Valorization of Dehydrated Grape Pomace Waste as a Low-Cost Feed Additive to Improve Reproduction and Growth Performance of Male Rabbits

This study aimed to investigate the effects of dietary supplementation with dehydrated grape pomace (DGP) on growth performance, in vivo nutrient digestibility, nitrogen balance, semen quality, fertility parameters, and biochemical metabolic parameters in blood plasma and seminal liquid of rabbit bucks. Eighteen California-bred rabbits aged 85 +/- 5 days with an average weight of 1657 +/- 147 g were divided into three homogeneous groups (n = 6). They were fed the same amount of conventional feed (140 g/day) with the addition of dehydrated grape pomace at 0% CT (control), 1% T1, and 2% T2 during 140 days. At the T1 level, DGP did not affect growth performance, feed intake, nitrogen retention, or improved fat digestibility. At the T2 level, DGP improved rabbits' growth performance and feed intake. These wastes also improved fat digestibility but decreased organic matter and crude protein digestibility without altering nitrogen balance. The addition of these wastes to the diet of rabbits at 1% and 2% did not amend age and body weight, testicular diameter at puberty, or blood and seminal fluid metabolites. The dose of 1% improved sperm mass motility and sperm concentration. Thus, the utilization of DGP waste as a feed additive at a 1% level in the diet of rabbit bucks is an eco-friendly strategy to improve the reproductive performance of rabbit bucks without compromising their growth performance.