Effects of Dietary Cauliflower Leaf Meal Supplementation on Growth Performance, Nutrient Utilization, Rumen Fermentation, and Methane Emission in Goats

Feed stress is a very critical factor impacting livestock health and productivity. One of the major contributors to quantitative feed deficiency is the continued adherence to conventional diets and feeding practices, which renders livestock populations vulnerable to environment-induced scarcity events as well as shortages arising from supply-chain bottlenecks. These challenges occur in the face of the ever-expanding demand from a continuously growing livestock population. In a world increasingly experiencing qualitative and quantitative resource constraints due to rising demand and increasing pollutant concentrations in the environment, conventional dietary compositions require timely modification and supplementation with alternative feed ingredients. These may include the hitherto unutilized by-products of agricultural production, which are often discarded as agricultural waste, in order to mitigate the stress induced by feed availability shortfalls. Cauliflower leaf meal is one such by-product whose suitability as a feed supplement was evaluated in the present study, with results that can be reliably described as promising. The present study assessed the impact of dried cauliflower leaf meal (CLM) on growth performance, nutrient utilization, rumen fermentation, and methane emission in goats. Fifteen non-descript male goats, aged 6–8 months, were randomly allocated into three groups of five animals each and housed separately in identical pens within the same shed for the duration of the experiment. Three dietary treatments were administered: T0 (control; concentrate, hybrid Napier, and wheat straw); T20 (20% replacement of wheat bran with CLM in the concentrate, along with hybrid Napier and wheat straw); and T30 (30% replacement of wheat bran with CLM in the concentrate, along with hybrid Napier and wheat straw). The results indicated that the goats in all groups achieved a similar body-weight gain with a comparable dry-matter intake (DMI). The feed conversion ratio (FCR), nutrient digestibility, and mineral balance were also comparable across treatments. However, the methane emission rate was significantly lower (p < 0.05) in the T30 group compared with the other groups. CLM supplementation did not cause deviations in rumen pH, NH3-N concentration, volatile fatty acid production, or bacterial and protozoal populations. The hematological parameters remained unaffected by the increased dietary inclusion of CLM, while both cell-mediated and humoral immune responses showed an improvement in the CLM-fed groups. Notable reductions in methane emission were observed in goats fed diets containing 20–30% dried CLM, highlighting the positive environmental implications of such a dietary inclusion.