Effects of emulsifier, betaine, and L-carnitine on growth performance, immune response, gut morphology, and nutrient digestibility in broiler chickens exposed to cyclic heat stress.

1. This experiment investigated the efficacy of varying doses of an emulsifier blend (EB; 0 and 1 g/kg of diet), betaine (BT; 0 and 1 g/kg of diet) and L-carnitine (CT; 0 and 0.5 g/kg of diet) in broilers subjected to circular heat stress (HS) conditions. A total of 1080 one-day-old male broiler chickens (Ross 308) were randomly assigned to one of nine treatment groups (six pens/treatment with 20 birds/pen) according to a completely randomised design. The thermoneutral control broiler chickens were housed at a comfortable temperature and fed a standard diet (no additives). The other eight groups were exposed to cyclic HS conditions (34°C) for 8 h (10:00-18:00).2. There were EB × BT × CT interactions for body weight (BW) at 24 d (P = 0.038) and average daily gain (ADG) during the 10-24 d period (P = 0.049), with the greatest values found with concurrent supplementation of three supplements.3. Inclusion of EB resulted in greater (P < 0.05) BW, ADG, European performance index, uniformity rate, primary antibody titres against sheep red blood cells (SRBC), duodenal villus height (VH) and villus surface area, digestible energy (DE) and the coefficient of apparent ileal digestibility (CAID) of dry matter, crude protein, and fat However, feed conversion ratio, mortality rate and heterophile to lymphocyte ratio were lower (P < 0.05).4. Dietary BT supplementation improved (P < 0.05) all performance indicators, primary antibody titres against SRBC and Newcastle disease virus, serum total antioxidant capacity, duodenal VH, Jejunal VH/crypt depth and the CAID of dry matter and crude protein. The effect of dietary supplementation with CT was limited to an increase (P < 0.05) in ADG (d 10-24) and a decrease (P < 0.05) in serum malondialdehyde concentration (42 d) and jejunal crypt depth (42 d).5. In conclusion, dietary supplementation of either EB or BT alone or in combination ameliorated some of the detrimental effects of HS on growth performance, immunity and intestinal health in broilers, while a minor positive effect on performance and antioxidant status was observed with CT supplementation.

Effect of chelated source of additional zinc and selenium on performance, yolk fatty acid composition, and oxidative stability in laying hens fed with oxidised oil.

1. The following study determined whether the effects of the combined addition of zinc amino acid complex (ZA) and selenomethionine (SM) was superior to their single addition in controlling the oxidative stress induced by dietary oxidised fat in laying hens.2. Two hundred and forty 32-week-old laying hens were divided into the following dietary treatments (each consisting of six replicates of eight birds): 1) a fresh soy oil (FSO) diet; 2) an oxidised soy oil (OSO) diet; 3) an OSO diet plus 20 mg zinc as ZA/kg (OSO+ZA); 4) an OSO diet plus 0.2 mg selenium as SM/kg (OSO+SM); and 5) an OSO diet plus ZA and SM (OSO+ZA+SM).3. After 10 weeks of feeding hens, feed intake, egg production, and egg mass in the OSO+ZA+SM group were similar to the FSO group but better (P < 0.05) than those in the OSO group. Shell thickness and shell breaking strength were significantly improved by the OSO+ZA and OSO+ZA+SM treatments.4. Increases in the yolk concentrations of palmitic acid and total saturated fatty acids (SFA), and decreases in yolk linoleic acid, n-6 polyunsaturated fatty acids (PUFA), total PUFA, and PUFA/SFA ratio were induced by dietary oxidised fat which were normalised (P < 0.05) by OSO+SM and OSO+ZA+SM.5. An increase (P < 0.05) in malondialdehyde and a decrease in 2,2-diphenyl-picrylhydrazyl radical scavenging activity in the yolk, induced by dietary oxidised fat, was significantly improved by all dietary supplementations, but only birds fed the OSO+ZA+SM diet exhibited similar values to those fed FSO.6. In conclusion, the simultaneous inclusion of organic zinc plus selenium in the oxidised fat diets was beneficial for improving egg-laying performance, yolk fatty acid profile, and oxidative stability, but not for internal egg quality, compared with either zinc or selenium alone in laying hens.

De-oiled soy lecithin positively influenced growth performance, nutrient digestibility, histological intestinal alteration, and antioxidant status in turkeys fed with low energy diets.

