Chicken primordial germ cells (PGCs) are used to restore and conserve genetic resources of some endangered birds or flocks of domestic chickens. When PGCs are transferred from a donor to a recipient, they can survive and gain sexual maturity in the recipient chicken. This indicates that PGCs retaining exogenous genes can proliferate and develop in recipient gonads, and proves that transferred PGCs are effective sources for establishing transgenic and germline chimeric chickens. The PGC transfer method has been used to produce germline chimeric chickens and may become popular in the field of reproductive science. Germline chimeric chickens have the potential to reconstruct and reproduce endangered birds, including both domestic and wild species.
In this study, we attempted to use amplified fragment length polymorphism (AFLP) in combination with selective genotyping to detect loci that affected shank length and body weight at 10 weeks of age in Japanese quail (Coturnix japonica). A total of 88 primer pairs were used in AFLP analyses of 10 and 13 males with the longest and shortest shank lengths, respectively, from an F2 intercross population derived from lines differentiated by large and small body size (LL and SS, respectively). Ten AFLP bands differed strikingly in frequency between the two groups (P<0.005). Genotyping of the 10 bands in 10 females with the longest shank lengths and 10 with the shortest revealed that one band differed significantly in frequency between the two groups for both males and females (P<0.05). This fragment shared 86.4% identity with a 361-bp sequence of chicken chromosome 1 located from position 51,672,791 to 51,673,152, as determined by chicken BLAT search. Polymerase chain reaction and sequence analysis revealed that a 190-bp insertion/deletion was the causal polymorphism. Genotypes of this indel marker were associated significantly with shank length and body weight in the F2 intercross population (P<0.005). The insertion allele had a positive effect on both traits. To confirm the association of this marker with the two traits, we conducted association analysis in a population derived from heterozygous quails of another line. In this analysis, the indel genotypes showed no significant association with shank length or male body weight (P>0.05), but did show a significant association with female body weight (P<0.05).
Fifty 18-day-old broilers were used to investigate the effects of 30% energy restriction from 18∼48 d on growth and slaughter performance, serum biochemical parameters, and gene expression of WDTC1 and Lpin2 in hepatic tissue. Fifty 18-day-old Arbor Acres female broilers were randomly divided to ad libitum group (control) and energy restriction group (experimental) and housed individually. The ad libitum group broilers were fed ad libitum with control diet, while energy restriction broilers were subjected to 30% metabolizable energy restriction (the supply of other nutrients was the same as that of ad libitum broilers). The results showed that: (1) Energy restriction significantly increased the feed efficiency (gain/feed) of birds. The average daily gain, the relative weight gain and the feed efficiency of energy restriction broilers were lower than that of ad libitum broilers during the earlier stage of the experiment (from 18∼39 d). While at latter stage of experiment (from 40∼48 d), the average daily gain, the relative weight gain and the feed efficiency of energy restriction broilers were higher than that of ad libitum broilers. (2) Energy restriction significantly reduced the abdominal fat ratio and the subcutaneous fat thickness, increased the muscle stomach weight, muscle stomach ratio, glandular stomach ratio, pancreas ratio, spleen ratio and the bursa of Fabricius ratio. There was no significant difference in leg muscle ratio and breast muscle ratio between control and experimental groups. (3) Energy restriction significantly increased serum superoxide dismutase, alkaline phosphatase, and serum uric acid, decreased serum total cholesterol, hig-density lipids, malondialdehyde, lactate dehydrogenase and blood urea nitrogen. (4) Energy restriction significantly elevated Lpin2 expression level in hepatic tissue, whereas it did not significantly affect the expression of chicken WDTC1 gene in hepatic tissue.
