Physical and mechanical properties of eggshell as affected by chicken breed and flock age.

1. A study was conducted to evaluate the relationship among physical and mechanical properties of the eggshell, as affected by breed and hen's age. 2. Data on eggshell quality (external characteristics and derived measurements) were obtained from 322 laying hens, from three breeds (Fayoumi, Dandarawi and Hy-Line Brown) during the laying cycle, starting from 38 wks of age for four experimental periods (38, 46, 54 and 62 wks). 3. Eggs obtained from the Fayoumi breed exhibited the highest shell thickness and breaking force. There was a linear improvement in eggshell quality attributes associated with hen's age up to 54 wks, thereafter a deterioration was found for all breeds. 4. Generally, eggs laid by native breeds (Fayoumi and Dandarawi) had better mechanical properties compared to those produced by the commercial strain (Hy-Line Brown). In addition, the interaction between breed and hen's age was not significant for any physical property or mechanical attribute. There was a highly significant (P ≤ 0.01) positive correlation between the breaking force and either eggshell toughness or shell thickness, and regression analyses suggested that eggshell toughness was the best predictor for breaking force, followed by shell thickness.

Influence of probiotic supplementation on immune response in broilers raised under hot climate.

1. The objective of the study was to evaluate the potential effects of dietary probiotic supplementation and stocking density and their interaction on growth performance, humoral and cellular immune responses of broiler chickens raised under hot climate conditions. 2. A total of 1800 1-d-old unsexed broiler chicks (Ross 308) were allocated in a completely randomised 3 × 2 factorial design, with three concentrations of dietary probiotic (0, 200 and 400 mg/kg) containing 4 × 109 cfu/g of Bacillus subtilis and two stocking densities (12 or 18 birds/m2) in a total of 6 treatment subgroups. 3. Dietary probiotic and stocking density had no significant effect on live body weight, feed consumption and feed conversion ratio. 4. Dietary probiotic supplementation had a positive effect on serum immunoglobulin M (IgM) and cell-mediated immunity when compared to the control at 6 weeks of age, whereas serum immunoglobulin A (IgA) and immunoglobulin Y (IgY) were improved, but not significantly so. Dietary probiotic and stocking density had no effect on relative weights of the bursa of Fabricius and spleen. 5. Dietary probiotic supplementation had a positive significant effect on serum IgM concentration and cell-mediated immunity without penalising growth performance in broilers raised under high ambient temperature.

Dietary supplementation of Eucalyptus leaves enhances eggshell quality and immune response in two varieties of Japanese quails under tropical condition.

The effect of dietary supplementation of Eucalyptus leaves (EL) powder on productive performance and immune response in 2 varieties of Japanese quail was investigated. A total of 180 twelve-week-old laying Japanese quails from 2 color varieties (gray and white) were randomly assigned and distributed according to a completely randomized design in a 3 × 2 factorial arrangement (dietary treatment × variety) forming 6 subgroups (30 each). EL were mixed with the diet in 3 levels (0, 0.1, and 0.2%). Each hen was individually housed in a wire cage of laying batteries and kept in an open house under hot environmental temperature. Productive traits were determined for an experimental period of 6 wk. Egg quality, carcass traits, blood parameters, and immune response were also determined. The results indicated that the productive traits were not significantly affected by EL supplementation. Shell quality and broken eggs significantly improved in quails fed a diet containing EL compared with those in the control. The quails fed a diet supplemented with 0.1% EL exhibited significantly higher cellular mediated and humoral immune responses than those in the other treatment groups. Glutathione peroxidase activity tended to be significantly increased by the dietary administration of EL at the level of 0.2%. Concerning quail varieties, it could be noticed that the gray quails exhibited higher productive performance, shell quality, and cellular immunity than the white counterparts. It could be concluded that supplementing a diet with 0.1 EL as a natural feed additive greatly enhances eggshell quality and immunocompetence and reduces number of broken eggs of Japanese quails raised under high environmental temperature.

Effect of the naked neck gene on carcase composition and immunocompetence in chicken.

1. An experiment was conducted to study the effect of naked neck gene (Na) on carcase measurements and some immunological responses of chickens. 2. The presence of naked neck gene in a single or double state increased body weight. 3. The naked neck genotypes (NaNa or Nana) exhibited higher relative weight of dressed carcase, drumstick and breast muscles compared to normally feathered individuals (nana). The proportion of abdominal fat was decreased in both naked neck genotypes compared with normally feathered ones. 4. A higher (non-specific) cell-mediated immune response was evoked in Na gene bearing birds. 5. Higher concentrations of antibodies occurred after injection of sheep red blood cells into naked neck birds, particularly at 14 d post-secondary injection. 6. The NaNa birds had a higher heterophil/lymphocyte ratio than Nana and nana siblings.

