Cold stress is a major environmental factor restricting the sustainable development of animal husbandry. To gain insight into the gene-regulation processes in broilers under cold stress, gene expression profiling was conducted using high-throughput Solexa sequencing of broiler liver tissue under cold stress conditions and control conditions. According to Solexa sequencing, we identified 255 genes whose expression levels differed between the treatment and control group. Under cold stress, 135 genes were up-regulated and 120 genes were down-regulated genes compared with levels in the control group. Moreover, 469 genes were expressed only in the control group, and 172 genes were expressed only in the treatment group. These data were confirmed by real-time quantitative PCR. Gene Ontology enrichment analysis showed that the differentially expressed genes (DEGs) were mainly enriched in material metabolism and immune functions. KEGG enrichment analysis showed that DEGs were enriched in pyruvate metabolism, glycolysis/gluconeogenesis, fatty acid metabolism，insulin signaling pathway and others. In conclusion, these results may serve as an important reference for broiler breeding and provide new clues for the elucidation of molecular mechanisms of cold stress.

The present work assessed the effect of supplementation of 0.8% dietary Arbocel^® RC Fine, a readily available commercial lignocellulose, to poultry feed. In a complete randomized design using 36 individually caged mature dubbed Hy-Line roosters (aged 55 weeks) grouped in 4 treatments with 9 birds per treatment, a digestibility trial was performed to determine apparent and true metabolizable energy values along with digestibility coefficients of protein and amino acid in Arbocel^® containing diets. Results showed that 0.8% Arbocel^® supplemented diets improved protein digestibility by 6% (P<0.05). Additionally, Arbocel^® caused an increase in apparent and true amino acid digestibility in roosters when compared to control diets and controls with 0.8% wheat bran (WB) supplementation. In a second experiment, 26,000 layers and 2,600 roosters aged 33 weeks (Ross 308 broiler breeder strain) were maintained in 6 poultry houses at a commercial breeding farm, with an average of 4330 layers and 433 roosters per house. Performance, egg grade, and hatchability rate were assessed over a post peak period of 6 months. Compared to the control group fed the 0.8% WB diet, the 0.8% lignocellulose dietary supplementation resulted in a decrease (P<0.05) in percent infertility leading to an average increase of 4.07% (P<0.05) in egg hatchability. The Arbocel^® fed group had 3.8 more eggs per housed hen compared to control birds. Overall, Arbocel^® supplementation at 0.8% resulted in the production of 5.7 more saleable chicks per housed hen during the 6 months trial, a sizeable profit to the farmer.

L-Aspartate (L-Asp), D-aspartate (D-Asp) or their chemical conjugates plays important physiological roles in regulating food intake, plasma metabolites and thermoregulation in animals. However, there are very few studies available in layers and no reports have been found in broilers. Broilers are very important commercial birds for meat production, so effects of L- or D-Asp in broilers would provide new physiological insight of this strain. Therefore, the purpose of this study was to determine the effect of oral administration of L- or D-Asp on feed intake, rectal temperature and some plasma metabolites in broiler chicks. Broiler chicks (5 days old) were orally administered with different doses (0, 3.75, 7.5 and 15 mmol/kg body weight) of L- or D-Asp. At 120 min after administration of L- or D-Asp, the blood was immediately collected through the jugular vein. The rectal temperature of chicks was measured at 30, 60 and 120 min after administration using a digital thermometer with an accuracy of ±0.1°C, by inserting the thermistor probe in the rectum to a depth of 2 cm. A repeated-measures two-way ANOVA was applied for the analysis of feed intake and rectal temperature. Plasma metabolites were statistically analyzed by one-way ANOVA and regression equations. The study showed that oral administration of both L- and D-Asp did not alter feed intake. However, D-Asp, but not L-Asp, dose-dependently decreased the rectal temperature in chicks. It was also found that D-Asp increased plasma glucose and decreased triacylglycerol concentrations. The changes in plasma metabolites further indicate that D-Asp treatment modulates the energy metabolism in broiler chicks. In conclusion, D-Asp may be a beneficial nutrient not only for layers but also for broilers, since orally administered D-Asp lowered rectal temperature without reducing feed intake.

