In Japan, the majority of chicken meat is obtained from fast-growing broiler chickens. Because most Japanese chicken breeds have a low meat yield and egg production, many of these breeds are endangered. Recently, the palatability of meat and eggs of native chickens has been reevaluated in the Japanese market. Jidori, which means chicken from the local, is an indigenous local chicken that is more delicious, firmer in texture, and more expensive than the broiler chickens. Most Japanese consumers recognize that the meat of Jidori chicken is richer in flavor than that of the broiler chicken. However, the reason for this rich flavor of the meat of Jidori chicken has not been elucidated. Recently, we found that arachidonic acid (AA) (C20:4n-6), a polyunsaturated fatty acid, is associated with the rich flavor of the meat and eggs of Jidori chicken. The present paper summarizes the discovery of the involvement of AA in the flavor characteristic of the meat and eggs of chicken, and also the genetic regulation of the AA content in the meat and eggs of Jidori chicken.
Calpain 3 (CAPN3), also known as p94, is associated with multiple production traits in domestic animals. However, the molecular characteristics of the CAPN3 gene and its expression profile in goose tissues have not been reported. In this study, CAPN3 cDNA of the Sichuan white goose was cloned, sequenced, and characterized. The CAPN3 full-length cDNA sequence consists of a 2,316-bp coding sequence (CDS) that encodes 771 amino acids with a molecular mass of 89,019 kDa. The protein was predicted to have no signal peptide, but several N-glycosylation, O-glycosylation, and phosphorylation sites. The secondary structure of CAPN3 was predicted to be 38.65% α-helical. Sequence alignment showed that CAPN3 of Sichuan white goose shared more than 90% amino acid sequence similarity with those of Japanese quail, turkey, helmeted guineafowl, duck, pigeon, and chicken. Phylogenetic tree analysis showed that goose CAPN3 has a close genetic relationship and small evolutionary distance with those of the birds. qRT-PCR analysis showed that in 15-day-old animals, the expression level of CAPN3 was significantly higher in breast muscle than in thigh tissues. These results serve as a foundation for further investigations of the function of the goose CAPN3 gene.
The aim of this study was to investigate the effects of synbiotic supplementation, a potential alternative to antibiotic, on growth performance, carcass characteristics, meat quality, immunity, and oxidative status of Cherry Valley ducks. In total, 540 1-day-old male Cherry Valley ducks were randomly subjected to 3 treatments, and each treatment consisted of 6 replicates with 30 birds each. Birds in the 3 treatments were fed a basal diet devoid of antibiotics (control group) or a basal diet supplemented with either 40 mg/kg zinc bacitracin or 1.5 g/kg synbiotic composed of xylooligosaccharide, Clostridium butyricum, and Bacillus subtilis for 42 days. Compared with the control group, dietary synbiotic and antibiotic supplementation decreased the feed/gain ratio of ducks (P=0.025) to a similar extent (P>0.05). Birds in the antibiotic group exhibited a lower average daily feed intake (P=0.024) whereas such an effect was not observed in the birds of the synbiotic group (P>0.05). Synbiotic and antibiotic supplementation reduced abdominal fat yield (P=0.032) and drip loss of the breast muscle (P<0.001) to similar extents (P>0.05). Additionally, synbiotic and antibiotic supplementation increased the relative weight of the bursa (P=0.005) and total superoxide dismutase activity in the ileal mucosa (P=0.025) to similar extents (P>0.05). Moreover, ileal malondialdehyde accumulation was reduced with the supplementation of synbiotic (P=0.028), but not antibiotic. The results indicated that dietary synbiotic supplementation was beneficial for growth performance, carcass compositions, meat quality, immune function, and antioxidant capacity of Cherry Valley ducks, and it could be used as an alternative to antibiotics in Cherry Valley ducks.
