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.

Comparative aspects of plant tannins on digestive physiology, nutrition and microbial community changes in sheep and goats: A review

“…Figure 5 shows the reduction in rumen ammonia concentrations as related to CT concentration compared with CT-containing forages or non-CT-containing forages. Figure 5 implies that CT in forages significantly reduced rumen degradation of forage protein F I G U R E 2 Relationship between sheep and goats for ruminal dry matter (DM) digestibility (DMD) in response to feeding tannin-containing forages (Barry & Manley, 1984;Waghorn et al, 1987Waghorn et al, , 1990Waghorn, Douglas, Niezen, McNabb, & Foote, 1998;Waghorn, Tavendale, & Woodfield, 2002;Barahona, Lascano, Cochran, Morrill, & Titgemeyer, 1997;Woodward and Reed, 1997;Min et al, 2002aMin et al, ,b, 2012Bengaly et al, 2007;Yisehak et al, 2014) Goat Condensed tannins, % DM DM digesƟbility, % F I G U R E 3 Relationship between cow and goats for in vitro rumen digestibility in response to feeding various condensed tannin (CT)-containing browse species (Lyons, 2017 F I G U R E 4 Relationship between sheep and goats for ruminal nitrogen (N)-digestibility in response to feeding tannin-containing forages (Barry & Manley, 1984;Waghorn et al, 1987Waghorn et al, , 1990Waghorn et al, , 1998Waghorn et al, , 2002Barahona et al, 1997;Woodward and Reed, 1997;Min et al, 2002aMin et al, ,b, 2012Bengaly et al, 2007;Yisehak, Kibreab, Taye, Lourenço, & Janssens, 2016) Therefore, sheep and goats exhibited different levels of tolerance to the effects of CT (Narjisse, Elhonsali, & Olsen, 1995). Narjisse et al (1995) reported that addition of oak tannins (Quercus ilex leaves; 1 g of tannins/kg of BW) depressed ammonia levels in sheep, but not goats.…”

Effect of Protection of Soybean Meal Using Mahogany Leaf Extract in Ruminant Diet on Rumen Fermentation Products

“…This situation shows that increasing level of mahogany leaf extract given will increase the total protein that is not degraded in the rumen. (Yisehak et al 2016) stated that the size of the protein that escapes degradation in the rumen is influenced by several factors, namely the solubility of the protein, the more excellent the solubility of a protein, the greater the degradation process. The increase followed the increased content of RUDP in the rumen in the range of ammonia, and this indicates that the degradation of feed protein in the rumen is high.…”

Inclusion of Cocoa Bean Shell in the Diet of Dairy Goats: Effects on Milk Production Performance and Milk Fatty Acid Profile

“…This demonstrates that a CBS inclusion level of 17% in the concentrate feed does not cause palatability issues in the caprine species. In cattle and sheep, dietary tannins can create complexes with lignocellulose, inhibiting cellulolytic microorganisms and fibrolytic enzymatic activity, and increasing rumen physical filling, with negative consequences on voluntary DMI and fiber digestion (62,63). However, goats and other browsing animal species are able to produce tannin-binding saliva and stimulate the proliferation of tannin-tolerant bacteria, mostly overcoming the negative effects of tannins on intake and nutrient digestion (64,65).…”