Paired box 7 (Pax7) gene: molecular characterisation,polymorphism and its association with growth performance in goose (Anser cygnoides)

1. Paired box (Pax7) gene is a member of the paired box family and plays a critical role in animal growth and muscle development. However, the molecular characterisation of the goose Pax7 gene is unknown.

2. The open-reading frame of goose Pax7 is composed of 1509 bp, which encodes a protein of 503 amino acids and shares high homology with Pax7 of other birds.

3. Ten single-nucleotide polymorphisms were identified in the genomic DNA sequence, 8 located in the intron region and two located in the exon region.

4. Association analysis showed the C122T locus was significantly associated with the body weight of Zhedong-White geese in week 4, 6, 8, 10 and 12.

5. It was concluded that the goose Pax7 gene may be an important candidate gene for goose growth traits and marker-assisted selection.     

Plasma disposition and tissue residue of Moxifloxacin in Japanese quails (Coturnix japonica) following different routes of administration

1. The disposition kinetics and the plasma availability of moxifloxacin were investigated in Japanese quails (Coturnix japonica) following different routes of administration at 5 mg/kg body weight.

2. Tissue residue profiles (liver, kidney, lung and muscle) and plasma were also studied after multiple intramuscular and oral administrations of 5 mg/kg body weight, once daily for 5 consecutive days.

3. Following intravenous injection, plasma concentration–time curves were best described by a two-compartment open model.

4. After intramuscular and oral administration of moxifloxacin, the peak plasma concentrations (C_max) were 2.14 and 1.94 μg/ml and were obtained at 1.40 and 1.87 h (T_max), post administration, respectively.

5. The systemic bioavailabilities following intramuscular and oral administration, respectively, of moxifloxacin were 92.48 and 87.94%.

6. Tissue concentrations following i.m. and p.o. administration were highest in liver and kidney, respectively, and decreased in the following order: plasma, lung and muscle. No moxifloxacin residues were detected in tissues and plasma after 120 h after i.m. or oral administration.     

Effects of dietary supplementation with Gynura procumbens (Merr.) on egg yolk cholesterol,excreta microflora and laying hen performance

1. The present study investigated the effects of dietary supplementation with Gynura procumbens on egg yolk and serum cholesterol and triglycerides, excreta microflora, laying performance and egg quality.

2. A total of 160 Hy-Line Brown layers (45 weeks old) were randomly assigned into 4 treatments on the basis of laying performance. Each treatment had 4 replicates with 10 birds each.

3. Dietary treatments were basal diet supplemented with 0 (control), 2.5, 5.0 and 7.5 g/kg diet G. procumbens during 56-d feeding period.

4. Serum (d 21, 42 and 56) and egg yolk (d 28, 42 and 56) cholesterol and triglycerides concentrations were linearly reduced with increasing dietary concentrations of G. procumbens.

5. Increasing dietary concentrations of G. procumbens linearly reduced the excreta total anaerobic bacteria (d 28), Clostridium sp. and Escherichia coli (d 28 and 56) populations.

6. Overall egg production and egg mass were linearly increased, and overall feed efficiency was linearly improved with increase in dietary G. procumbens.

7. Dietary increasing concentrations of G. procumbens linearly improved egg yolk colour (d 28 and 56) and breaking strength of eggs (d 56).

8. The results obtained in the present experiment indicate that dietary supplementation with G. procumbens could reduce the egg yolk cholesterol, suppresses harmful excreta microflora and improves layers performance.     

A mathematical representation of the Ovulatory cycle of the domestic hen

1. The ovulatory cycle of the domestic hen (Gallus domesticus) was postulated to be the result of the interaction of two independent systems.

2. A circadian system was postulated to control the restriction of ovulation to an 8‐h period of the day under conventional 14 h light: 10 h dark regimes.

3. The final phase of follicular maturation was postulated to commence after ovulation of the preceding ovum in the hierarchy.

4. Ovulation was postulated to occur when a mature follicle was present in the ovary during the appropriate phase of the circadian‐linked system.

5. The predicted times of oviposition were within the standard error of the observed times of oviposition under 21‐, 24‐ and 28‐h photoschedules.

6. It was concluded that this hypothesis for the control of the ovulatory cycle of the hen is consistent with current knowledge.     

The effects of restricted feeding on adrenal cortical activity in the immature domestic fowl

1. The effect of reducing food intake to 75% of the ad libitum intake was determined from hatching to 8 weeks in young Light Sussex chickens.

2. Restricted birds were lighter throughout the experiment.

3. Relative adrenal weight tended to be greater in restricted birds but the difference decreased with time.

4. There was no depletion of adrenal cholesterol: from week 5 there was a significantly greater amount in the adrenals of restricted birds.

