The relationship between linear type traits and fertility traits in high-yielding dairy goats.
Reproductive data collected from 13 medium-size goat farms in central Mexico (582 goats), were used to investigate if linear type traits influenced reproductive performance of high-yielding dairy goats. Data were analysed using multiple stepwise forward logistic regressions. Goats with the higher scores for strength were 1.43 times more likely (p < 0.05) to have larger litters (1.49 vs 1.39) than goats with lower strength. Goats approaching level rump angles were 1.68 times more likely (p < 0.01) to have larger litters, compared with goats with extremely sloped rump angles (1.48 vs 1.37). Goats with rear legs nearly straight (posty) in hock tended (p < 0.08) to presented larger litters than goats with rear legs slightly angled (sickled) in hock (1.49 vs 1.38). Less pronounced rump angle was favourable associated (p < 0.05) with litter weight (4.88 vs 4.53 kg) compared with goats with low pin bones. Goats with poorer udder texture were 1.42 more likely (p < 0.05) to have heavier litters than goats with good udder texture. Goats with faulty mammary system tended (p < 0.07) to have heavier litters than goats with good mammary system. Increasing udder height was associated (p < 0.05) with increasing number of services per conception. Goats with good fore udder attachment and non-refined heads were at reduced risk (p < 0.05) for stillbirths. Goats with stronger median ligament were 65% less likely (p < 0.05) to lose their foetuses than those with looser udder support. Our findings indicate that a greater litter size and litter weight is expected in goats as rump angle becomes less sloped. This study showed that a relationship exists between strength of goats and litter size, and that some traits linked to high milk yield were antagonist to some reproductive traits.
Mellado
M
M
Department of Nutrition and Foods, Universidad Autonoma Agraria Antonio Narro, Saltillo, México. mmellbosq@yahoo.com
Mellado
J
J
Valencia
M
M
Pittroff
W
W
D000818:Animals; D001947:Breeding; D005260:Female; D005298:Fertility / Q000235:genetics / Q000502:physiology; D006041:Goats / Q000235:genetics / Q000502:physiology*; D007774:Lactation / Q000235:genetics / Q000502:physiology*; D008098:Litter Size / Q000235:genetics / Q000502:physiology*; D016015:Logistic Models; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000235:genetics / Q000502:physiology*