Effect of polyethylene glycol-6000 on nutrient intake, digestion and growth of kids browsing Prosopis cineraria

A study was completed to assess effects of polyethylene glycol-6000 (PEG-6000) feeding on nutrient intake, its utilisation and growth performance of kids browsing on tannin-containing Prosopis cineraria shrub foliage. Twenty Kutchi weaner kids of comparable body weight (11.2±0.53 kg) and age (3.0±0.11 month) were divided into two groups of 10 either supplemented with PEG-6000 (PEG group), or without PEG-6000 (tannin group). All kids were grazed as a flock from 08:00 to 17:00 h. During a 90 days period (December to March) they were fed freshly cut leaves of P. cineraria on range. Before grazing, each kid in the PEG group was drenched with 5 g of PEG-6000, dissolved in 10 ml of water. P. cineraria leaves contained 165 g/kg crude protein (CP), 552 g/kg neutral detergent fibre (NDF), 349 g/kg acid detergent fibre (ADF) and 198 g/kg acid detergent lignin (ADL). The dry matter (DM) intake (DMI) in PEG drenched kids was 871 g per day versus 691 g per day (P<0.01) in the tannin group. PEG feeding improved (P<0.05) CP digestibility from 0.436 to 0.504 and intake of digestible CP increased from 52 to 72 g per day (P=0.002). Energy intake increased from 9.83 to 12.39 MJ per day (P=0.009). Blood haemoglobin (Hb) and urea N levels were 11.02 g/dl and 15.52 mg/dl in kids receiving PEG compared to 9.16 g/dl and 13.70 mg/dl in control kids (all P<0.05). Six hours after introduction in to range, the rumen pH of 7.1 in PEG group was lower (P<0.05) than that of 7.4 in the tannin group kids. Rumen ammonia nitrogen (NH3N), total N and total volatile fatty acid (TVFA) concentrations were 6.16, 4.06; 146.4, 120.2 mg/dl and 10.64, 8.90 mmol/dl in the PEG and tannin groups, respectively and all differences were P<0.05. The body weight gain in PEG group (5.69 kg) was higher (P<0.05) than that of the tannin group (4.72 kg). Feeding of 5 g per day PEG alleviates negative effects of Prosopis tannin on DM intake and digestion of nutrients.