Daniel et al. (1981) reported that feed restriction programs limit the increase in egg weight and decrease
in egg shell thickness which is generally accepted to
contribute to the decrease in hatchability occurring
during post-peak production.
There is a direct relationship between the pullet's
development during rearing and subsequent
performance and the bird's ability to reach optimum
peak production during the laying cycle. In addition, body
weight at 16 weeks of age has been shown to be
positively correlated with performance (Hudson et al.,
2001). Usually, when flock uniformity is high at 16 week
of age, egg production is higher and mortality is lower
after 55-60 weeks of age. Thus, every attempt should be
made to attain a good uniformity and proper body weight
at 16 weeks of age. Pullets on or above target body
weight at this age are usually the best performers during
the laying period. If a pullet is not on target body weight
by 12 weeks of age, she will more than likely to be a
small pullet entering the laying house and possibly a
financial burden for the rest of the laying period. The
restricted feeding regimen used during the rearing
period in this study was designed to control pullet body
weight and to reduce reproductive problems resulting
from the intensive selection of meat type chicken for
growth, however, it is difficult to determine the optimum
degree of restriction, because of strain differences and
changes in the genetic constitution of stocks by primary
breeders (Robinson et al., 1993). Such programmes
require intensive management to avoid under estimation
of feed allotments (Dozier et al., 2003). Renema et al.
(1999) found that improving body weight and uniformity
would be beneficial for a more uniform onset of lay and
reduced early production losses from small hens.
Hocking et al. (2002) reported that conventional feed
restriction results in a decrease in average daily feed
consumption during rearing and early lay and in an increase after the peak rate of egg production.
Daniel et al. (1981) reported that feed restriction programs limit the increase in egg weight and decreasein egg shell thickness which is generally accepted tocontribute to the decrease in hatchability occurringduring post-peak production.There is a direct relationship between the pullet'sdevelopment during rearing and subsequentperformance and the bird's ability to reach optimumpeak production during the laying cycle. In addition, bodyweight at 16 weeks of age has been shown to bepositively correlated with performance (Hudson et al.,2001). Usually, when flock uniformity is high at 16 weekof age, egg production is higher and mortality is lowerafter 55-60 weeks of age. Thus, every attempt should bemade to attain a good uniformity and proper body weightat 16 weeks of age. Pullets on or above target bodyweight at this age are usually the best performers duringthe laying period. If a pullet is not on target body weightby 12 weeks of age, she will more than likely to be asmall pullet entering the laying house and possibly afinancial burden for the rest of the laying period. Therestricted feeding regimen used during the rearingperiod in this study was designed to control pullet bodyweight and to reduce reproductive problems resultingfrom the intensive selection of meat type chicken forgrowth, however, it is difficult to determine the optimumdegree of restriction, because of strain differences andเปลี่ยนแปลงรัฐธรรมนูญทางพันธุกรรมของหุ้นโดยหลักบรีดเดอร์ส (โรบินสัน et al., 1993) โปรแกรมดังกล่าวต้องเร่งรัดจัดการเพื่อหลีกเลี่ยงการภายใต้การประเมินของอาหารส่วนแบ่ง (Dozier et al., 2003) Renema et al(1999) พบว่าการปรับปรุงตัวน้ำหนักและความรื่นรมย์จะเป็นประโยชน์ต่อการเริ่มขึ้นเป็นรูปแบบของการวาง และลดขาดทุนจากการผลิตเริ่มต้นจากไก่ขนาดเล็กHocking et al. (2002) รายงานว่า อาหารธรรมดาจำกัดผลลัพธ์ในการลดลงในอาหารประจำวันโดยเฉลี่ยปริมาณการใช้ใน ระหว่างการเพาะเลี้ยง และเริ่มต้นวาง และเพิ่มหลังจากอัตราสูงสุดของการผลิตไข่
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