5. After 1 week of restriction plasma corticosterone concentration was 73% greater than in controls. It decreased progressively, falling within the normal range at 5 weeks.

6. Restricted birds were hypoglycaemic from weeks 2 to 7 and hyper‐lipacidaemic throughout. A negative correlation between plasma glucose and free fatty acids was found.     

Encapsulated benzoic acid supplementation in broiler diets influences gut bacterial composition and activity

1. The present study investigated the effects of encapsulated benzoic acid (BA) supplementation in broiler feed on performance and gastrointestinal microbiota.

2. Eighty broilers were randomly divided into two groups. Birds in the control group were fed on maize–soybean-based diets. Birds in the treatment group were provided the same diet supplemented with 2 g/kg BA encapsulated in a vegetable oil matrix.

3. At the end of the trial (d 35), pH, bacterial composition and metabolites were determined in the crop, jejunum, ileum and caecum.

4. Growth performance variables and pH were not significantly different.

5. BA concentration decreased rapidly in the proximal gut. However, the treatment diet showed higher BA in the crop, jejunum, ileum and caecum.

6. Total lactate in the crop and D-lactate in the jejunum was higher in the BA treated group. Caecal total and branched chain fatty acids were decreased due to the treatment.

7. Lactobacilli populations were significantly altered by BA supplementation. A trend for increased lactobacilli was observed in the crop, while it became significant in the jejunum and ileum. Lactobacillus species responded differently to the treatment. Four of 5 measured Lactobacillus species, particularly in the ileum, followed the course observed for total lactobacilli; only Lactobacillus salivarius was not modified.

8. Correlation analysis showed that BA modified the intestinal microbiota. Lactobacilli correlated negatively to all studied clostridial clusters and enterobacteria. Clostridial clusters IV and XIVa were significantly increased in the jejunum, whereas only clostridial cluster XIVa was increased in the caecum.

9. Encapsulated BA modified the intestinal microbiota which can lead to the conclusion, that the main beneficial mode of action of BA in the gut appears to be the enhancement of lactic acid bacteria, which in turn may act as a vanguard against pathogens.     

Effect of age and sex on the chemical composition of edible offal and blood from broilers

1. The effects of age and sex on the proximate composition and inorganic constituents in edible offal and whole blood from a commercial British broiler chicken strain were studied.

2. Although the protein content of all tissues varied with age, the only statistically significant effect was on the level of protein in the gizzard.

3. The moisture content of the gizzard was significantly affected by age and blood by age and sex.

4. The fat content of the gizzard was significantly affected by age, as was the effect of sex on the fat content of blood.

5. The ash contents of heart and gizzard were significantly affected by age.

6. The phosphorus contents of the gizzard, heart and liver were significantly affected by age, as were the chloride content of heart and the calcium content of the liver. Blood potassium was significantly affected by sex. Fluctuations in the contents of other elements are discussed.

7. The variability in organ composition is discussed with respect to the degree of trimming and preparation of the samples.     

Protein and energy metabolism in two lines of chickens selected for growth on high or low protein diets

1. Genetic adaptation was investigated in broilers selected for seven generations on a normal (A) or a low (B) protein diet.

2. Protein and energy metabolism were studied in males from these selected lines fed on a diet of intermediate protein content.

3. All selected birds retained more nitrogen than those studied 10 years previously.

4. There was no difference in nitrogen retention between groups, although relative growth rate of group B birds was higher.

5. Heat productions relative to gross energy intake were 0.38 (group B) and 045 (group A). Energy retentions relative to gross energy intake were 0.39 (group B) and 0.35 (group A); the difference being primarily due to higher fat retention in group B.

6. Using a common maintenance requirement for metabolisable energy, group B utilised metabolisable energy for growth (0.78) better than did group A (0.71).

7. At 53 d of age plasma glucose (10%) and insulin (50%) were higher in group B than in group A.     

Dextran sulphate sodium (DSS) causes intestinal histopathology and inflammatory changes consistent with increased gut leakiness in chickens

1. The clinical severity, histological changes, indicators of gut leakiness and inflammatory cytokine profiles were studied in chickens with dextran sulphate sodium (DSS)-induced intestinal inflammation.

2. The experimental groups (1.25%, 1.5% and 2.5% DSS) showed clinical signs, such as loose stools and weight loss, which increased with additional treatment days and, as expected, the effects of DSS-induced intestinal inflammation were time and dose-dependent.

3. After 10 d, histological manifestations were evident, including goblet cell depletion, mucus layer loss, significantly shorter villi and a thinner total ileal mucosa.

