Responses to betaine and inorganic sulphur of sheep in growth performance and fibre growth

Sulphur‐containing amino acids (SAA) are essential and usually the first limiting amino acids for growth, milk and wool production. The keratin fibre that grows from epidermal tissue is rich in SAA. The rate of fibre growth and its S content are influenced by the availability of SAA. Betaine is a dietary source for a labile methyl group and actively participates in methionine metabolism by donating methyl groups for the remethylation of homocysteine to methionine. Ruminants are capable of synthesizing SAA from inorganic S sources, and most bacteria in the rumen can use inorganic S to meet their requirements for growth. The objective of this study was to examine whether betaine and an inorganic sulphur supplement could provide methyl groups and sulphur amino acids in a way that growth performance and wool production of ewes and lambs are improved. Treatments performed included betaine supplementation, sulphate supplementation and betaine plus sulphate supplementation with five replications for each treatment. The dry matter intake of the ewes was affected by betaine plus sulphate supplementation (p < 0.05). In the ewes, betaine plus sulphate supplementation increased (p < 0.05) the wool growth rate, wool yield, staple length and wool sulphur concentration, while decreasing wool wax and wool yellowness (p < 0.05). In the lambs, wool growth rate, wool yield, fibre diameter, staple length, staple strength, wool sulphur concentration, wool wax and fibre percentage did not differ (p > 0.05) between treatments. In the ewes, plasma methionine concentration increased (p < 0.05) with betaine plus sulphate treatment. No corresponding difference (p > 0.05) was observed in plasma methionine concentration in the lambs. It can be concluded that betaine plus sulphate supplementation has the potential to change wool characteristics in the ewes, while these compounds were without any effect on growth and wool production of the lambs. Combining the two supplements was advantageous.     

Effect of dietary fish oil on fatty acid deposition and expression of cholesterol homeostasis controlling genes in the liver and plasma lipid profile: comparison of two animal models

The objective of the present study was to compare hepatic fatty acid deposition, plasma lipid level and expression of cholesterol homeostasis controlling genes in the liver of rats (Wistar Albino; n = 32) and pigs (Large White × Landrace; n = 32) randomly assigned into two groups of 16 animals each and fed 10 weeks the diet with either 2.5% of fish oil (F; source of eicosapentaenoic and docosahexaenoic acid, EPA+DHA) or 2.5% of palm oil (P; high content of saturated fatty acids; control). F‐rats deposited in the liver three times less EPA, but 1.3 times more DHA than F‐pigs (p < 0.05). Dietary fish oil relative to palm oil increased PPARα and SREBP‐2 gene expression much strongly (p < 0.01) in the pig liver in comparison with the rat liver, but expression of Insig‐1 and Hmgcr genes in the liver of the F‐pigs relative to the expression of these genes in the liver of the P‐pigs was substantially lower (p < 0.01 and p < 0.05 respectively) as compared to rats. When plasma lipid concentration in the F‐animals was expressed as a ratio of the plasma concentration in the P‐counterparts, dietary fish oil decreased HDL cholesterol less (p < 0.01), but LDL cholesterol and triacylglycerols more (p < 0.05 and p < 0.001 respectively) in rats than in pigs: more favourable effect of fish oil on rat plasma lipids in comparison with pigs can therefore be concluded. Concentration of total cholesterol and both its fractions in the rat plasma was negatively correlated (p < 0.01) with hepatic DHA, but also with unsaturated myristic and palmitic acid respectively. It has been concluded that regarding the similarity of the plasma lipid levels to humans, porcine model can be considered superior; however, using this model, dietary fish oil at the tested amount (2.5%) was not able to improve plasma lipid markers in comparison with saturated palm oil.     

Effect of dietary Schizochytrium microalga oil and fish oil on plasma cholesterol level in rats