1. The purpose of this research was to investigate the effects of supplementing an emulsifier (de-oiled soybean lecithin (DSL)) in a low metabolisable energy (ME) diet on growth performance, nutrient digestibility, carcase characteristics, intestinal morphology, blood metabolites, and antioxidant status in growing turkeys.2. A total of 480 one-day-old turkeys were assigned to one of four dietary treatments with of eight replicates of 15 birds each. Experimental treatments included a basal diet (BE) with commercially recommended levels of ME, a reduced energy diet (RE) with 0.42 MJ/kg reduction in dietary ME content, the RE diet + 1 g/kg DSL (DSL-1), and RE + 2 g/kg DSL (DSL-2).3. After 112 days, the body weight, average daily gain, and feed:gain in turkeys fed the supplemented for BE diets were better (P < 0.05) than in those fed RE, and those fed diet DSL-2 had the best performance. Although the RE diet decreased abdominal fat and relative liver weight (P < 0.05), compared to the BE diet, and supplementation with either level of DSL did not influence these variables.4. There were linear increases (P < 0.05) in fat digestibility, nitrogen-corrected apparent ME, and duodenal villus height, villus height/crypt depth ratio, and villus surface area in LE diet supplemented with DSL. From the jejunal morphology, crypt depth was decreased by DSL-supplemented diets (P < 0.05).5. Serum triglyceride, total cholesterol, and malondialdehyde concentrations were lower, whereas the serum superoxide dismutase activity was greater for the DSL-2 group compared to the BE and RE groups (P < 0.05).6. The findings suggested that, while low-ME diets impaired turkey growth performance, dietary supplementation of DSL could reverse such impacts of these diets. The DSL-supplemented diet at the inclusion level of 2 g/kg was advantageous over both BE and RE diets in terms of intestinal morphology, lipid profile, and antioxidant status in growing turkeys.

Nutritional value of whole date waste and evaluating its application in ostrich diets.

Although date waste products have been used as an alternative feed source in the diets of poultry for a long time, there is no quantitative information available regarding date waste used in ostrich diets. Therefore, two experiments were performed to evaluate the feeding value of whole date waste (WDW) as a feed ingredient in ostrich diets. In the first experiment, apparent metabolizable energy corrected to zero nitrogen balance (AMEn) of WDW was determined using 12 young ostriches (6 months old). The treatments included a reference diet and a test diet consisting of 60% of the reference diet and 40% of WDW. The AMEn of the WDW determined by total collection was 3216 kcal/kg. In the second study, four groups of eight growing ostriches (seven month old), with almost similar BW (60.4 ± 1.6 kg), were individually housed in outdoor paddocks of ≈24 m2 and were tested from 7 to 9 months of age. The groups were fed four isocaloric (2420 kcal of AMEn/kg) and isonitrogenous (16.4% CP) diets containing 0, 10, 20, and 30% WDW. The results demonstrated that there were no significant differences among treatments in average daily feed intake, average daily gain, feed conversion ratio, and apparent total tract digestibility coefficients of DM, organic matter, energy, ether extract, ash, nitrogen-free extract, calcium, and phosphorus. In contrast, birds fed 0, 10, and 20% WDW diets had similar CP digestibility and this was significantly (P < 0.001) higher than that of birds on 30% WDW diet. The least crude fibre digestibility (P = 0.003) was also observed in birds fed 30% WDW diet. Blood RBC count, lymphocyte percentage, glucose concentration, and glutathione peroxidase activity increased linearly (P < 0.01), whereas heterophil percentage and heterophil-to-lymphocyte ratio decreased linearly (P = 0.002), in response to dietary inclusion of WDW. It can be concluded that WDW can be incorporated into the diets of ostrich chicks at levels of up to 30% without compromising growth performance. These results also suggest that WDW could be used as a feed ingredient for growing ostriches to improve stress-related variables and antioxidant status.

Identification of potential genomic regions for egg weight by a haplotype-based genome-wide association study using Bayesian methods.

