of estrus and ovulation. According to the points mentioned above, the aim of the present study was to investigate and compare mating method and influence of fixed factors on birth and weaning weight of lambs. Statistical analysis showed that exist difference in the body weights between genotypes of lambs. In the first group, the difference in weight of lambs at birth, regardless of mating method was not significant (P> 0.05), while in the second group, the difference was slightly significant (P <0.05). As for the birth type, sex and within the same genotype, there was a statistical significance (P <0.05) between singles obtained naturally, between the triplets obtained naturally and between triplets received hormonal method. All the differences between body weight at 30 days (mating method, sex and birth type under the same genotype) were statistically significant (P <0.05).The determined differences in the body weights at 60 days (sex, mating method and type of birth under the same genotype) were statistically significant (P <0.05). The results showed that the differences (mating method, sex and type of birth under the same genotype) were statistically significant (P <0.05), except in between body weight at 90 days in twins among two genotypes obtained by natural method, which were not statistically significant (P> 0.05). [Projekat Ministarstva nauke Republike Srbije, br. TR31001 i br. TR31053]