ABSTRACT The aim of this study was to investigate the effects of different dietary levels of L-arginine on the growth performance, blood parameters, and lipogenic gene expression of Arian broiler chickens. For this purpose, 168 Arian broiler chicks (40.33±1.7 g) were assigned to four treatments with three replicates of14 birds each, according to completely randomized design. The experimental treatments consisted of 100, 124, 139, and 154% dietary arginine levels relative to the published requirements of Arian broilers. On 42 d of the experiment, blood samples were collected from two birds (six birds per treatment) for blood metabolite measurements. These birds were then euthanized for carcass evaluation and collection of tissue samples. Increasing dietary arginine levels reduced (p<0.05) the gene expression of fatty acid synthase, acetyl-coenzyme A carboxylase, and malic enzyme in the liver and lipoprotein lipase in the abdominal fat tissue, as well as abdominal fat relative weight. Increasing dietary arginine levels significantly increased (p<0.05) body weight, feed efficiency, carcass yield, breast and thigh relative weights, and glucose and HDL (high-density lipoprotein) blood levels, and reduced cholesterol, triglyceride, and LDL (low-density lipoprotein) blood levels. Since almost similar performance and carcass trait results were obtained both with 124 and 139% arginine levels, supplying Arian broiler diets with 124% arginine is suggested.

Conscious animals typically experience sensory (nociception) and emotional pain, whereas unconscious animals that were minimally anesthetized would experience minimal emotional pain. To determine whether 'silencing' the emotional component through a minimally anesthetized model would minimize stress response, and thus improve animal welfare, this study aimed at comparing changes in electroencephalographic (EEG) activities associated with possible noxious stimuli following neck-cut slaughter in conscious non-anesthetized versus minimally anaesthetized Boer cross-bred goats. Ten bucks were randomly assigned to two groups of five animals each, and subjected to neck-cut slaughter when fully conscious (HS) or under minimal anaesthesia (AS) and exsanguinated. The anaesthesia was induced with propofol (5 mg/kg) administered to effect by rapid injection into a cephalic vein and maintained with halothane in 100 % oxygen. Changes in the root mean square (RMS) for each of alpha, beta, delta and theta waves, median frequency (F50) and total power of the EEG (Ptot) were compared in each group before and after neck cut and between groups following treatments. Electroencephalographic parameters did not differ between goats that were fully conscious or slaughtered under minimal anaesthesia. These findings showed that the noxious stimuli from neck cut were present in both conscious and minimally anaesthetized goats. Most importantly, the presence of emotional pain and nociception did not affect the extent of electroencephalographic responses significantly compared with animals that were experiencing nociception only.

Mangosteen peel (MP), an agricultural by-product of tropical countries, has been reported to contain condensed tannins and saponins, which can affect rumen microbes to reduce enteric methane emission. In the present study, the effects of mangosteen peel on in vitro ruminal fermentation, gas production, methane production, fatty acid biohydrogenation, and microbial population were investigated. Results showed that MP at medium and high levels (25 % and 50 % replacing alfalfa) were able to reduce (P <0.05) in vitro methane production without affecting volatile fatty acid (VFA) production and the pH of the substrate. The lowering effect of MP on methane production was because of suppression of the rumen microbial populations, especially total protozoa and total methanogens. MP at the higher level (50%) reduced (P <0.05) the amounts of biohydrogenation for linoleic acid (C18:2n-6), α-linolenic acid (C18:3n-3) and the total C18 unsaturated fatty acids (UFA) owing to the reduction of the Butyrivibrio fibrisolvens population, that is, the most important rumen microorganism involved in the biohydrogenation process. In conclusion, mangosteen peel has potential to be used in ruminant livestock feeds, with the advantage of reducing ruminal methane production and biohydrogenation, without adverse effects on ruminal pH and VFA production.