The purpose of the study was to test the hypothesis that the dietary oils with different content of n‐3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) affect plasma lipid level in rats in a different degree. The diets with 6% of fish oil (FO) and Schizochytrium microalga oil (SchO; EPA+DHA content in the diets 9.5 + 12.3 and 2.6 + 29.5% of the sum of total fatty acids, respectively) were used; the diet with 6% of safflower oil (high content of n‐6 PUFA linoleic acid, 65.5%; EPA+DHA content 0.7 + 0.9%) was used as a control. The difference between FO and SchO was established only in the case of plasma triacylglycerol (TAG) level: plasma TAG of the FO‐fed rats did not differ from the control rats (p > 0.05), while SchO decreased (p < 0.05) plasma TAG to 46% of the control. On the other hand, FO and SchO decreased (p < 0.05) total plasma cholesterol (TC) in rats in the same extent, to 73% of the control. Regarding the underlying mechanisms for the TC decrease, both SchO and FO up‐regulated hepatic Insig‐1 gene (181 and 133% of the control; p < 0.05), which tended (p = 0.15 and p = 0.19 respectively) to decrease the amount of hepatic nSREBP‐2 protein (61 and 66% of the control). However, neither SchO nor FO influenced hepatic 3‐hydroxy‐3‐methyl‐glutaryl‐CoA reductase gene expression (p > 0.05); SchO (but not FO) increased (p < 0.05) low‐density lipoprotein receptor mRNA in the liver. It was concluded that the decrease of total plasma cholesterol might be caused by an increased cholesterol uptake from plasma into the cells (in the case of SchO), but also by other (in the present study not tested) mechanisms.     

Effects of different sulphur amino acids and dietary electrolyte balance levels on performance,jejunal morphology,and immunocompetence of broiler chicks

As alterations of dietary electrolyte balance (DEB) can influence amino acid metabolism via changes the ions incur in their configurations, performance and immunological responses of broiler chicks might be affected. So, the current study was carried out to investigate the effects of different levels of sulphur amino acids (SAA) and DEB on performance, jejunal morphology and immunocompetence of broiler chicks. A total of 360 1‐day‐old male Ross 308 broiler chicks were randomly assigned to nine experimental treatments with four replicates of 10 birds each. Experimental treatments consisted of three levels of SAA (100, 110, and 120% of NRC recommendation, provided by methionine supplementation in diets with the same cysteine level) and three levels of DEB (150, 250, and 350 mEq/kg) that were fed during the entire of trial in a 3 × 3 factorial arrangement. Results showed that the relative weights of intestine and abdominal fat were decreased markedly (p < 0.001) with increasing levels of SAA and DEB respectively. Antibody titre against sheep red blood cell was neither individually nor in combination influenced by supplementation of SAA or DEB. Nevertheless, a decrease in DEB level led to a suppression in heterophile (p < 0.05) and an increase in lymphocyte counts (p = 0.06); consequently, heterophile to lymphocyte ratio was significantly decreased (p < 0.05) by decremental levels of DEB. Albumin to globulin ratio was increased after inclusion of at least 10% SAA (p < 0.001) and 150 mEq DEB/kg in the diet (p = 0.11). Although feeding high‐DEB level led to a remarkable decrease in villus height (p < 0.01) and goblet cell numbers (p < 0.001), supplementing the highest level of SAA improved the height of jejunal villus. During the entire trial period, average daily feed intake (ADFI) was increased by incremental SAA levels (p < 0.05). However, inclusion of 150 mEq/kg led to not only a remarkable increase (p < 0.0001) in both ADFI and average daily weight gain (ADWG) but also to improved (p < 0.001) feed conversion ratio (FCR) both during the growing and over the entire trial periods. The present findings indicated that inclusion of low DEB decreased the heterophile to lymphocyte ratio and improved both the albumin to globulin ratio and intestinal health indices. The best growth performance was obtained with 150 mEq DEB/kg in the diet for each level of SAA.     

Leucine alone or in combination with glutamic acid,but not with arginine,increases biceps femoris muscle and alters muscle AA transport and concentrations in fattening pigs

