With the objective of testing the influence of photoperiod on development of lambs, twenty-six crossbred Ile de France x Corriedale male lambs were studied slaughtered with 38 to 40kg The lambs were slaughtered with 38 to 40kg. Animals were ramdomly divided in two groups: long photoperiod (18h light/ 6h darkness) and control (12h light/ 12h darkness). Food consumption was daily evaluated. Weekly, lambs were weighted and blood samples collected for Triiodotironine (T3), Thyroxine (T4) and Cortisol plasmatic levels determination. Jejunal and ileal samples were collected for morphometric analyses of the intestinal epithelium. Carcass characteristics were also studied. Lambs submitted to the long photoperiod have greater food consumption and live weight gain when compared to control (P<0.05). No significant differences were observed on the plasmatic levels of the hormones, in the morphology of the intestinal epithelium or carcass characteristics. In conclusion, long photoperiod has a positive effect on the development of lambs, being an economically viable techinic.
photoperiod; lambs; growth; hormones; intestinal morphology