The objective of this research was to evaluate effects of partial replacement of trace mineral (Cu, Mn, Zn) sulfate by methionine hydroxy analog (MHA) chelates on laying performance, egg quality, enzyme activity and mineral retention in layers. Laying hens (Hyline Brown) of 37 weeks old were fed with 4 different diets with organic or inorganic trace mineral supplementations at equal levels. Treatments are: 1) Control (CON): a basal diet was supplemented with inorganic trace minerals (sulfate source, i.e. Cu 10, Zn 30 and Mn 30 mg/kg of diet); 2) Cu-MHA: Cu in control diet was replaced with 10 mg/kg as Cu-MHA; 3) Zn-MHA: Zn in control diet was replaced with 20 mg/kg as Zn-MHA; 4) Mn-MHA: Mn in control diet was replaced with 20 mg/kg as Mn-MHA. Experiment lasted for 14 weeks from 39 to 52 wk of age. Results showed that eggshell thickness was increased (P<0.05) by Mn-MHA and Zn-MHA supplementation. The supplementation of organic minerals increased (P<0.05) Haugh unit after 10 d storage. Ceruloplasmin (CP, P=0.051), carbonic anhydrase (CA, P<0.05) and Mn-superoxide dismutase (SOD, P<0.05) activities were increased in animals treated with organic minerals. Compared with control group, Cu-MHA significantly increased (P<0.01) Cu concentration in liver, and Zn-MHA increased (P<0.05) Zn concentration in yolk. No difference was found in Mn concentration between the two Mn sources. Interactions between mineral sources and feeding length were observed in yolk Cu (P<0.01), tibia Zn (P<0.05), liver (P<0.05) and yolk (P=0.063) Mn retention. In conclusion, MHA chelates of trace minerals (Cu, Zn and Mn) showed higher bioavailability compared with the sulfates when fed to laying hens.
This experiment was conducted to study methionine requirements in broiler breeder hens aged from 26-35 weeks. The treatments were consisted of six levels of methionine (0.2, 0.25, 0.3, 0.35, 0.4 and 0.45%), with five replicates of eight birds (Seven hens and one rooster). The results showed that different levels of methionine had no significant (p>0.05) effects on egg weight, unsettable (double yolk, small size) and settable eggs. The methionine levels significantly (p<0.05) changed egg production percentage, egg mass (g/h/d), egg content (g) and feed conversion ratio. Different levels of methionine did not affect on cell-mediated responses, newcastle and bursa diseases titer, and IgM (p>0.05), but total titer against sheep red blood cell (SRBC) and IgG responses were influenced (p<0.05). Using of two-slope quadratic broken-line analysis indicated that methionine requirements for egg mass (g/h/d), feed conversion ratio, settable eggs, SRBC and IgG were 446, 450, 494, 580 and 492 (mg/d), respectively. In conclusion, methionine requirement for settable eggs was similar to those needed for the optimum immune responses. Since, settable eggs are an important factor in broiler breeder industries, so the authors recommend 494 mg/d methionine for broiler breeder hens. This amount is higher than those needed for egg mass and feed conversion ratio.
One alpha-hydroxycholecalciferol (1α-OH D3), an analog of cholecalciferol (vitamin D3), improves growth performance and phosphorus retention in broilers. In the present study, we investigate the effects of dietary calcium (Ca) levels on the efficacy of 1α-OH D3 in the phosphorus (P)-deficient corn-soybean meal diets of 1- to 21-d-old broilers. Four hundred female Ross 308 broilers, 1-d-old, were randomly allotted to 10 treatments with 4 cages of 10 birds each. A 5×2 factorial experiment was designed to test 0.40, 0.60, 0.80, 1.00, and 1.20% Ca combined with 0 and 5μg/kg of 1α-OH D3 in a basal diet (0.25% non-phytate phosphorus (NPP), 0.48% total phosphorus (tP)) without vitamin D3. The lowest levels of body weight gain (BWG), feed intake (FI), feed efficiency (FE), tibia quality (except of ash and P), as well as the highest value of mortality, were observed at 0.40% Ca. Additional Ca corrected the Ca deficiency and eventually 1.2% Ca caused a P deficiency. The addition of 1α-OH D3 improved BWG, FI, FE, serum inorganic phosphate concentration, tP retention, tibia weight, length, breaking-strength, and content of ash, Ca, and P, and decreased mortality. However, 1α-OH D3 efficacy responded negatively to dietary Ca level. These results indicate that 1α-OH D3 exerts the highest activities at lower concentration of dietary Ca.
Morphological and histological studies of the adrenal gland of the adult White Leghorn chicken (Gallus domesticus) were performed. Macro- and microscopic observations of azan- or formal-dichromate stained (to observe the chromaffin reaction of adrenal medulla) sections were conducted. The right and left adrenal glands differed in shape, position, weight, length, width and thickness. The adrenal glands were encapsulated with a thin connective tissue containing blood vessels. The adrenal parenchyma was composed of two main tissue types, the cortex and medulla; these were mixed throughout the organ. The adrenal gland could be divided into a subcapsular layer, peripheral zone, and central zone. The whole subcapsular layer was occupied by medulla, and the proportion of medulla in the central zone (49.7%) was larger than that in the peripheral zone (24.8%). Approximately 60% of the adrenal gland was cortex, 39% was medulla, and the remaining 1% was sinusoids. The adrenal cortico-medullary ratio in the adult chicken was approximately 1.6:1. Cortical cells were arranged in columns with a small, round to slightly oval, eccentric nucleus approximately 4 μm in diameter. Medullary cells were polygonal in shape with a large, spherical, centrally placed nucleus approximately 5 μm in diameter.
