Compensation for seasonal changes in eggshell conductance and hatchability of goose eggs by dynamic control of egg water loss

1. The water loss for optimal hatchability of goose eggs was 12% of initial egg mass.

2. Mass specific eggshell water vapour conductance, G_sp, increased by approximately 50% over about 13 weeks during the winter breeding cycle. A similar increase occurred over 8 weeks during summer.

3. Constant setting of humidity in goose incubators and changes in mean G_sp may cause sub‐optimal egg water loss which increases late mortality.

4. Mean G_sp was measured for every batch from each flock. Humidity was changed accordingly in order to reach optimal water loss. A significant improvement of 6% in hatchability and of 8% in Class‐A goslings was noted during 14 successive weeks compared with the previous 11 weeks.

5. Dynamic humidity control for optimising water loss according to mean batch G_sp thus increases hatchability.     

Inhibitory effects of epidermal growth factor on progesterone production of ovarian granulosa cells in Tsaiya duck (Anas platyrhynchos var. domestica)

1.?The purpose of this study was to investigate the effects of epidermal growth factor (EGF) on progesterone (P₄) secretion from ovarian granulosa cells in Tsaiya ducks (Anas platyrhynchos var. domestica).

2.?We obtained the largest (F1) follicle from Tsaiya duck, the granulosa layer was separated and the cells were isolated according to their proximity to the germinal disc.

3.?The granulosa cells were cultured in vitro, the culture media and the cells were used to determine P₄ and steroidogenic enzyme concentrations, respectively.

4.?P₄ concentrations were decreased in cultured granulosa cells taken proximal to the germinal disc (GD) compared to those distal to the germinal disc (NGD).

5.?EGF inhibited both basal and ovine luteinising hormone (oLH)-induced P₄ concentrations. It also inhibited the P₄ secretion via protein kinase A (PKA) pathway when cultured with GD and NGD granulose cells (mixed together) in vitro.

6.?Western blot results showed decreased concentrations of cytochrome P450 side-chain cleavage (P450scc) enzyme, 3β-hydroxysteroid dehydrogenase (3β-HSD) enzyme and steroid acute regulatory (StAR) protein expression, when the cells were co-treated with EGF and oLH.

7.?The inhibitory effect of oLH-induced P₄ production was attenuated by EGF by the addition of MAP-erk kinase (MEK) inhibitor (PD98059) suggests EGF may inhibit P₄ production by affecting via the mitogen-activated protein kinase (MAPK) pathway.     

Comparison of nutritive values of groundnut oil cake and Niger oil cake for laying pullets

1. The nutritive value of Niger oil cake (Guizotia abyssinica, Cass.) as a protein supplement for layers’ diets has been assessed.

2. Replacing groundnut oil cake (GNC) by Niger oil cake (NC) on an isonitrogenous basis, did not affect egg production, egg weight or the amount of food required per dozen eggs.

3. The percentage retention of nitrogen from diets containing 30% GNC or 30% NC was similar.

4. The ME value of NC used was 3025 kcal/kg.

5. It is concluded that NC can replace GNC in layers’ diets.     

Prevalence of and risk factors for Campylobacter colonisation in broiler flocks at the end of the rearing period in France

1. A study was conducted to estimate the prevalence and quantification by species of Campylobacter infection in broiler flocks at the end of the rearing period and to identify associated risk factors.

2. A questionnaire about the rearing period was completed and caecal samples were collected from 121 broiler flocks in Brittany, France, during 2008.

3. Campylobacter was isolated in 87 out of 121 flocks – a prevalence of 71.9% (95% CI, 63.7–80.1%), including 40.5% of Campylobacter jejuni and 29.8% of Campylobacter coli.

4. The average concentration, in positive flocks, was 7.96 log₁₀ cfu/g and ranged from 3.15 to 10.32 log₁₀ cfu/g.

5. The average concentration by species was: 7.57 log₁₀ cfu/g for C. jejuni and 8.44 log₁₀ cfu/g for C. coli.

6. There was a seasonal effect, with increased risk of Campylobacter colonisation in June, July and August (odds ratio (OR) = 9.59, 95% CI 1.15–79.75).

7. The other factors, associated with lower risk of Campylobacter colonisation, were the acidification of drinking water (OR = 0.33, 95% CI 0.13–0.86), antibiotic treatment at the beginning of the rearing period (OR = 0.20, 95% CI 0.07–0.55) and rodent control around the house (OR = 0.18, 95% CI 0.03–0.95).

