The present study in Japanese quail was aimed to develop multi-trait genetic selection program for a meat type sire line utilizing the mixed-model methodology. In total, 2000 pedigreed quail were formed the basis of the research where a multi-trait animal model was performed. A flock consisting of a total of 160 families (1 male: 3 female) was developed from the initial flock (base population of sire line), so as to obtain a selection flock sire line. Body weight at 5 weeks of age was chosen as a primary selection criterion in flock. The age at point of inflection derived from Gompertz growth curve, feed conversion ratio between 3 to 5 weeks of age, and carcass yield at 5 week of age were determined as selection criteria. Multi-trait BLUP methodology was carried out for genetic improvement of birds. In flock, 25 percent of males and females with highest breeding value were selected to produce next generation. Genetic parameter estimates, realized genetic parameters, selection responses, and genetic trends were obtained. Significant (P<0.01) selection responses for body weight, age at point of inflection, feed conversion ratio, and carcass yield traits on generations were observed. The results of the study revealed that the negative genetic relationships exhibited between some studied traits had overcame by modern poultry breeding methods such as selection via multi-trait BLUP.
The chaperonin containing TCP-1 complex protein 1 subunit zeta (CCT6A) is the only cytosolic chaperonin in eukaryotes assisting in the folding of cytoplasmic proteins. Previous study revealed that the mRNA expression of chicken CCT6A gene was remarkably elevated in the sexually mature ovaries. However, the mechanism underlying chicken CCT6A expression changes remains largely unknown. In this study, haplotypes caused by two single nucleotide polymorphisms (SNPs) of chicken CCT6A gene promoter (g.-2215 T>C and g.-1959 T>C) were identified and their associations with egg production traits as well as effects on gene expression were analyzed. Altogether four haplotypes including A (C-2215-T-1959), B (C-2215-C-1959), C (T-2215-T-1959) and D (T-2215-C-1959) were detected in all of the five chicken populations. Diplotypes AA, AD and DD were predominant in Xinyang brown hens, among which diplotype AD was associated with higher egg number at the age of 28 weeks old (E28) (P<0.05). In addition, diplotype AD was also predominant in Xinyang brown and Hy-line brown chicken populations with high egg production; whereas in Wenchang and Shouguang chicken populations which are Chinese indigenous chicken breeds and relatively lower in egg production, diplotype AA was predominant. Compared with diplotypes AA and DD, the mRNA expression of CCT6A in diplotype AD birds is the highest in F1, F5, and POF1 follicles of Hy-line brown hens (P<0.05). These results suggest that the two SNPs in chicken CCT6A promoter region are potential DNA marker for improving egg production trait.
Differential lipid metabolic requirements of sexually-mature males and females may influence the regulation of lipid metabolism-associated genes and hence the content of adipose tissue. We measured the expression of eight lipid metabolism-associated genes (fatty acid synthase, FASN; acylglycerol- 3- phosphate O-acyltransferase 9, AGPAT9; peroxisomal proliferator-activated receptor γ, PPARγ; lipoprotein lipase, LPL; carnitine palmitoyl transferase 1 A, CPT1A; carnitine palmitoyl transferase 1 B, CPT1B; acyl-COA dehydrogenase long chain, ACADL; monoglyceride lipase, MGL) in eight tissues (hypothalamus, HYP; liver; heart; pectoralis major muscle, PM; gastrocnemius muscle, GAS; abdominal fat, AF; clavicular fat, CF; subcutaneous fat, SF) of five male and five female white feather chickens using real time PCR at 217 d (when the females were at peak egg production). There were no difference between sexes, nor were there sex by tissue interactions for CPT1A and MGL. In both cases expression was greater for liver than the other tissues. When interactions of sex by tissue were significant, the FASN mRNA abundance in HYP, liver, and PM was greater for females than males. There was no sexual dimorphism for any tissue for PPARγ. Overall values were greater for adipose depots than HYP and liver with muscles intermediate for AGPAT9. LPL mRNA abundance in PM and AF was greater for females than males, with the pattern reversed for heart and SF. CPT1B mRNA abundance in GAS and CF was greater for females than males, with the relationship reversed for liver. ACADL mRNA abundance in HYP, liver, and GAS was greater for females than males, and lower in PM than males.The results demonstrated that expression of lipid metablism-associated genes varies among sexes in mature chickens depending on the gene and the tissue.