Evaluation of genetic diversity of Saudi native chicken populations using microsatellite markers.

The present study was conducted to evaluate the genetic diversity and relationships of 5 Saudi native chicken populations and a White Leghorn (L) strain as an exotic breed, using 25 microsatellite markers. According to morphological appearance and plumage color and pattern, they were classified into black (BL), black-barred (BR), dark brown (DB), light brown (LB), and gray (G) breeds. Twenty-five microsatellite markers were chosen based on the degree of polymorphism reported in the previous literature. The results revealed that all studied markers exhibited a varied percentage of polymorphism among native chicken populations. However, there were 81 polymorphic loci out of 109 loci. Based on cluster analysis, 3 main clusters of chicken populations were identified. Two clusters comprised native chicken breeds, while the L strain set the third one. Higher similarity was found between either black and gray populations (BL and G) or brown populations (LB and DB). They had a closer relationship to each other. Genetic distance between each couple was 0.11 and 0.12, respectively. The productive results revealed that the black breed had significantly (P < 0.0001) lighter body weight at sexual maturity compared to the other breeds. There was no significant difference between light and dark brown breeds for most productive traits. The genetic diversity we found among Saudi chicken populations may be of interest for improving productive performance and adaptability.

Effect of long-term selection for egg production on eggshell quality of Japanese quail (Coturnix japonica).

An experiment was conducted to evaluate egg quality and ultrastuctural measurements of eggshell using a Scanning Electron Microscope (SEM) in 2 lines (selected and control) of Japanese quail. A selection program was applied over 22 consecutive generations for higher egg production and lower broken egg percentage. The results revealed that the females of the selected line produced significantly (P < 0.01) higher egg mass compared to that of the control line. Also, the selection procedure significantly improved feed conversion ratio. The eggshells of the selected line had a higher breaking strength compared to those of the control line, although there was no difference between them in shell thickness. Significantly higher wet (P < 0.01) and dry (P < 0.05) eggshell percentages were found in the selected line. In general, the eggshells of the selected line had a lower total score (good) of ultrastructural evaluation compared to the control line. According to scanning electron microscope data, the incidence of certain structural variants was more common in eggshells of the control line suggesting poor shell strength. The incidence of alignment was more prevalent in control eggshells compared to selected ones, suggesting lower resistance to breakage. Late fusion and large interstitial spaces of the palisade layer indicating decreased resistance to fracture were observed in control eggshells. It could be concluded that the improvement eggshell quality may be caused by the long-term selection for lower cracked and broken egg rates from generation to generation.

Phylogenetic analysis using d-loop marker of mtDNA of Saudi native chicken strains.

This study was carried out to figure the potentiality of d-loop of mitochondrial DNA in discriminating among Saudi native chicken strains and other species of genus Gallus. The first 500 base pairs of d-loop region were amplified and successfully sequenced. The results indicated that native chicken strains and genus Gallus species have a tandem repeat sequence with (14) base units into a two copy. Also, there was clear evidence that the native chickens have a unique tandem repeat sequence with (42) base units as a two copy. Two haplotypes (T) and (C) were observed in native chicken strains. Our research displayed approximately (26) transition substitutions in nucleotide sequences specific for native chicken strains, whereas it was 120 mutant sites in case of other species of Gallus. We found that the genetic divergence between these types of chickens was very low (0.022). The phylogenetic tree revealed that each strain of native chicken belonged to each other with the same cluster. In addition, each strain has its own cluster in some individuals. The results showed that the native chicken strains are closely related to Gallus gallus and its subspecies G. g. spadiceus and G/. g. bankiva.

Effect of drugs on brain acetylcholine level in Gerbillus pyramidum.

1. The quantitative estimation of total acetylcholine content in the whole brain tissue in normal Egyptian gerbil Gerbillus pyramidum, gives an average of 1.43 +/- 0.06 micrograms of acetylcholine chloride/g fresh brain tissue. 2. The brain acetylcholine level in Gerbillus pyramidum was generally found to vary with the changes induced in the brain activity by drugs. 3. Depressants caused a increase and convulsants a decrease in total brain acetylcholine level. 4. Phenytoin depressed the brain activity but lowered brain acetylcholine level.

Effect of tranquilizers on the total acetylcholine content and acetylcholinesterase activity in the brain tissue of Arvicanthis niloticus.

