Diets based on plants from Brazilian Caatinga altering ruminal parameters, microbial community and meat fatty acids of Santa Inês lambs

Meta-Analysis of Dietary Tannins in Small Ruminant Diets: Effects on Growth Performance, Serum Metabolites, Antioxidant Status, Ruminal Fermentation, Meat Quality, and Fatty Acid Profile

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.

Chestnut tannin extract modulates growth performance and fatty acid composition in finishing Tan lambs by regulating blood antioxidant capacity, rumen fermentation, and biohydrogenation

Tannins as plant extracts have emerged as promising and potential alternatives for antibiotics in modern livestock cultivation systems. This study investigates the effect of dietary chestnut tannin extract (CTE) in finishing Tan lambs. Twenty-seven male Tan lambs were randomly divided into three groups: (1) control group (CON; basal diet); (2) low-dose CTE group (LCTE; basal diet + 2 g/kg CTE, dry matter [DM] basis); (3) high-dose CTE group (HCTE; basal diet + 4 g/kg CTE, DM basis). The HCTE group exhibited markedly higher average daily gain (ADG) and DM intake than CON (P < 0.01). The ruminal total volatile fatty acid concentration increased linearly with increasing CTE supplementation (P < 0.01), while the opposite trend was observed for butyrate molar proportion (P < 0.01). Upon increasing CTE dosage, plasma glucose, high-density lipoprotein cholesterol, glutathione peroxidase, and superoxide dismutase content increased linearly (P < 0.05), whereas low-density lipoprotein cholesterol and urea nitrogen decreased linearly or quadratically (P < 0.05), respectively. A linear increase was also observed in ruminal t6 C18:1 and t9, c12 C18:2 proportions (P < 0.01), and plasma C18:2n-6 and n-6 polyunsaturated fatty acids proportions with increased CTE supplementation (P < 0.01). In the longissimus dorsi muscle, the atherogenic index decreased linearly (P < 0.05), while c11 C18:1 and C20:5n-3 increased linearly (P < 0.05). Moreover, c9, t11 conjugated linoleic acids proportion increased in subcutaneous fat with CTE supplementation (P < 0.01). In conclusion, Dietary CTE enhances the ADG of finishing Tan lambs in a dose-dependent manner, modulates plasma metabolites and antioxidant capacity, and improves rumen fermentation and body fatty acid composition. These results provide a reference for the rational application of CTE in ruminant production.

Technologies Used in Production Systems for Santa Inês Sheep: A Systematic Review

This study identifies the number of publications that presented technologies used in the production systems of Santa Inês sheep in the last 5 years (2017–2021) carried out in Brazil. Therefore, the objective was to identify where we are in terms of knowledge about technologies in different fields (health, reproduction, animal breeding, behavior and welfare, nutrition and feeding, forage and pasture, carcass and meat quality, and economics and management of livestock systems). After rigorous selection, 114 studies were appointed and classified by knowledge field, and the main approaches within each theme were evaluated, pointing out research gaps. Most technologies have been in northeastern states. However, government agencies should develop public policies to disseminate techniques in rural areas because the production system in this region is still subsistence. This study highlighted the need for works that present management practices and tools that impact the improvement of animal welfare. Agro-industrial by-products have been widely used as an alternative for sheep feeding. However, economic feasibility analyses are recommended with these foodstuffs to substantiate their use as an option to reduce production costs. There is a lack of research allusive to the management of production systems, especially those related to estimates of economic feasibility indicators.

Growth Performance, Meat Quality and Antioxidant Status of Sheep Supplemented with Tannins: A Meta-Analysis

The objective of this study was to evaluate the effects of dietary supplementation with tannins (TANs) on productive performance, carcass characteristics, meat quality, oxidative stability, and blood serum antioxidant capacity of sheep through a meta-analysis. Using Scopus, Web of Science, ScienceDirect, and PubMed databases, a systematic search was performed for studies published in scientific journals that investigated the effects of TANs supplementation on the variables of interest. Only studies with weaned or older sheep were included. The data analyzed were extracted from 53 peer-reviewed publications. The sheep included in the present study were between 2 and 6 months old, and between 12 and 31 kg of body weight. The effects of TANs were analyzed using random-effects statistical models to examine the standardized mean difference (SMD) between treatments with TANs and control (no TANs). Heterogeneity was explored by meta-regression and a subgroup analysis was performed for covariates that were significant. Supplementation with TANs did not affect dry matter intake, pH, color (L* and b*), Warner-Bratzler shear force, cooking loss and meat chemical composition (p > 0.05). Supplementation with TANs increased daily weight gain (SMD = 0.274, p < 0.05), total antioxidant capacity (SMD = 1.120, p < 0.001), glutathione peroxidase enzyme activity (SMD = 0.801, p < 0.001) and catalase (SMD = 0.848, p < 0.001), and decreased malondialdehyde (MDA) concentration in blood serum (SMD = -0.535, p < 0.05). Supplementation with TANs decreased feed conversion rate (SMD = -0.246, p < 0.05), and the concentration of MDA (SMD = -2.020, p < 0.001) and metmyoglobin (SMD = -0.482, p < 0.05) in meat. However, meat redness (SMD = 0.365), hot carcass yield (SMD = 0.234), cold carcass yield (SMD = 0.510), backfat thickness (SMD = 0.565) and the Longissimus dorsi muscle area (SMD = 0.413) increased in response to TANs supplementation (p < 0.05). In conclusion, the addition of tannins in sheep diets improves productive performance, antioxidant status in blood serum, oxidative stability of meat and some other characteristics related to meat and carcass quality.

