The aim of the present work is to make a review on the literature concerning the incidence of some major pathologies of leg skeleton in broiler chickens and broiler breeders, related to poor animal welfare. On the basis of data on the incidence of leg skeletal pathology published by us and by other researchers, this review goes through some reports on femoral head necrosis (FHN), tibial dyschondroplasia (TD), rupture of the gastrocnemius tendon (RGT) and rickets. The welfare of broiler chickens and breeder flocks continues to be closely related to leg skeletal pathology. Although some reports establish that most abnormalities related to legs in chickens were largely overcome by selection work and improvement of production systems by the end of the 20th century, the problems still occupy an important place in broiler production. Apart published literature data, own results from the last decade (2001-2011) were also used.
Native chickens in Myanmar and Thailand have been being domesticated for generations and yielded a wide variety of chickens. The objective of the research is to analyze the genetic variation and relationships of native chicken populations in Myanmar and Thailand. A total number of 249 genomic DNA samples from a total nine populations including the commercial lines, were genotyped using 98 autosomal SNP markers. The average heterozygosity of each population was in the range of 0.181-0.262. The neighbor-joining trees constructed by pair-wise FST estimates corresponded that the native chickens in Myanmar and Thailand were at a distance from the commercial chickens. The STRUCTURE analysis revealed that the nine chicken populations used in this study might be derived from six genetic populations (K=6). The AMOVA showed significant value of FST with 79-90% of the total genetic variation found within populations. The FCT value was significant but accounted for only 4.45% of the total variability among countries. Finally, the mantel test for Isolation by Distance result (r=0.5964; P<0.01) suggested the contribution of geographic distance to the genetic structure of native chicken populations in Myanmar and Thailand.
Japanese quail egg white lysozyme possesses two alleles (S and F). In our previous study, the F phenotype was more effective against bacteria than the S phenotype, whereas the female-derived S phenotype led to improved hatchability. In this study, we analyzed gene frequency of egg white lysozyme using Acid-PAGE and mismatch PCR-RFLP in 22 Japanese quail populations in Japan and compared with five populations in INRA, France. Genotyping of the lysozyme locus in 22 Japanese quail populations in Japan revealed that this locus is polymorphic in all populations except Nagoya University and Kagoshima University (LL and SS) populations. The S allele was a major allele with frequency from 0.69 to 1.00. In five French populations, it was polymorphic in all populations except AA population. The S allele was a major allele with frequency from 0.69 to 1.00. From these results, the lysozyme locus was polymorphic in the Japanese quails and the S allele was a major allele. The S allele was fixed in several populations which have been maintained as closed and small population.
The amino acid contents of whole body were determined in male ducks at 5 age intervals from d 1 to 29 post hatch. Whole body homogenates were analyzed of dry matter, nitrogen, and amino acids and used to determine amino acid accretion rates and efficiency of utilization of digestible amino acids for amino acid accretion. During periods d 1 to 8, d 8 to 15, d 15 to 22, and d 22 to 29 post hatch, growth rates of the duck averaged 29, 61, 79, and 92 g/d, respectively. There were rapid increases in rates of amino acid accretion during the periods of d 1 to 8, d 8 to 15, and d 15 to 22 and a leveling off during d 22 to 29 period of growth as shown by the linear (P<0.01) and quadratic (P<0.05) effects for all amino acids except tryptophan (Trp), which showed only a linear (P<0.01) effect. The respective rates of lysine (Lys) and methionine (Met) accretion increased from 0.264 and 0.081 g/(d·duck) during d 1 to 8 post-hatch period to 0.883 and 0.269 g/(d·duck) during d 15 to 22 post-hatch period and plateaued at 0.854 and 0.265 g/(d·duck) during d 22 to 29 post-hatch period. Accretion rate for glutamic acid (Glu) was greatest, followed by glycine (Gly), aspartic acid (Asp), leucine (Leu), arginine (Arg), lysine (Lys), alanine (Ala), proline (Pro), and valine (Val) in decreasing order. Trp had the least accretion rate of all the amino acids. The efficiency of digestible amino acid utilization for amino acid accretion was highest from d 2 to 5 post hatch and decreased progressively thereafter with increasing age and body weight. The efficiency of digestible Trp utilization was much lower than any other indispensable amino acid. Digestible Met was utilized with highest efficiency followed by Lys, Val, and threonine (Thr) in decreasing order. Efficiencies of utilization were 0.70, 0.645, 0.667, and 0.630 at 2 to 5 d of age and 0.522, 0.486, 0.465, and 0.436 at 29 d of age for Met, Lys, Val and Thr, respectively.
