Growth performance of faunated and defaunated Malpura weaner lambs

An experiment was conducted to study the effect of presence or absence of r umen ciliate protozoa on nutrient intake, its utilization, rate of body wei ght gain and feed conversion efficiency of lambs in post-weaning phase of g rowth. Forty five weaned Malpura lambs, divided into three equal groups (G1 , G2 and G3) were either defaunated by periodic dosing of sodium lauryl sul fate at the rate of 8 g/100 kg body weight (G1) or defaunated and refaunate d (G2) or maintained faunated (G3). The lambs were fed for 90 days on 50:50 pala (Zizyphus nummularia) leaf and concentrate based complete feed. With care and segregation the defaunated lambs were maintained free of rumen pro tozoa for 47 days after which Entodinomorphid appeared while Holotrichs wer e not detected. The total and differential protozoa count was similar in re faunated and faunated lambs and the residual toxic effect of sodium lauryl sulfate if any was not detected. Even with similar dry matter intake in the three groups, body weight gain and feed conversion efficiency were higher in defaunated lambs. The digestibilities of cell and cell wall contents wer e generally poor in defaunated lambs while intake of digestible protein and energy were similar in the three groups. The lambs in the three groups wer e in positive nitrogen balance while percent N retention was higher in defa unated than in refaunated and faunated lambs. It was concluded from the study that with similar dry matter intake and pla ne of nutrition, the growth performance and feed conversion efficiency were better in defaunated than refaunated and faunated lambs. In spite of reduc ed digestibility of neutral detergent fibre, acid detergent fibre and cellu lose, the metabolise energy availability for body synthetic activity was pr obably higher in defaunated lambs as evident from the observed production t raits. (C) 2000 Elsevier Science B.V. All rights reserved.