Search Results (175)

This experiment evaluated whether a high-forage, low-starch, and high-oil diet (experimental) could improve lamb meat fatty acid composition without compromising growth performance or overall meat quality, compared with a high-cereal diet typically used in intensive fattening systems (control). Ninety lambs were randomly assigned to six pens (fifteen animals/pen), with each diet provided to three pens for 32 days. Feed intake was monitored daily, and animal weight was monitored weekly. The feeding cost was also assessed. Four lambs per pen were slaughtered to assess carcass and meat traits. Average daily gain was unaffected by diet, but the experimental diet increased the feed conversion ratio. Kidney knob channel fat was higher in the experimental diet, while other carcass traits were unchanged. Meat sensory attributes and most physicochemical properties, including colour and lipid stability during storage, did not differ between diets. However, the experimental diet reduced meat pH and increased the proportions of t11–18:1, c9,t11–18:2, 18:2n-6, and 18:3n-3 in intramuscular fat, while t10–18:1 remained unchanged, and n-6 PUFA/n-3 PUFA ratio increased. A low-starch, high-forage, high-oil diet can be effectively used in lamb feedlots to enhance the intramuscular fat content of healthy fatty acids without compromising animal growth or meat characteristics, although it results in higher feeding costs. Full article

This study was conducted to investigate potential regulatory mechanisms of hybridization increased the meat production performance in sheep. Thirty-six 3-month-old male lambs of Suffolk sheep (SFK, n = 12), Hu sheep (HH, n = 12), and their F₁ hybrids (SH, n = 12) were selected and raised in individual pens under identical nutritional supply and husbandry management regimes over a 95-day (including a 15-day pre-trial period) experimental period. At the end of the feeding trial, six sheep closest to the average body weight were selected from each group for the subsequent trial, involving the collection of Longissimus dorsi samples and the determination of production performance, muscle fiber characteristic and transcriptomic and metabolomic analysis. The results showed that the SH sheep had significantly higher pre-slaughter live weight and carcass weight than the HH sheep, while lower than those of the SFK sheep (p < 0.05). The muscle fiber density of the SH group was significantly higher than that of the parental groups, while the muscle fiber diameter and cross-sectional area were significantly smaller (p < 0.05). The collagen fiber content of the SH group was intermediate between the two parental groups and significantly higher than that of the SFK group (p < 0.05). Transcriptomic analysis identified 2920 differentially expressed genes (DEGs), which were mainly enriched in the AMPK, PI3K-Akt, and PPAR signaling pathways. Metabolomic analysis detected 1617 differential metabolites (DMs), which were enriched in the fatty acid degradation and steroid hormone biosynthesis pathways. Integrated analysis revealed that core genes SESN3 and metabolites (malate, testosterone) enhance energy supply capacity through AMPK pathway, thereby promoting muscle fiber proliferation and increasing meat yield in the hybrid sheep. In conclusion, the heterosis of the SH group originates from the remodeling of muscle fiber structure and the synergistic regulation of related pathways, which provides a theoretical basis for sheep crossbreeding. Full article

This study aimed to investigate the interactive effects of dietary starch concentration (220 or 420 g/kg DM) and supplementation with calcium salts of palm fatty acids (CSPFAs; 0 or 30 g/kg DM) on carcass characteristics and meat quality in lambs. Thirty-two castrated Dorper × Santa Inês male lambs (initial body weight 25.0 ± 2.85 kg) were randomly assigned to four experimental diets in a 2 × 2 factorial arrangement for 44 days. Although carcass yield remained unaffected (average 49.4%; p > 0.05), CSPFA supplementation significantly increased fat deposition, including perirenal fat mass (590 vs. 400 g; p = 0.005), renal fat score (2.90 vs. 2.66; p = 0.035), and subcutaneous fat thickness (3.8 vs. 1.9 mm; p = 0.017). A starch × CSPFA interaction (p = 0.014) was observed for carcass cooling, where high-starch diets reduced the 24 h temperature only in lambs not receiving CSPFA (7.45 vs. 8.48 °C; p = 0.028). CSPFA also altered the muscle fatty acid profile by increasing C16:0 and total saturated fatty acids (SFA) while reducing polyunsaturated fatty acids (PUFA). In conclusion, palm-oil–derived CSPFA enhances carcass fatness but compromises the nutritional value of lamb meat by promoting an unfavorable fatty acid profile. Full article