Forty‐eight Duroc × Large White × Landrace pigs with an average initial body weight of 77.09 ± 1.37 kg were used to investigate the effects of combination of leucine (Leu) with arginine (Arg) or glutamic acid (Glu) on muscle growth, free amino acid profiles, expression levels of amino acid transporters and growth‐related genes in skeletal muscle. The animals were randomly assigned to one of the four treatment groups (12 pigs/group, castrated male:female = 1:1). The pigs in the control group were fed a basal diet (13% Crude Protein), and those in the experimental groups were fed the basal diet supplemented with 1.00% Leu (L group), 1.00% Leu + 1.00% Arg (LA group) or 1.00% Leu + 1.00% Glu (LG group). The experiment lasted for 60 days. Results showed an increase (p < 0.05) in biceps femoris (BF) muscle weight in the L group and LG group relative to the basal diet group. In longissimus dorsi (LD) muscle, Lys, taurine and total essential amino acid concentration increased in the LG group relative to the basal diet group (p < 0.05). In LG group, Glu and carnosine concentrations increased (p < 0.05) in the BF muscle, when compared to the basal diet group. The Leu and Lys concentrations of BF muscle were lower in the LA group than that in the L group (p < 0.05). A positive association was found between BF muscle weight and Leu concentration (p < 0.05). The LG group presented higher (p < 0.05) mRNA levels of ASCT2, LAT1, PAT2, SANT2 and TAT1 in LD muscle than those in the basal diet group. The mRNA levels of PAT2 and MyoD in BF muscle were upregulated (p < 0.05) in the LG group, compared with those in the basal diet group. In conclusion, Leu alone or in combination with Glu is benefit for biceps femoris muscle growth in fattening pig.     

Short‐term methionine supplementation during the early post‐partum period in primiparous rabbits improves prolificacy associated with an increase in serum concentrations of IGF‐I

The aim of this study was to evaluate the effects of methionine supplementation on energy metabolism and reproductive performance during the early post‐partum period in primiparous does. Forty nulliparous New Zealand White does were used. Females were randomized in two groups at calving: the control group (n = 20) was fed with the basal diet, and the methionine group (n = 20) was fed the basal diet plus 1 g/animal/day of methionine from the day of calving to 4 days post‐partum. Results showed that methionine supplementation increased (p = 0.032) the concentration of insulin‐like growth factor‐1 with respect to control group 4 days post‐partum. It similarly increased the prolificacy (p = 0.03), the number of kits born alive per litter (p = 0.06) and the body gain weight of the litter during supplementation (p = 0.035). These results were observed despite the does in the methionine group having a deeper negative energy balance than the does in the control group. Finally, methionine supplementation did not affect receptivity (p = 0.23), fertility (p = 0.49), the number of kits born dead per litter (p = 0.86) insulin and metabolites as glucose, non‐esterified fatty acids and triglycerides. In conclusion, our results show that methionine supplementation during the first 4 days of the post‐partum period in rabbits increases total litter size and the corporal weight of kits and is associated with an increase in blood concentration of IGF‐1.     

Effects of dietary supplementation with betaine on muscle growth,muscle amino acid contents and meat quality in Cherry Valley ducks

The effects of dietary betaine supplementation on growth performance, carcass characteristics, muscle amino acid contents, meat quality, antioxidant capacity, myogenic gene expression and mechanistic target of rapamycin (mTOR) signalling pathway in Cherry Valley ducks were evaluated. A total of 720 1‐day‐old Cherry Valley ducks were randomly distributed into four groups with six replicates of 30 birds for a 42‐day feeding trial. Ducks were fed a basal diet supplemented with 0 (control), 250, 500 or 1,000 mg/kg betaine, respectively. Growth performance was not affected by betaine. Incremental levels of betaine linearly (p < 0.05) increased the breast muscle yield and linearly (p < 0.05) decreased the subcutaneous fat thickness and the abdominal fat yield. The contents of methionine, serine, glycine, glutamate and total non‐essential amino acid in breast muscle were linearly (p < 0.05) increased by betaine supplementation. With increasing betaine levels, the drip loss and the content of malondialdehyde (MDA) were linearly (p < 0.05) decreased, and the redness of meat (linear p < 0.05), the activities of catalase (CAT) (linear p < 0.05) and total superoxide dismutase (T‐SOD) (linear p < 0.05, quadratic p < 0.05) were increased. Moreover, the myogenic differentiation factor 1 (MyoD1) mRNA expression and the mTOR mRNA expression and protein phosporylation were linearly (p < 0.05) up‐regulated, and the myostatin (MSTN) mRNA expression was linearly (p < 0.05) down‐regulated by betaine supplementation. Overall, this study indicated that betaine supplementation did not affect the growth performance of Cherry Valley ducks, but could linearly increase some amino acid contents in breast muscle, especially glycine, and increase muscle antioxidant activity to improve meat quality. Moreover, betaine supplementation could improve the breast muscle yield by increasing MyoD1 mRNA expression, decreasing MSTN mRNA expression and regulating mTOR signalling pathway.     

