Abstract:In this study, two groups of 60 neonatal Euler ewe lambs with similar initial body conditions were subjected to different rearing methods. And the primary phenotypic traits, including 18-month body weight and body dimensions were analyzed and compared. The results indicate that the experimental group exhibited continuous growth from birth to 18 months of age. Compared to the control group, at weaning, 6 months, 12 months, and 18 months of age, the experimental group displayed significant increases in body weight, with the highly statistically significant differences (P<0.01) of 5.15 kg, 5.58 kg, 6.31 kg, and 6.86 kg, respectively. The average body height and length increased by 15 cm, 2.24 cm, 2.16 cm, 2.37 cm and 2.68 cm, 3.17 cm, 3.41 cm, 4.16 cm, respectively, both with the highly significant differences (P<0.01). The average chest circumference increased by 1.63 cm, 2.72 cm, 3.78 cm, and 4.43 cm, except at weaning where the difference was significant (P<0.05), and highly significant(P<0.01) at 6 months, 12 months, and 18 months of age. Chest depth and chest width indicators also showed significant increase, with differences (P<0.05) of 1.12 cm, 1.27 cm, 1.35 cm, 1.29 cm, and 1.84 cm, 1.60 cm, 1.10 cm, 1.89 cm, respectively. Additionally, daily weight gain, weaning survival rate, and oneyear survival rate were significantly higher in the experimental group compared to the control group, with highly statistically differences (P<0.01). The production performance of the experimental group met the standards of the " Euler Sheep" DB62/T490 breed for specialclass and firstclass sheep, with high breeding value and significant breeding effects, while the control group only reached the thirdclass sheep of that. And such difference suggesting that the "grazing & timely supplementary feeding" rearing approach is a more rational method for the production of Tibetan breeding sheep in highaltitude pastoral areas.