This study investigated whether supplying rumen-protected lysine (RPL), alone or in combination with tannins, could modify the fatty acid (FA) profile, physicochemical characteristics, carcass traits, and sensory attributes of lamb meat. Forty Santa Inês × Dorper lambs (≈23 kg, 4 months old) were assigned to four dietary treatments for 55 days: a control diet, free lysine (0.44%), RPL microencapsulated in a carnauba-wax matrix, and RPL + tannins blend (1.34%). Feed intake, carcass weight, and quantitative carcass measurements did not differ among treatments (p > 0.05). Likewise, pH, color, proximate composition, water-holding capacity, cooking losses, and shear force remained unchanged. Dietary supplementation influenced the FA composition of the meat. RPL, especially when added with tannins, increased concentrations of conjugated linoleic acid (C18:2 cis–9, trans–11), eicosapentaenoic (C20:5 n–3), and docosahexaenoic acids (C22:6 n–3), improving the n–6:n–3 ratio (p < 0.05). The sum and ratio of other FA and cardiometabolic indices were not altered. Lipid oxidation was reduced in RPL treatments, indicating enhanced oxidative stability. Sensory attributes scores were not affected (p > 0.05), ranging from “liked slightly” to “liked very much”. RPL, particularly when combined with tannins, improved specific health-related FA without adversely affecting carcass characteristics or consumer acceptance. Full article

This study investigated the effects of dietary supplementation with an alkaline metal ion complex (AMIC) on growth performance, meat quality, rumen microbiota, and metabolome in Hu lambs. Fifty lambs were randomly assigned to either a control group (basal diet) or an AMIC group (basal diet + 0.15% AMIC) for 60 days. The results showed that AMIC significantly increased carcass weight, Longissimus dorsi area, crude protein, intramuscular fat, ash content, and meat luminosity (L*). Amino acid profiles and key flavor compounds were elevated, while off-flavor hydrocarbons were reduced. 16S rRNA sequencing revealed that AMIC altered rumen microbiota composition, enriching butyrate-producing genera such as Butyrivibrio and Saccharofermentans. Metabolomic analysis identified 398 differentially expressed metabolites, with upregulated pathways including butanoate metabolism and xylene degradation. Correlation analyses indicated strong associations between specific microbial taxa, metabolites, and meat quality traits. These findings suggest that AMIC enhances meat quality by modulating rumen microbial ecology and metabolic pathways, leading to improved nutrient deposition and flavor development. This study provides novel insights into the microbe–metabolite–muscle axis in ruminants and supports the use of AMIC as a dietary strategy for quality lamb production. Full article

