[Effect on energy and nitrogen balances of replacing part of the tallow in a milk replacer for preruminant calves by tricaproin or coconut oil: effect of previous feeding level].
Using two open-circuit respiratory chambers, the effects of medium chain fatty acid intake on digestibility, energy and nitrogen balance were investigated in 4 groups of preruminant Friesian male calves. One group of 7 animals was fed a control diet with a skim-milk powder and tallow base (diet 1). The other three groups were fed diets in which one-third of the tallow was replaced by either 1/3 coconut oil (6 animals, diet 2) or 1/3 tricaproin (6 animals, diet 3). In diet 4, two-thirds of the tallow was replaced by 1/3 coconut oit + 1/3 tricaproin (5 animals). Apparent digestibility and energy metabolizability (q) were similar for diets 1, 2, 3 and significantly higher (P less than 0.05) for diet 4: 97.5 vs 95.1% for dry matter digestibility 97.3 vs 94.5% for energy digestibility, 95.6 vs 93.7% for crude protein digestibility and 94.6 vs 92.8% for q. Whatever the diet, metabolizable energy (ME) efficiency for tissue deposition was 70 +/- 9% and maintenance requirements amounted to an average of 90 kcal ME/d/kgW0.75. However, the latter were related to previous feeding level and increased by .13 +/- 0.06 kcal/d/kgW0.75 for an increase of 1 kcal/d/kgW0.75 of previous ME intake. The lipids in each of the 4 diets were also deposited at a rate of 0.40 +/- 0.09 kcal. Lipid gain was decreased by 0.12 +/- 0.08 kcal for an increase of 1 kcal/d/kgW0.75 of previous Me intake. The regression coefficients of protein energy gain on Me intake were 0.25 +/- 0.01; 0.25 +/- 0.06; 0.30 +/- 0.04 and 0.29 +/- 0.06 kcal PF/kcal of ME, respectively, for protein gain did not depend on the previous level of ME intake. Finally, for each of the four diets, respective adjusted energy gains were 107.5a; 122.6b; 105.6a and 99.1a kcal/d/kgW0.75, adjusted lipid gains 60.4a; 69.0a; 50.9b and 42.6c kcal/d/kgW0.75 and adjusted protein gains 47.6a; 53.6b; 53.8b and 57.5c kcal/d/kgW0.75 (data with a different superscript are significantly different; P less than 0.05). In the present study, the energy cost of protein deposition amounted to 2.29 +/- 0.21 kcal ME/kcal of protein and that of lipid deposition to 0.99 +/- 0.20 kcal ME/kcal of lipid.
D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle; D004041:Dietary Fats / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects*; D005526:Food, Formulated; D008297:Male; D008892:Milk; D009584:Nitrogen / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism
D004041:Dietary Fats; D011506:Proteins; D009584:Nitrogen
Influence du remplacement d'une partie du suif d'un aliment d'allaitement par de la tricaproïne ou de l'huile de coprah, sur l'utilisation de l'énergie et de l'azote par le veau préruminant; influence du niveau d'alimentation antérieur.