A trial was conducted to investigate the effects of dietary mannan level and β-mannanase supplementation on egg production performance, nutrient retention and blood metabolites of laying hens. Two hundred and forty Hy-Line Brown layers (52 wk-old) were randomly allotted to 6 treatments on the basis of laying performance. Each treatment had 8 replicates with 5 birds (40 birds per treatment). Laying hens were fed low or high mannan diets containing 0, 0.4 or 0.8 g β-mannanase/kg diet in a 2×3 factorial arrangement during 56 d feeding period. Laying hens fed diets supplemented with high β-mannanase level had greater (P<0.05) overall egg production, egg weight, egg mass, retention of gross energy, crude protein and mannan than hens fed the diets without β-mannanase. Laying hens fed diets without β-mannanase or supplemented with high β-mannanase level had greater (P<0.05) retention of dry matter than hens fed diets with low β-mannanase level. Moreover, laying hens fed high mannan diets had higher (P<0.05) feed intake and feed conversion ratio than that of hens fed low mannan diets. Furthermore, laying hens fed diets supplemented with a high level of β-mannanase had increased serum glucose (P<0.05) concentrations but these diets had no effect on total cholesterol, total protein or blood urea nitrogen. The results obtained in the present study indicate that a high mannan content in diets had adverse effect on the performance of laying hens and that dietary supplementation with β-mannanase has the potential to improve laying hen performance and nutrient retention.

The aim of the present study was to investigate the effects of oregano, attapulgite, benzoic acid and their combination on broiler performance, microflora composition of jejunum and cecum, intestinal architecture and breast and thigh meat composition. A total of 400 one-day-old broiler chicks were used in a 42-day trial. They were randomly distributed into five treatments with four replicates of twenty chickens per pen: Control group; Attapulgite group; Oregano essential oil group; Benzoic acid group; Mixed group. At the end of the trial, total counts of bacteria, Enterobacteriaceae, Lactobacilli, and Clostridium perfringens were enumerated by real time PCR at both jejunum and cecum. Intestinal morphology was carried out in duodenum, jejunum and ileum, for villus height and crypt depth. Cell proliferation was also evaluated in the small intestine and the cecum. The results showed that oregano and benzoic acid improved some growth performance parameters. The combined use of the examined substances increased enterobacteria counts in the jejunum, and cell proliferation in the duodenum and the jejunum. Benzoic acid improved intestinal wall morphology in the ileum. In conclusion, the combined dietary supplementation with oregano, attapulgite and benzoic acid can be a novel tool to beneficially modulate broiler chickens performance.

This study aims at investigating the effects of different grain sources during pre-hatch (from diet of the breeders) and post-hatch (from the diet of broilers) on coloration (Roche color fan scores; L*, lightness; a*, redness; and b*, yellowness) as well as the growth performance in yellow-skinned chickens at market age (42 days old). In this experiment, six thousand yellow-skinned broiler breeders at 27 weeks were fed with a corn or sorghum and barley-based diet in which contained high (＋) or low (−) xanthophyll levels, respectively. After the beginning of the trial, from day 41 to 42, eggs from two treatments were collected to artificial incubation. In this trial, 2×2 factorial designs were used and male chicks hatched from breeders fed with a corn or sorghum-based diet. According to the results, it demonstrated that hens fed with a corn-base diet were observed an elevated coloration both in the eggs and newly-hatched chicks (p<0.05). The dietary pigments improved pigment deposition in the egg yolk and the tissue of newly-hatched chicks. Besides, there was no difference in growth performance attributed to dietary grain sources both from hens or chicks. There showed no difference of coloration in abdominal fat, shank or breast skin (or kept at 4°C for 24 hours and 7 days) between two breeder grain sources (p>0.05). However, abdominal fat, shank and breast skin from the broiler chicks fed with the corn-based diet had a significantly higher RFC scores, a* and b* value than that fed with the sorghum and barley-based diet. The current results indicated that the broiler dietary grain sources (different xanthophyll contents), other than the breeder dietary grain sources influenced the pigmentation in abdominal fat, shank and breast skin, and the skins stored at 4°C in broiler. Therefore, it can be suggested that a low xanthophyll-containing diet (sorghum and barley-based diet) might be applied in yellow-skinned broiler breeders without causing negative effects of coloration or growth performance on their offspring at market age.

Sixty broilers (initially 1.6 kg and 35 d-old) were used to determine the effect of Bacillus subtilis C14 and RX7 strains on growth performance, blood parameter, and intestinal microbiota in response to experimental challenge with Salmonell gallinarum. Broilers were distributed to 4 treatment groups include: C1 (control group; no challenge, no B. subtilis), C2 (Salmonella-challenged group; S. gallinarum 10⁸ cfu/bird), T1 (C2+supplemented with of B. subtilis C14 (1.0×10⁹ cfu/g) at 0.1% in diet) and T2 (C2+supplemented with of B. subtilis RX7 (1.0×10⁹ cfu/g) at 0.1% in diet). Results indicated that inclusion of B. subtilis (T1, T2) in the diet increased (P<0.05) the weight gain and feed intake, and improved feed conversion of challenged broilers compared with no B. subtilis supplementation diet (C2). Improvements (P<0.05) in the immunoglobulin A concentration were observed by the addition of B. subtilis compared with C2 treatment, whereas tumor necrosis factor-α was decreased (P<0.05). Latobacillus number in small and large intestines was higher (P<0.05) by B. subtilis additon than C2 treatment but Salmonella numbers were lower (P<0.05). The results suggested that dietary supplementation of B. subtilis C14 and RX7 improved the growth performance, and affected the blood profiles and intestinal microbiota of broilers against S. gallinarum infection. Therefore, B. subtilis C14 and RX7 may have beneficial effects, in relieving the stress of broilers infected with S. gallinarum.