The present study was conducted to improve the nutritional quality of shrimp meal (SM) comprising of heads with hulls of black tiger shrimp (Penaeus monodon) waste by autoclaving and chemical treatments. The sun-dried SM was divided into 5 treatment groups, such as 1) control (untreated), 2) autoclaved (autoclaved at 121°C for 10 min), 3) NaOH (treated with 3% NaOH), 4) HCl (treated with 3% HCl) and 5) formic acid (treated with 3% formic acid) groups. After treatment, they were ground to pass through 1.0 mm mesh screen and then used for analyses of chemical composition and in vitro dry matter (DM) and CP digestibilities. Data were subjected to one-way ANOVA and differences among treatment means (P<0.05) were distinguished with Tukey’s test. There were no significant difference in chemical composition and in vitro DM and CP digestibilities between control and autoclaved groups, except ether extract level (P<0.05), suggesting that autoclaving affected the nutritional quality of SM little. NaOH group exhibited significantly decreased CP level and in vitro DM digestibility, increased crude ash (CA) level and unchanged in vitro CP digestibility, comparing with control group. These results suggest that NaOH treatment affected the nutritional quality of SM adversely. HCl and formic acids groups showed significantly increased CP level and in vitro digestibilities of DM and CP, and decreased CA level, showing that acid treatment can improve nutritional quality of SM: formic acid treatment may be more effective because of the greater values in CP level and digestibilities and decreased crude fibre level which was not observed in HCl group (P<0.05). The results obtained here suggest acid, especially formic acid, treatment is promising to improve the nutritional quality of SM but autoclaving and NaOH treatments.
The effects of Flavomycin, Bacillus licheniformis and Enramycin on broiler performance, nutrient digestibility, gut morphology and the intestinal microflora were studied in a 42-d experiment. A total of 288, one-day-old, male, Arbor Acres broilers were randomly assigned to 1 of 4 dietary treatments with 12 pens per treatment and 6 birds per pen. The treatments were comprised of a control diet without supplementation, a diet supplemented with 5 ppm Flavomycin, a diet supplemented with the combination of 5 ppm Flavomycin and 1.35×109 CFU/kg Bacillus licheniformis, as well as a diet supplemented with 5 ppm Enramycin. The average daily gain (ADG) and feed conversion ratio (FCR) of birds fed the diet with Flavomycin combined with Bacillus licheniformis and the Enramycin diet were improved (P<0.05) compared with the control diet. The digestibility of dry matter, energy, and calcium for birds fed the combination of Flavomycin and Bacillus licheniformis and the Enramycin diet were also enhanced compared with the control diet. All additives improved the villus height and crypt depth in the duodenum, jejunum and ileum on d 21. In addition, reduced numbers of cecal E. coli (P<0.01) were found in birds fed all three supplemented diets on d 42. In conclusion, supplementation with Flavomycin and Bacillus licheniformis in combination or Enramycin would appear to be superior to supplementation with Flavomycin alone. All three supplemented diets were superior to the control.
Little information has been available about the influence of genetic background and dietary L-arginine (Arg) supply on organ growth of chickens. Therefore, the present study examined the effects of a graded ad libitum Arg supply providing 70, 100 and 200% of recommended Arg concentration on organ growth of female chickens from hatch to 18 weeks of age. The chickens derived from four layer lines of different phylogeny (white vs. brown) and laying performance (high vs. low). Based on residual feed and absolute body and organ weights recorded in six-week-intervals, feed consumption, changes of relative organ weights and allometric organ growth were compared between experimental groups. Surplus Arg caused higher feed intake than insufficient Arg (p<0.01) that induced growth depression in turn (p<0.05). During the entire trial chicken’s heart, gizzard and liver decreased relatively to their body growth (p<0.001) and showed strong positive correlations among each other. On the contrary, proportions of pancreas and lymphoid organs increased until week 12 (p<0.001) and correlated positively among each other. Due to their opposite growth behaviour (p<0.001), internal organs were assigned to two separate groups. Furthermore, insufficient Arg induced larger proportions of bursa, gizzard and liver compared with a higher Arg supply (p<0.05). In contrast to less Arg containing diets, surplus Arg decreased relative spleen weights (p<0.01). The overall allometric evaluation of data indicated a precocious development of heart, liver, gizzard, pancreas and bursa independent of chicken’s genetic and nutritional background. However, insufficient Arg retarded the maturation of spleen and thymus compared with an adequate Arg supply. In conclusion, the present results emphasised the essential function of Arg in layer performance, and indicated different sensitivities of internal organs rather to chicken’s dietary Arg supply than to their genetic background.
The present study was conducted to measure the growth performance in growing broilers given shrimp meal (SM) made of heads of black tiger (Penaeus monodon) (BT) and white leg (Litopenaeus vannamei) (WL) shrimps. Forty-two male broiler chicks (8 days old, Ross 308) were randomly divided into 7 dietary groups (control, 5% BT, 10% BT, 15% BT, 5% WL, 10% WL and 15% WL) having similar body weight (6 birds per diet). Metabolisable energy and CP were adjusted to about 3,180 kcal/kg and about 235 g/kg, respectively, and other nutrients were formulated to meet or slightly exceed the requirements. Diet and water were provided ad libitum during the experimental period (8 to 21 days old). The results revealed that body weight gain decreased in BT groups with increasing level of SM (P<0.05), and feed intake decreased slightly with increasing level of SM in diets. As the result, feed conversion ratio also deteriorated with increasing level of SM. Similar trend was observed in WL groups, but the adverse effects of SM were milder comparing with BT groups. Nitrogen retention in both BT and WL groups tended to decrease with increasing level of SM. Chitin digestibilities in WL groups were greater than the corresponding values in BT groups. In conclusion, it is suggested that WL heads can be more nutritious SM for broiler diets than BT heads.
