Replacement of Egyptian Clover (Trifolium alexandrinum) Hay with Tanniniferous Legumes in Sheep Diets: Nutritional Assessment
Hani El-Zaiat1, Mohamed Moharam2, Marwa Attia1, Adibe Luiz Abdalla3, Sobhy M.A. Sallam1
1University of Alexandria, Faculty of Agriculture, Department of Animal Production, Egypt
In Egypt, a large diversity of tanniniferous legumes are widely grown in abundance all year even during droughts. Thus, the objetives of this study were to assess the partial (50%) replacement of Egyptian clover (Trifolium alexandrinum) hay with tanniniferous legumes under in vitro and in vivo conditions. Dietary treatments were as follows: CTL: the experimental basal diet (clover hay and concentrate; 50:50 ratio) as control; AS, the basal diet with 50% Acacia saligna replaced clover hay; LL, the basal diet with 50% Leucaena leucocephala replaced clover hay; and AH, the basal diet with 50% Atriplex halimus replaced clover hay. An in vitro semi-automatic system was employed to evaluate gas production (GP), degradability and fermentation profile of diets. For the in vivo experiment, twelve Barki rams (43.29 kg of BW) were assigned to 1 of 3 treatments in a complete randomised design and housed in metabolic cages for total collection of faeces and urine (21 days as adaptation and 7 days for data collection). Enteric CH4 emission was measured using 6 open-circuit respiration chambers with some modifications. The net GP was lower (P = 0.022) with the AS diet than with CTL, LL and AH diets. Whereas, net CH4, truly degraded organic matter, ruminal NH3-N concentrations and total protozoa were decreased (P < 0.05) with AS, LL and AH diets than for CTL diet. Acetate and acetate:propionate ratio were lower, while propionate and partitioning factor were increased with AS or LL than with CTL diet (P < 0.05). Sheep fed with LL diet lowered digestibility of OM (P < 0.05) compared with those fed with CTL or AS diets. Urinary-N was decreased, while faecal N and retained N was increased (P < 0.05) for sheep fed with AS or LL compared to CTL diet. Methane emission was higher (P = 0.021) from sheep fed with AS or LL than for those fed with CTL diet. Thus, use of such tanniniferous legumes provides a promising source of forages for sheep with positive impact on mitigation of methane emission without adverse effects on animal performance.
Keywords: Feed degradability, methane emission, nutrients digestibility
Contact Address: Hani El-Zaiat, University of Alexandria, Faculty of Agriculture, Department of Animal Production, Aflaton St. El-Shatby P.O Box 21545, Alexandria, Egypt, e-mail: hani.elzaiatalexu.edu.eg