Effects Of Different Granularities Of Calcspar In Dietary On Cage Layer's Bone Metabolism And Production Performance In Late Laying Hens

Cage layer osteoporosis is defined as a progressive loss of structural bone, leading to increase in bone fragility and susceptibility to fracture during the laying period. Providing particulate form of calcareous stone could alleviates cage layer osteoporosis in laying period. We study the effect different granularities calcspar in dietary on bone metabolism and production performance in cage layer. The mainly objective was to elucidate the mechanism of relieving effects on osteoporosis by using particulate calcareous stone. The present research includes two parts as follows:1 Effect of Different Calcspar Granularities in Dietary on Cage Layer's Bone Metabolism and Production Performance in Late Laying HensObjective: Effects of different particulates of calcspar on preventing and curing cage layer osteoporosis. Methods: 75 ISA cage layers for 58 weeks old were randomly divided into 3 groups(A, B, C) which were fed basic diet containing 100 mu,10 mu and 6 mu calcspar as calcium resource, respectively. The test lasted for 10 weeks. Results: â‘ The egg laying rate of B and C groups were significantly higher than that of A group(P<0.01). The feed/egg rate of B and C groups were significantly lower than that of A(P<0.01). The abnormal and broken egg ratio of C Group was significantly lower than that of A group. The eggshell thickness of B and C groups were higher than that of A group(P>0.05).The mean egg weight of A group was significantly higher than B and C groups; â‘¡Compared with A group, the tibial index of B and C groups increased 6.66%(P>0.05) and 8.03%(P<0.05), respectively. Although the body weight, long bone weight, humerus index and femur index of B and C groups were higher than A group, there were not significant differences among them; â‘¢Compared with A group, the humerus radiographic density of B and C groups increased by 19.03%(P<0.05) and 14.19%(P>0.05) respectively. The tibial radiographic density increased by 9.81% (P<0.05) and 3.73%(P>0.05)respectively. The keel radiographic density increased by 24.91 %(P<0.05) and 29.46%(P<0.01) respectively. Although the femur radiographic density of B and C groups were higher than A group, there were not significant...