8. The results show that hygiene practices and biosecurity measures could lead to a reduction in Campylobacter colonisation.     

Long‐term selection for increased egg production 1

1. Results are presented of a closed White Leghorn flock selected for increased egg production over a period of 17 years.

2. During the last 7 years a random breeding sample of the production flock served as a genetic control.

3. Regressions of deviations of the production flock from the control flock on years, were highly significant for age at sexual maturity (‐2.18 d), egg production up to 275 d old (3.04 eggs), egg production to 500 d old (5.04 eggs) and egg weight at 14 months old (October) ( — 0.79 g).

4. The heritability of egg production up to 275 d old declined significantly from 0.35 to 0.19.

5. The realised heritability of egg production up to 275 d old was estimated to be 0.14.

6. The genetic correlation between egg production up to 275 d old and production in the residual part of the year was 0.48.

7. The rate of inbreeding in the production flock was 0.515% per generation and the expected rate of inbreeding in the control flock 0.21% per generation.     

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.     

Traits influencing the hatching performance of Japanese quail eggs

1. Japanese quail eggs from moderately heavier sires showed superior fertility; while fertile eggs from moderately heavier dams hatched slightly better than the eggs from lighter dams.

2. Higher rates of fertility and hatchability of Japanese quail eggs were observed from parents of 10 to 19 weeks of age, with peak fertility and hatchability at 14 and 12 weeks of age, respectively.

3. Sex ratios of 1:2 to 1:5 gave comparable fertility and hatchability results.

4. The hatching performance of quail eggs from cage and deep litter reared breeders was comparable.

5. Fertility and hatchability were directly proportional to the egg weight.

6. Quail egg shell colour, tints and blotches were found to influence hatching performance.

7. Storing quail eggs at 16 ± 2°C and 75 ± 5% relative humidity for more than 4 d reduced hatchability.

8. Hatchability of eggs stored at room temperature was improved if they were sealed in polyethylene bags.

9. Provision of light during the first 14 d of incubation resulted in a photo‐acceleration of about 3.2 h.     

Different characteristics in chick embryos of two broiler lines differing in susceptibility to ascites

1. The relationship between the length of incubation, hatching, hypoxic condition, thyroid hormones and the occurrence of ascites were studied in embryos of 2 broiler lines differing in susceptibility to the ascites syndrome.

2. Both the time of external pipping (ep) and hatching of embryos from the ascites‐resistant (AR) broiler line was earlier compared to the ascites‐sensitive line (AS). The interval between internal pipping (ip) and ep was the same between the lines, but the interval between ep and hatching was shorter in the resistant line.

3. The T₃ and T₄ concentrations in plasma of the AS line were lower compared to the AR line.

4. Analyses of partial pressures of oxygen (pO₂) and carbon dioxide (pCO2) in the air cell of the egg revealed that at day 18 the AS embryos had lower pO₂ and higher pCO₂ concentrations compared to the AR embryos.

5. The delay in hatching of the AS embryos might induce a more pronounced and/or extended hypoxic environment, thereby creating an environment that evokes ascites.     

Defective egg production in a population of dwarf white leghorns 1

1. The incidence of defective eggs during the first 60 weeks of age increased with time due to significant increases in broken and membranous eggs in a population of dwarf White Leghorn hens.

2. The production of double‐yolked eggs/100 hen d, high during the initial weeks of lay, rapidly declined and disappeared by 30 weeks of age.

3. The frequencies of broken, membranous and soft‐shelled eggs were significantly correlated with each other and with the frequency of multiple daily ovulations indicating a common aetiology for these defective egg types.

4. Double‐yolked eggs were produced by the heavier, earlier‐maturing pullets in the population.

5. Normal egg production in dwarf White Leghorns may be enhanced by reducing the incidence of defective eggs.     

Welfare assessment of broiler breeder and layer females subjected to food restriction and limited access to water during rearing

1. A factorial experiment was conducted to assess the welfare at different ages of two strains of broiler breeder and one layer strain during rearing using a range of indicators. The birds were fed ad libitum or restricted and provided with free or limited access to water.

2. Food‐restricted birds spent a large proportion of time scratching and pecking the litter compared with birds fed ad libitum.

3. The heterophil/lymphocyte ratio and the proportion of basophils were raised at 8, 12 and 16 weeks, and the plasma concentrations of corticos‐terone were higher at 8 and 12 weeks of age in restricted birds compared with those fed ad libitum.

