SHELL CHARACTERISTICS OF EGGS FROM HISTORIC STRAINS OF SINGLE COMB WHITE LEGHORN CHICKENS AND THE RELATIONSHIPS OF EGG SHAPE TO SHELL STRENGTH
SHELL CHARACTERISTICS OF EGGS FROM HISTORIC STRAINS OF SINGLE COMB WHITE LEGHORN CHICKENS AND THE RELATIONSHIPS OF EGG SHAPE TO SHELL STRENGTH
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DOI：
10.3923/ijps.2004.17.19
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
K.E. Anderson;J.B. Tharrington;P.A. Curtis;F.T. Jones
中科院分区：
文献类型：
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作者：
K.E. Anderson;J.B. Tharrington;P.A. Curtis;F.T. Jones
通过分析从1950年基础种群中获得的加拿大农业部渥太华控制株系5的鸡蛋，确定了长期遗传选择对蛋壳特性的影响；7，从1959年的人口；还有10个是1972年出生的。H&N“Nick Chick”1993年的商业菌株也被包括在内，因为它与三种历史菌株具有相同的遗传血统。从28周龄开始采蛋，每4周至试验结束的第86周进行一次产蛋周期，测量蛋重、蛋高、蛋宽、壳重、壳厚、蛋比重和破壳力。研究了鸡蛋形状和重量对蛋壳强度的影响。从1950年菌株到现在菌株，不同菌株之间的卵形、卵重和卵表面积均有显著差异（P < 0.05）。形状指数表明，当前菌株增加了鸡蛋的大小，鸡蛋的宽度增加最大。在壳重百分比、壳厚百分比和比重均无差异的情况下，本品系产蛋的平均破碎力高于其他品系产蛋（P< 0.05）。在生产期间，所有菌株的断裂力、壳重百分比和比重都有所下降。这项研究的结果表明，基因选择产生了更大、形状更圆的卵子。
The effect of long term genetic selection on shell characteristics was determined by analyzing eggs acquired from Agriculture Canada: Ottawa Control Strain 5, from a 1950 base population; 7, from a 1959 population; and 10, from a 1972 population. H&N "Nick Chick" 1993 commercial strain was also included because it shares genetic ancestry with the three historic strains. Eggs were collected beginning at 28 wk of age, then every 4 wk through the end of the study at 86 wk of the laying cycle and egg weight, egg height, egg width, shell weight, shell thickness, egg specific gravity, and shell breaking force measured. The relationship of egg shape and weight as factors affecting shell strength were also investigated. Significant differences (P < 0.05) were found between strains for egg shape and a progressive increase in weight and surface area of eggs from the 1950 strain to the current strain. The shape index indicates that the current strain has increased egg size with the greatest increase seen in egg width. The mean breaking force of eggs from the current strain was higher (P< 0.05) than the other strain's eggs with no strain differences in percent shell weight, shell thickness, or specific gravity. A decline in breaking force, percent shell weight, and specific gravity was observed among all the strains over the production period. The results from this study suggest that genetic selection has produced larger eggs that are rounder in shape.