Availability of Macroelements from a Concentrate Diet Supplemented with Soybean Meal or Poultry Manure Fed to Sheep

Eight young Merino rams fitted with T-shape cannulas in the duodenum and terminal ileum were allotted to two equal groups to study net absorption of calcium, phosphorus, and magnesium from concentrate diets supplemented by ensiled manure from caged layers or by soybean meal. Mean net absorption (percent of intake) of calcium, phosphorus, and magnesium from manure from caged layers and soybean meal diets were 1.94, 14.8; 55.4, 55.8; and 44.2, 35.0. Irrespective of diet, the small intestine was the major site for calcium and phosphorus absorption and the rumen for absorption of magnesium. Secretion of phosphorus in rumen was 2.31 and 5.34 g/day for manure and soybean meal diets. Manure from caged layers supplies phosphorus and magnesium for sheep and can supplement deficient diets. Because of low calcium absorption from poultry manure, it appears that for limited inclusion, the extra calcium contributed by manure should not be detrimental.