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.     

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.     

Long-bone properties and development are affected by caponisation and breed in Polish fowls

1. The aim of the study was to investigate the effects of caponisation on bone development of males of two native breeds in Poland.

2. The weight, length and cross-sectional area of tibiae and femora were measured, densitometric measurements and tests of strength were determined and dimensions were calculated.

3. Breed and caponisation did not influence bone weight and length. Higher mechanical strength of the femur was found in entire males, mainly in the Polbar breed. Tibial strength was reduced in capons of the Green Partridge breed. Maximum elastic strength was greater in the Polbar, irrespective of caponisation. Bone cross-sectional area was influenced by breed, while caponisation reduced femoral bone mineral density in both breeds.

4. Caponisation thus increased growth rate but had adverse effects on bone development.

5. Caponisation had fewer negative effects in the Polbar than in the Greenleg Partridge.     

Physical and chemical nature of eggs from six breeds of domestic fowl

1. The physical nature and chemical composition of the eggs from several breeds, White Leghorn, Rhode Island Red, Sussex, Maran, Dwarf Sussex and English Gamecock, have been studied.

2. The water content was highest in White Leghorn eggs, which were the heaviest.

3. Cholesterol content was similar in all eggs except for Dwarf Sussex in which it was less.

4. English Gamecock eggs contained a higher proportion of protein than those of the other breeds.

5. From the data presented, egg size, under similar conditions of feeding, does not determine the contents of components of the egg, but there are underlying genetic factors.     

Comparison of the productive performances of the Sinai Bedouin fowl,the white leghorn and their crossbreds: Study under natural desert conditions

1. The productive performances of the Sinai Bedouin fowl, the commercial White Leghorn and their reciprocal crossbreds were compared under natural desert conditions in the Sinai peninsula.

2. Seasonal temperature changes did not affect egg weight of any of the breeds or crosses, but laying rate of all was considerably reduced under heat wave conditions and that of Sinai and Sinai x Leghorn decreased during winter, probably due to the short photoperiod.

3. Egg production of the Leghorn was poor compared with that in normal conditions.

4. The Leghorn was the most vulnerable to heat stress, mortality was 24% during two heat waves.

5. The results suggest that the Sinai breed and its crosses are more resistant to the extreme conditions of the desert environment. This feature might be used in the future selection of heat tolerant breeds.     

Grass meal as an ingredient in diets for broiler chickens

1. Six diets of equal energy and nitrogen contents containing between 0 (control) and 125 g grass meal/kg were each fed to 4 groups of 42 male and 4 groups of 42 female broiler chicks, in floor pens, from 0 to 56 d of age.

2. Increments of 25 g grass meal/kg and 7.3 g maize oil/kg replaced a mixture of soyabean, wheat and barley meals in the control diet.

3. Gain: food ratio (y) of the birds decreased linearly as dietary grass meal content (x) increased such that y = 0.4295 ? 0.0032x.

4. Carcass analyses indicated that the decrease in gain : food ratio was caused by less deposition of body fat.

5. Skin colour became significantly yellower as the dietary grass meal content increased.     

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.     

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.     

Natural resistance of Sri Lankan village chicken to Salmonella gallinarum infection

1. An experiment was conducted to compare the natural resistance of an indigenous breed of local village chickens to Salmonella gallinarum with two commercial breeds: ISA Brown and ISA White layers under experimental conditions.

2. A total of 72 chickens from each of these breeds were randomly distributed to 4 pens to provide equal numbers of two replicate pens maintained as infected and control (uninfected). All chickens in infected groups were inoculated orally with 1 × 10⁸ CFU (1 ml dose) of a field isolate of S. gallinarum, at the age of 8 and 16 weeks given over 5 consecutive days. Growth performance, clinical signs, gross pathological lesions and antibody responses were measured.

3. A significantly higher mortality was observed in the brown layers compared with the white layers, and clinical signs and mortality were absent in village chickens. However, a large number of birds with gross lesions and high antibody titres were detected in village chickens, indicating that birds had the disease subclinically. Commercial breeds had a significantly higher body weight, feed intake and feed conversion efficiency.

