Fatty acid, chemical, and tissue composition of meat comparing Santa Inês breed sheep and Boer crossbreed goats submitted to different supplementation strategies

Effects of Different Dietary Energy Levels on Development, Quality of Carcass and Meat, and Fatty Acid Profile in Male Lambs

This experiment was conducted to study the effects of dietary energy level on the growth performance and meat quality of weaned Alpine Merino lambs. The study ran for a total of 104 days (20-day pretrial, 84-day trial). From three groups of test lambs, we randomly selected ten lambs per group to determine slaughter performance, meat quality characteristics, and organ indexes. The slaughter performances of the lambs improved as the dietary energy level increased. The live weight before the slaughter of the lambs was significantly higher in the high group than in the low and medium groups. The carcass weight was significantly higher in the high group than in the low group. Dietary energy level had little effect on the organ weight of lambs. Meat quality differed among the three dietary energy levels. The muscle yellowness and redness scores decreased significantly as the energy levels increased. The C18:0, C21:0, C20:1, C18:2n6c, and C20:2 contents in the muscle were significantly higher in the high group than in the medium and low groups. The C18:3n6 content in the muscle was significantly higher in the low group than in the medium group. The C20:5n3 content in the longissimus dorsi was significantly higher in the high group than in the medium and low groups. The monounsaturated and unsaturated fatty acid contents in the muscle were significantly higher in the high group than in the low group. A dietary energy level of 10.5 MJ/kg is suitable for fattening weaned male Alpine Merino lambs.

Effects of Increasing Levels of Total Tannins on Intake, Digestibility, and Balance of Nitrogen, Water, and Energy in Hair Lambs

This study aims to evaluate the effects of increasing tannin levels from Mimosa tenuiflora hay on the intake, digestibility, and balance of nitrogen (N), water, and energy in hair lambs. Thirty-two Santa Ines lambs, at an average age of 150 days and body weight of 26.75 ± 2.29 kg, were randomly assigned to four treatments in a completely randomized design. The treatments consisted of four diets: a control diet, tannin-free, and three diets with increasing levels of total tannin, 26.2, 52.4, and 78.6 g tannin/kg dry matter (DM). Including the total tannins in the lambs' diet led to a quadratic increase in the intake of nutrients, N-retention (g/day), water intake, water absorption and retention, energy intake, and energy excretion in feces and gases. However, the digestibility of crude protein, neutral and acid detergent fibers, and total carbohydrates decreased. It was observed that there is a correlation between the variable nutrient digestibility and N-ingested and the N-absorbed, N-urinary, and N-retained. However, the N-excreted in feces did not correlate with any of the variables studied. It is recommended to include 33 g/kg DM of total natural tannins from Mimosa tenuiflora hay in the diet of hair lambs, as it improves intake, energy balance, dietary N, and body water composition while reducing the excretion of N-urinary and gas emissions to the environment.

A Short-Term Supplementation with a Polyphenol-Rich Extract from Radiata Pine Bark Improves Fatty Acid Profiles in Finishing Lambs

The aim of this study was to evaluate the effects of a short-term supplementation with a polyphenol-rich extract from radiata pine bark (PBE) on animal performance, blood parameters, and fatty acid (FA) profiles in finishing lambs. Twenty-seven Suffolk lambs (4 months old) fed a finishing diet were randomly assigned to one of the following treatments: diet without PBE or diet supplemented with PBE on a 1 or 2% dry matter (DM) basis, for 35 d (14 d adaptation and 21 d of experimental period). Data were compared using Tukey's test and orthogonal and polynomial contrasts. The results indicated that the supplementation with PBE increased (p = 0.008) relative growth rate (RGR) and improved (p = 0.003) protein conversion (CPC), whereas weight gain, carcass characteristic, and blood parameters were unaffected (p ≥ 0.106). Total mono- and polyunsaturated FAs, conjugated linoleic acid (CLA), and vaccenic and oleic acids were linearly increased (p ≤ 0.016) by PBE supplementation. In contrast, total saturated FAs (ΣSFA), Σn-6/Σn-3 ratio, atherogenicity index (AI), thrombogenic index (TI), and the proportion of elaidic acid were linearly decreased (p ≤ 0.018). In conclusion, the supplementation with 1 or 2% DM of PBE improves subcutaneous FA profiles by increasing CLA and reducing ΣSFA, Σn-6/Σn-3 ratio, AI, and TI. Additionally, PBE supplementation has the potential to improve RGR and CPC, with unaffected intake, growth performance, blood parameters, or carcass characteristics.