Yeast culture (YC) is a microbial product that enhances ruminal fiber breakdown and improves nutrient digestion and utilization. Our previous research showed that oxalic acid (OA) is a crucial metabolite in YC that enhances rumen function. This study aimed to investigate the effects of YC, OA, and their combination (YO) on rumen function, growth, and fattening in sheep. Twenty lambs were divided into 4 groups (ctrl, YC, OA, and YO; n = 5 each) and fed a diet supplemented with 2 levels of YC and 2 doses of OA for 60 days in a 2 × 2 factorial design. Growth and fattening performance, rumen microbiome analysis, serum indices and anti-oxidant levels, and metabolomic profiling were performed. Individual supplementation with YC and OA significantly increased the digestibility of dry matter (DM), organic matter (OM), and crude protein (CP) (p < 0.001); neutral detergent fiber (NDF) (p < 0.05); and acid detergent fiber (ADF) (p < 0.001) and their interaction significantly increased dry matter intake (DMI) (p = 0.05). Serum IgA and IgM levels were higher in the supplemented groups (p < 0.05). Serum calcium levels were higher in the OA and YO groups (p < 0.001). The supplemented groups showed significantly higher growth hormone and superoxide dismutase levels (p < 0.05). The longissimus dorsi muscle had higher levels of iron in the OA and YO groups; zinc in the OA, YO, and YC groups (p < 0.01); and selenium in the YC group (p < 0.05). The OA group had a higher total antioxidant capacity. All supplemented groups showed higher bacterial richness and diversity. Ruminococcus, Succinivibrio, and Fibrobacter were positively correlated with the fermentation and digestibility parameters. The supplementation also altered metabolite levels and types in key physiological pathways. In conclusion, this supplementation improved bacterial composition, nutrient digestibility, weight gain, carcass weight and quality, serum indices, antioxidant levels and metabolomic profiles. This suggests potential for the development of dietary supplements for ruminants. Full article

Thirty-six Dorper × Katahdin intact male lambs [44.0 ± 0.27 kg initial body weight (BW)] were used in a randomized complete block design to evaluate the effects of supplementing different organic chromium (OrCr) sources on growth performance, dietary energetics, carcass traits, meat quality, and economic return. Treatments (n = 9 lambs/treatment) were (1) Control (no Cr), (2) chromium-enriched yeast (Cr-Yeast), (3) chromium–methionine (Cr-Met), and (4) chromium–propionate (Cr-Pr). All Cr sources were provided at 1.2 mg elemental Cr/lamb/d for 45 d. Lambs received a high-energy finishing diet (78:22 concentrate/forage; steam-rolled corn-based). Dry matter intake was not affected (p = 0.583; 1.27 ± 0.034 kg/d). Compared with Control, Cr-Pr increased final BW (+5%; p = 0.025) and average daily gain (+66%; p = 0.034), and improved feed efficiency (+59%; p = 0.045) and observed-to-expected net energy ratio (+22%; p = 0.042); Cr-Met and Cr-Yeast showed intermediate responses. No differences were observed (p > 0.05) in longissimus lumborum muscle area, cold carcass weight, dressing percentage, cooling loss, or zoometric traits. Rib and rump fat thickness decreased with Cr-Met (−15 and −12%; p = 0.024 and p = 0.048) and with Cr-Pr (−19 and −13%; p = 0.024 and p = 0.048), and all OrCr sources reduced omental (−6 to −25%; p = 0.034), mesenteric (≈−7%; p = 0.042), visceral (−12 to −16%; p = 0.034), and perirenal fat (−25 to −39%; p = 0.028). Empty body weight and hot carcass weight increased with Cr-Pr (p = 0.029 and p = 0.031, respectively). Cr-Yeast and Cr-Pr increased muscle proportion (+5 to +7%; p = 0.003) and reduced carcass fat (−20 to −27%; p = 0.018), improving the muscle/fat ratio (+42 to +50%; p = 0.045). Cr-Pr improved water-holding capacity (+27%; p = 0.014) without affecting pH_24h, purge loss, cooking loss, or Warner–Bratzler shear force (p > 0.05). Cr-Pr reduced cost per kg of gain (−31%; p < 0.001) and increased income (+188% live; +105% carcass; p < 0.001), whereas Cr-Met and Cr-Yeast provided moderate benefits. In conclusion, OrCr supplementation improved dietary energy utilization, growth, carcass traits, and meat quality, enhancing profitability in lambs finished at heavier weights, with Cr-Pr producing the greatest responses. Full article