1. Theoretically, haplotype blocks might be a more suitable alternative to SNP genotypes as they are usually better at capturing multi-allelic QTL effects, compared to individual SNP genotypes in genome-wide association studies. The objectives of this study were to identify genomic regions related to egg weight traits by Bayesian methods (BayesA, BayesB, and BayesN) that fit fixed-length haplotypes using GenSel software. 2. Genotypes at 294,705 SNPs, that were common on a 600K Affymetrix chip, were phased for an egg-laying hen population of 1,063 birds. Recorded traits included first egg weight (FEW) and average egg weight at 28, 36, 56, 66, 72 and 80 weeks of age. 2. Fitting 1Mb haplotypes from BayesB resulted in the highest proportion of genetic variance explained for the egg weight traits. Based on the trait, the genetic variance explained by each marker ranged from 27% to 76%. 3. Different haplotype windows associated with egg weight traits only explained a small percentage of the genetic variance. 4. The top one 1-Mb window on GGA1 explained approximately 4.05% of total genetic variance for the FEW. Candidate genes, including PRKAR2B, HMGA2, LEMD3, GRIP1, EHBP1, MAP3K7, and MYH were identified for egg weight traits. 5. Several genomic regions, potentially associated with egg weight traits, were identified, some of which overlapped with known genes and previously reported QTL regions for egg production traits.

Effect of synbiotic supplementation and dietary fat sources on broiler performance, serum lipids, muscle fatty acid profile and meat quality.

A 42-d trial was conducted to investigate the effect of adding a synbiotic supplement to diets containing two different types of fat on performance, blood lipids and fatty acid (FA) composition and oxidative stability of breast and thigh meat in broilers. A total of 800 one-d-old male broiler chickens were randomly assigned into 1 of 8 treatments with 4 replicates of 25 birds per treatment. The experiment consisted of a 4 × 2 factorial arrangement of treatments including 4 concentrations of synbiotic (0, 0.5, 1 or 1.5 g/kg diet) and 2 types of fat [sunflower oil (SO) or canola oil (CO)] at an inclusion rate of 50 g/kg diet. Dietary fat type did not affect body weight gain (BWG) or feed conversion ratio (FCR) during the overall experimental period (0-42 d). However, fat type modified serum lipid profile and FA composition and 2-thiobarbituric acid-reactive substances (TBARS) content in breast and thigh meat. The addition of synbiotic to the diet linearly improved overall BWG and FCR and also decreased serum cholesterol and low-density lipoprotein cholesterol concentrations. The TBARS value in thigh meat after 30 d of storage at 4°C was linearly decreased as the synbiotic inclusion concentrations in the diets increased. Dietary synbiotic also decreased the proportion of monounsaturated fatty acids and increased n-6 polyunsaturated fatty acid (PUFA) concentration in thigh meat, whereas the FA profile of breast meat was not affected by synbiotic supplementation. Moreover, the PUFA/SFA ratio in the breast meat was linearly increased when synbiotic was included in the CO-containing diets. In conclusion, the addition of synbiotic to broiler diets had a positive effect on growth performance, blood lipid profile and meat quality. The results also support the use of synbiotic to increase the capacity of canola oil for enhancing PUFA/SFA ratio of breast meat in broilers.

Comparative effects of using black seed (Nigella sativa), cumin seed (Cuminum cyminum), probiotic or prebiotic on growth performance, blood haematology and serum biochemistry of broiler chicks.

A 42-day trial was conducted to compare the effects of the following seven experimental diets, which varied in black seed, cumin seed, probiotic or prebiotic concentrations, on the broiler chicks: control (no additives), diet BS1 (4 g/kg black seed), diet BS2 (8 g/kg black seed), diet CS1 (4 g/kg cumin seed), diet CS2 (8 g/kg cumin seed), diet Pro (1 g/kg probiotic Primalac(®)) and diet Pre (2 g/kg prebiotic Fermacto(®)). A total of 420 1-day-old male broiler chicks, initially weighing an average of 43 g, were distributed into 28 floor pens at a stocking density of 15 birds per pen. At 28 day of age, the body weight in the birds fed diets BS2, CS2 and Pro was significantly higher than in the control group, but final body weight was not affected. Additionally, the birds fed diets BS2, Pro and Pre exhibited better feed conversion ratio than control birds from 0 to 42 day of age. Diets BS2, CS2 and Pro also statistically increased the relative weight of thymus and bursa of Fabricius, whereas only diet Pro decreased the abdominal fat percentage compared with control diet. Regarding the haematological parameters, feeding diet BS2 yielded a significant increase in red blood cell count, haemoglobin concentration and haematocrit percentage compared with control diet. Serum total cholesterol and low-density lipoprotein cholesterol levels in the birds fed diets BS2, Pro and Pre were also significantly lower than in the birds fed the control diet. Without exception, no diets affected feed intake, internal organs weights, carcass characteristics, antibody titres against Newcastle and influenza viruses and leucocyte subsets. In general, current study showed promising results regarding the use of spice additives as growth and health promoters, especially at higher levels of their incorporation in the diets, which were comparable to the probiotic- or prebiotic-containing diets.