Palm kernel cake in high-concentrate diets improves animal performance without affecting the meat quality of goat kids

Context Goat farming is an important socio-economic activity. The feedlot system allows the finishing of the animals in short periods through use of concentrated diets; however, these diets increase the system’s production costs. Palm kernel cake (PKC) has proved to be a good alternative feed source in diets for cattle and sheep because of its nutritional characteristics and potential to reduce production costs. Aim This experiment aimed to evaluate the effect of high-concentrate diets with the inclusion of PKC on carcass traits and meat quality of feedlot goat kids. Methods Thirty-two crossbred, castrated Boer goat kids, 4 months old and of average initial body weight 19.65±3.00kg, were used in the study. The animals were assigned to treatments in a completely randomised design, with four experimental diets containing PKC at 0%, 12%, 24%, and 36% on a dry matter basis. Measurements included total weight gain at slaughter, quantitative and sensory meat characteristics, and fatty acid profile. Key results A quadratic effect (P<0.05) on total weight gain, and on meat marbling, lightness, and yellowness, was observed. The highest total weight gain and marbling were recorded with the diet containing 12% PKC. Loin eye area was also highest at 12% PKC, then decreased, whereas protein content and shear force increased (P<0.05) at the higher PKC levels. Diet affected (P<0.05) saturated, monounsaturated, and polyunsaturated fatty acids. No effect was observed from the inclusion of PKC on sensory attributes or on nutritional quality of the lipid fraction of the meat. Conclusion It is recommended the use up to 12% of this alternative source of nutrients, owing to the higher total weight gain and improved quantitative aspects of the goat kids’ meat such as marbling and loin eye area. Implications High-concentrate diets and the use of by-products for animal nutrition have become common in animal production systems. The increasing use of PKC in animal nutrition leads us to determine the best dietary inclusion level, avoiding undesirable production or product quality characteristics.

Impact of Diet Supplementation and Age at Slaughter on Carcass Characteristics of Creole Goats

The objective of this study was to evaluate the effects of diet and age on finishing performances and carcass characteristics of male Creole goats. A total of 91 weaned male Creole kids [84 days old ± 7 days, 9.2 kg live weight (LW) ± 0.5 kg] were randomly allocated in a 2 × 3 experimental design. The animals were fed individually with two diets: C0: a 28-day-old Digitaria decubens grass alone, or C50: the same grass plus a commercial concentrate (50% of the total diet) and then slaughtered at 7, 11, or 15 months of age. Significant feeding regimen and age at slaughter effects were observed on the goat carcass characteristics. The addition of concentrate improved the average daily gain (ADG), the dressing percentage, and the conformation score (1-5 scale) from 46 to 88 g/day, 52.8 to 62.4%, and 2.2 to 4.9, respectively. Moreover, carcasses of the C0 group appeared lean with less developed fat than the C50 group and lighter than visceral fat. The meat color was significantly more affected by diet than age. Our data suggested that the production of heavy carcasses with low proportions of fat in the meat is possible in this local breed. The valorization of such a forage feeding system until 11 months of age or with the addition of concentrate from 7 to 11 months of age should be evaluated economically.

Epigenetic Regulation of Key Enzymes CYP7a1 and HMGCR Affect Hepatic Cholesterol Metabolism in Different Breeds of Piglets

Liver is the place where cholesterol is synthesized, transported, secreted, and transformed, thus liver takes an irreplaceable role in cholesterol homeostasis. Hepatic cholesterol metabolism differs between breeds, yet the molecular mechanism is unclear. In this study Large White (LW) and Erhualian (EHL) piglets (at birth and 25-day-old) were used, 6 each time point per breed. Erhualian piglets had significantly lower body and liver weight compared with Large White at birth and weaning, but the liver/ body weight ratio was higher at weaning, associated with increased serum and liver cholesterol and triglyceride content. The mRNA expression of Cholesterol-7alpha-hydroxylase (CYP7a1) and Recombinant Acetyl Coenzyme Acetyltransferase 2 (ACAT2) were down-regulated in Erhualian piglets at birth, while hepatic Sterol-regulatory element binding protein 2 (SREBP2) mRNA expression was up-regulated in Erhualian piglets at weaning, as well as SREBP2 protein content, compared with Large White piglets. At birth, the depressed CYP7a1 transcription in Erhualian piglets was associated with decreased Histone H3 (H3) and increased Histone H3 lysine 27 trimethylation (H3K27me3). While the results revealed significant promoter hypermethylation of 3-Hydroxy-3-methylglutaryl-CoA reductase (HMGCR) promoter in Erhualian piglets at weaning, together with increased Histone H3 lysine 9 monomethylation (H3K9me1) and Histone H3 lysine 4 trimethylation (H3K4me3). These results suggest that epigenetic modification may be an important mechanism in hepatic cholesterol metabolism among different species, which is vital for maintaining cholesterol homeostasis and decreasing risk of cardiovascular disease.