Amadori products are non-enzymatically formed by binding carbonyl groups and amino groups. Glycated amino acids generated by reacting amino acid and glucose are also in a group of Amadori products of which the transport and metabolism have been investigated mainly in mammals but not in avians. In the present study, therefore, we examined whether dietary fructosyl-valine, which is one of the glycated amino acids, orally administrated to chickens can be incorporated into blood or not. Fructosyl-valine was orally administrated to the chicken and blood samples were collected at 0, 20, 40, 60, 120 and 180 min after administration. Plasma concentration of fructosyl-valine was measured by using LC/MS. The plasma concentration of fructosyl-valine was increased by passing time from 0 to 180 min after administration, and no change was observed in the control group. Conclusively, it was clarified that fructosyl-valine orally administrated to the chicken could be absorbed from gastrointestinal tract and incorporated into blood.
Prolactin receptor (PRLR) is expressed in a wide variety of tissues and mediates diverse biological actions of prolactin (PRL). In mammals, PRL signaling is thought to be involved not only in the process of spermatogenesis and steroidogenesis in the testis, but also in the survival of ejaculated sperm. In avian species, although the expression of PRLR with several variants in the testis was reported, the role of PRL in testicular function is still unclear. The aim of this study was to examine the expression of PRLR in the testis and mature sperm in quail. It is revealed that PRLR was mainly localized in the round- and elongated-spermatid by immunohistochemical analysis on the testis suggesting that PRL signaling may participate in the spermatogenesis. Western blot analysis confirmed the presence of PRLR in the plasma membrane of the ejaculated sperm (SPML), whereas the size of PRLR in the sperm was smaller than that in the hypothalamus. Moreover, PRLR was detected on the surface of the midpiece and flagellum of sperm by immunostaining. To evaluate the functionality of the sperm PRLR, the dot blot assay was performed to test the binding of pituitary PRL to PRLR in the SPML, and resulted in the detection of specific binding of PRL to the component of SPML, most likely to sperm PRLR. Furthermore, when the ejaculates were incubated with pituitary PRL to investigate the role of PRL on the sperm, the occurrence of spontaneous acrosome reaction was significantly decreased. In addition, the expression of PRL on the surface of utero-vaginal junction of oviduct was detected by immunohistochemistry. These results may suggest a novel system that the interaction between oviductal PRL and sperm PRLR is involved in the maintenance of the fertilizability of the spermatozoa through the prevention of the spontaneous acrosome reaction in Japanese quail.
To determine the influence of media composition on Salmonella exclusion of Nurmi-type cultures, two and four types of cultures in the first and second trial, respectively, were prepared from the cecal contents of conventional laying hens, and Salmonella exclusion was assessed in newly hatched chicks. In the first trial, modified Viande Levure (VL) broth or nutrient broth (NB) were used to prepare Nurmi-type cultures (N-VL and N-NB), which were administered to the newly hatched chicks. Twenty-four hours later, the chicks were challenged with Salmonella enterica Typhimurium EF85-9 (ST). ST recoveries (log10 colony forming units/g of cecal contents) from the N-VL-, N-NB-, and control-treated groups 5 days after the challenge were 7.6±0.6, 0.9±1.9, and 7.7±0.4, respectively. The results suggested the influence of L-cysteine (Cys) present in the VL broth. Thus, we determined the effect of Cys in the second trial. We prepared two other cultures using VL broth without Cys (N-VL—Cys) and NB with Cys (N-NB＋Cys). ST recoveries from the cecal contents of the N-VL-, N-VL—Cys-, and control-treated groups were 6.3±0.9, 2.1±2.5, and 9.2±0.8, respectively. ST was not recovered from the N-NB- and N-NB＋Cys-treated groups. To identify bacteria with Salmonella exclusion activity, we isolated 41 bacterial strains from the ceca of N-NB-treated chicks without Salmonella challenge. Most isolates were identified as Enterococcus faecalis or E. mundtii based on 16S rRNA gene sequencing, and only four cultures excluded Salmonella. Therefore, VL broth containing Cys was not always required for preparing Nurmi-type cultures. The use of media prepared with Cys at the lowest possible concentration or without Cys would promote to enhance Salmonella exclusion from Nurmi-type cultures.