Laying performance, genetic parameters, and the expression of FSHß, LHß, FSHR, and LHR genes in Japanese quails selected for early egg production.

Investigating the impact of early egg production selection (the first 90 d of laying) on egg production features, cumulative selection response (CSR), and the mRNA expression of gonadotropins (FSHß and LHß), and their receptors (FSHR and LHR), in Japanese quails was the goal. The selection experiment involved 1293 females in all, 257 from the base group and 1036 from the 4 selected generations. Age and body weight at sexual maturity (ASM, BWSM), weight of the first egg (WFE), days to the first 10 eggs (DF10E), egg mass for the first 10 eggs (EMF10E), egg weight (EW), egg number at the first 90 d of laying (EN90D), and egg mass at the first 90 d of laying (EM90D) were all recorded. Most egg production traits had heritability estimates that were low to moderate and ranged from 0.17 to 0.33., where the highest estimates were reported for EN90D (0.33) and BWSM (0.32). With the exception of EN90D, low to moderate positive genetic correlations were observed between ASM and other egg production traits (0.17-0.44). The fourth generation showed significantly (P < 0.05) lower ASM and DF10E but higher BWSM, WFE, EN90D, EM10E, and EM90D when compared with the base generation. CSR were significant (P < 0.05) for ASM (-6.67 d), BWSM (27.13 g), WFE (0.93 g), DF10E (-1.25 d), EN90D (7.24 egg), EM10E (10.57 g), and EM90D (140.0 g). FSHß, LHß, FSHR, and LHR gene mRNA expression was considerably (P < 0.05) greater in the fourth generation compared to the base generation. In conclusion, selection programs depending on the efficiency of egg production (EN90D) could improve the genetic gain of egg production traits and upregulate the mRNA expression of FSHß, LHß, FSHR, and LHR genes in selected quails (fourth generation). These findings might help to enhance breeding plans and create commercial lines of high egg production Japanese quails.

Muscle oxidative stability, fatty acid and amino acid profiles, and carcass traits of broiler chickens in comparison to spent laying hens.

This research compared muscle oxidative stability, meat composition, and carcass traits in commercial broilers and spent laying hens. At week 65 of age, 40 ISA Brown laying hens were randomly selected to create 10 replicate cages (4 birds per cage). Also, 60 day-old Ross chicks were equally divided into six replicates (10 chicks each). Broiler chickens had a higher dressing percentage than spent hens (P = 0.027), but a lower abdominal fat percentage (P = 0.009). Spent hens had higher level of malondialdehyde (MDA) in the breast muscles (P = 0.001). Meanwhile, the MDA levels in thigh muscles did not differ in both groups (P = 0.328). Broiler chickens showed greater concentrations of saturated fatty acids (palmitic and stearic) in the breast (P = 0.012 and 0.006, respectively) and thigh (P = 0.033 and 0.038, respectively) muscles as compared to spent hens. Meanwhile, broiler chickens had lower concentrations of palmitoleic, oleic and eicosapentaenoic in the breast muscles (P = 0.002, 0.004 and 0.001, respectively). Also, spent hens had greater concentrations of linoleic in the breast and thigh muscles (P = 0.018 and 0.035, respectively). When compared to broiler chickens, spent hens had greater essential amino acids (isoleucine, methionine and tyrosine) concentrations in the breast muscles (P = 0.002, 0.001 and 0.036, respectively). Finally, while broiler chickens had superior carcass traits, spent hens showed better meat composition (higher polyunsaturated fatty acids and essential amino acids). Furthermore, the oxidative stability of the breast muscles of spent hens was lower than that of broilers. Spent hens can be used as an attractive source of chicken meat if certain precautions are adopted.

Performance, Blood Lipid Profile, and the Expression of Growth Hormone Receptor (GHR) and Insulin-like Growth Factor-1 (IGF-1) Genes in Purebred and Crossbred Quail Lines.