Spineless cactus, known for its high heat tolerance and low water requirements, offers a sustainable alternative for animal feed in regions where conventional crops struggle to thrive. This study aimed to evaluate the carcass characteristics, leg tissue composition, and non-carcass constituents of lambs fed increasing levels (0, 15, 30, and 45% based on dry matter) of spineless cactus as a replacement for Tifton hay. Additionally, we estimated body weight and carcass traits using biometric measurements (BM). Forty male lambs, with an average initial body weight of 23.6 ± 2.58 kg, were subjected to a feedlot regime. Empty body weight was the only variable that showed a significant orthogonal contrast between the control group (0%) and those fed spineless cactus (p < 0.05). A quadratic regression effect (p < 0.05) was observed for the weights of the cold half carcass, neck, shoulder, and leg cuts. No significant effects were found on non-carcass components or biometric measurements. Biometric measurements showed strong positive correlations with slaughter weight and carcass characteristics. Based on these findings, replacing 30% of Tifton hay with spineless cactus is recommended as the optimal level, as it maintains carcass quality, tissue composition, and non-carcass traits. Moreover, biometric measurements prove to be effective tools for predicting slaughter weight and carcass characteristics, offering practical value for farmers seeking efficient and sustainable production strategies. The inclusion levels of 24.25% to 27.50% of spineless cactus in the diet of confined sheep appear to be the most efficient, promoting high-value commercial cuts without compromising carcass quality parameters. These levels balance productive performance and sustainability, especially in semi-arid regions. Full article

Improving livestock nutrition with natural supplements can enhance productivity and meat quality. This study evaluated whether a clayey micromineral compound (CMC) in lamb diets improves feed efficiency, health, and meat traits. Twenty-four 60-day-old Dorper/Santa Inês crossbred lambs (28.41 ± 4.147 kg initial weight) were randomly assigned to four CMC doses (0%, 0.4%, 0.8%, or 1.2% of dry matter intake/day) for 90 days, following a 15-day adaptation. The lambs were individually housed, with daily feed intake monitoring, weekly weight measurements, and blood analyses at the start and end. On day 89, rumen fluid was sampled for digestion analysis, and post-mortem evaluations were used to assess meat quality and rumen health. The results showed that 0.8% CMC optimized fat and fiber digestion (p < 0.05), while higher doses linearly improved meat color intensity (p < 0.05). Blood tests indicated better liver function at intermediate doses (p < 0.05). However, the CMC did not affect overall growth, feed intake, or carcass traits. The supplement was safe but provided selective benefits. These findings suggest that CMCs could enhance feed efficiency and meat appeal, although further research is needed to refine dosing for maximum impact. Full article

Twenty Dorper × Katahdin lambs (10 males and 10 females) were distributed in a 2 × 2 factorial arrangement under a randomized complete block design to evaluate the effects of thiamine diphosphate (TD) supplementation (0 vs. 250 mg/kg feed) and gender (males vs. females) on physiological responses, feedlot performance, carcass characteristics, and meat quality in a hot desert environment. The average temperature and temperature–humidity index recorded during the study were 33.60 °C and 35.89 units, respectively, indicating an extremely severe heat stress environment for lambs. Study variables were not affected (p ≥ 0.12) by the TD × gender interaction, except for dry matter intake (DMI; p = 0.02) and some head temperatures (p ≤ 0.05) and carcass zoometric measurements (p ≤ 0.05). In females, but not in males, TD decreased DMI and increased thorax depth, as well as eye, ear, and forehead temperatures. Overall, TD increased (p ≤ 0.05) surface temperatures of neck, shoulder, loin, rump, forelimb, testicles, vulva, anus, and perineum without affecting (p ≥ 0.58) rectal temperature and respiratory rate. Supplemental TD did not affect (p ≥ 0.16) growth rate, feed efficiency, carcass weight and yield, Longissimus thoracic muscle area, backfat thickness, internal fat deposition, wholesale cut yields, and meat quality traits. In conclusion, in hair ewe lambs but not in male lambs, TD supplementation at a dose of 250 mg/kg of feed in the fattening diet is an HS mitigation strategy that improves dietary energy efficiency for growth and carcass mass deposition. Furthermore, thiamine increases heat losses through the body surface, regardless of gender. Full article

