Japanese quail (Coturnix japonica) is a valuable bird for both research and production. From a mainly biomedical research point of view, this article describes characteristics of mutations of Japanese quail that have been found in the last 20 years, along with the recent (10 or 15 years) advances in molecular genetics of Japanese quail. In the 50 years following the first report of a mutation in Japanese quail in 1940, approximately 50 mutations were found, and during the subsequent 20 years, approximately 25 mutations have been added to the list of mutations in Japanese quail to date. Based on advances in molecular genetics of Japanese quail, two main genetic linkage maps have been constructed, mostly using microsatellite DNA and amplified fragment length polymorphism (AFLP) markers, and several mutations have been solved at the molecular level for their causative genes. It is anticipated that molecular studies will further reveal the nature of Japanese quail in the near future and enhance its value as a laboratory research animal and agricultural (industrial) animal.
The purpose of the present study was to collect information about the possible genetic background of glutathione peroxidase (GSHPx) activity in four pure breeds and their crosses of chickens, and its correlation with body weight (BW) and studying the effect of cross-breeding and sex on GSHPx activity. Blood samples were collected from six breeds of chickens, New Hampshire (NH), Naked Neck Plymouth (NNP) and their cross (NH×NNP), White Plymouth Rock (WPR), Naked Neck New Hampshire (NNNH) and their cross (WPR×NNNH) at the age of sexual maturity. GSHPx activity measured in blood plasma (BP) and red blood cell haemolysate (RBC). Results showed that there were significant differences in BW and GSHPx activities in RBC and BP among genetic groups and their crosses. NNP had the highest average BW (1.97kg) and NH had the lowest (1.11kg). WPR had the highest RBC GSHPx activity (6.24U/g protein) and NH×NNP cross had the lowest (3.98U/g protein). WPR×NNNH had the highest BP GSHPx activity (7.23U/g protein) and NNNH had the lowest (6.22U/g protein). Crosses had intermediate values for BW compared to their parents. The two crosses had lower RBC GSHPx activity than their parent breeds. NH×NNP had lower BP GSHPx activity than their parent breeds while WPR×NNNH had higher values. Sex had significant effect on BW and GSHPx activity in RBC and BP, males had higher values than females for BW and BP GSHPx activity while the opposite was found in RBC GSHPx activity. Heterosis as a percentage of the midparent values of the GSHPx activities in RBC and BP also average BW has high values and affected by sex. Significant negative correlation was found between BW and RBC GSHPx activity (-0.27; P<0.01) while, positive correlation was found between BW and BP GSHPx activity.
The present investigation was carried out on six crossbred chicken populations to estimate variability of microsatellites and their association with growth and other traits. Five microsatellite markers located on chromosome 1, 2, 5 and 10 were screened and association study was performed following general linear model technique. All the microsatellites were polymorphic showing three to six alleles. The polymorphic information content (PIC) of the markers was more than 0.536. Genotype and allelic frequency was estimated showing a large variability from microsatellite to microsatellite. The genotypes of MCW007 microsatellite were found to be significantly (P<0.05) associated with body weight at day old, 8th, 12th, 20th, 28th and 40th week of age. A significant association between ADL020 microsatellite and body weight at 8th, 12th and 40th week of age was estimated at P<0.05 in different crossbred chicken populations. ADL176 genotypes were observed to be significantly associated with body weight at 40 weeks of age. MCW007, ADL020, ADL023 and ADL176 microsatellites were found to be significantly correlated with age at sexual maturity whereas humoral immune response to sheep RBC were observed to be non-significantly associated with the microsatellites.
