| Abstract: |
On a total of 37 preruminant calves (individual body weight range: 48 - 241 kg) fedexclusively milk replacer (MR) as liquid diet, 12 digestibility trials (with a total of 40collection periods) were performed. The trials consisted of a different number atexperimental periods (trial I, part A: 3; trial I, part B: 4; trial I, part C: 2; trial I, part 0: 4;trial 11, part A - 0: 4; trial Ill-V: 3 and trial VI: 2). The length of experimental periods variedfrom 7 days (trials I and 11, parts A, B, C and 0 each) over 14 days (trials IV - VI) to 21days (trial Ill). Chromic oxide was added to the milk replacers, so that feces had not tobe collected quantitatively. In trial III also N-balance was measured, urine was collectedquantitatively.The (apparent) digestibility (dry matter(OM), crude protein (CP) and gross e.nergy(E)) of 19 feedstuffs as constituents of a milk replacer was determined (3 sources ofreconstitued skimmilk powder (RSMP), poultry by-products (PBP), blood meal (BM),blood plasma (BPL), feather meal (FM), animal by-products (ABP), gelatine (GEL),qelatine hydrolysed (GEH), soy bean flour (SBF), soybean concentrate (danpro),soybean isolated protein (purina), linseed (LS), coconut meal (CNM), cottonseed meal(CSM), corn gluten (CG), wheat gluten (WG), potatoe protein (PP)). In the trials I and 11,acommercial 55 % skimmilk powder (SMP) containing milk replacer (only milk proteinas protein sources) served as control diet. The experimental diets were obtained byblending the control diet with the test-feedstuffs. In the trials III - VI, the milk replacercomposition was calculated by linear programming (LP) providing an equal supply withdigestible protein, lysine, methionine + cystine and with metabolisable energy. Thecontrol diet consisted of 27,6 % SMP, 7,5 % danpro and 40,9 % whey products, theamino acid supplemented (aas) PBP-diet of 20 % PBP, 7,5 % danpro and 31,5 % wheyproducts (without SMP), the aas-SBF-diet of 20 % SBF, 26,2 % SMP and 25,5 % wheyproducts and the aas-BM-diet of 7,5 % BM, 13,8 % SMP, 7,5 % danpro and 42,2 % wheyproducts.
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