作者: Beth E. Keene
DOI:
关键词: Lactation 、 Dentistry 、 Non invasive 、 Dairy cattle 、 Animal science 、 Bone mineral 、 Parity (mathematics) 、 Peak load 、 Bone mineral content 、 Biology 、 Breaking strength
摘要: The objectives of this research were to evaluate non-invasive measures bone mineral content (BMC) and density (BMD) as rapid, on-farm tools assess phosphorus (P) status in dairy cows. In addition, the effects parity stage lactation on BMC fused 3 4 metacarpal caudal vertebrae 14 15 assessed. right front (sample pairs) excised from 107 Holstein cull cows following slaughter. Parity, age, days milk (DIM) donor animal obtained for 43 pairs samples. Samples grouped by (1, 2, 3, ≥ 4) (Stage 1 = 90 150 250 DIM). analyzed BMD with dual energy X-ray absorptiometry (DXA), radiographic photometry (RP), breaking strength mechanical methods, chemical procedures. Estimates RP DXA poorly related actual strength. 15, increasing decreased peak load lowest values observed late lactation. Stage had no effect measured chemically or metacarpal. Parity did not affect total ash P any bone. Results indicated that imaging techniques are useful mature cattle.