4. There was a significantly lower proportion of positive reactors in village chickens in the whole-blood agglutination test (35%) compared to brown (100%) and white (90%) layers even after the second inoculation. Uninfected birds were negative in all groups. The indirect enzyme-linked immunosorbent assay confirmed these observations.

5. These results suggest that the indigenous breed had superior natural resistance to S. gallinarum than the commercial breeds.     

The response of egg weight to the inclusion of different amounts of vegetable oil and linoleic acid in the diet of laying hens

1. Four diets containing different amounts of vegetable oil and linoleic acid were fed to White Leghorn hens throughout a full laying year.

2. Egg weight was poor with the low fat basal diet but increased in relation to the amounts of maize oil (4 and 30 g/kg) included in the diet.

3. With a diet containing 30 g olive oil/kg, egg weight was similar to that obtained with the diet containing the same amount of maize oil.

4. Rearing the birds on diets containing low or moderate amounts of linoleic acid did not affect the response to fatty acid content of the layer's diet.

5. It is concluded that the requirement of the laying hen for linoleic add is not higher than 9 g/kg but that egg weight does respond to higher dietary amounts of readily absorbable fatty acids.     

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.     

Effect of gradual acclimation to temperatures up to 44 °C on productive performance of the desert Bedouin fowl,the commercial White Leghorn and the two reciprocal crossbreds

1. The effect of daily exposures to increasing ambient temperatures (for 7 months) on egg production was evaluated in the desert Bedouin fowl of Sinai, a commercial White Leghorn and the two reciprocal cross breds.

2. High ambient temperatures did not adversely affect egg weight, laying rate or output per bird (g egg per day per g body weight) of the acclimated hens.

3. Best productivity was attained during periods of exposure to 38 to 40° C in all breeds.

4. Rates of decrease from maximal productivity to productivity at 42 and 44 °G differed with breed. Productivity of Leghorn and Leghorn x Sinai crossbred decreased curvilinearly above 40 °C, while productivity of Sinai and Sinai ( Leghorn crossbred decreased at 42 °C and then stabilised.

5. When changes in egg weight and laying rate were examined on an individual basis (comparison between successive months), the differences between Sinai and the Leghorn were more pronounced.

6. The results support previous findings that the Sinai breed and its crosses are able to withstand extreme environmental temperatures, reflecting genetic adaptation to desert conditions.     

Differences in egg‐shell quality among the Sinai Bedouin fowl,the commercial white leghorn and their crossbreds

1. A comparison of egg‐shell characteristics was made among the Sinai breed (a desert inhabiting strain), the commercial White Leghorn and their reciprocal crossbreds.

2. The Sinai egg was smaller and its shell thicker and stronger than the Leghorn egg. All the differences were statistically significant.

3. Shell thickness and strength of Leghorn eggs were in accordance with values predicted on the basis of egg mass, while those of the Sinai and the two crosses were considerably higher than predicted.

4. The apparent differences in mean egg mass between Sinai and Leghorn breeds did not explain the differences in egg‐shell quality, neither did the shape index which was very similar among all breeds.

5. The findings suggest that the differences in egg‐shell properties are of a genetic origin.

6. The thick, strong and less permeable egg‐shell of the Sinai breed may reflect adaptations to its arid environmental origin and to incubation in the open.

7. These genetically‐determined egg‐shell characteristics might serve in a future selection for improved egg‐shell quality in poultry.     

An analysis of sexual size dimorphism in goose

1. Sexual size dimorphism (SSD) is a common phenomenon in animals. Rensch’s rule states that larger species generally exhibit a higher male to female body size ratio than smaller ones.

2. Domesticated animals offer excellent opportunities for testing predictions of the functional explanations of Rensch’s rule and this was tested in a meta-analysis of SSD in 38 breeds of domestic geese compared among themselves and with their wild relatives (subfamily Anserinae, 35 species).

3. Domestic geese and wild Anser species taken together supported Rench’s rule but the wild species did not.

4. The non-targeted sex selection hypothesis seems to provide the best intuitive explanation for the lack of SSD in geese.     

Broiler weight estimation based on machine vision and artificial neural network

1. Machine vision and artificial neural network (ANN) procedures were used to estimate live body weight of broiler chickens in 30 1-d-old broiler chickens reared for 42 d.

