Tannins are secondary metabolites naturally present in various plants as a defense mechanism. In animal nutrition, they play a dual role, acting as both antinutritional factors and bioactive agents, with potential benefits in nutrient metabolism and product quality. This meta-analysis aimed to evaluate the effects of dietary tannin on nutrient intake and digestibility, blood serum metabolite levels, growth performance, carcass characteristics, and meat quality in small ruminants. Ninety-seven studies were included in this meta-analysis. The effects of tannins were analyzed using a random-effects model to determine the weighted mean difference between treatments with tannins and the control (without tannins). Publication bias and heterogeneity between studies were explored, and meta-regression and subgroup analyses were performed. The results indicated that tannin significantly increased the intake of dry matter, crude protein, nitrogen (N), fecal N, and meat fatty acids (FA), such as C18:2 ω6, C18:3 ω3, C20:4 ω6, C20:5 ω3, total ω3 and ω6 FA, and total polyunsaturated FA (PUFA). However, NH₃-N, urinary N, blood urea nitrogen, cold carcass weight, subcutaneous fat thickness, drip loss, and nutrient digestibility decreased. In conclusion, tannin in small ruminants did not affect animal productivity and antioxidative status, but mainly modified nitrogen metabolism and improved the fatty acid profile of meat.

Sulla flexuosa (Hedysarum flexuosum L.) is an endemic legume growing in some Mediterranean areas in rainfed and cold mountainous conditions. It could be used in goat diets as an alternative protein source instead of alfalfa to supplement forest rangeland. This study aimed to test the effects of incorporating Sulla flexuosa (SF) hay in the diet of Beni Arouss goats on their milk production and quality. The hay was introduced at two levels, i.e., 35 or 70% (SF70), on a DM basis; it partially or totally replaced the alfalfa hay of the control diet. Sulla flexuosa incorporation did not affect milk production or physicochemical composition. However, milk FA content varied in proportion to the percentage of SF incorporation. The SF70 diet was associated with increased milk levels in C18:1n-9, C18:2n-6, C18:3n-3, and C22:6n-3 and total monounsaturated, polyunsaturated, and n-3 fatty acids. As a consequence, atherogenic and thrombogenic indices were improved. Additionally, better antioxidant capacity was observed in SF70.

The present work was part of assessing wild genetic plant resources of forage interest in Northern Morocco and aimed to study the agro-morphology and nutritional value of Sulla flexuosa (L.) Medik. (Hedysarum flexuosum L.) ecotypes. The seeds of twenty-one wild S. flexuosa (L.) Medik. ecotypes were collected from 21 sites. The edaphic and climatic characteristics of the collection sites were studied and testified to the remarkable adaptability of S. flexuosa (L.) Medik. These 21 ecotypes were cultivated in three complete randomized blocks design for two consecutive years. Statistical analysis showed substantial variability between the collected ecotypes. Principal component analysis and heatmap analysis allowed to distinguish four groups of ecotypes mainly based on nutritional parameters (fiber content and digestibility), forage production (dry matter yield, number of leaves per plant, and total number of branches), and reproduction (number of inflorescences per plant and, weight of thousand seeds and seeds per plant). Furthermore, the present study pointed out the value of ecotype 1, which was dual purpose with its high productivity, nutritional value, and reproductive parameters. Ecotype 4 was also highlighted as having late flowering but intermediate productivity, which can be used mainly for haymaking as the drying period could coincide with the last rainfall in the region.

Bitter vetch and sorghum grains are alternative local feed resources that are underutilized in the southern Mediterranean area. This study aimed to assess the effects of incorporating these grains into the diet of local goat breeds on growth performance, carcass characteristics, and meat quality. Twenty-four goat kids were divided into three groups. The control group received a conventional diet consisting of oat hay, barley, and fava beans. In the first group, fava beans were replaced with bitter vetch, and in the second group, barley was replaced with sorghum. At the end of the trial, the animals were slaughtered and carcass characteristics and meat fatty acid profiles of the longissimus dorsi (LD) muscle were determined. Alternative grain incorporation had no significant effect on the growth parameters. Still, it significantly affected carcass characteristics, especially in the sorghum group compared to the control group, where mesenteric fat was lower (266 vs. 437 g). The back color was lighter ($L^{*}=\mathrm{55.1}$ vs. 59.1) and less yellow ($a^{*}=-\mathrm{1.29}$ vs. 2.22). The diet also influenced the meat's chemical composition, with less protein and ash in the chevrons of animals receiving bitter vetch and sorghum grains, respectively. Regarding the fatty acid (FA) profile, sorghum grains had decreased C18:2 n-6 and polyunsaturated FA (PUFA), whereas bitter vetch grains had increased C18:3 n-3, elongase activity, and nutritive value index (NVI). The control group exhibited intermediate results for C15:0, C16:0, C16:1, C20:3 n-3, n-3, health promoting index (HPI), and thrombogenic index (TI). No significant effects were reported for saturated FA (SFA) and monounsaturated FA (MUFA). Bitter vetch and sorghum grains can be safely incorporated into fattening diets of goat kids.