Chemical composition and some anti-nutrient content of raw and processed bitter vetch (<Emphasis Type="Italic">Vicia ervilia</Emphasis>) seed for use as feeding stuff in poultry diet

An experiment was conducted to determine chemical composition of raw and treated bitter vetch seed for use in poultry diets. Processing methods were: soaked in water for 12 h, then autoclaved and dried (SA); coarsely ground, soaked in water for 24 h, autoclaved and dried (GSA); coarsely ground, soaked in water for 47 h with exchange of water every 12 h, cooked and dried (GSC); coarsely ground, soaked in solution of 1% acetic acid for 24 h at 60°C and dried (GAA). Raw bitter vetch seed was contained 94.52, 26.56, 0.4, 58.86, 3.38, 5.32, 12.28 and 14.20 percent DM, CP, EE, NFE, Ash, CF, ADF and NDF, respectively. Its GE, AME, AMEn, TME and TMEn values were 18.10, 13.15, 14.38, 14.10 and 14.69 MJ/kg, respectively. Results indicated that bitter vetch is a good source of Fe (340 ppm) and Cu (46.7 ppm). It s amino acid profile was suitable and methionine was the first limiting amino acid when compared with broiler and layer chicks requirements. Its canavanine and tannin content were 0.78 and 6.7 mg/kgDM, respectively. Processing methods improved CP and in some cases AMEn. All processing methods especially GSC resulted in a significant (P < 0.05) reduction in canavanine and tannin.     

Effect of dietary threonine on laying performance and intestinal immunity of laying hens fed low‐crude‐protein diets during the peak production period

Threonine (Thr) may be a limiting amino acid for laying hens fed diets with lowered protein level. An experiment was conducted to examine laying performance, and the intestinal immune function of laying hens provided diets varying in digestible Thr levels. Lohmann Brown laying hens (n = 480), 28 weeks of age, were allocated to six dietary treatments, each of which included five replicates of 16 hens. Dietary crude protein (CP) 16.18% diet was offered as the positive control diet. L‐Thr was added to the negative diet (14.16% CP) by 0, 1.0, 2.0, 3.0 and 4.0 g/kg, corresponding 0.44%, 0.43%, 0.49%, 0.57%, 0.66% and 0.74% digestible Thr. At 40 weeks, a reduction in CP level decreased laying performance (p < 0.05). In the low CP, increasing dietary Thr increased (p < 0.05) egg production and egg mass and rose to a plateau between 0.57% and 0.66%. The hens fed 0.66% Thr showed the lowest value (p < 0.05) of feed conversion ratio (FCR). Serum level of uric acid showed the lowest values (p < 0.05) at 0.57–0.66%. In addition, serum‐free Thr maximized (p < 0.05) between 0.66% and 0.74%. Digestive trypsin activity decreased (p < 0.05) when hens fed the low‐CP diet compared with hens fed CP (16.18%) and hens fed 0.57–0.66%. Expressions of ileal MUC2 mRNA maximized (p < 0.05) at 0.66% Thr. Occludin mRNA increased with increasing Thr level (p < 0.05). sIgA mRNA reached to the maximum level (p < 0.05) at 0.66% and 0.74% Thr. INF‐γ mRNA reached to the lowest level (p < 0.05) at 0.65%. Expressions of ileal IL‐2, IL‐6, IL‐1β mRNA decreased with increasing Thr level (p < 0.05). In conclusion, Thr supplementation resulting in optimal laying performance and stimulated the mucosal immune system, suggesting that it is a limiting amino acid in the low‐crude‐protein diet of laying hens during the peak production period.     

High levels of whole raw soybean in diets for Nellore bulls in feedlot: effect on growth performance,carcass traits and meat quality