The aim was to evaluate the performance, blood lipid profile, and the relative expression of growth-related genes in purebred white and brown quail lines and their crossbred lines. A total of 240 one-day-old Japanese quail chicks of white and brown line, their crossbred line (WBQ: male white × female brown), and reciprocal crossbred line (BWQ: male brown × female white) were divided into four equal groups (60 birds each). The white quail line showed significantly higher final body weight, daily gain, and feed intake compared with the other quail lines (p < 0.001). Meanwhile, both crossbred quail lines (WBQ and BWQ) showed significantly lower FCR compared with both purebred quail lines (p = 0.001). Both crossbred quail lines showed greater dressing percentages compared with both purebred quail lines (p = 0.038). The brown quail line showed significantly (p = 0.05) higher levels of serum triglycerides and VLDL compared with the white and BWQ lines. The WBQ crossbred line exhibited significantly higher mRNA expression of GHR and IGF-1 genes compared with other quail lines (p < 0.001). Both crossbred lines (WBQ and BWQ) exhibited negative heterosis percentages for body weight (−4.39 and −3.90%, respectively) and feed intake (−10.87 and −14.59%, respectively). Meanwhile, heterosis percentages for FCR (−6.46 and −9.25%, respectively) and dressing percentage (7.54 and 6.38%, respectively) were improved in both crossbred lines. The WBQ line showed high heterosis percentages for the expression of GHR and IGF-1 genes (52.28 and 88.81%, respectively). In conclusion, the WBQ line exhibited significantly greater dressing percentage and better FCR, as well as higher mRNA expression of GHR and IGF-1 genes. These results may be helpful to improve breeding programs and to develop commercial lines of meat-type Japanese quail.

Association of LEPR polymorphisms with egg production and growth performance in female Japanese quails.

This study aimed to screen intron 8 of the leptin receptor (LEPR) gene for polymorphisms in female Japanese quails. Two adjacent novel SNPs (A277G and A304G) were detected using PCR-SSCP and sequencing. These SNPs produced three haplotypes (AA/AA, AG/AG, and GG/GG) that were significantly (p ≤ 0.05) associated with growth and egg production traits. GG/GG haplotype-quails had significantly (p ≤ 0.05) lower egg production, feed intake, growth performance, lipid profile, serum levels of sex hormones (estradiol, progesterone, FSH, LH), and ovarian expressions of survivin, FSHR, and IGF1 than other quails. However, GG/GG quails had significantly (p ≤ 0.05) higher serum levels of LEP and mRNA levels of LEPR, LEP, and caspase 3 in the hypothalamus and ovaries. These higher levels of LEP/LEPR could not only reduce feed intake and body weight gain but also could induce apoptosis of ovarian cells (as indicated by lower survivin and IGF1 and higher caspase3 expression) which could inhibit the development of the follicles and the release of sex hormones with a subsequent decrease in egg production in GG/GG quails. Therefore, with these results, we suggest selecting Japanese quails with AA/AA and AG/AG haplotypes to improve the reproduction and growth performance of this flock.

Reproductive Performance and Culling Rate of Purebred Holstein Cows and Their Crosses With Fleckvieh and Brown Swiss Cows Under Subtropical Conditions.

This study aimed to elucidate the reproductive performance of purebred Holstein (HO) cows with their crosses with Fleckvieh (FV) and Brown Swiss (BS) cows under subtropical conditions. A total of 677 cows [487 HO, 104 HO × FV (HFV); 50% FV and 50% HO and 86 HO × BS (HB); 50% BS and 50% HO] were enrolled in this study. Pure HO cows had significantly greater service per conception (S/C; 3.69), days open (147.9 days), and calving interval (449.6 days), than the HFV (2.89, 116.7, and 407.4 days, respectively) and HB (3.07, 134.3, and 434.2 days, respectively) crossbred cows. At day 28, the conception percentage was significantly greater among HFV crossbred cows vs. pure HO cows [crude odds ratios (COR) = 2.16], but embryonic loss, abortion percentage, calving difficulty, and retained placenta percentage were similar (p > 0.05) among pure HO cows and their crosses. HFV crossbreds had significantly lower incidence of endometritis (COR = 0.70, p = 0.035), mastitis (COR = 0.69, p = 0.015), and ketosis (COR = 0.53, p = 0.004) vs. other cows. HB and pure HO cows had a similar incidence of mastitis, lameness, and ketosis (COR = 0.76, 0.75, and 0.81; p = 0.223, 0.468, and 0.492, respectively). HFV crossbred cows had a lower risk of culling rate than HB crossbred cows. In summary, HFV cows demonstrated the best reproductive performance in terms of S/C, days open, calving interval, conception at 28 days, mastitis percentage, ketosis percentage, and endometritis.

