The Body Weight Egg Production Paradox

Relationships between body composition and reproductive performance in the laying hen

“…In agreement with Dickerson and Hughes (1964), Nordskog and Briggs (1968) and Fowler and Quisenberry (1970), the graphs demonstrate that heavier i.e., better conditioned, birds tend to be better producers.…”

“…On the other hand, producers usually find that the best performers are birds with the heavier body weights. Nordskog and Briggs (1968) hypothesized that maximum performance is obtained when husbandry practices permit the flock to reach its optimum frequency norm for body weight. Since genetically different strains theoretically have different norms for each environment, practices that cause body weight to deviate from the optimum norm would lower egg pro duction.…”

“…and Egg Production Nordskog and Briggs (1968) indicated that body weight is a function of size as represented by bone framework, and condition, as represented by fleshing. Reports in the literature suggest that variation in size is primarily genetic whereas variation in condition is primarily environ mental, being largely influenced by factors of disease, management and nutrition.…”

“…Dickerson and Hughes (1964) and Nordskog and Briggs (1968) have concluded that the maintenance of satisfactory body condition is an important component of efficient egg production. Tierce (1973) used shank length, breast probe and abdominal skin pinch, respectively, as estimators of bone, muscle and fat in laying hens at 21 weeks of age.…”

Genetic aspects of body weight and growth parameters as related to reproductive performance in the fowl

“…Dickerson and Hughes (1964) and Nordskog and Briggs (1968) have shown that fleshing or condition is an economically important component in terms of laying house performance. Variation in condition was as sumed to be mostly determined by variable husbandry practices.…”