This study aimed to evaluate the effects of dietary supplementation of lysolecithin emulsifier on growth performance, nutrient digestibility, and blood lipid profiles in growing broiler chickens. In total, 1,020 1-day-old male Ross 308 broiler chickens with an average initial live weight of 43±1.2 g were randomly allotted to five dietary treatments for a 35 d experiment. The treatments included: (1) NC, negative control (metabolizable energy (ME)=3,100 kcal/kg for phase 1 and phase 2), (2) PC, positive control (ME=3,200 kcal/kg), (3) T1, NC+0.03% lysolecithin, (4) T2, NC+0.06% lysolecithin, and (5) T3, NC+0.09% lysolecithin. During days 1–35, the feed conversion ratios (FCR) of broiler chickens fed with T2 and T3 diets were lower than those of broiler chickens fed with NC diet (P<0.05). On day 35, the total tract nutrient retention (TTNR) of gross energy and ether extract of broiler chickens fed with PC and T3 diets was higher than those fed with NC diet (P<0.05). However, serum total cholesterol, triglyceride, and free fatty acid levels were not influenced by lysolecithin supplementation. In conclusion, lysolecithin supplementation improved FCR and TTNR of energy and ether extract when broiler chickens were offered a reduced energy diet.
To date, few reports have been published on the sensitivity of birds to sweet tastes. Therefore, in this study, the behavioral responses of White Leghorn chicks to the sweet taste of saccharin and the bitter taste of quinine were assessed. Three chicks were provided with a solution of 3.0 mM quinine and a mixture of 3.0 mM quinine mixed with 0.1, 0.5, 1.0, or 10.0 mM saccharin in a two-bottle choice test for 48 h. It was found that the chicks consumed more of the 0.5 mM saccharin/3.0 mM quinine mixture but significantly less of the 10.0 mM saccharin/3.0 mM quinine mixtures than the quinine solution alone (P<0.05). The aversive behavior of 3.0 mM quinine solution was eased when mixed with 0.5 mM saccharin, indicating that chicks are detecting the sweetness associated with the 0.5 mM saccharin. The aversion to the 1.0 and 10.0 mM saccharin solutions might be stronger than to the 3.0 mM quinine solution alone. These findings suggest that chicks are able to detect this artificial sweetener.
Glucagon-like peptide (GLP)-1 is released from the intestinal L cells in response to food ingestion and stimulates insulin secretion from the pancreatic B cells, by binding to its specific receptor (GLP-1R), which is expressed on the pancreatic B cells in the mammalian pancreas. Previously, we demonstrated that chicken GLP-1R was expressed on the pancreatic D cells by using a specific antibody against chicken GLP-1R. In the present study, we compared the localization of GLP-1R in the pancreases of three avian species; white leghorn chicken, northern bobwhite, and common ostrich, using the double immunofluorescence technique. We found that the types of pancreatic islets in the northern bobwhite pancreas were similar to those found in the chicken pancreas. The ostrich pancreas contained several types of pancreatic islets. GLP-1R-immunoreactive cells were found in all types of pancreatic islets in both northern bobwhite and ostrich and expressed somatostatin immunoreactivity. The present results indicate that the pancreatic D cells are the target cells of GLP-1, and GLP-1 might play a physiological role via somatostatin in the avian species.
Bitterness is one of the five basic tastes, and sensitivity to bitterness is important in that it enables animals to avoid harmful and toxic substances. In humans, taste sensitivity decreases with age, although the extent of loss varies depending on the taste quality. In chickens (Gallus gallus domesticus), baby chicks have been found to be more sensitive to salt and sour taste qualities than adults. In this study, therefore, we investigated the growth-associated changes in bitter taste sensitivity in chicks. We examined the behavioral perceptions toward the bitter compounds chloramphenicol and andrographolide in chicks at three different growth stages. Then, we measured the relative expression of the functional bitter taste receptors in the chick palate. In behavioral drinking tests, the 0–1-week-old chicks consumed a significantly lower amount of bitter solutions than water, whereas the 8–9-week-old chicks showed lower avoidance of the bitter solutions than the 0–1-week-old and 4–5-week-old chicks. Real-time PCR assay showed that the 0–1-week-old chicks had significantly higher expression of one of the functional bitter taste receptors in the palate than that in the older chicks. These results suggest that baby chicks are more sensitive to bitterness than older chicks. These findings may be useful in the production of new feedstuff for chicks according to their growth stages.