The aim of the study to evaluate relationship between breed, GH and CAST genotypes, and FA composition in the ovine intramuscular fat of musculusSemimembranosus. To fulfil this aim, 175 blood samples were drawn by jugular vein puncture from Lithuanian Black-Headed (N43), Lithuanian Black-Headed *Ile de France (N43), Lithuanian Black-Headed *Suffolk (N44), and Lithuanian Black-Headed *Texel (N45) lambs. The lambs were weighed weekly, and the growth rate was calculated using birth weight and month weight values. Genomic DNA was extracted from blood samples taken into EDTA containing tubes, using a “GeneJET Genomic DNA Purification Kit” (Thermo Scientific, Waltham, MA, USA). The method of polymerase chain reaction and restriction length polymorphism were used to genotype growth hormone (GH) and (CAST) gene polymorphisms. Meat samples of four lamb breeds were taken for analysis (200–250 g from musculusSemimembranosus were taken 48 h after carcass meat cooling). The fatty acid methyl esters (FAMEs) were analyzed using a gas chromatography mass spectrometry (GC/MS) instrumental technique. All data were evaluated statistically. Studies have shown that purebred Lithuanian Black-Headed lambs are born with a higher weight, so it is not advisable to mix them with Ile de France, Suffolk, or Texel breeds. Also, our research shows that the most beneficial breed are lambs that have the BB genotype of the GH gene and the MN genotype of the CAST gene, as these lambs are born with the greatest weight and gain. The meat of Lithuanian Black-Headed lambs showed the lowest content of SFA and the largest content of PUFA. The ratio ω-6/ω-3 FA varied from 2.71 (Lithuanian Black-Headed * Suffolk) to 4.52 (Lithuanian Black-Headed). Based on the research, it can be concluded that the purebred Lithuanian Black-Headed lambs had higher birth weight, therefore it is not appropriate to mix them with Ile de France, Suffolk, or Texel breeds. Full article

L-carnitine supplementation enhances fatty acid oxidation and antioxidant defense mechanisms in livestock. Twenty-four wether lambs were randomly assigned to one of three dietary treatments: a control (basal diet), a low-L-carnitine diet (0.01%), or a high-L-carnitine diet (0.05%). After a 15-day adaptation period, all lambs underwent a 45-day experimental phase to assess the impact of L-carnitine supplementation on performance, carcass, muscle, and antioxidant capacity. Although growth performance did not show significant differences (p > 0.05), muscle pH increased in the L-carnitine group (p < 0.05), while drip loss decreased in both the low- and high-dose groups (p < 0.05). The a* value of the Longissimus dorsi muscle significantly increased (p < 0.01), enhancing meat color saturation (p < 0.05), with a reduction in the hue angle observed in the high-dose group (p < 0.01). L-carnitine supplementation led to an elevated myoglobin content and a higher proportion of oxymyoglobin, driven by a significant increase in MRA activity (p < 0.01). The concentration of L-carnitine was positively correlated with the a* value, which in turn was associated with higher total myoglobin content and a greater proportion of oxymyoglobin. In terms of antioxidant capacity, the L-carnitine group exhibited a significant increase in superoxide dismutase content. Moreover, there was upregulation of TFR1 and CAT expression at the mRNA level, while HEPH showed downregulation (p < 0.01). Significant increases were observed in both content and mRNA expression of LDHB and NADHBR5 (p < 0.01). The addition of 0.05% L-carnitine to the diet significantly enhanced muscle color stability in hybrid sheep. This improvement was primarily driven by a significant increase in MRA activity in the high-dose group, which facilitated the conversion of metmyoglobin to oxymyoglobin, thereby significantly boosting meat quality prospects for the sheep industry. Full article

