ANSC 340 Lecture Notes - Lecture 15: Dairy Cattle, Heterosis, Photoperiodism
28 Oct 2016
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Document Summary
Beef cow: 12 months (range of 10-18 months) Dairy cow: 9 months (range of 7-12 months) Animal must be near right age of puberty before surge center fully responds to increasing estrogen levels. Animals should be 85% of body weight when birthing for the first time. Maternal breeds hit puberty earlier and mature earlier. Superiority of offspring to average of 2 parents (each a different breed) A way to improve genes that otherwise could not be improved. Maintenance requirements can be met before reproduction or other requirements are met. Sheep are fall breeders, want to birth in spring. When species want to give birth is often associated with. Photoperiod- when species breed (sheep prefer birthing in spring because abundant resources) Presence of male increases cycling (whether contact is allowed or not) G(cid:374)rh (cid:374)euro(cid:374)s dete(cid:272)t (cid:862)(cid:373)o(cid:373)e(cid:374)t to (cid:373)o(cid:373)e(cid:374)t(cid:863) (cid:272)ha(cid:374)ges i(cid:374) (cid:271)lood glu(cid:272)ose+ fatty a(cid:272)ids.
