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INFLUENCE OF AGE, CALCIUM, PHOSPHORUS REGIMEN AND STRAIN ON THE PERFORMANCE AND BONE METABOLISM OF LARGE WHITE TURKEYS
Abstract
Seven hundred and twenty female and 900 male day-old poults from three Large White turkey strains, Mile High 170 (MH-170), Nicholas (N) and Orlopp 61 (0-61), were used in two experiments conducted to study the influence of Ca and P regimen and strain on performance and bone metabolism. Levels of Ca and P in dietary regimens were reduced periodically with age and given to females or males to 20 or 24 weeks of age, respectively. Body weight, cummulative feed efficiency, serum calcium, phosphorus and alkaline phosphatase (AP) were periodically determined. Tibia samples were measured for length, fat-free dry weight, breaking strength, ash (%), bending moment, moment of inertia, breaking stress and modulus of elasticity. The incidence of leg abnormalities in each dietary Ca and P regimen and strain was also obtained. In males, the middle Ca and P regimen produced the greatest overall responses in body weight, blood (except serum phosphorus) and bone parameters measured. In females, the low Ca and P regimen produced the greatest body weight and serum phosphorus levels. The high Ca and P regimen in the females produced the greatest responses in serum AP, tibia weight, ash (%), breaking strength and stress, bending moment, moment of inertia and elastic moduli. Serum AP and calcium declined with age, but the decline in serum calcium stopped at 16 weeks and subsequently, it rose slightly. Bone ash, breaking strength, bending moment and moment of inertia increased with age in both sexes. Bone weight also increased with age but in females, bone weight peaked at 18 weeks. A significant negative correlation occurred between serum AP and phosphorus, while positive correlations occurred between serum AP, tibia length, weight, breaking strength and ash (%). The mechanical properties also correlated positively with tibia breaking strength and ash (%). Sex differences were apparent in the Ca and P requirements of turkeys for body weight gain and bone development. Male turkeys had the greatest body weight gain and best bone characteristics when the middle Ca and P regimen (containing 1.25-0.75% and 0.95-0.60%, respectively) was fed. Female turkeys given the low dietary Ca and P regimen (1.00-0.60% and 0.80-0.50%, respectively) had the greatest body weight, while the high Ca and P regimen (1.50-0.90% and 1.10-0.70%, respectively) produced the best overall bone characteristics. Males of the 0-61 strain had significantly greater final body weight, tibia length and serum phosphorus than either the N or MH-170 males. However, 0-61 strain males had the lowest serum calcium, tibia breaking strength, ash (%), bending moment, moment of inertia, breaking stress and elastic moduli. The N strain males had the shortest tibiae and the highest serum AP, tibia breaking strength, ash (%), bending moment and moment of inertia. The 0-61 females had significantly greater final body weight, longer tibia as well as serum phosphorus at the termination of the study as compared to other strains. The 0-61 females also had the least ash (%), and intermediate values of breaking strength and stress, bending moment and elastic moduli at the end of the study. The MH-170 females had the highest overall serum AP, bone ash, moment of inertia and the least serum phosphorus. Most differences among strains were not statistically significant. However, the MH-170 strain in both sexes tended to show better characteristics for bone development, followed closely by the N strain. The 0-61 birds had the greatest mature body weights and somewhat poorer bone development characteristics, which could dispose this strain to more leg weakness problems and bone abnormalities. The 0-61 strain in this study did show a greater (but not statistically significant) incidence of leg abnormalities.
Subject Area
Livestock
Recommended Citation
NJOKU, PLACID CHIKE, "INFLUENCE OF AGE, CALCIUM, PHOSPHORUS REGIMEN AND STRAIN ON THE PERFORMANCE AND BONE METABOLISM OF LARGE WHITE TURKEYS" (1980). ETD collection for University of Nebraska-Lincoln. AAI8110579.
https://digitalcommons.unl.edu/dissertations/AAI8110579