Phenotypic and genetic correlations between gilt estrus, puberty, growth, composition, and structural conformation traits with first-litter reproductive measures
Phenotypic and genetic correlations between gilt estrus, puberty, growth, composition, and structural conformation traits with first-litter reproductive measures
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DOI：
10.2527/jas.2009-2673
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发表时间：
2011-04-01
影响因子：
3.3
通讯作者：
See, M. T.
中科院分区：
文献类型：
--
作者：
Knauer, M. T.;Cassady, J. P.;See, M. T.
目的是估计母猪发情，青春期，生长，组成和结构构象性状与第一窝繁殖措施的相关性。4组后备母猪（n = 1，225; NC遗传改良服务，Newton格罗夫，NC）进入NC猪评价站（克莱顿，NC），平均年龄为162日龄，每天观察发情症状。一旦在70%的后备母猪中观察到第一次发情的症状，利用围栏公猪接触，每12小时记录一次所有后备母猪的发情症状，持续30天。主观发情特征是站立反射的最大和总强度，如在有和没有公猪的情况下观察到的，以及外阴发红和肿胀的强度。客观发情性状包括外阴红度、外阴宽度、发情期长短和青春期年龄。生长和组成特征包括青春期体重、体重达到114 kg的天数、体重达到114 kg时和青春期的第10肋背膘和LM面积。主观结构形态特征包括肌肉质量、肋骨宽度、前腿侧视图、后腿侧视图、前腿正视图、后腿后视图和运动。第一窝母猪性状包括后备母猪是否分娩（Stay）、首次分娩年龄（AFF）、出生仔猪总数（TNB）和断奶至受孕间隔（WCI）。使用动物模型估计方差分量，线性性状使用AIREMLF 90，分类性状使用THRGIBBS 1F 90。Stay、AFF和TNB的遗传力估计值分别为0.14、0.22和0.02。发情期长度、站立反射性状和青春期年龄与Stay的遗传相关分别为0.34、0.34 ~ 0.74和-0.27，与AFF的遗传相关分别为-0.11、-0.04 ~-0.41和0.76。达到114 kg的天数与Stay、AFF和TNB的遗传相关性分别为0.52、-0.25和-0.08。114 kg背膘厚与Stay、AFF和TNB的遗传相关分别为-0.29，0.14和0.47。外阴发红与TNB呈表型负相关（r = -0.14），与遗传负相关（r = -0.53）。结构构象性状与Stay，AFF，TNB和WCI之间的关联一般为低至中等和有利的。选择更长的发情期、更强的站立反射或更年轻的青春期年龄将增加产仔的后备母猪比例，并降低首次分娩的年龄。
The objective was to estimate correlations of gilt estrus, puberty, growth, composition, and structural conformation traits with first-litter reproductive measures. Four groups of gilts (n = 1,225; Genetic Improvement Services of NC, Newton Grove, NC) entered the NC Swine Evaluation Station (Clayton, NC) averaging 162 d of age and were observed daily for symptoms of estrus. Once symptoms of first estrus were observed in 70% of gilts, recording of symptoms of estrus in all gilts occurred every 12 h for 30 d, utilizing fence-line boar contact. Subjective estrous traits were maximum and total strength of standing reflex, as observed with and without the presence of a boar, and strength of vulva reddening and swelling. Objective estrous traits consisted of vulva redness, vulva width, length of estrus, and age at puberty. Growth and composition traits included BW at puberty, days to 114 kg, and 10th rib backfat and LM area at 114 kg and at puberty. Subjective structural conformation traits were muscle mass, rib width, front leg side view, rear leg side view, front legs front view, rear legs rear view, and locomotion. First-litter sow traits included if gilt farrowed (Stay), age at first farrowing (AFF), total number of piglets born (TNB), and weaning to conception interval (WCI). Variance components were estimated using an animal model with AIREMLF90 for linear traits and THRGIBBS1F90 for categorical traits. Heritability estimates for Stay, AFF, and TNB were 0.14, 0.22, and 0.02, respectively. Genetic correlations between length of estrus, the standing reflex traits, and age at puberty with Stay were 0.34, 0.34 to 0.74, and -0.27, respectively, and with AFF were -0.11, -0.04 to -0.41, and 0.76, respectively. Days to 114 kg had genetic associations with Stay, AFF, and TNB of 0.52, -0.25, and -0.08, respectively. Backfat at 114 kg had genetic correlations with Stay, AFF, and TNB of -0.29, 0.14, and 0.47, respectively. Vulva redness and TNB were negatively correlated phenotypically (r = -0.14) and genetically (r = -0.53). Associations between structural conformation traits with Stay, AFF, TNB, and WCI were generally low to moderate and favorable. Selection for longer length of estrus, stronger standing reflex, or younger age at puberty would increase the proportion of gilts that farrow and reduce age at first farrowing.