The chicken leptin receptor (chLEPR) activates Janus kinase (JAK) - signal transducers and activator of transcription (STAT) signaling pathway after leptin stimulation. We have previously developed a bioassay using leptin inducible reporter gene in cultured cells. However, we failed to detect leptin-like activity in chicken blood. In the present study, we expressed green fluorescent protein (GFP) fused chSTAT3 (GFP-chSTAT3) in cells expressing chLEPR and analyzed leptin dependent activation of the chSTAT3. Leptin phosphorylated GFP-chSTAT3 and by which fluorescent signal translocated into nuclei in COS-7 cells transiently expressing GFP-chSTAT3 with chLEPR. Furthermore, we established CHO-K1 cells stably expressing chLEPR and chSTAT3 (CHO-chLEPR/chSTAT3), and in which detected time- and dose-dependent activation of chSTAT3 by leptin. Therefore, the CHO-chLEPR/STAT3 cells would be an excellent tool to detect and monitor leptin-like activity in avian tissues.
The present study was undertaken to examine the acute toxicity (LD50) and neurobehavioral manifestations in the open-field activity and tonic immobility tests in 7-14 day-old chicks treated with the H1-receptor antagonist diphenhydramine. Plasma and whole brain cholinesterase activities were also determined in the chicks. The LD50 of diphenhydramine in chicks was 49.3mg/kg, intramuscularly (i.m.). The signs of diphenhydramine toxicosis in the chicks which appeared within one hour after injection included excitation, jumping, whole body tremor, ataxia, gasping, frequent defecation, paralysis and recumbency. Fifteen minutes after i.m. injection, diphenhydramine at 2.5 and 5 mg/kg decreased the general locomotor activity of the chicks in the 5-min open-field activity test, as seen by a significant increase in the latency to move from the center of the open-field arena and decreases in the numbers of lines crossed and escape jumps in comparison with control values. Diphenhydramine significantly decreased the frequencies of pecking and defecation only at 5mg/kg when compared with respective control values. Diphenhydramine treatments at 2.5and 5mg/kg also significantly increased the durations of tonic immobility of the chicks and decreased their whole brain cholinesterase activity by 33 and 30%, respectively, in comparison with the control values. In conclusion, the data suggest that diphenhydramine induces central nervous system depression in chicks at doses below the LD50 value of the drug which is reported here for the first time.
This research was conducted to investigate the effects of single or combined use of probiotic (Primalac), prebiotic (Fermacto) and butyric acid glycerides (Baby C4) compared to salinomycin on resistance against coccidiosis in broiler chickens challenged with Eimeria. One day-old male Ross 308 broiler chicks were divided into 9 cages with 15 birds per each. Birds of different treatments received a regular corn-soybean meal basal diet supplemented with feed additives; none of them in negative control (C-), salinomycin in positive control (C+), probiotic in PRO group, prebiotic in PRE group, butyric acid glycerides in BAG group, probiotic+prebiotic in PRO+PRE group, probiotic+butyric acid glycerides in PRO+BAG group, prebiotic+butyric acid glycerides in PRE+BAG group, and probiotic+prebiotic+butyric acid glycerides in PRO+PRE+BAG group. At 28 d of age, 8 birds from each treatment were removed and kept separately in other cages (2 birds/cage) to challenge with Eimeria. These separated chicks were orally challenged with 1×105E. acervulina and 9×104E. tenella. Positive effect (P<0.05) was observed in the duodenal and cecal lesion scores in any of the supplemented groups when compared to that of the C-. There was no significant difference between all supplemented groups and C+ for cecal lesion score. PRO, PRE+BAG, PRO+PRE, PRO+BAG and PRO+PRE+BAG reduced (P<0.05) oocyst shedding in birds challenged with Eimeria oocysts compared to the C-, and there was no significant difference between PRO+PRE, PRO+BAG, PRO+PRE+BAG and C+. These results demonstrate that prebiotic, butyric acid glycerides and especially probiotic or its combination with prebiotic or butyric acid glycerides enhance the resistance of birds and partially protects against coccidiosis. Therefore, it seems some of these supplements, in comparison to salinomycin, can diminish partially the adverse effects of coccidiosis.