Energy values of bermudagrass, forage sorghum, and sweet sorghum to pigs and the use of carbohydrases to enhance energy utilization

Abstract Text:

This study was to determine DE and ME of ground bermudagrass, forage sorghum, and sweet sorghum fed to pigs and the supplemental effects of carbohydrases (Allzyme SSF, Alltech, Nicholasville, KY) on energy utilization of these feedstuffs. The study had 4 sets of quadruplicated 2 x 2 Latin square design using 32 barrows (38.7 ± 11.9 kg). Each Latin square consisted of 2 treatments and 2 periods. Each period was 14 d (10 d adjustment and 4 d collection). Particle size was 400 to 600 μm for forages and corn. Basal diet contained 94% corn with 4% amino acids, minerals, and vitamins. Test diets contained 85% BA + 15% Bermuda grass, forage sorghum, or sweet sorghum. For the basal diet and each test diet, carbohydrases were supplemented (0 or 200 mg/kg). Pigs received experimental diets twice daily (0700 and 1700 h) at a fixed amount based on BW of pigs (0.09 x BW^0.75 kg). On d 10, chromium oxide (0.5%) was added to the evening meal as an external marker to indicate initiation of fecal collection. Fecal and urine samples were collected during 4 consecutive days. Gross energy of feed, urine, and feces was measured using a bomb calorimeter (IKA, Wilmington, NC) to calculate DE and ME. Basal diet contained 3,427 kcal DE/kg and 3,354 kcal ME/kg which were not affected by enzyme supplementation. Bermudagrass contained 856 kcal DE/kg and 810 kcal ME/kg which tended to be increased by enzyme supplementation to 1,154 kcal DE/kg (P = 0.099) and 1,129 kcal ME/kg (P = 0.081). Forage sorghum contained 1,057 kcal DE/kg and 1,042 kcal ME/kg, which were not affected by enzyme supplementation. Sweet sorghum contained 1,035 kcal DE/kg and 1,011 kcal ME/kg, which were not affected by enzyme supplementation. In conclusion, pigs could utilize nutrients in bermudagrass, forage sorghum, and sweet sorghum to obtain energy indicating that these feedstuffs could potentially be used in feeding pigs. Use of Allzyme SSF benefited pigs providing more energy from bermudagrass.  This study provides energy values for alternative feedstuffs that can be used in a least cost formulation software to feed pigs.

Keywords: bermudagrass, enzyme, forage sorghum, pigs, sweet sorghum