4. The d(-)-lactate value, which was used as a gut leakiness indicator, was significantly increased in the 2.5% DSS group.

5. Expression of the inflammatory cytokines interleukin-1Beta, tumour necrosis factor alpha and interleukin-10 in the serum significantly increased with DSS treatment.

6. This study indicates that the experimental intestinal inflammation induced by DSS is an ideal model to study the pathogenic mechanisms of intestinal inflammation in chickens and to test the efficacy of therapies.     

A 31P topical magnetic resonance study of embryonic development in hens' eggs

1. A ³¹P topical magnetic resonance study of whole chicken's eggs in vivo is described.

2. Resonances from adenosine triphosphate, phosphocreatine, inorganic phosphate and phosphorous storage protein were observed. These changed in relative intensity as the embryo developed.

3. No ill effects due to exposure to radiofrequency radiation or magnetic fields were observed.

4. It is concluded that topical magnetic resonance can make a useful contribution to the study of embryonic development in avian eggs.     

Quality characteristics of quail eggs

1. An experiment was carried out with laying Japanese quail to study the influence of age on their egg quality.

2. Egg, yolk, albumen and shell plus membrane weights increased, whereas the egg shape, specific gravity and shell thickness decreased between 49 and 154 days of age.

3. Yolk, albumen and shell plus membrane comprised 32–59%, 53–57% and 7–80%, respectively of the total egg weight.

4. Regression between the quail's age and the characteristics of eggs were derived and correlation coefficients ranged from —0–42 to — 0–86. The albumen weight was more highly correlated with egg weight than yolk weight.

5. Relationships were also derived between egg shape and specific gravity, and egg shape and albumen weight.

6. It was concluded that the eggs’ characteristics were modified as the quails aged, and the best criterion of the shell's strength was the egg shape.     

Lipopolysaccharide reduces food passage rate from the crop by a prostaglandin-independent mechanism in chickens

1. We examined the effect of lipopolysaccharide (LPS), a component of Gram-negative bacteria, on food passage in the digestive tract of chickens (Gallus gallus) in order to clarify whether bacterial infection affects food passage in birds.

2. Food passage in the crop was significantly reduced by intraperitoneal (IP) injection of LPS while it did not affect the number of defecations, suggesting that LPS may affect food passage only in the upper digestive tract.

3. Similar to LPS, prostaglandin E2 (PGE2), one of the mediators of LPS, also reduced crop-emptying rate in chickens while it had no effect on the number of defecations.

4. Pretreatment with indomethacin, which is an inhibitor of cyclooxygenase (COX), a prostaglandin synthase, had no effect on LPS-induced inhibition of crop emptying.

5. IP injection of LPS did not affect the mRNA expression of COX2 in the upper digestive tract of chickens.

6. It is therefore likely that LPS and PGE2 reduced food passage rate in the crop by a prostaglandin-independent pathway in chickens.     

Comparison of the productive perform. Ances of the Sinai Bedouin fowl,the white leghorn and their crossbreds: Study under laboratory conditions

1. A comparison of the productive performances of the Sinai Bedouin fowl (from the Sinai desert), the commercial White Leghorn and their reciprocal crossbreds was made under uniform normal conditions.

2. The Sinai produced significantly fewer, smaller eggs, resulting in lower egg mass output (g/bird d), than the Leghorn and the crossbreds.

3. Egg weight of both crossbreds was intermediate between Sinai and Leghorn but laying rate was closer to that of the Leghorn.

4. Differences in egg mass output apparent at 8 to 10 months of age decreased considerably with age.

5. These findings suggest that selection or crossbreeding of the Sinai might improve productive performance while maintaining improved eggshell quality.     

Bioprocess enhancement of feather degradation using alkaliphilic microbial mixture

1. The main aim of this work is to develop a robust method to generate a microbial mixture which can successfully degrade poultry feathers to overcome environmental problems.

2. Four different alkaliphilic microbes were isolated and shown to degrade poultry feathers.

3. Two of the isolates were phylogenetically identified as Lysinibacillus and the others were identified as Nocardiopsis and Micrococcus.

4. The best microbial co-culture for white and black feather degradation was optimised for pH, temperature and relative population of the isolates to achieve almost 96% of degradation compared with a maximum of 31% when applying each isolate individually.

5. The maximum activity of keratinase was estimated to be 1.5 U/ml after 3 d for white feathers and 0.6 U/ml after 4 d for black feathers in a basal medium containing feather as the main carbon source. Additionally, non-denaturing polyacrylamide gel electrophoresis showed 4 and 3 protease activity bands for white and black feather, respectively.

