Effect of Schoenoplectus americanus on ruminal fermentation and digestibility in sheep

Abstract

Ruminal cannulated crossbred sheep (70±2 kg BW) were used to measure the effects of different levels of the aquatic plant Schoenoplectus americanus Volkari (SA) on a basal diet consisting of forage oats (Avena sativa) supplemented with 30% of a slow release urea supplement (SRUS). The diets (D1, D2, and D3) included 0%, 20% and 40% SA. SRUS was made of 17.0% corn, 17.0% molasses, 16.0% poultry litter, 14.0% rice polishing, 8.0% cottonseed meal, 5.0% animal lard, 4.0% fish meal, 4.0% salt, 4,0% urea, 3.2% calcium carbonate, 3.0% orthophosphate, 2.2% ammonium sulphate, 1.6% cement kiln dust and 1.0% mineral salt. Feed were dried and chopped to 2 cm particles. Animals were kept in metabolic cages. Each experimental period lasted for 21 days: 14 of adaptation and 7 for rumen content sampling. Chemical analysis showed an increment in CP, EE and ash when 20% and 40% SA where administered on D1. Ruminal pH did not varied among treatments; however, differences were found in sampling time. Ruminal ammonia values were different among treatments. The N-retention was higher in D1 (8.40 g/day) and D2 (8.77 g/day) compared with D3 (6.57 g/day). The DM1 was similar in all diets. DM digestion was higher in D1 that (0.062%-h) compared to D2 (0.052%-h) and D3 (0.057%-h). Substitution of oats by 20% SA did not reduce DMI. This study demonstrated that the SA could be alternative forage for sheep, giving a recycling use for SA.