Growth performance, total tract nutrient retention and whole body nutrient accretion rates responses of broilers to supplementation of enzymes containing phytase or xylanase activities were investigated using 300 broilers. At day old, 280 broilers were assigned to 5 dietary treatments which were: 1) positive control (PC) diet which met NRC (1994) nutrient requirement for broilers, 2) negative control (NC) diet which was marginally deficient in phosphorus and ME, 3) NC plus phytase added at 1,000FTU/kg, 4) NC plus xylanase added at 4,000U/kg and, 5) NC plus phytase and xylanase added at 1,000 and 4,000units/kg, respectively. Each treatment had 8 replicate cages with 7 birds per replicate cage. Comparative slaughter technique was used for determination of whole-body nutrient accretion rate. Twenty broilers with the same initial body weight as the 280 broiler chicks used in the growth trial made up the initial slaughter group killed at day 0. A final slaughter group of 40 birds, one bird from each cage, were slaughtered on day 21. The birds selected were those with body weight closest to the average body weight of the birds in each replicate cage. Phytase alone or combined with xylanase improved weight gain and bone ash (P<0.05). Phytase alone improved (P<0.5) total tract P retention and ME, phytase and xylanase combined improved (P<0.01) total tract dry matter and ME. Phytase alone improved (P<0.5) whole body daily accretion rates of dry matter, protein, fat, P, and Ca in comparison to NC treatment. Overall, phytase in wheat-based diet improved growth performance and whole body accretion of minerals and protein, the improvement in protein accretion is an indication of improvement in nutrient utilization resulting from phytase use.
An experiment was conducted to evaluate the effect of dietary incorporation of raw and alkali [1.5% NaOH and 3% Ca (OH)2, w/w] treated solvent extracted karanj (Pongamia glabra) cake (SKC) on growth performance and carcass characteristics in broiler chickens during 0 to 6 weeks of age. A basal reference diet was formulated containing soybean meal (SBM) as the major protein source. Another six isonitrogenous and isocaloric test diets were formulated incorporating SKC, 1.5% NaOH treated SKC (NaOH-SKC) and 3% Ca (OH)2 treated SKC (Ca (OH)2-SKC) at 6.43 or 5.5% during starter phase and 12.86 or 11.0% during finisher phase replacing SBM nitrogen of reference diet at 12.5 and 25%, respectively. Each diet was offered ad. libitum to 4 replicates of 10 chicks each. The body weight gain and feed efficiency of broilers fed 6.43% NaOH-SKC incorporated diet was comparable with reference diet during 0 to 28d. However, weight gain and feed efficiency reduced in all karanj cakes incorporated diet during 29 to 42d. The overall weight gain during 0 to 42d was significantly higher in the reference diet. Significantly higher nutrient intake was observed in the reference group except 6.43% NaOH-SKC diet during both the balance trials and 6.43% Ca (OH)2-SKC during 2nd trial. The percent retention of DM, N, Ca, P and GE did not differ significantly. Higher liver weight was observed due to dietary incorporation of SKC and NaOH-SKC at 25%, and Ca (OH)2-SKC. The gizzard weight was significantly higher in SKC incorporated diet, at both the levels of replacement compared to reference diet. The breast yield lowered significantly when soybean meal nitrogen was replaced with processed or unprocessed karanj cake at 25% level. The findings suggested that 1.5% NaOH (w/w) treated SKC could be incorporated upto 6.43% level, replacing 12.5% of soybean nitrogen of reference diet in broiler chicken upto 4 weeks of age.
The objective of the present study was to investigate the effects of a low percentage of dietary chitosan on growth performance, carcass quality, plasma cholesterol, triacylglycerol levels, and the concentration of plasma very low density lipoprotein (VLDL) levels in broilers. Three hundred and sixty male Arbor Acre broiler chicks were randomly allotted into 4 groups with 3 replicates of 30 chickens per replicate. Chitosan was supplemented to a basal diet at 0 (control), 0.01, 0.03 and 0.06% for 7 weeks. Basal diet was starter (21% CP, 3200kcal/kg ME) at 0-3 weeks, grower (19% CP, 3200kcal/kg ME) at 3-6 weeks and then changed to finisher (17% CP, 3200kcal/kg ME) until 7 weeks. Compared with the control, body weight, feed efficiency, and weights of drumstick and breast tended to increase in all chitosan groups, although not statistically significant. The weight of visceral organs and the total plasma cholesterol, triacylglycerol and VLDL levels did not show a significant difference among the groups. These results suggest a low level of dietary chitosan tended to improve growth performance. These results suggest that a low level of dietary chitosan diet for broilers cannot reduce the total plasma cholesterol, but tended to have better growth performance.