Mitochondrial content is regarded a useful feature to distinguish muscle-fiber types in terms of energy metabolism in skeletal muscles. Increasing evidence suggests that specific mitochondrial bioenergetic phenotypes exist in metabolically different muscle fibers. A few studies have examined the energetic properties of skeletal muscle in domestic fowls; however, no information on muscle bioenergetics in broiler chickens selectively bred for faster growth is available. In this study, we aimed to characterize the mitochondrial contents and functions of chicken skeletal muscle consisting entirely of type I (oxidative) (M. pubo-ischio-femoralis pars medialis), type IIA (glycolytic/oxidative) (M. pubo-ischio-femoralis pars lateralis), and type IIB (glycolytic) (M. pectoralis) muscle fibers. Citrate synthase (CS) activity was the highest in type IIA muscle tissues and isolated mitochondria, among the muscle tissues tested. Although no difference was registered in mitochondrial CS activity between type IIB and type I muscles, tissue CS activity was significantly higher in the latter. Histochemical staining for NADH tetrazolium reductase and the ratio of muscle-tissue to mitochondrial CS activity indicated that type I, type IIA, and type IIB muscle-fiber types showed decreasing mitochondrial content. Mitochondria from type I muscle exhibited a higher coupled respiration rate induced by pyruvate/malate, palmitoyl-CoA/malate, and palmitoyl-carnitine, as respiratory substrates, than type IIB-muscle mitochondria, while the response of mitochondria from type IIA muscle to those substrates was comparable to that of mitochondria from type I muscle. Type IIA-muscle mitochondria exhibited the highest carnitine palmitoyltransferase-2 level among all tissues tested, which may contribute to the higher fatty acid oxidation in these mitochondria. The results suggest that mitochondrial abundance is one of the features differentiating metabolic characteristics of different chicken skeletal muscle types. Moreover, the study demonstrated that type IIA-muscle mitochondria may have distinct metabolic capacities.
The aim of this study was to optimize and characterize Flavourzyme hydrolysis conditions for the preparation of antioxidant peptides from duck meat, using response surface methodology. The results indicated that optimal Flavourzyme hydrolysis conditions for preparation of antioxidant peptides from duck protein were a temperature of 50.19°C, pH 5.45, and a reaction time of 1.03 h. Compared to non-hydrolyzed duck meat, Flavourzyme hydrolysis significantly improved the hydroxyl-radical scavenging, DPPH radical-scavenging, ferrous ion-chelating, reducing, and ABTS radical cation-scavenging activities of duck meat. Therefore, Flavourzyme can be regarded as an effective hydrolytic enzyme for the preparation of antioxidant peptides from duck meat.
We investigated a reproductive flock of Zatorska geese. The birds were divided into four groups: three-year-old ganders (n=10), and one-, two-, and three-year-old layers (n=30). Mature feathers were collected from the birds between July and September (i.e., after breeding). Before collection, the feathers and down were evaluated to determine their maturity. The quantitative composition of each sample of feathers was evaluated manually. The evaluated quality traits of the feathers were turbidity of an aqueous extract, acidity, oxygen index number, and fat content. The data were analyzed using the SAS statistical package with multivariate analysis of variance for repeated measures.
The weight of feathers collected from all three gatherings was the highest for the three-year-old ganders. In subsequent gatherings, the weight of the collected feathers tended to increase. There was a statistically significant difference in down composition between the first and the subsequent two gatherings in all age-groups of geese. Neither the age nor the gender of the birds had an effect on the quantity of down obtained, which was 80–85 g.
The turbidity of the feather extract was lowest for feathers collected in the first gathering. For the layers, the turbidity of the feather extract was lowest in feathers obtained from the one-year-old birds. The feathers ranged from slightly acidic to neutral, with pH values between 5.9 and 7.2. The fat content was lowest in feathers collected in the first gathering (2.4–2.7%), and tended to increase in subsequent gatherings. There was no statistically significant difference in the oxygen index number between individual gatherings, or between the three-years-old layers and the ganders.