The objective of this study was to evaluate the effect of whole raw soybean (WRS) in the finishing diet of Nellore cattle on productive performance, carcass traits, meat quality, fatty acid profile of meat, and blood parameters. In a completely randomized design, 52 Nellore bulls (mean body weight ± SD: 380 ± 34 kg) were allotted for 84 days. The animals received the following diets with a forage: concentrate ratio of 40/60: (i) WRS0: control diet without soybean grains; (ii) WRS8: diet containing 8% WRS in dry matter basis; (iii) WRS16: diet containing 16% WRS, and (iv) WRS24: diet containing 24% WRS. At intervals of 28 days, the animals were weighed, muscle and adipose tissue was analysed by ultrasound, and blood samples were collected. The animals were slaughtered on day 85 and liver weight and hot carcass weight were measured during slaughter. The pH and carcass dressing were calculated at 24 h after slaughter. Longissimus dorsi muscle samples were collected for the determination of fatty acid profile of meat, ether extract, tenderness and sensory analysis of meat aged for 14 days. Blood cholesterol content increased linearly with increasing proportion of whole raw soybean grains. The diet did not affect performance or carcass attributes. The WRS8 had the highest shear force values. In fatty acid profile, C14:0 decreased (p = 0.05), whereas 16:1, 20:0 and 20:1 fatty acids increased linearly with increasing proportion of WRS (p < 0.05). However, concentration of conjugated linoleic acid cis 9, trans 11 and 17:0 increased with WRS24 and WRS16. In the sensory analysis, WRS24 was more tender with respect to the other treatments (p < 0.05). Finally, the inclusion of WRS in the finishing diet of feedlot Nellore bulls only evidenced little changes in fatty acid profile and tenderness, in animals fed diets containing 16 or 24% soybean.     

The effect of grapeseed oil on performance,rumen fermentation,antioxidant status and subcutaneous adipose fatty acid profile in lambs

This experiment was carried out to examine the effect of grapeseed oil (GSO) on performance, rumen fermentation, antioxidant status and subcutaneous adipose fatty acid (FA) profile in lambs. Eighteen Baluchi lambs, 196 ± 14 days of age and 39.8 ± 1.7 kg body weight, were randomly assigned to three experimental diets: (i) diet without GSO (control), (ii) diet containing 2% of GSO (GSO2) and (iii) diet containing 4% of GSO (GSO4) for 42 days. Results showed that the experimental diets had no significant effect on dry matter intake and performance (p > 0.05). The supplemented diets with GSO had no effect on pH and NH₃‐N of rumen fluid (p > 0.05), but GSO4 increased (p = 0.003) the concentration of propionic acid and reduced (p = 0.002) the concentration of acetate acid compared to the control. Inclusion 4% of GSO to the diet increased total antioxidant activity and decreased malondialdehyde in serum and muscle (p < 0.001). The level of blood glutathione peroxidase in diets containing GSO was higher than control diet (p = 0.02), but diets had no effect on superoxide dismutase in blood and muscle tissues (p > 0.05). The concentration of vaccenic acid, rumenic acid and linoleic acid and thus polyunsaturated fatty acid in subcutaneous fat was affected by experimental diets (p < 0.001), as control had the lowest amount of these FAs and GSO4 had the highest amount of them. Therefore, it can be concluded that the use of GSO up to 4% improves the antioxidant status and adipose fatty acid profile in lambs without effects on performance.     

Effect of dietary Schizochytrium microalga oil on selected markers of low‐grade inflammation in rats

The objective of the present study was to evaluate a potential of Schizochytrium microalga oil to alleviate possible negative effects of high‐fat‐high‐energy diets. Forty adult male rats (Wistar Albino) were fed 7 weeks the diet containing beef tallow + evaporated sweetened milk (diet T) intended to cause mild obesity and low‐grade systemic inflammation. Consequently, the animals were divided into four groups by 10 animals each and fed either the T‐diet (control) or the diet containing 6% of safflower oil (S), 6% of fish oil (F) and 6% of Schizochytrium microalga oil (A), respectively, for another 7 weeks. The A‐diet decreased (p < 0.05) live weight to 86% and glycaemia to 85% of control, respectively; an effect of the S‐ and F‐diet on these markers was insignificant (p > 0.05). In comparison with control, higher (p < 0.05) deposition of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) in the epididymal adipose tissue (EAT) of the A‐rats correlated with increased (p < 0.05) plasma adiponectin concentration, but it was without the effect (p > 0.05) on cellular adiponectin content in the EAT. Higher (p < 0.05) EPA+DHA deposition in the liver of the A‐rats correlated with higher expression (149% of control; p < 0.05) of the gene coding for peroxisome proliferator‐activated receptor gamma, and with lower expression (82% and 66%; p < 0.05) of the genes coding for adiponectin receptors AdipoR1 and AdipoR2; no relationship to the expression of receptor GPR120 was found. The A‐diet did not affect amount of the nuclear fraction of the nuclear factor kappa B in the liver, but increased plasma level of anti‐inflammatory cytokine TGF‐β1 (p < 0.05). The presented data agree with results of other in vivo rodent and human studies, but not with literature data regarding in vitro experiments: it can be concluded that the effects of dietary oils on inflammatory markers need further investigation.     