The link between the consumption of saturated fatty acids of ruminant meat and the incidence of chronic diseases in humans substantiates efforts to modify its lipid profile. However, altering the lipid profile of ruminant meat could affect its quality attributes and shelf life. This study investigated the effect of a blend of 80% canola oil and 20% palm oil (BCPO) and post mortem ageing on lipid composition, antioxidant status, colour, metmyoglobin reducing activity (MRA) and lipid and protein oxidation in biceps femoris muscle in goats. Twenty-four bucks were randomly assigned to diets containing on a dry matter basis, 0%, 4% or 8% BCPO, fed for 100 d, and slaughtered. The biceps femoris was subjected to 7 d post mortem ageing (4 °C). Neither diet nor post mortem ageing altered catalase, superoxide dismutase and glutathione peroxidase activities or sensory attributes of the biceps femoris. Dietary BCPO improved α- and γ-tocopherol, but did not affect total carotenoids and δ-tocopherol, colour, metmyoglobin content, MRA, TBARS, carbonyl content and free thiol content. Goats fed 4% BCPO had higher cis-9 trans-11 CLA, while those fed 8% BCPO had higher C18:3n-3 and C20:5n-3 compared with other treatments. The 4% and 8% BCPO meat had lower C14:0, but higher C18:1n-9 and C22:5n-3 than the control goats. Post mortem ageing decreased muscle polyunsaturated fatty acids (PUFA), antioxidant compounds, redness, MRA and oxidative stability of lipid and proteins, but increased metmyoglobin content. Dietary BCPO enhanced beneficial muscle lipids without compromising the sensory quality, and lipid and protein stability of the goat meat.

A study was conducted to evaluate the fatty acid (FA) profile of subcutaneous adipose tissue and tailfat of two fat-tailed sheep breeds under identical feeding conditions. Twelve male lambs from two breeds, Sanjabi (n = 6), weighing 23.3 ± 0.48 kg, and Mehraban (n = 6), weighing 26.1 ± 2.14 kg, were used in this investigation. All animals were weighed and slaughtered at the end of a 90-day fattening period and FA composition of subcutaneous adipose tissue and tailfat was determined. Significant breed differences in total FA, total polyunsaturated fatty acid (PUFA) and n-6PUFA contents were observed in the subcutaneous adipose tissue, but not in the tailfat. Breed differences were observed in the conjugated linoleic acid (CLA) content of subcutaneous adipose tissue, with higher levels in Sanjabi than in Mehraban lambs. Linoleic and α-linolenic acid of subcutaneous adipose were significantly higher in the Sanjabi breed than in the Mehraban breed. Thus, adipose tissue from fat-tailed Sanjabi lamb has a higher proportion of health-promoting linoleic and α-linolenic acids, unsaturated fatty acids (UFA) and CLA, suggesting that the Sanjabi breed could be used for producing healthier lamb products.

The aim of the present study was to evaluate the effects of three feeds containing 6% oils: palm oil (PO), soybean oil (SO) and linseed oil (LO); and three calcium levels (NRC recommendation, 1.25% and 1.50%) on the fatty acid profile, lipid oxidation and cholesterol concentrations of broiler breast meat in a 3 χ 3 factorial experiment. A total of 378 one-day-old chicks were randomly assigned to the diets and fed for six weeks. Birds fed diet supplemented with LO, SO and PO had higher proportions of α-linolenic, linoleic and oleic acids, respectively. The LO diet increased the total n-3 fatty acids and decreased the n-6 : n-3 compared with the PO and SO diets. Birds fed the PO diet had higher oxidative stability and cholesterol compared with those fed the SO and LO diets. However, the level of cholesterol in all treatments was within the normal range. The level of calcium and interaction between source of oil and calcium level did not influence lipid oxidation, fatty acid profile and cholesterol level of broiler breast muscle. It can be concluded that dietary LO and SO enhanced n-3 and n-6 polyunsaturated fatty acids, respectively, while dietary PO enhanced the oleic acid and oxidative stability of broiler breast muscle. Thus, this study showed that PO can be used as an alternative oil source in broiler diets with a positive effect on the oxidative stability of chicken meat refrigerated at seven days when compared with vegetable oils that are rich in linoleic and α-linolenic acid.