2. Imaging was performed two times daily. To localise chickens within the pen, an ellipse fitting algorithm was used and the chickens’ head and tail removed using the Chan–Vese method.

3. The correlations between the body weight and 6 physical extracted features indicated that there were strong correlations between body weight and the 5 features including area, perimeter, convex area, major and minor axis length.

5. According to statistical analysis there was no significant difference between morning and afternoon data over 42 d.

6. In an attempt to improve the accuracy of live weight approximation different ANN techniques, including Bayesian regulation, Levenberg–Marquardt, Scaled conjugate gradient and gradient descent were used. Bayesian regulation with R² value of 0.98 was the best network for prediction of broiler weight.

7. The accuracy of the machine vision technique was examined and most errors were less than 50 g.     

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.     

Influence of ascorbic acid on the adverse effect of feeding a diet containing excess tyrosine to chicks

1. The effects of dietary or parenteral administration of ascorbic acid on the adverse effects of excess dietary tyrosine were investigated with young male White Leghorn chicks in a 2‐week experiment.

2. Addition of 10 g ascorbic acid/kg to the control diet (without excess tyrosine) produced no beneficial effects on performance. Excess dietary tyrosine caused depressions in all measures of performance.

3. Adding 0.1, 1, 10 or 20 g ascorbic acid/kg to the diet containing excess tyrosine tended to improve performance.

4. Subcutaneous injection of 50 mg ascorbic acid/bird d to chicks receiving excess tyrosine brought about a significant improvement in body‐weight gain.

5. The elevation of plasma free tyrosine caused by excess dietary tyrosine decreased as dietary ascorbic acid increased.

6. Ascorbic acid can alleviate, though not completely counteract, the adverse effect of excess dietary tyrosine.     

Effects of method of processing and chilling of Turkey carcasses on processing losses,water absorption and yields

1. The effects of wet or dry plucking, wet or dry evisceration procedures and method of chilling on processing losses and water uptake during chilling were studied using 19‐week‐old female large white turkeys.

2. Dry plucking increased weight loss due to plucking and eviscerating, and reduced chilled carcass yield.

3. Dry eviscerating increased carcass water uptake during chilling.

4. Pre‐chilling with running water increased carcass water uptake compared with chilling in ice and water alone.

5. Water uptake during chilling appeared to be increased by longer eviscerating time.     

Selection for high specific gravity of eggs in a flock of Australorp hens

1. A realised heritability of 0.23 was obtained in an Australorp flock (S) selected for five generations for high egg specific gravity.

2. A comparison with an unselected control flock (C) over 50 weeks of lay in the final generation indicated a number of statistically significant correlated responses in commercially important traits in the S line in addition to the direct response of + 0.004 in specific gravity.

3. With an increase in specific gravity, there was a decrease of 3.4 in the percentage of soft‐shelled eggs laid.

4. The weight and albumen height of eggs measured within 1 hour of lay declined by 1.8 g and 2.1 Haugh units respectively.

5. There were reductions in the weight and albumen height losses of eggs stored over a 10‐d period (C 0.74, S 0.62 g and C 17.9, S 15.0 Haugh units respectively), so that at the end of this period the albumen heights in both lines were the same.

6. Average body weight and daily food intake were less by 0.28 kg and 7.5 g respectively.

7. Although there was no change in egg production, the average age at first egg was reduced by 11.3 d.     

The effects of feeding regime and stocking rate on the performance of medium‐bodied layers in the humid tropics

1. The effects of housing laying hens 1 or 2 per cage (1 452 or 726 cm² /bird), and three feeding regimes (ad libitum, 70% ad libitum and 6 days/ week) were investigated.

2. With 2 birds/cage egg production and food utilisation were adversely affected, but there were no significant effects on egg weight, food consumption, shell thickness, body‐weight change, mortality and abdominal fat.

3. Food restriction significantly increased body‐weight loss and decreased egg production, food consumption, final body weight and abdominal fat, but had no significant effect on egg weight, shell thickness and mortality. The effect on food utilisation was inconsistent.

4. There were significant interactions between feeding regime and stocking rate for egg weight and final body weight.

5. It is suggested that in the humid tropics birds caged singly could be fed at 70% ad libitum while those caged in pairs should be fed ad libitum to avoid multiple stress.