Effects of high peanut meal with different crude protein level supplemented with amino acids on performance,carcass traits and nitrogen retention of Chinese Yellow broilers

This study assessed the effects of feeding high peanut meal diets of reduced crude protein (CP) content supplemented with essential amino acids (EAA) on growth performance, carcass traits, biochemical indices in plasma, and nitrogen (N) retention of male and female Lingnan Yellow broilers from day 22 to day 42 of age. Each of four dietary treatments (19%, 18%, 17% or 16% CP, dietary CP level reduced by the reduced dietary peanut meal) contained six replicate pens with 35 birds of each sex (males and females with equal number), separately (1680 in total). The three diets with reduced CP were supplemented with 5 EAA to meet the requirements and provide the same levels as in the 19% CP diet. Average daily gain decreased and feed:gain ratio was worse in both sexes with reduced CP% (linear, p < 0.05). Dressing percentage increased as CP% decreased in males (linear, p < 0.05) and thigh muscle percentage reduced slightly in females (linear, p < 0.05). Abdominal fat percentage of males fed the 17% CP was the lowest (quadratic, p < 0.05). The plasma metabolic indices, concentrations of triglycerides and malondialdehyde, showed linear responses to reduced CP% (p < 0.05) with triglycerides increasing while malondialdehyde decreased. Plasma uric acid increased in females (linear, p < 0.05), but not in males, as CP% decreased. Efficiency of N retention increased and N excretion strikingly decreased with lower CP diets (p < 0.001), and both variables showed significant (p < 0.05) linear and quadratic effects. It is concluded that there was a limit to which dietary CP of broilers could be reduced without adverse effects. Dietary CP could be reduced to 17% for males and 18% for females (or 18% when fed together) between day 22 and day 42, if diets are supplemented with synthetic EAA.     

Effects of supplementation with green tea by‐products on growth performance,meat quality,blood metabolites and immune cell proliferation in goats

Forty‐eight castrated male goats were used to determine the effects of feeding green tea by‐products (GTB) on growth performance, meat quality, blood metabolites and immune cell proliferation. Experimental treatments consisted of basal diets supplemented with four levels of GTB (0%, 0.5%, 1.0% or 2.0%). Four replicate pens were assigned to each treatment with three goats per replicate. Increasing dietary GTB tended to linearly increase the overall average weight gain and feed intake (p = 0.09). Water holding capacity, pH and sensory attributes of meat were not affected by GTB supplementation, while cooking loss was reduced both linearly and quadratically (p < 0.01). The redness (linear; p = 0.02, quadratic; p < 0.01) and yellowness (quadratic; p < 0.01) values of goat meat were improved by GTB supplementation. Increasing dietary GTB quadratically increased protein and decreased crude fat (p < 0.05), while linearly decreased cholesterol (p = 0.03) content of goat meat. The proportions of monounsaturated fatty acid, polyunsaturated fatty acid (PUFA) and n‐6 PUFA increased linearly (p < 0.01) and n‐3 PUFA increased quadratically (p < 0.05) as GTB increased in diets. Increasing dietary GTB linearly increased the PUFA/SFA (saturated fatty acid) and tended to linearly and quadratically increase (p ≤ 0.10) the n‐6/n‐3 ratio. The thiobarbituric acid‐reactive substances values of meat were lower in the 2.0% GTB‐supplemented group in all storage periods (p < 0.05). Dietary GTB linearly decreased plasma glucose and cholesterol (p < 0.01) and quadratically decreased urea nitrogen concentrations (p = 0.001). The growth of spleen cells incubated in concanavalin A and lipopolysaccharides medium increased significantly (p < 0.05) in response to GTB supplementation. Our results suggest that GTB may positively affect the growth performance, meat quality, blood metabolites and immune cell proliferation when supplemented as a feed additive in goat diet.     

