Khaleel Jawasreh

Thermal manipulation during chicken embryogenesis results in enhanced Hsp70 gene expression and the acquisition of thermotolerance

The aim of this study was to evaluate the effect of thermal manipulation (TM) during embryogenesis on hatchability, growth performance and thermotolerance acquisition parameters during thermal challenge (TC). Seven-hundred and fifty fertile chicken eggs were divided randomly into three groups (250 eggs each): control group was maintained at 37.8°C and 56% relative humidity (RH), TM1 was subjected to TM at 38.8°C for 6h and 65% RH during embryonic days (ED)10-18 and TM2 was subjected to TM at 38.8°C for 18 h and 65% RH during ED10-18. Hatched chicks from each treatment group were then randomly divided into two sub-treatment groups (Naive and TC). Chicks in TC groups were subjected to TC by adjusting room temperature to 41.0°C for 6h on days 3, 7, and 42 of age while naïve chicks were kept under regular conditions (25 ± 1°C and 50-60% RH). Percentage of hatched eggs was recorded and post-hatch chick performance was evaluated by recording chick body weight (BW). Chicks response to TC was evaluated by determination of body temperature (T(b)), plasma T3 and T4 levels, and muscle mRNA levels of Hsp70. There was a significant increase in muscle mRNA levels of Hsp70 during embryogenesis and during TC in post-hatch chicks. While hatchability was not adversely affected, the body weight in TM2 chicks was significantly higher at the end of the study period (42 days). Results of this study indicated a long-term enhancement of Hsp70 gene expression associated with improved thermotolerance acquisition in treated chicks without adversely affecting performance.

Hsp90, Hsp60 and HSF-1 genes expression in muscle, heart and brain of thermally manipulated broiler chicken.

The effect of thermal manipulation (TM) during embryogenesis (ED 12-18) on mRNA expressions of heat shock proteins (Hsp90, Hsp60 and HSF-1) in muscle, heart and brain tissues during thermal challenge (TC) at post-hatching days 10 and 28 was investigated. Fertile chicken eggs were randomly divided into four groups: Control group (37.8 °C), TM1 (39 °C for 9 h), TM2 (39 °C for 12 h) and TM3 (39 °C for 18 h). At days 10 and 28 of age, chicks in TC groups were subjected to thermal challenge (TC) at 43.0 °C for 6 h while naïve chicks were kept under regular conditions. When compared with the control, TM resulted in a significant increase in mRNA levels of Hsp90, Hsp60 and HSF-1in muscle, heart and brain tissues during embryogenesis and during TC at days 10 and 28 post-hatching. These results indicate a long-term enhancement of Hsp90, Hsp60 and HSF-1 gene expressions associated with improved thermotolerance acquisition in thermally manipulated chicks.

Female reproductive tract anatomy of the endangered Arabian oryx (Oryx leucoryx) in Jordan

Female reproductive anatomy of the Arabian oryx is unknown. In this study, reproductive tracts of seven female Arabian oryx (aged 2 to 7 years) were examined to characterize their reproductive anatomy. Observations and measurements were obtained in situ from dead animals during necropsy. Animals were allocated into two groups: cycling (n = 3; follicles or corpora lutea present) and not-cycling (n = 4; follicles or corpora lutea absent). Different reproductive tract segments for each animal in both groups were measured using a digital caliper. The mean, SD and range for each reproductive tract segment were generated and compared between groups. Female oryx reproductive anatomy share some anatomical characteristics with that of domestic ruminants except that the oryx uterus has no distinct uterine body and the cervix has two internal openings for each respective uterine horn. In addition, there were more than 8 rows of caruncles within each uterine horn. There were significant differences in the length and width (P < 0.05), but not in height, of both the right and left ovaries between cycling and not-cycling animals (P > 0.05). Posterior and anterior vaginal lengths varied between cycling and not-cycling groups (P < 0.05). Length of right and left oviducts, left and right uterine horns, cervix and vulva did not vary between cycling and not-cycling groups (P > 0.05). Defining this unique morphology of female Arabian oryx reproductive anatomy will help in the development of appropriate reproductive techniques in order to propagate this endangered species and control its reproduction.