This on-farm study explored the effects of diverse pasture systems and seaweed bio-stimulants (AgriSea NZ Seaweed Products, Paeroa, New Zealand) on sheep performance, metabolic health, milk composition, and carcass characteristics. A 3 × 2 factorial design was used to compare three pasture systems; ryegrass-white clover (RW), a 23-species diverse mix (DI), and functionally diverse strip swards (ST), with (SW) or without (CO) a seaweed bio-stimulant. Ninety pregnant ewes were stratified by live weight and allocated across six treatment groups (15 ewes per treatment). Lambing occurred on treatment paddocks. At weaning, 90 lambs (15 per treatment) were selected based on body weight and sex balance to continue through to finishing. Pasture chemical composition differed among treatments: ST had lower fibre (neutral detergent fibre, NDF; acid detergent fibre, ADF) than RW and DI, while SW increased dry matter digestibility (DMD) and metabolisable energy (ME), and reduced NDF and ADF (p < 0.05). Strip pastures improved lamb average daily gain (ADG) by 17% from lambing to weaning compared to DI, and by 14% from weaning to finishing compared to RW (p < 0.05). Seaweed bio-stimulant treatment enhanced lamb ADG by up to 12% and improved carcass traits, including loin and shoulder yields (p < 0.05). Ewes and lambs on seaweed-treated pastures exhibited lower serum non-esterified fatty acid (NEFA) concentrations (p < 0.05), indicating better energy balance. Milk from ST and/or SW treated ewes had elevated omega-6 fatty acids and essential amino acids, suggesting enhanced nutritional value. These findings demonstrate that combining botanical diversity with natural bio-stimulants can improve animal growth, metabolic health, and product quality, offering a promising strategy for sustainable and welfare-oriented sheep production systems. Full article

The increasing adoption of digital technologies in the agriculture sector has significantly contributed to optimizing on-farm routines, especially in data-driven decision-making. This study aimed to develop an application to determine the slaughter point of lambs by predicting subcutaneous fat thickness (SFT) using pre-slaughter parameters such as body weight (BW), body condition score (BCS), and skinfold measurements at the brisket (BST), lumbar (LST), and tail base (TST), obtained using an adipometer. A total of 45 Pantaneiros lambs were evaluated, finished in feedlot, and slaughtered at different body weights. Each pre-slaughter weight class showed a distinct carcass pattern when all parameters were included in the model. Exploratory analysis revealed statistical significance for all variables (p < 0.001). BW and LST were selected to construct the predictive equation (R² = 55.44%). The regression equations were integrated into the developed application, allowing for in-field estimation of SFT based on simple measurements. Compared to conventional techniques such as ultrasound or visual scoring, this tool offers advantages in portability, objectivity, and immediate decision-making support. In conclusion, combining accessible technologies (e.g., adipometer) with traditional variables (e.g., body weight), represents an effective alternative for production systems aimed at optimizing and enhancing the value of lamb carcasses. Full article

The aims of the current study were to characterize the natural compounds of Salsola tragus via GC-MS and determine its effects as a forage source on lamb growth, in vitro rumen fermentation kinetics, carcass quality, cellular damage, and metabolomic meat interaction. Twenty-one Rambouillet lambs were randomly assigned to one of three experimental diets (seven lambs per treatment): (1) a control diet (W/o-Salsola) containing 300 g/kg dry matter (DM) of sorghum stover; (2) a diet with a medium inclusion of Salsola tragus (15-Salsola), which contained 150 g/kg DM of Salsola tragus and 150 g/kg DM of sorghum stover; and (3) a diet comprising 300 g/kg of Salsola tragus (30-Salsola). The results showed there were no differences (p > 0.05) in lamb growth performance during the fattening phase. The in vitro gas analysis demonstrated that the 30-Salsola treatment increased lag time h⁻¹ (p < 0.05) and reduced gas production (p = 0.03). The metabolomic analysis findings suggest that the treatments that included Salsola tragus significantly positively affect the metabolomic composition of meat (p < 0.05). The use of 15-Salsola as a source of forage is promising for feeding lambs during the fattening phase. Full article