Effects of dietary substitution of zinc‐methionine for inorganic zinc sources on growth performance,tissue zinc accumulation and some blood parameters in broiler chicks

This study was designed to evaluate the effects of dietary inclusion of zinc‐methionine (ZnMet) as a replacement for conventional inorganic zinc sources on performance, tissue zinc accumulation and some plasma indices in broiler chicks. A total of 450‐day‐old Ross male broiler chicks were randomly assigned to five pen replicates of nine experimental diets. Dietary treatments consisted of two basal diets supplemented with 40 mg/kg added Zn as feed‐grade Zn sulphate or Zn oxide in which, Zn was replaced with that supplied from ZnMet complex by 25, 50, 75 or 100%. At 42 days of age, three randomly selected birds from each pen were bled to measure plasma metabolites; then, the chicks were slaughtered to evaluate carcass characteristics. Results showed that dietary treatments affected (p < 0.05) feed intake during the starter period, and chicks on Zn oxide diets consumed more feed than sulphate counterparts. Furthermore, dietary substitution of inorganic Zn sources by ZnMet caused improvements (p < 0.01) in body weight gain during all experimental periods. Dietary supplementation of ZnMet improved feed conversion efficiency during 1–21 and 1–42, but not in 21–42 days of age. Complete replacement of inorganic Zn by that supplied from ZnMet caused an increase (p < 0.05) in relative liver weight. Similarly, dietary inclusion of ZnMet increased breast meat and carcass yields and reduced abdominal fat percentage (p < 0.05). Incremental levels of ZnMet increased (p < 0.05) zinc concentrations in liver and thymus, and the highest zinc accumulations were seen in 100% ZnMet‐supplemented birds. Interestingly, introduction of ZnMet into the diets partially in place of inorganic sources resulted in decreases (p < 0.01) in plasma uric acid and triglycerides concentrations. The present findings indicated that dietary ZnMet inclusion in replacement of inorganic sources in addition to improving growth performance, reduced plasma uric acid and triglycerides concentrations, consequently decreased abdominal fat pad and increased carcass meat yield.     

Regulation of free glutamate content in meat by dietary lysine in broilers

Regulation of taste is important for improving meat quality and glutamate (Glu) is one of the important taste‐active components in meat. Here, the effects of dietary lysine (Lys) content on taste‐active components in meat, especially free Glu, were investigated. Fourteen‐day‐old broiler chicks (Gallus gallus) were fed on diets containing 100% or 150% of the recommended Lys content for 10 days. Concentrations of free amino acids in plasma, muscle and liver were measured. The levels of messenger RNAs (mRNAs) for enzymes related to Glu metabolism were determined in muscle and liver. The concentration of muscle metabolites was also determined. The free Glu content in muscle of chicks fed the Lys150% diet was increased by 44.0% compared with that in chicks fed the Lys100% diet (P < 0.01). The mRNA level of lysine α‐ketoglutarate reductase, which is involved in Lys degradation and Glu production, was significantly increased (P < 0.05) in the Lys150% group. Metabolome analysis showed that the Lys degradation products, muscular saccharopine, pipecolic acid and α‐aminoadipic acid, were increased in the Lys150% group. Our results suggest that free Glu content in muscle is regulated by Lys degradation. These results suggest that a short‐term feeding of high‐Lys diet could improve the taste of meat.     

Effects of Dietary Supplementation of β‐hydroxy‐β‐methylbutyrate on Sow Performance and mRNA Expression of Myogenic Markers in Skeletal Muscle of Neonatal Piglets

The effects of dietary β‐hydroxy‐β‐methylbutyrate (HMB) supplementation during gestation on reproductive performance of sows and the mRNA expression of myogenic markers in skeletal muscle of neonatal pigs were determined. At day 35 of gestation, a total of 20 sows (Landrace × Yorkshire, at third parity) were randomly assigned to two groups, with each group receiving either a basal diet or the same diet supplemented with 4 g/day β‐hydroxy‐β‐methylbutyrate calcium (HMB‐Ca) until parturition. At parturition, the total and live litter size were not markedly different between treatments, however, the sows fed HMB diet had a decreased rate of stillborn piglets compared with the sows fed the control (CON) diets (p < 0.05). In addition, piglets from the sows fed HMB diet tended to have an increased birth weight (p = 0.08), and a reduced rate of low birth weight piglets (p = 0.05) compared with piglets from the CON sows. Nevertheless, lower feed intake during lactation was observed in the sows fed the HMB diet compared with those on the CON diet (p < 0.01). The relative weights of the longissimus dorsi (LD) and semitendinosus (ST) muscle were higher (p < 0.05) in neonatal pigs from the HMB than the CON sows. Furthermore, maternal HMB treatment increased the mRNA levels of the myogenic genes, including muscle regulatory factor‐4 (MRF4, p < 0.05), myogenic differentiation factor (MyoD) and insulin‐like growth factor‐1 (IGF‐1, p < 0.01). In conclusion, dietary HMB supplementation to sows at 4 g/day from day 35 of gestation to term significantly improves pregnancy outcomes and increases the expression of myogenic genes in skeletal muscle of neonatal piglets, but reduces feed intake of sows during lactation.     