4. Creatine kinase activity was higher in broiler breeders fed ad libitum compared with layers and restricted broiler breeders. The activity of aspartate transaminase was higher in restricted layers compared with birds fed ad libitum and was similar in broiler breeders.

5. Plasma viscosity was lower in food‐restricted compared with ad libitum‐fed birds.

6. Limiting access to water had little or no effect on the welfare indicators although food‐restricted birds with free access to water spent more time drinking than birds fed ad libitum.

7. There were no important differences between the two broiler strains. Layers spent less time resting than broiler breeders and had higher plasma corticosterone concentrations at 3 and 16 weeks of age.

8. It was concluded that there was evidence for physiological stress associated with restricted feeding at least between 8 and 16 weeks of age. It was suggested that the altered behaviour of broiler breeders kept on litter may indicate that they can cope with food restrictions and that this may be acceptable in relation to the long‐term benefits of limiting body weight during rearing. The same may not be true for layers.     

In vitro initiation of the acrosome reaction in the emu (Dromaius novaehollandiae)

1. An assessment of the efficiency of the acrosome reaction (AR) provides an important predictor of the fertilizing potential of semen and for diagnosis of the causes of infertility. A standardized protocol was therefore developed for initiation of the acrosome reaction in emu spermatozoa in vitro, and the role of CaCl₂ or perivitelline membrane (PVM) proteins in determining the outcome of the reaction was investigated.

2. The acrosome reaction (assessed by FITC-PNA) was successfully induced in live spermatozoa by incubation for 2 min in NaCl-TES medium supplemented with 5 mM CaCl₂. The maximum response was 32% live acrosome-reacted spermatozoa (LAR) achieved after 10 min incubation.

3. Compared to the outcome with 5 mM CaCl₂ or PVM protein alone, the response was significantly better with a combination of PVM protein and CaCl₂.

4. A significant variation in the percentage of LAR spermatozoa among individual males was observed. No treatment affected the percentage of dead acrosome-reacted spermatozoa.

5. The results emphasize the important role played by both PVM proteins and Ca²⁺ in the in vitro initiation of the acrosome reaction.     

Eggshell of the domestic guinea fowl

1. Physical characteristics of eggs of the domestic guinea fowl, Numida meleagris galeata, were measured and compared with those of its wild counterpart and with other birds using allometric relationships.

2. The shell thickness increased and the area density of pores decreased from the blunt to the pointed end of the egg. During incubation, shell thickness decreased, but the shell diffusive conductance to water vapour (G_H2O) remained constant.

3. Fresh egg mass (m₀), length and breadth of the egg, G_H2O and specific water vapour conductance, spG_H2O (G_H2O per g of m₀ ), were affected by the age of the laying flock.

4. Eggs of the domestic guinea fowl were bigger and heavier than eggs of the wild one.

5. Allometry showed that guinea fowl eggs differ from those of the other birds by their greater shell thickness and density of pores. However spG_H2O was normal, the thickness of the shell being compensated for by a greater density of pores for gas exchanges.     

Effect of lighting treatment on the productivity,health, behaviour and sexual maturity of heavy male Turkeys

1. Turkey poults (1620) were used to compare the effects of three lighting programmes on heavy strain males reared to 188 d: constant light (24L:0D, CON); increasing light (6L:18D at 7 d gradually increasing to 20L:4D by 63 d, INC); a pattern identical to INC followed by a decrease in daylength from 84 d to 10L:14D at 112 d (DID).

2. Lighting affected growth pattern but had no effect on body weight at 118 d or overall food to gain ratio.

3. Both INC and DID lighting reduced overall mortality in comparison to CON light primarily because of a reduction in the incidence of skeletal disease and spontaneous cardiomyopathy. INC and DID lighting increased the incidence of cannibalism.

4. Turkeys given INC or DID lighting had a superior ability to walk in comparison to those birds given CON light.

5. INC and DID males stood, ate and drank more frequently, and sat less often than CON turkeys during behavioural observation.

6. There were no lighting effects on carcase composition except that INC and DID birds had heavier keel bones. The ultimate force per cm² (stress) required to break femora was greater for turkeys given INC and DID lighting (P = 0.065).

7. Plasma testosterone concentrations at 117 d were 272.5, 115.2 and 29.5 pg/ml for turkeys given CON, INC and DID lighting, respectively (P= 0.072). Testosterone concentration was not related to growth rate.