Growth rate and age at boar exposure as factors influencing gilt puberty
Growth rate and age at boar exposure as factors influencing gilt puberty
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DOI:
10.1016/j.livsci.2008.04.009
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发表时间:
2009-01-01
影响因子:
1.8
通讯作者:
Bortolozzo, F. P.
中科院分区:
文献类型:
--
作者:
Amaral Filha, W. S.;Bernardi, M. L.;Bortolozzo, F. P.
The objective Of this Study was to verify whether pubertal estrus could be influenced by the growth rate and age of gilts at the onset of boar exposure. Gilts (n= 1486) were evaluated according to two groups of age at boar exposure (A= 130-149 d and B= 150-170 d) and three classes of growth rate (Low=550 649 g/d; Intermediate=650 725 g/d and High=726-830 g/d). Gilts of groups A and B were, respectively, 142.6 +/- 4.9 and 157.0 +/- 5.1 days of age at the onset of boar exposure. Overall, 85% of gilts showed estrus within 40 days of boar exposure. Within group A gilts a higher (P < 0.05) cumulative percentage of estrus within 20 days of stimulation was observed in High than in Intermediate and Low growth rate gilts (59.7% vs. 48.7% vs. 48.2%; P 0.05). Within group A, puberty was attained earlier in High than in Low growth rate gilts (159.6 vs. 164.8 days). However, age at puberty was not affected by growth rate, when gilts were exposed to boar in an older age (group 13). Overall, age at puberty was positively associated with the age at the onset of boar exposure (r=0.38; P < 0.0001) and the older the gilts were at boar exposure the lower was the interval (r=-0.19; P