Effects of feeding different levels of corn steep liquor on the performance of fattening lambs

This study was conducted to assess the effect of feeding corn steep liquor (CSL) on in vivo digestibility, ruminal pH, ammonia and hydrolytic enzyme activities, blood metabolites, feed intake (FI) and growth performance in fattening lambs. The CSL is a by‐product of wet milling process of maize starch industry. The crude protein (CP), rumen‐degradable protein (RDP), lactic acid and metabolisable energy contents of this by‐product were 420, 324, 200 g/kg dry matter (DM) and 12.6 MJ/kg DM respectively. Twenty‐seven male Moghani lambs were assigned randomly into three groups of nine lambs each in a completely randomised design. Three iso‐energetic and iso‐nitrogenous diets containing different levels (0, 50 or 100 g/kg dry matter) of CSL were offered ad libitum three times a day. Forage to concentrate ratio of the diets was 30:70. With inclusion of CSL in diet, the contents of canola meal, fish meal, wheat bran, corn grain and sugar beet pulp were decreased. The contents of DM, ash‐free neutral detergent fibre (NDFom), ether extract, starch, Ca and S were numerically lower, but soluble protein, RDP and non‐fibre carbohydrates were greater in the diets containing CSL in comparison with the control diet. The lambs fed with the diets containing CSL had lower [linear (L), p < 0.06] digestibility coefficients of DM and NDFom as compared to those fed with the diet free of CSL. Ruminal ammonia‐N concentration increased (L, p < 0.05), but pH decreased (L, p < 0.05) with raising CSL level in diet. Carboxymethyl cellulase and filter paper‐degrading activities decreased (L, p < 0.05), while proteases activity increased (L, p < 0.05) as dietary rates of CSL increased. Microcrystalline cellulase and ɑ‐amylase activities were similar among the treatments. Within blood metabolites, only urea‐N concentration increased (L, p < 0.05) in the lambs receiving CSL as compared to those fed with diet without CSL. Dietary inclusion of CSL resulted in linear decreases (L, p < 0.05) in the intakes of DM, organic matter, CP, NDFom and ash‐free acid detergent fibre, and average daily gain. However, the feed conversion ratio was similar among the experimental animals. Overall, feeding CSL up to 100 g/kg diet DM in lamb resulted in reductions of rumen fibrolytic microbial enzyme activities, in vivo digestibility, FI and growth performance, but rumen proteases activity increased.     

Effects of dietary methionine source on productive performance, blood chemical, and hematological profiles in broiler chickens under tropical conditions

This study was conducted to investigate the effects of supplementation of dl-methionine (DLM) and liquid dl-methionine hydroxy analog free acid (MHA) in diets on productive performance, blood chemical, and hematological profiles in broiler chickens under tropical conditions. In all, 216 commercial male broiler chicks were used to compare two dietary methionine sources, DLM and MHA. Chicks were raised for 35 days in battery cages situated in high ambient temperature and relative humidity open-side housing. The chicks were divided into three treatments in six replications with 12 chicks each. A completely randomized design was used. The treatment groups were (1) control group (methionine and total sulfur amino acid deficient diet), (2) supplementation of DLM as the methionine source in diet, and (3) supplementation of MHA as the methionine source in diet. The productive performance of DLM and MHA was not significantly different. Both supplementation of DLM and MHA significantly improved final body weight, body weight gain, average daily gain, and feed conversion ratio when compared to the control group (P?<?0.01). Both DLM and MHA supplementation significantly increased the plasma cystine concentration level (P?<?0.05). The use of DLM enhanced the plasma methionine concentration (P?<?0.01) and increased the heterophil/lymphocyte ratio (P?<?0.05). While MHA elevated the plasma taurine and uric acid concentration levels (P?<?0.05). In conclusion, under tropical conditions, there was no significant difference between DLM and MHA supplementation on productive performance; plasma methionine concentration was increased by DLM supplementation, while plasma taurine and uric acid concentration were significantly increased by MHA supplementation.