Nutrient utilization, performance, and milk fatty acid composition of grazing cows fed supplements with babassu coconut

This study evaluated the effects of dietary inclusion of cracked babassu coconut (CBC) in the supplement on nutrient utilization, performance, and milk fatty acid (FA) composition of dairy cows grazing Megathyrsus maximus cv. Mombasa. Five multiparous Holstein × Zebu mid-lactation cows (125 ± 16.5 days in milk) were assigned to five dietary treatments (replacement of 0%, 20%, 40%, 60%, and 80% of ground corn with CBC, on a dry matter (DM) basis) in a 5 × 5 Latin square design. The intake of DM from the supplement, crude protein (CP), non-fiber carbohydrate (NFC), fat (ether extract (EE)), and total digestible nutrients (TDNs) decreased linearly (P < 0.05), while the intake of DM from forage increased linearly (P < 0.05), with the increase in CBC inclusion in the supplement. Conversely, total DM intake was unaffected (P > 0.05). The DM, NFC, EE, and TDN digestibility decreased linearly (P < 0.05), while organic matter (OM) digestibility decreased in a quadratic fashion (P < 0.05), as CBC inclusion in the supplement increased. Nevertheless, digestibility of CP was unaffected (P > 0.05). Milk yield and composition (lactose, fat, protein, casein, and majority of FA) showed a linearly decreasing pattern (P < 0.05) with the increasing of CBC inclusion. However, proportions of trans-vaccenic acid, rumenic acid, total monounsaturated FA, and odd- and branched-chain FAs increased linearly (P < 0.05). On the opposite, total saturated FA (SFA) and the n-6:n-3 FA ratio in milk fat decreased linearly (P < 0.01). Hence, replacement of corn meal with CBC up to 80% in the supplement decreases nutrient intake and digestibility, as well as milk yield response in grazing dairy cows. However, CBC inclusion may enhance the nutritional properties of milk fat.

Gangba sheep in the Tibetan plateau: Validating their unique meat quality and grazing factor analysis

Gangba sheep are known for having typical sensory characteristics attributed to free range conditions and grazing on wild plants. The genuine Gangba mutton was selected as the experimental group, and the commercial Tibetan mutton was selected as the control group, the nutritive composition of basic chemical components, amino acids and fatty acids in mutton were investigated to correlate its unique meat quality and eating satisfaction. The results showed that fatty acids were significantly higher (P<0.05) in Gangba mutton than in commercial mutton, and the higher content of flavoring amino acids (glutamic acid and aspartame) were primarily responsible for the taste attributes umami of meat juices. Moreover, the trace elements analysis in mutton and grazing factors (forage, water source and soil) were conducted, to explain the source of essential trace elements in mutton. The concentrations of essential trace elements show that the Gangba mutton was a valuable source for highly available Cu and Zn in human nutrition, and well managed with few detected of toxicity metal. The concentrations of essential trace elements in mutton are closely related to the trace elements in environmental grazing factors. In conclusion, the congenital grazing conditions (a highly mineralized water resource, natural forages and clean soils) were shown to contribute to the unique meat characteristics of Gangba sheep.

Rumen degradability and gas production as influenced by different strains of Bacillus thuringiensis

The effect of six Bacillus thuringiensis (Bt) strains on diet degradability was evaluated using an in vitro gas production technique. Spores (5.7 × 106 spores) of different Bt strains (907, 1192, 2036, 2493, 2496, and S1185) plus a control (no spores) were used as treatments with four replicates (inocula) in duplicate. Fermentation processes were evaluated and ruminal microorganisms were quantified. Compared with the control, the Bt907 strain decreased dry matter (DM) and organic matter (OM) degradability without affecting the Fibrobacter succinogenes population, whereas the other strains reduced this population without altering DM and OM degradability.

Trichostrongylus colubriformis infection: Impact on digesta passage rate and lamb performance

In this study we aimed to evaluate the effect of Trichostrongylus colubriformis infection on digesta passage rate, rumen fermentation and lamb performance. Eighteen three-month-old Santa Ines castrated male lambs (16.9 ± 1.43 kg of body weight) were randomly distributed in two experimental treatments: Infected with T. colubriformis (I, n = 9) and Uninfected (U, n = 9). The I lambs received a total of 45,000 L₃ larvae of T. colubriformis (5,000 infective larvae, three times per week for three weeks). Daily feed intake was assessed using the I lambs as a reference for their respective pairs on the U group (pair-fed). Weight, body condition score and faeces (stool) samples were obtained every 15 days for 75 days. In both treatments, faecal egg count (FEC), digesta passage rate, rumen fermentation parameters, protozoa count and short chain fatty acids (SCFA) were evaluated. The lambs presented moderate infection (FEC = 620). The retention time of the digesta in the rumen-reticulum segment was lower (P < 0.05) in I lambs. The I lambs presented no inappetence, however, lower concentrations of total SCFA and butyrate, while higher acetate concentration were observed in these lambs (P < 0.05). The present findings highlight that T. colubriformis infection decreased the retention time (solid and liquid content) of the digesta in the rumen-reticulum, as well as negatively affected lamb growth.