Author
ENNEKING, S - Purdue University | |
Cheng, Heng-Wei | |
JERRERSON-MOORE, K - North Carolina Agricultural And Technical State University | |
EINSTEIN, M - Purdue University | |
HESTER, P - Purdue University |
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/22/2012 Publication Date: 9/1/2012 Citation: Enneking, S.A., Cheng, H., Jerrerson-Moore, K.Y., Einstein, M.E., Hester, P.Y. 2012. Pre-pubertal exposure to mechanical loading in White Leghorn pullets. Poultry Science. 91:2114-2120. Interpretive Summary: Osteoporosis, a progressive decrease in mineralized structural bone, causes 20 to 35% of all mortalities in caged White Leghorn hens. The objective of the current study was to determine the effect of mechanical loading on pullet health, bone mineralization, and muscle deposition in caged White Leghorns given access to perches. From 0 to 17 wk of age, half of the chicks were placed in cages with 2 round metal perches, while the other half did not have perches (controls). The results suggest that mechanical loading achieved through perching have beneficial effects on pullet health by stimulating leg muscle deposition and increasing the mineral content of certain bones without causing a concomitant decrease in bone mineral density. These results are extremely beneficial to the scientific community in better understanding the role of mechanicall loading on the bone development. These data can be used by egg producers to develop guidelines for improving chicken welfare by proving perches. Technical Abstract: Osteoporosis, a progressive decrease in mineralized structural bone, causes 20 to 35% of all mortalities in caged White Leghorn hens. Previous research has focused on manipulating the egg laying environment to improve skeletal health with little research on the pullet. The objective of the current study was to determine the effect of mechanical loading on pullet health, bone mineralization, and muscle deposition in caged White Leghorns given access to perches. From 0 to 17 wk of age, half of the birds were placed in cages with 2 round metal perches, while the other half did not have perches (controls). Bone mineralization and bone size traits were determined in the tibia, femur, sternum, humerus, ulna, radius, and phalange using dual energy x-ray absorptiometry. Muscle weights were obtained for the breast and left leg (drum and thigh). A sample of pullets from each cage was evaluated for foot health, BW, right adrenal weight, and packed cell volume. Most measurements were taken at 3, 6, and 12 wk of age. Access to perches did not affect breast muscle weight, % breast muscle, % leg muscle, bone mineral density, bone length, bone width, adrenal weight, packed cell volume, and hyperkeratosis of the foot-pad and toes. There were no differences in BW, bone mineral content, and leg muscle weight at 3 and 6 wk of age. However, at 12 wk of age, BW (P = 0.025), bone mineral content of the tibia, sternum, and humerus (P = 0.015), and the left leg muscle weight (P = 0.006) increased in pullets with access to perches as compared to controls. These results suggest that mechanical loading achieved through perching have beneficial effects on pullet health by stimulating leg muscle deposition and increasing the mineral content of certain bones without causing a concomitant decrease in bone mineral density. |