The aim of this study was to identify the avian β-defensin-12 (AvβD-12) protein in the ovarian follicles and to determine the changes in its localization during follicular growth and in response to lipopolysaccharide (LPS). Anti-AvβD-12 polyclonal antibody was raised using synthetic peptide. White Leghorn laying hens were i.v. injected with or without LPS (1mg/kg BW). White follicles and yellow follicles (the largest and the third largest follicles; F1 and F3, respectively) were collected before and after 12 or 24h of LPS injection (n=3 in each group). Immunocytochemistry using an avidin-biotin-peroxidase complex method was performed using their paraffin sections. The immunoreactive AvβD-12 (irAvβD-12) was not found in the white follicles. The irAvβD-12 was localized in the capillary-associated cells in the outer theca interna, granulosa cells and perivitelline layer of yellow follicles. The irAvβD-12 in the theca interna and granulosa layers of yellow follicles was decreased by 12h and disappeared by 24h of LPS injection. Perivitelline layer was kept positive for irAvβD-12 even after 24h of LPS injection. No significant difference was found in the distribution of irAvβD-12 between F3 and F1 for the above results. No immunoreaction products were observed in the sections incubated with absorbed antibody of AvβD-12 instead of first antibody (control staining). These results suggest that the theca interna, granulosa and perivitelline layers contain AvβD-12. Its amount is likely increased with follicular growth from a white follicle to a yellow follicle, whereas the protein may be released from the cells by LPS stimulation, probably as a host defense response.
The effects of intracerebroventricular injection of L-tryptophan on feeding behavior and the levels of brain neurotransmitters (amino acids or monoamines) were investigated in ad libitum chicks. The tryptophan treatment (3 or 6μmol) significantly inhibited food intake in chicks at 30min postinjection. The levels of serotonin (5-HT) and its metabolite, 5-dihydroxyindolacetic acid, in chicks treated with tryptophan were significantly higher than those with saline at 15min postinjection. However, there were no differences in the levels of catecholamines (adrenaline, noradrenaline and dopamine) and amino acid neurotransmitters (e.g., γ-aminobutyric acid, glycine and glutamic acid). The tryptophan-induced anorexia tended to be attenuated by the 5-HT2A receptor antagonist ketanserin (10μg). These results suggest that the administration of tryptophan into the chick brain produces the anorexic effect, and that the change in brain 5-HT content may be involved in this anorexia.
Although many studies have shown that P450aromatase (P450arom), anti-Müllerian hormone (AMH) and estrogen receptor α (ERα) play pivotal roles in sexual differentiation of the gonads during early embryonic development in chickens and quail, few studies have been reported for other domestic birds. Furthermore, little information is available in relation to the mRNA expression in gonads after sexual differentiation in posthatching birds. The present study was conducted to assay mRNA expression of P450arom, AMH and ERα in gonads at day of hatch in turkey and duck and 2 days after hatching in goose using the real-time PCR. The mRNA expression was also determined at one week of age in gonads of these birds. At the time of collection of the left gonads for total RNA extraction, the external appearance of the left and right gonads of male and female was documented by digital camera. Clear asymmetry was observed in the female ovary in which the right ovary was regressed completely by 1-2 days in posthatching turkey, duck and goose. Although gonadal asymmetry was as remarkable as in females, the left testis was larger than the right one in males. Remarkable expression of P450arom mRNA was observed only in females in all the 3 species but substantially no expression was detected in males. Significantly higher expression of AMH mRNA was detected in males than females only in goose but there was no sex difference in turkey and duck at 1-2 days posthatching and one week of age. Weak ERα mRNA expression without a sex difference was detected in the 3 birds. These results suggest that estrogen plays a key role for ovarian development via P450arom mRNA expression after hatching, whereas absence of its expression in males leads to testis development in turkey, duck and goose.
This study was intended to investigate a contamination of Salmonella in broilers (intensive production system) and laying hens with different housing system (conventional and enriched (furnished) cages, aviary) in Lithuania. In total 470 samples, including faeces, dust, water and caecum contents (during slaughtering of broilers) were taken from 6 broiler and 8 laying hen farms for the estimation of the prevalence of Salmonella. The results of investigations of Salmonella spp. indicated that the most infected broiler samples were faeces and caecum (32.9% and 23.1%, respectively) as to compare with dust and water (14.7% and 10.0%, respectively). No significant differences could be found in prevalence of Salmonella between laying hens reared in conventional and enriched cages and aviary. In most cases the prevalence of Salmonella in broilers was spring; in laying hens - winter, spring and autumn. The prevalent Salmonella serovars found in broilers and laying hens were Salmonella Enteritidis and Salmonella Typhimurium.