Genetic diversity and population structure of local and exotic sheep breeds in Jordan using microsatellites markers

Aim: This study was conducted to study the genetic and population structure of local (Awassi) and exotic (Romanov, Charollais, Assaf, Awassi, and Suffolk) sheep breeds in Jordan using eight microsatellite markers. Materials and Methods: A total of 125 sheep were used (25 from each breed) in the study. The number of alleles (A), the mean values of observed (Ho) and expected (He) heterozygosity, polymorphism information content (PIC), fixation index as a measure of heterozygote deficiency or excess, and Hardy–Weinberg equilibrium (HWE) were analyzed using PopGen and CERVUS softwares. Nei’s standard genetic distances among breeds and dendrogram of unweighted pair group method with arithmetic mean (UPGMA) were calculated and constructed using PopGen software. Results: A total of 40 alleles were detected with an average number of alleles of 5. The mean Ho value was higher than the mean He value for all breeds. Awassi breed showed the highest average PIC value while Romanov had the lowest. There was a significant (p<0.05) deviation from HWE at each locus within and between breeds. Deviations from HWE were found to be highly significant for all markers except OARFCP304 locus. The genetic distance estimates revealed a close relationship between Romanov and Charollais and between Awassi and Charollais. In the UPGMA dendrogram, Charollais, Romanov, and Awassi breeds were placed together in one main cluster while Assaf was in a different subcluster. Awassi was placed alone in a second main cluster. Conclusion: Results of this study offer insight toward the genetic conservation of the studied breeds and a base on which breeding plans can be made.

The effects of Saccharomyces cerevisiae supplementation on intake, nutrient digestibility, and rumen fluid pH in Awassi female lambs

Aim: The aim of this study was to evaluate the effect of feeding low (LO)- or high (HI)-fiber diets supplemented with Saccharomyces cerevisiae (SC) on nutrient intake, digestibility, nitrogen balance, rumen fluid pH, and serum concentrations of glucose and urea nitrogen in Awassi female lambs in a 2×2 factorial arrangement of treatments. Materials and Methods: Experimental diets were as follows: (1) LO-fiber diet with no SC supplementation (−LO), (2) LO-fiber diet supplemented with SC (+LO), (3) HI-fiber diet with no SC supplementation (−HI), or (4) HI-fiber diet supplemented with SC (+HI). Eight female lambs were used in a replicated 4×4 Latin square design with 15-day experimental periods (10-day adaptation period and 5-day collection period). Results: A fiber×SC interaction (p≤0.05) was detected for dry matter (DM) and crude protein (CP) intake among diets showing greater DM and CP intake for +LO diet compared to +HI group supplemented with SC, whereas −LO and −HI were intermediate. A fiber×SC interaction (p=0.05) was also detected for the neutral detergent fiber (NDF) intake among diets. Intake of NDF was greater for the –HI diet compared with +LO and –LO diets. Similarly, NDF intake was greater for +HI diet than –LO diet. A tendency (p=0.07) for a fiber×SC interaction was detected for acid detergent fiber (ADF) intake among diets as well. ADF intake tended to be greater for HI-fiber diets. No difference was observed in the rumen fluid pH for lambs fed with the different diets. No fiber×SC interactions were detected for the digestibility of DM, CP, NDF, and ADF among dietary treatments. Digestibility of DM was greater (72.9 g/100 g vs. 67.1 g/100 g; p=0.0002) for LO versus HI fiber. However, NDF and ADF digestibilities were greater (60.8 and 61.9 g/100 g vs. 55.8 and 52.7 g/100 g for NDF and ADF digestibility, respectively; p≤0.01) for the HI-fiber than the LO-fiber diets. Conclusion: Results obtained in the current study indicate that SC supplementation has a minimal effect on the performance of Awassi female lambs fed with varying fiber levels.

Genetic parameter estimation for pre-weaning growth traits in Jordan Awassi sheep

Aim: The aim of this study was to estimate the heritability, genetic and phenotypic correlations, and the genetic trends for pre-weaning growth traits including the birth weight (BWT), weaning weight (WWT), pre-weaning daily gain (PWDG), and weaning age (WA) in Awassi lambs. Materials and Methods: A total of 5131 Awassi lambs from two Jordanian sheep breeding stations were used. A multitrait animal model and restricted maximum likelihood methods were used to estimate the covariances between the studied traits. Results: The mean±standard deviation of BWT, WWT, PWDG, and WA was 4.48±0.8 kg, 17.13±0.7 kg, 0.2±0.07 g, and 65.5±0.7 days, respectively. Heritability estimates were 0.30±0.04 for BWT, 0.19±0.04 for WWT and PWDG, and 0.2±0.04 for WA. Positive genetic correlations were obtained between BWT and other traits, while negative correlations were obtained between WWT, PWDG, and WA (−0.50±0.12) and between WWT and WA (−0.67±0.14). The positive phenotypic correlation was obtained between WA and PWDG (0.63±0.01). The highest additive genetic variance was obtained for WA (34.58), while the lowest was estimated for PWDG (6.22E-04). The highest phenotypic variance was obtained for WA (175.5), while the lowest value obtained was for BWT (0.54). Maternal additive variance ranged between 0.13 and 0.03. The genetic trends were around zero for all studied traits. Conclusion: Selection should be conducted using animals with high estimated breeding values through controlled breeding.