Dietary calcium and phosphorus repletion of lambs [sheep]
1990
Ternouth, J.H. | Sevilla, C.C. (Queensland Univ., St. Lucia (Australia). Dept. of Agriculture)
Three-month-old Corriedale lambs, confined in metabolism crates, were repleted with calcium (Ca) or phosphorus (P) or both Ca and P for 6 weeks (repletion diets HL, LH, HH respectively) after being offered a low Ca and P, roughage-based diet (LL) for 12 weeks. Feeding the depletion diet substantially reduced the plasma P levels, dry matter intake and digestiblity, liveweight gain, and Ca and P content of the bones. During the 6 week repletion period there was complete remineralization of the rib bones of lambs fed diet HH, but only partial remineralization of the metatarsal bones. The results indicated the need to feed supplementary Ca as well as P during dietary mineral repletion. The dry matter digestibilities of the lambs fed the LL depletion diet did not improve during repletion. There was found to be strong correlations between dry matter intake and plasma inorganic P, muscle P or exchangeable P pool, but not dry matter digestiblity, suggesting that the reductions in food intake with P deficiency are due to some effect on intermediary metabolism of the animal rather than on the gastro-intestinal tract.
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