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Humbolt-Universität zu Berlin (2000)

Comparative performance evaluation of Horro and Menz sheep of Ethiopia under grazing and intensive feeding conditions

Awgichew, Kassahun

Titre : Comparative performance evaluation of Horro and Menz sheep of Ethiopia under grazing and intensive feeding conditions

Auteur : Awgichew, Kassahun

Université de soutenance : Humboldt-Universität zu Berlin

Grade : Doktor Rerum Agriculturarum (Dr. re. agr.) 2000

Résumé partiel
Lambs from second parity ewes had a higher rate of weight gain between birth and 30 days of age and between birth and weaning (90 days) compared to lambs born from ewes that have lambed for the first time, indicating a strong maternal influence of second parity ewes probably through higher milk production compared to the first time lambers. Lamb survival within two weeks of birth was strongly influenced by birth type, dam parity, and season of birth but not by breed and sex. More than 97 % of single born lambs survived to 15 days of age compared to 91 % for twins (P < 0.001). Likewise more (97 %) lambs born to second parity ewes survived to 15 days after birth as opposed to about 92 % for lambs born from ewes of first parity (P <0.001). The survival rate between birth and weaning (90 days) for Menz lambs (89 %) was significantly (P < 0.001) higher than that for the Horro (76 %). Menz lambs had also a much better post-weaning survival rate from birth to 180, 270 and 365 days of age (81, 71 and 62 %, respectively) compared to Horro (51, 39 and 37 %, respectively). This shows that Horro lambs might have adaptation problems as they are introduced from a different region of the country. Horro and Menz lambs did not differ significantly in heart girth measurement. However Horro lambs were taller (P < 0.001) at withers at one year of age compared to Menz (61.91 ± 0.62 cm vs 59.89 ± 0.44 cm). The greatest difference observed between the two breeds is in tail length at all stages. Although both breeds are characterised as fat tailed sheep, Horro sheep have longer tail while Menz have a shorter and relatively wider tail. A strong and significant (P < 0.001) correlation between body weight and the linear body measurements considered in this study was observed at all stages of growth. From what is observed in this study, body weight at one year of age for both breeds could be fairly accurately estimated from heart girth (r = 0.90 for Menz and r = 0.86 for Horro).

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