Recently, there has been an emphasis on research on sustainable and environmentally friendly agricultural practices. Microalgae are a promising feed that is rich in essential nutrients, and research has been oriented toward their incorporation into ruminant diets. This study aimed to evaluate the inclusion of microalgae in goat diets using a meta-analysis methodology. The data were acquired from 17 peer-reviewed scientific papers. The raw mean difference between the treatment diets supplemented with microalgae and the control diets was evaluated using the random-effects model. Experimental characteristics such as animal breed, days in milk, experimental duration, microalgae species, inclusion levels, and concentrate were used as covariates in meta-regression and subgrouping analyses. Microalgae supplementation did not affect dry matter intake (DMI, p=0.170) but significantly improved the intake of crude protein (CP, p<0.001) and neutral detergent fiber (NDF, p=0.005). The incorporation of microalgae into the goat diet improved all digestibility parameters (p<0.01), with an improvement in fermentation parameters, including ruminal pH (p=0.010) and propionate (p<0.001). Microalgae inclusion in goat diets increased blood glucose levels (p<0.001) but did not affect blood antioxidant activity (p>0.05). Microalgae supplementation did not affect milk yield (p=0.480) but increased the yield of lactose (p<0.001), protein (p<0.001), and fat (p<0.001). Microalgae inclusion in goat diets improves the fatty acid (FA) profile. The milk of goats had significantly decreased C18:0 (p=0.001) and C18:1 n-9 (p=0.028) and increased C20:5 n-3 (p=0.027), C22:6 n-3 (DHA, p<0.001), polyunsaturated FA (PUFA, p=0.039), and n-3 (p=0.006). Subgroup analysis showed that an inclusion level higher than 30 g per kg DM was advisable to obtain this total improvement. However, even a moderate inclusion level (15–30 g per kg DM) improved the FA profile. The microalgae species Schizochytrium sp. and the Alpine–Greek crossbreed goat breed were covariates that showed interesting results concerning the improvement of DHA and PUFA. In addition, supplementation of goat diets with microalgae could be used as a nutritional approach to enhance milk production and quality.

Sorghum Bicolor is a cereal used for grains as feed and food, mainly cultivated in dry areas. To study the possibilities of increasing its cultivation for feed purposes, ecological, morpho-agronomical, and bromatological characterization of some local ecotypes was conducted as the first steps toward selecting better cultivars. Indeed, twenty-one ecotypes were collected from farms in Northern Morocco in 2018. The edapho-climatic parameters of the collection sites were evaluated. The ecotypes were cultivated in 2019 in an experimental field with a randomized complete block design with three replicates. At the maturity stage, plants were evaluated for agro-morphological parameters, and grains and straw (leaves and stems) were harvested and analyzed. The results indicated significant variations between ecotypes for almost all parameters and an interesting grain yield of 3.5 T/ha with a 176% yield variation. The nutritive value of grains was interesting compared to straw, especially for mean protein contents (10.5% DM) and organic matter digestibility (81.4%). The calculated genetic parameters emphasized the possibility of selecting highly productive and nutritive cultivars. Multivariate analysis clustered the ecotypes into five groups based on agro-morphological, bromatological, and antioxidant activity parameters; the third group was characterized by high grain-yielding ecotypes, and the fifth one by high nutritive ecotypes. The E21 ecotype, belonging to this last group, was a promising selection candidate as it combines both. No significant correlation link between agro-morphological and bromatological traits of grains and geographical distances was discerned. Sorghum bicolor could thus be improved only according to the researched agro-morphological and bromatological traits.