title: Response to dietary tannin challenges in view of the browser/grazer dichotomy in an Ethiopian setting: Bonga sheep versus Kaffa goats.
abstract: It has been suggested that goats (typical browser) are better adapted to digest tannin-rich diets than sheep (typical grazer). To evaluate this, Bonga sheep and Kaffa goats were used in a 2 × 3 randomized crossover design with two species, three diets, and three periods (15-day adaptation + 7-day collection). The dietary treatments consisted of grass-based hay only (tannin-free diet = FT), a high-tannin diet (36% Albizia schimperiana (AS) + 9% Ficus elastica (FE) + 55% FT (HT)), and HT + polyethylene glycol 6000 (PEG). Animals were individually fed at 50 g dry matter (DM)/kg body weight (BW) and had free access to clean drinking water and mineralized salt licks. Nutrient intake, apparent nutrient digestibility, nutrient conversion ratios, and live weight changes were determined. Condensed tannin concentrations in AS and FE were 110 and 191 g/kg DM, respectively. Both sheep and goats ate 47% more of HT than FT, and dry matter intake further increased by 9% when PEG was added, with clear difference in effect size between goats and sheep (P < 0.001). The effects of the tannin-rich diet and PEG addition were similarly positive for DM digestibility between sheep and goats, but crude protein (CP) digestibility was higher in HT + PEG-fed goats than in sheep fed the same diet. However, PEG addition induced a larger improvement in growth performance and feed efficiency ratio in sheep than in goat (P < 0.001). The addition of PEG as a tannin binder improved digestion and performance in both species, but with the highest effect size in sheep.
authors.affiliation: Department of Animal Sciences, Arba Minch University, P.O. Box 21, Arba Minch, Ethiopia. yisehakkechero@yahoo.com.|Laboratory of Animal Nutrition, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820, Merelbeke, Belgium. yisehakkechero@yahoo.com.
authors.forename: Kechero
authors.initials: K
authors.lastname: Yisehak
authors.affiliation: Bonga Agricultural Research Centre, P. O. Box 309, Bonga, Ethiopia.
authors.forename: Yoseph
authors.initials: Y
authors.lastname: Kibreab
authors.affiliation: Department of Animal Sciences, Jimma University, P.O. Box 307, Jimma, Ethiopia.
authors.forename: Tolemariam
authors.initials: T
authors.lastname: Taye
authors.affiliation: Laboratory of Animal Nutrition, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820, Merelbeke, Belgium.
authors.forename: Marta Ribeiro Alves
authors.initials: MR
authors.lastname: Lourenço
authors.affiliation: Laboratory of Animal Nutrition, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820, Merelbeke, Belgium.
authors.forename: Geert Paul Jules
authors.initials: GP
authors.lastname: Janssens
mesh_terms: D031289:Albizzia / Q000737:chemistry; D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D018592:Cross-Over Studies; D004032:Diet / Q000662:veterinary*; D004063:Digestion / Q000187:drug effects; D002149:Energy Intake / Q000187:drug effects; D005002:Ethiopia; D005247:Feeding Behavior; D030681:Ficus / Q000737:chemistry; D006041:Goats / Q000502:physiology*; D012756:Sheep / Q000502:physiology*; D013045:Species Specificity; D013634:Tannins / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D013634:Tannins
keywords: Digestibility; Goat; Nutrition; Polyethylene glycol; Sheep; Tannin