Effects of protein and energy supplementation of wheat straw-based diets on site of nutrient digestion and nitrogen metabolism of lambs.
A 4 x 4 Latin square metabolism trial with 2 x 2 factorial arrangement of treatments was conducted with lambs to determine effects of energy and CP supplementation of wheat straw-based (WS) diets on apparent N digestion, retention, and flow to the abomasum. Four wether lambs (average weight, 32 kg) fitted with ruminal and abomasal cannulas were fed 70 vs 42% WS (remainder of the diet was concentrate) and 9.5 vs 12.5% CP. Ruminal and total tract DM and OM digestion was 41 and 33% greater (P less than .03) for high-energy than for low-energy diets. Apparent N digestibility was greater (P less than .05) for 12.5% CP than for 9.5% CP diets (69.2 vs 62.0%, respectively) and also greater (P less than .03) for high-energy than for low-energy diets (67.4 vs 63.7%, respectively). High-energy diets resulted in a 23% greater (P less than .03) N retention (percentage of N intake) than did low-energy diets; 12.5% CP diets resulted in a 9% greater N retention (P less than .10) than did 9.5% CP diets. Nitrogen retention (percentage of N digested) was 15% higher (P less than .03) for high-energy than for low-energy diets. Protein level had no effect (P greater than .10). Nitrogen retention (grams/day) was 5.65, 6.97, 5.28, and 7.43 for low-energy, high-energy, low-protein, and high-protein diets, respectively; there were responses to energy level (P less than .03) and protein level (P less than .05). Total N flow (grams/day) to the abomasum did not differ (P greater than .10) due to treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Sultan
J I
JI
Department of Animal Science, Ohio State University, Wooster 44691.
Loerch
S C
SC
D000018:Abomasum / Q000502:physiology; D000821:Animal Feed; D000818:Animals; D004043:Dietary Fiber / Q000008:administration & dosage / Q000378:metabolism; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000378:metabolism; D004063:Digestion; D002149:Energy Intake; D008297:Male; D009584:Nitrogen / Q000378:metabolism*; D012417:Rumen / Q000502:physiology; D012756:Sheep / Q000378:metabolism / Q000502:physiology*; D014908:Triticum
D004043:Dietary Fiber; D004044:Dietary Proteins; D009584:Nitrogen