6. This study provides a robust method to develop potential new mixtures of microorganisms that are able to degrade both white and black feathers by applying a Central Composite Design.     

Ostrich (Struthio camelus) embryonic development from 7 to 42 days of incubation

1. Hatching success of ostrich eggs is poor (50–60% of fertile eggs). The current study was designed to identify the timing of key stages in the development of the ostrich embryo.

2. Growth of both embryo and wing length during 42 d of incubation was comparable and approximately linear, with a more or less weekly doubling in size up to 35 d of incubation.

3. The embryo eye size increased more rapidly than beak length and reached a maximum of ~16.2 mm by 28 d of incubation, whereas beak length increased continuously until hatching at 42 d.

4. Linear regression equations were derived from morphometric measurements of embryos between 7 and 42 d.

5. Information stemming from these results can be used to estimate the age of dead-in-shell embryos in an attempt to identify timing of incubation problems that potentially result in low hatchability of fertile eggs.     

Gene expression profile of IGF1 and MSTN mRNA and their correlation with carcass traits in different breeds of geese at 70 d of age

1. The expression of insulin-like growth factor-1 (IGF1) and myostatin (MSTN) mRNA in breast and leg muscle was quantified in 70-d-old Taihu and Wanxi geese by using a Multiplex Competitive Fluorescent–PCR method and the correlations between mRNA levels and carcass traits were analysed.

2. IGF1 mRNA expression in breast muscle in Taihu geese was significantly higher than that in Wanxi geese and the MSTN mRNA level in leg muscle in Taihu geese was significantly higher than that in Wanxi geese.

3. There was no significant difference in breast muscle MSTN or leg muscle IGF1 mRNA expression between the two breeds.

4. Within the same breed, the IGF1 mRNA expression in leg muscle of male geese was significantly higher than that in female geese, and MSTN mRNA expression in leg muscle was significantly higher than that in breast muscle.

5. There was no difference in the IGF1 mRNA expression between tissues.

6. There was a positive correlation between IGF1 mRNA and MSTN mRNA and a negative correlation between IGF1 mRNA expression of breast muscle and leg muscle ratio.

7. In Wanxi geese, MSTN mRNA expression in leg muscle was negatively associated with body weight and leg muscle weight.     

The occurrence of giant fibres in different muscles of two chicken genotypes

1. The occurrence of Giant Fibres (GF) in three muscles (Pectoralis major (PM), Iliotibialis lateralis and Semimembranosus) with different types of energy metabolism was studied in slow- and fast-growing chicken strains.

2. A total of 20 one-day-old Leghorn chicks (slow-growing) and 20 broiler (Ross 508) chicks (fast-growing) were reared to 100 and 45 d, respectively.

3. A small percentage of GF was seen in pre rigor muscle samples even at 3 min post mortem in both genotypes and in all muscle types studied.

4. From 3 min to 24 h post mortem GF increased both in Leghorn and broiler chickens but to a different extent according to muscle type and genotype.

5. The highest GF 24 h post mortem value was found in the PM muscles belonging to the fast-growing broiler line.

6. It was concluded that every type of muscle can develop GF, but this phenomenon is more evident in the PM especially in animals selected for increased growth rate.     

Polymorphism and expression of insulin-like growth factor 1 (IGF1) gene and its association with growth traits in chicken

1. The objectives of the study were to detect polymorphism in the coding region of the IGF1 gene, explore the expression profile and estimate association with growth traits in indigenous and exotic chickens.

2. A total of 12 haplotypes were found in Cornish, control layer and Aseel breeds of chicken in which the h1 haplotype was most frequent.

3. Nucleotide substitutions among haplotypes were found at 21 positions in the IGF1 gene in which 4 substitutions resulted in non-synonymous mutations in the receptor binding domain of the IGF1 protein.

4. The haplogroup showed a significant effect on body weight at 24 and 42 d of age in the control layer line, body weight at 42 d and daily weight gain between 29 and 42 d in the control broiler line, daily weight gain between 29 and 42 d in Cornish, and body weights at 42 d as well as daily weight gain between 29 and 42 d in Aseel birds.

5. IGF1 expression varied among the breeds during embryonic and post-hatch periods. The expression among the haplogroups varied in different chicken tissues. The effect of haplogroup on myofibre number in pectoral muscle was non-significant, although there was significant variation in numbers between d 1 and d 42, and between broiler and layer lines.

6. It was concluded that the coding region of the IGF1 gene was polymorphic, expressed differentially during the pre-hatch and post-hatch periods, and haplogroups showed significant association with growth traits in chicken.