The objective of this study was to investigate the effect of dietary supplementation with modified arabinoxylan rice bran (MGN-3) on the immune system and inflammatory response in broiler chickens. The levels of cluster of differentiation 3 (CD3), interleukin (IL)-2 and interferon (IFN)-γ mRNA in the spleen of chickens increased with the supplementation of MGN-3 at 100 ppm in diet, while those expression levels in the foregut did not change. Mitogen-induced proliferation of splenic mononuclear cells (MNC) and blood MNC phagocytosis in chickens fed MGN-3-supplemented diets were significantly greater than in chickens fed a basal diet (control). These results provide the first evidence that the use of dietary MGN-3 supplementation induces the T-cell immune system in chickens. Two hours after Escherichia coli (E. coli) lipopolysaccharide (LPS)-induced immune stimulation, the levels of mRNA encoding pro-inflammatory cytokines, such as IL-2, IFN-γ and tumor necrosis factor-like ligand 1A (TL1A), in the spleen of chickens fed a MGN-3-supplemented diet were significantly lower than those in chickens exposed to other treatments. The levels of toll-like receptor -4 and -7 mRNAs in the foregut of chickens fed MGN-3 supplemented diets were lower than those in control chickens at 2h after injection of LPS. The plasma ceruloplasmin concentration in chickens fed a MGN-3-supplemented diet was significantly lower than in controls at 24h after injection of LPS. These results show that MGN-3 might be useful as an immunomodulator to stimulate T-cells in growing broiler chickens, thereby protecting chickens from disease, particularly colibacillosos, without reducing growth performance.
Effect of Aspergillus oryzae (CAO) culture on systemic inflammatory response and mRNA expression of immune-related mediators in intestine was studied in male broiler chicks. Feeding CAO alleviated enhancement of early inflammatory response such as changes in acute phase substance and growth performance during immunological stress induced by lipopolysaccharide and Sephadex. Furthermore, changes in mRNA expression of immune-related mediators in the upper and lower intestine at 5 and 14 days of age were investigated in chicks fed a diet with antibiotics, CAO or without both as control. The CAO and antibiotic feeding lowered interferon (IFN)-γ and interleukin (IL)-1β mRNA expression compared to the control group. The expressions of toll like receptor (TLR)-4 mRNA in the antibiotic and CAO fed group were greater than that of the control group at 5 days of age, but not at 14 days of age. The findings suggest that CAO has anti-inflammatory effect and changes in IFN-γ, IL-1β and TLR-4 mRNA in immune-related cells of the gut in the CAO fed chicks appears to be similar to that of the antibiotics fed group. These immune-related mediators in the intestine may be a useful marker to select alternative to antibiotics.
This study was performed to evaluate the effect of supplementation of low crude protein (CP) corn-soybean meal diets which contained low ME levels with lysine (Lys), methionine (Met) and threonine (Thr) above that recommended by the National Research Council (NRC, 1994) on broiler performance, carcass characteristics and serum constituents from 12 to 33 d of age. A total of 100 Ross chicks were randomly distributed in a randomized complete block design among 20 cages with 5 replicate cages / treatment with four dietary treatments: T1=Control diet (21% CP and 3150 kcal/kg ME); T2, T3 and T4 contained 19.5% CP and 115% of Lys, Met and 108% of Thr compared to the NRC requirements; T2, T3 and T4 contained 3150, 3100 and 3050 kcal of metabolizable energy (ME) /kg, respectively. Cumulative feed intake, body weight gain and feed conversion ratio from 12 to 33 d of age was not affected by treatment. Birds which had received T2 and T3 had a higher dressing percentage compared to those which had received T1. Breast muscle yield followed the same trend; heavier breasts were obtained from birds which had received T2 and T3. Serum uric acid concentration was influenced by treatment; it was significantly higher for birds which had received the control diet compared to all other treatments. Based on presented evidences, it can be concluded, that by fortifying crystalline amino acids to broilers diet at this stage of production, dietary CP and ME could be reduced to 19.5% and 3050 kcal/kg, respectively.
The ban on the use of antibiotics as growth promoters has stimulated the search for alternative feed supplements in poultry production. The active principles of thyme essential oil act as a digestibility enhancer, balancing the gut microbial ecosystem and stimulating the secretion of endogenous digestive enzymes and thus improving growth performance in poultry (Lovkova et al., 2001; Williams and Losa, 2001). A study was performed to investigate the effects of thyme essential oil (TEO) on performance, carcass characteristics, some blood parameters and ileal microflora of Japanese quail. This study lasted 35 days of age. One hundred and fifty day-old male Japanese quail chicks in a completely randomized design with two treatments (with or without 1 g/kg TEO) and five replicates of 15 birds each were used. All parameters were measured at the end of the experiment. The supplementation of TEO significantly (P<0.05) increased live body weight and relative weights of carcass and breast, lowered serum triglyceride, total cholesterol and glucose and improved ileal microflora. It was concluded that the addition of 1 g/kg TEO might offer some beneficial effects on Japanese quail to increase live body weight and improve some blood parameters and gut miroflora.
