Intake, digestibility, performance, and carcass traits of rams provided with dehydrated passion fruit (Passiflora edulis f. flavicarpa) peel, as a substitute of Tifton 85 (Cynodon spp.)

Abstract

Two experiments were performed to evaluate the substitution of Tifton 85 (Cynodon spp.) hay by dehydrated passion fruit (Passiflora edulis f. flavicarpa) peel on intake, digestibility, nitrogen balance, and carcass traits in Santa Inês×Dorper rams. In Experiment 1, 12 rams were penned in individual metabolic crates for 21 days to evaluate DMI, nitrogen balance, and digestibility. Four treatments were evaluated: (1) control, with no inclusion of passion fruit peel; (2) 20% substitution of Tifton 85 hay by passion fruit peel; (3) 40% substitution of Tifton 85 hay by passion fruit peel; and (4) 60% substitution of Tifton 85 hay by passion fruit peel (n=3 rams per treatment). In Experiment 2, 20 rams were randomly assigned into individual dry-lot pens for 63 days, and the same treatments from Experiment 1 were randomly assigned to pens (n=5 pens per treatment). Body weight was weekly determined, and at the end of the experimental period, rams were humanely slaughtered, for assessment of carcass traits. No effect (P>0.33) of passion fruit peel inclusion was observed for DM and CP apparent digestibility. However, NDF apparent digestibility had a quadratic effect (P=0.01). Quadratic regression (P=0.02) was observed for nitrogen intake, but no effect (P>0.16) was observed for fecal and urine nitrogen excretion, and nitrogen balance. Daily DMI, DMI as % of BW, and NDF and CP intake had quadratic effect (P<0.01) with level of inclusion of passion fruit peel in the diet. A quadratic regression (P<0.01) was found for thorax circumference, with peak at 38.6%. Commercial cuts and carcass traits were not affected (P>0.16) by substitution of Tifton-85 by passion fruit peel. In conclusion, these experiments indicate that providing passion fruit peel as a substitute of Tifton 85 in diets for Santa Inês×Dorper rams at approximately 30% can be a good option for producers willing to reduce feeding costs, without impairing performance and carcass traits.