EFFECT OF EXTRUSION OF SWINE GROWER FEED ON NUTRIENT DIGESTIBILITY AND PRODUCTION PERFORMANCE IN LARGE WHITE YORKSHIRE PIGS

A study was conducted to determine the effect of extrusion of swine grower feed on the nutrient digestibility and production performance in twenty- four conventionally weaned LWY piglets 30 days of age and 7.60 kg average body weight. They were grouped in to two groups with twelve piglets in each group and fed individually with mash feed (MF) and extruded feed (EF) ad libitum.The experiment was conducted for 90 days. The feed was formulated with maize (62.5%), soybean meal (10%), fish meal (6%), wheat bran (8%), deoiled rice bran (11%), mineral mixture (2%) and salt (1%). The extrudate was air-dried overnight and analysed for its chemical composition.The results indicated that the moisture (MF- 9.54% and EF - 5.17%), total ash -TA (MF- 7.77% and EF - 6.35%), crude protein-CP (MF- 18.14% and EF - 17.36%), ether extract -EE (MF- 2.04% and EF - 1.74%), crude fibre– CF (MF- 6.13% and EF - 5.04%), nitrogen free extract – NFE (MF- 65.05% and EF - 69.51%), calcium (MF- 0.07% and EF - 0.06%), phosphorus (MF- 0.44% and EF - 0.45%) and gross energy– GE (MF- 3870.55 kcal/kg and EF - 4105.75 kcal/kg). The extrusion process decreased moisture, TA, EE and CF significantly (P<0.05) and also increased NFE and GE significantly (P< 0.01) in the extruded feed.The digestibility of dry matter (MF- 84.19% and EF -87.28%), CP (MF- 91.29% and EF -93.21%), EE (MF- 69.21% and EF - 1.74%), CF significantly (P<0.05) and also increased NFE and GE significantly (P< 0.01) in the extruded feed.The digestibility of dry matter (MF- 84.19% and EF -87.28%), CP (MF- 91.29% and EF -93.21%), EE (MF- 69.21% and EF - 1.74%), CF (MF- 81.44% and EF -87.54%) and energy (MF- 77.94% and EF -83.36%) were recorded.The digestible nutrients of EE and CF were increased significantly (P<0.05) and energy of (MF – 77.94%) extruded feed was increased significantly (P<0.01) by 7 per cent than the mash feed (EF- 83.36%).The average feed intake was significantly (P<0.05) different from MF (2417.43g/day) to EF (2106.97g/day) group. The average daily gain (MF- 446.02g and EF - 479.44g) and feed conversion ratio (MF- 5.42 and EF - 4.39) were highly significant (P<0.01) in EF group. The average feed cost for every kg body weight gain was Rs.108.40/- for mash feeding and Rs. 92.29/- for extruded feeding. Extrusion of mash feed increases the gelatinization and surface area of starch granules, which improves starch utilization present in the maize, energy utilization, palatability and nutrient digestibility. Extruded feed increases the feed conversion ratio and reduces the feed cost. Hence, it is concluded that extruded feed is recommended for feeding pigs to improve the production performance.