Evaluation of Brassica Vegetables as Potential Feed for Ruminants

SIMPLE SUMMARY: According to Food and Agriculture Organization of the United Nations (FAO) estimations, nearly 50% of the initial production of vegetables and fruits is lost or wasted. Losses can happen at different stages of the food chain supply, but mainly at agricultural production (cultivation and harvest), distribution, and consumption. The wasted vegetables represent a significant volume that could be used for ruminant feeding, but before using them in practice, it is necessary to evaluate their nutritive value. In this study, we analyzed the chemical composition, in vitro rumen fermentation, and intestinal digestibility of wastes of four types of cabbages: Brussels sprouts, white cabbage, Savoy cabbage, and red cabbage. All cabbages wastes had high moisture content, but their dry matter was rich in protein and sugars and was rapidly and extensively fermented in the rumen. The in vitro results of this study provided useful information for including cabbage wastes in ruminant diets, indicating that Brussel sprouts could be included up to 24% of the concentrate of a dairy sheep diet, replacing cereals and soybean meal, without negatively affecting rumen fermentation. In vivo studies are required to confirm these results. ABSTRACT: The objective of this study was to analyze the chemical composition, in vitro ruminal fermentation, and intestinal digestibility of discarded samples of four Brassica vegetables: Brussels sprouts (BS), white cabbage, Savoy cabbage, and red cabbage, and to assess the effects of including increasing amounts of BS in the concentrate of a dairy sheep diet on in vitro fermentation, CH(4) production, and in situ degradation of the diets. All cabbages had low dry matter content (DM; <16.5%), but their DM had high crude protein (19.5–24.8%) and sugars (27.2–41.4%) content and low neutral detergent fiber (17.5–28%) and was rapidly and extensively fermented in the rumen. Rumen degradability of protein at 12 h of in situ incubation was greater than 91.5% for all cabbages, and in vitro intestinal digestibility of protein ranged from 61.4 to 90.2%. Replacing barley, corn, and soybean meal by 24% of dried BS in the concentrate of a diet for dairy sheep (40:60 alfalfa hay:concentrate) increased in vitro diet fermentation and in situ degradability of DM and protein, and reduced in vitro CH(4)/total volatile fatty acid ratio. In vivo trials are necessary to confirm these results.