EFFECT OF STOCKING DENSITY ON BEHAVIOUR AND PRODUCTIVE PERFORMANCE IN GROWING LAMBS

Abstract

Introduction: Intensive production is characterized by raising a high number of animals per unit of space, which affects their behaviour and productive performance. The objective of this study was to evaluate the effect of three space allowances on the behaviour and productive performance of growing hair lambs. Methodology: The three space allowances evaluated were: A) 2.4, B) 1.2 and C) 0.6 m²/lamb. The space allowances were met by housing 5, 10 and 20 lambs, respectively per pen. The lambs were weighed every 10 days for 30 days. Twice a week the evaluated behaviours were recorded. Results: The last 10 days weight gain reduced significantly by 22% in treatment C, compared to treatments A and B (P <0.05); feed conversion was significantly higher in treatment C (6.4) than in treatment A (5.6) and B (4.7) (P> 0.05) and feed consumption was approximately 8% lower in treatments B and C in comparison to A (P <0.05). The behaviour associated with food consumption was more frequently in treatments A and B (0.34 and 0.33, respectively) than in treatment C (0.29) (P <0.05). Standing animals were observed more frequently in treatment C (0.30) than in the other treatments (0.26 and 0.27, for treatment A and B, respectively) (P <0.06). More aggressions (P <0.06) were also observed in treatments B and C (0.71 and 0.81, respectively) than in treatment A (0.53). Conclusion: Productive performance and comfort of the animals were affected negatively as stocking density increase in the pens.