This study was conducted to elucidate the effects of dietary phytic acid supplementation on organs and serum components in broiler chickens. A total of 30 1-day-old broiler chicks were divided into three treatment groups (n=10, each). The control group was fed normal diet and the other groups were fed diet supplemented with 0.06% and 0.12% phytic acid for 30 days. No differences in body and muscle weights and 21 serum biochemical parameters were detected between phytic acid treatments and the control. However, abdominal fat weight decreased significantly with 0.12% phytic acid treatment (P<0.05). Liver weight and certain serum lipid parameters changed slightly, although differences were not statistically significant. In addition, the correlation coefficient between abdominal fat and liver weights was 0.69 (P<0.05) in the control group, whereas no significant differences were observed in the phytic acid fed groups. It is possible that phytic acid may affect lipid metabolism in liver and/or abdominal adipose.
The present study was conducted to develop a technique for generating primordial germ cells expressing GFP gene and introducing them into gonads of recipient embryos. Primordial germ cells isolated from embryonic blood were cultured on feeder cells for more than 40 days. They proliferated, occasionally formed cell colonies, and showed the characteristics of germline cells as detected by anti-CVH antibody. The cultured PGCs were transferred to the stage X blastoderm, bloodstream of stages 14-15 embryos, and the coelomic epithelium of stages 17-19 embryos, and examined to determine whether they could migrate to the gonads of recipient embryos. As a result, they successfully entered the gonads of recipient embryos when they were transferred to the coelomic epithelium, although they failed to migrate to the gonads of recipient embryos when they were transferred to the stage X blastoderm or bloodstream. The cultured PGCs were then transfected with GFP gene by nucleofection and selected for PGCs expressing GFP gene in the presence of G418. Cultured PGCs expressing GFP gene proliferated slowly, forming cell colonies, and successfully entering the gonads by transferring into the coelomic epithelium of recipient embryos. Those results suggest that gene transfer into the chicken germline is possible via cultured PGCs, and that the PGC culture system thus holds enormous possibilities for avian embryo manipulation.
Early researches have shown that the bursa of Fabricius is a critical organ for development of B lymphocytes in birds. Exogenous proteins from the gut lumen or the environment are taken up by the follicle-associated epithelium and enter into the bursal follicle. Not all of the B lymphocytes in the bursal follicle mature and emigrate to the periphery and antigen-dependent selection for B lymphocytes may occur in the bursa. However, the actual impact of antigens in the bursa on B cells is not clear. In this study, dinitrophenyl (DNP) or 2,4,6-trinitrophenyl (TNP) coupled bovine serum albumin (BSA) was injected into the bursa of one-day-old chickens, a time when most B lymphocytes in the bursal follicles begun to emigrate from the medulla to the cortex. Immunohistochemical analysis showed that DNP-BSA was only distributed in the bursal medulla. By injecting TNP-BSA into the bursa of one-day-old chickens, and immunizing the chickens with TNP-HSA 3 weeks later, we found that injection of TNP-BSA increased anti-TNP titers in the sera of chickens after immunization. Taken together, the results suggest that the bursa is the site of B cell-antigen interaction and is capable of causing Ag-specific B cell emigration and increasing an antigen-specific immune response at the B cell level.
We used a real-time PCR for Salmonella Enteritidis to detect the genomic DNA of Salmonella Enteritidis live vaccine in the immune organs, including the bursa of Fabricius, thymus, spleen, and Harderian gland, from chicken after subcutaneously vaccinated at different time points. Significant numbers of Salmonella Enteritidis genomes in the immune organs were first detected at 12 hour (post-vaccination) p.v., and subsequently rose to peak levels during 48 h to 72 h p.v. The rapid early increase of vaccine levels in all samples examined followed by a steady decline from 84 h to 15 days p.v. The real-time PCR analysis of a variety of tissues is significant for further investigation of the mechanism of vaccinal protection, and the optimization of vaccination regimes.
Eighteen hundred eggs obtained from Ross broiler breeders at 32 and 48 wk age were randomly assigned to two incubation treatments: T1 eggs were incubated at 37.6°C throughout, while for T2 eggs the incubation temperature was reduced 1°C for 6 h daily at embryonic ages (EA) 10 to 18. Embryo and organ weights and body composition were measured at EA 14, 19 and day of hatch (DOH). Hatchability and hatching duration, as well as serum triiodothyronine (T3), thyroxin (T4), and triglycerides were measured at DOH. T1 eggs contained less water than T2 eggs at EA 18. Hatchability was lower and the incubation period was 4.2 h longer for T2 than T1 chicks. On DOH for older breeders chick weights and serum T3 levels were higher for T2 than T1; however, those from younger breeders were similar at both incubation temperatures. These results may show a beneficial effect of T2 treatment in older breeders. Incubation temperature did not affect triglycerides levels. On DOH, higher body lipids content of T2 than T1 chicks may contribute to their resistance to cold post hatch.