The effect of reserpine and meprobamate on the total acetylcholine content and acetylcholinesterase activity in the brain tissue of the kusu rat, Arvicanthis niloticus, was studied. The total acetylcholine content and acetylcholinesterase activity were determined 1 hr after i.p. injection of different doses of reserpine (0.25, 0.5 and 1 mg/ml/100 g body wt) and meprobamate (6.25, 12.5 and 25 mg/ml/100 g body wt). The effect of different time intervals (1, 10, 30 min, 1, 2.5, 5, 8, 12, 24 and 48 hr) on the total acetylcholine content and acetylcholinesterase activity was investigated after i.p. injection of 0.5 mg of reserpine and 12.5 mg of meprobamate/ml/100 g body wt. Both reserpine and meprobamate caused an increase in the total ACh content in the brain tissue of Arvicanthis niloticus which was suggested to be due to a decrease in the release of ACh, since both reserpine and meprobamate inhibited AChE activity after some tested periods. The effect of meprobamate was observed to be stronger than that of reserpine.

Effect of barbitone sodium and thiopental sodium on brain dopamine, noradrenaline, serotonin and 5-hydroxyindoleacetic acid content in Arvicanthis niloticus.

The quantitative estimation of total dopamine (DA), noradrenaline (NE), serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) content in the whole brain tissue of normal Nile grass rat, Arvicanthis niloticus, gives and average of 631 +/- 12 ng DA/g, 366 +/- 12 ng NE/g, 617 +/- 15 ng 5-HT/g and 431 +/- 10 ng 5-HIAA/g fresh brain tissue. The effect of barbitone sodium and thiopental sodium on the total DA, NE, 5-HT and 5-HIAA content in the brain tissue of the Nile grass rat, Arvicanthis niloticus, was studied. The total DA, NE, 5-HT and 5-HIAA contents were determined 5 hr after i.p. injection of different doses of barbitone sodium (20, 40 and 80 mg/ml/100 g body wt) and thiopental sodium (5, 10 and 20 mg/ml/100 g body wt). The effect of different time intervals (1, 10, 30 min, 1, 2.5, 5, 8, 16, 24 and 48 hr) on the total brain DA, NE, 5-HT and 5-HIAA content was investigated after i.p. injection of 40 mg of barbitone sodium and 10 mg of thiopental sodium/ml/100 g body wt. Both barbitone sodium and thiopental sodium caused an increase in DA, NE and 5-HT content and a decrease in 5-HIAA content in the brain tissue of Arvicanthis niloticus. The increase in the whole brain contents of DA, NE and 5-HT after the administration of barbitone sodium and thiopental sodium may be due either to inhibition of transmitter release by an action at the monoamine nerve terminal or to effects causing a decrease in nerve impulse flow. On the other hand, the decrease in 5-HIAA may be due to the decrease in the turnover of 5-HT.

Effect of thiopental sodium and barbitone sodium on the total acetylcholine content and acetylcholinesterase activity in the brain tissue of Arvicanthis niloticus.

The total ACh content and AChE activity were determined 1 hr after the i.p. injection of different doses of thiopental sodium (5, 10 and 20 mg/ml/100 g body wt) and barbitone sodium (20, 40 and 80 mg/ml/100 g body wt). The effect of different time intervals (1 min, 10 min, 30 min, 1 hr, 2.5 hr, 5 hr, 8 hr, 12 hr, 24 hr and 48 hr) on the total ACh content and AChE activity was investigated after i.p. injection of 10 mg thiopental sodium and 40 mg barbitone sodium/ml/100 g body wt. Both thiopental sodium and barbitone sodium increased the total ACh content in the brain tissue of Arvicanthis niloticus. Both drugs inhibited the brain AChE activity. It is thought that the increase in the total ACh content in the brain tissue of Arvicanthis niloticus may be due to a decrease in the release of ACh from the neuronal tissue and a decrease in AChE activity.

Accuracy of ultrasound in the diagnosis of nonfunctioning kidneys.

The accuracy and reliability of ultrasound were assessed in 246 patients with 338 radiologically nonfunctioning renal units. The causes of nonfunction included hydronephrosis, pyonephrosis, renal parenchymal disease, renal agenesis, renal neoplasm and polycystic disease. Obstruction was proved in 158 patients, with an accuracy of 98.1 per cent. Retrograde pyelography was avoided. The diagnosis of a small end stage kidney was correct in 42 patients. In 9 patients with a unilateral nonfunctioning kidney less than 9 cm. long a thin coarsely textured cortex with dilatation of 1 or more calices was found. To our knowledge the presence of dilated calices in a small kidney, suggestive of chronic pyelonephritic changes, has not been described previously by ultrasound. Nonvisualization occurred in 16 cases (4.7 per cent) despite the anatomical presence of a kidney. An advanced degree of pyonephrosis with thick inspissated pus sometimes may mimic the ultrasonic appearance of a renal neoplasm.