Glycation is a chemical reaction in which reducing sugars bind non-enzymatically to compounds containing amino groups. Avian species like chickens are hyperglycemic animals and have high body temperature compared to mammalian species, which enables avian species to accelerate the glycation of proteins and amino acids with glucose. Although varying dietary crude protein (CP) levels alter plasma concentrations of proteins and amino acids, the influence of varying CP levels on the glycation of plasma proteins and amino acids has not been studied so far. In the present study, therefore, glycation of albumin, tryptophan and valine in the plasma of chickens fed diets with varying CP levels (0, 10, 20, 40 and 60%) was examined. At the end of the experimental period, blood samples were collected and plasma concentrations of glycoalbumin, glycated tryptophan (tryptophan-Amadori product and (1R, 3S) - 1 - (D - gluco - 1, 2, 3, 4, 5 - pentahydroxypentyl) - 1, 2, 3, 4 - tetrahydro - β - carboline - 3 - carboxylic acid (PHP-THβC)), and valine-Amadori product were measured. Although plasma albumin concentration was reduced along with the decrease in dietary CP levels from 20% to 0%, glycoalbumin in the plasma was increased under such dietary conditions. Similar increase in the ratios of tryptophan-Amadori product to tryptophan and valine-Amadori product to valine in the plasma of chickens fed a protein-free diet was observed. These results suggest that dietary protein deficiency might enhance the non-enzymatic glycation of plasma proteins and amino acids in chickens.

The expression of atrogin-1/MAFbx, a muscle-specific E3 ubiquitin ligase, is increased in catabolic conditions that result in muscle atrophy. The expression of atrogin-1/MAFbx mRNA is also decreased by the insulin-like growth factor-I (IGF-I) in mammalian skeletal muscle cell cultures. This study investigated the effect of IGF-I on the expression of atrogin-1/MAFbx in chicken skeletal muscle cell cultures. Chick myotubes were incubated with IGF-I for 1, 6, or 24 h. Protein content was increased by IGF-I (100 ng/ml) and incubated for 24 h in chick myotubes. The expression of atrogin-1/MAFbx mRNA decreased in the presence of IGF-I (1, 10, and 100 ng/ml) for 6 h in chick myotubes. The expression of the m-calpain large subunit and cathepsin B mRNA was not decreased by IGF-I. Phosphorylation of Akt and FOXO1 increased in the presence of IGF-I (100 ng/ml) for 1 h in chick myotubes. These results indicate that IGF-I suppresses atrogin-1/MAFbx mRNA expression by phosphorylation of Akt and FOXO1, resulting in an increase in muscle growth in chick myotube cultures.

Separating breast meat with low water-holding capacity, conformation parameters (thickness, volume, bottom sarea, and perimeter), and color of chicken breast meat were measured by direct measurement and by imaging analysis with a digital camera. Samples were obtained from a production line. The L* value was used to separate the samples by three characteristics designating the quality of the meat: dark-colored samples (L*<50), normal-colored samples (50≤L*≤56), and light-colored samples (L*>56). Light-colored samples had higher moisture content, thawing loss, drip loss, and lower pH compared with those of normal- and dark-colored samples. Lower thickness was observed in the light-colored samples compared with those of normal- and dark-colored samples. Light- and normal-colored samples had a greater volume of meat than did the dark-colored samples. Imaging analysis showed that light-colored samples had a greater bottom area and perimeter compared with those of normal- and dark-colored samples. However, these conformation parameters showed low correlation with water-holding capacity, which was determined as thawing and drip loss of the samples. Therefore, the conformation parameters, determined by direct measurement or imaging analysis, could not be used to predict the water-holding capacity of breast meat. Nevertheless, water-holding capacity showed high correlation with the L* value of breast meat. Imaging analysis could be used to separate light-colored breast meat with mostly low water-holding capacity. The accuracy of determining the characteristics of light-, normal-, and dark-colored samples by imaging analysis was evaluated. The characteristics of light-colored samples were determined with higher accuracy by imaging analysis than were the characteristics of normal- and dark-colored samples. This result indicated that imaging analysis using a digital camera could be used to separate light-colored breast meat with mostly low water-holding capacity from normal- and dark-colored meat.