Oxidative Stability, Carcass Traits, and Muscle Fatty Acid and Amino Acid Profiles in Heat-Stressed Broiler Chickens.

The objective was to elucidate the effects of chronic heat stress on carcass traits, muscle oxidative stability, muscle fatty acids and amino acid profiles in broiler chickens. A total of 100-day-old male Ross broiler chicks were divided into two equal groups of five replicates. The control group (TN) was maintained on a thermoneutral condition, while the experimental group (HS) was subjected to 8 h of heat stress (34 °C). The HS group showed lower dressing percentage and breast yield compared with the TN group (p = 0.040 and 0.042, respectively). Meanwhile, heat stress significantly increased the percentage of abdominal fat in broiler chickens (p = 0.001). The HS group showed significantly lower levels of PUFA (linoleic, docosahexaenoic and eicosapentaenoic) in the breast (p = 0.003, 0.002 and 0.001, respectively) and thigh (p = 0.001, 0.009 and 0.003, respectively) muscles than did the TN group. The levels of α-lenolinec acid in the breast and thigh muscles did not differ between both experimental groups (p = 0.818 and 0.060, respectively). With exception of threonine, tyrosine and phenylalanine, the levels of essential AA in the breast muscles were significantly (p ˂ 0.05) reduced in the HS group. The HS group showed significantly higher concentration of malondialdehyde (MDA) in the breast muscles (p = 0.032). Meanwhile, the concentration of MDA in the thigh muscles did not differ between both experimental groups (p = 0.149). Furthermore, the HS group showed significantly lower superoxide dismutase and catalase in heart tissues (p = 0.005 and 0.001, respectively). In conclusion, chronic thermal stress deteriorates carcass yield and the oxidative stability of breast muscles, as well as the levels of PUFA and essential AA in broiler chickens. However, the oxidative stability of thigh muscles was not affected.

Performance, Carcass Yield, Muscle Amino Acid Profile, and Levels of Brain Neurotransmitters in Aged Laying Hens Fed Diets Supplemented with Guanidinoacetic Acid.

Guanidinoacetic acid (GA) is a natural precursor of creatine in the body and is usually used to improve the feed conversion and cellular energy metabolism of broiler chickens. The objective was to elucidate the effect of dietary supplementation of GA on carcass yield, muscle amino acid profile, and concentrations of brain neurotransmitters in laying hens. In total, 128 72-week-old ISA Brown laying hens were assigned to four equal groups (32 birds, eight replicates per group). The control group (T1) was fed a basal diet with no supplements, while the other experimental groups were fed a basal diet supplemented with 0.5 (T2), 1.0 (T3), and 1.5 (T4) g GA kg-1 diet. The T3 and T4 groups showed higher hen-day egg production and carcass yield compared to the control group (p = 0.016 and 0.039, respectively). The serum creatine level increased linearly with the increased level of dietary GA (p = 0.007). Among the essential amino acids of breast muscle, a GA-supplemented diet linearly increased the levels of leucine, isoleucine, phenylalanine, methionine, and threonine in the breast (p = 0.003, 0.047, 0.001, 0.001, and 0.015, respectively) and thigh (p = 0.026, 0.001, 0.020, 0.009, and 0.028, respectively) muscles. GA supplementation linearly reduced the level of brain serotonin compared to the control group (p = 0.010). Furthermore, supplementation of GA in the diet of laying hens linearly increased the level of brain dopamine (p = 0.011), but reduced the level of brain Gamma-aminobutyric acid (p = 0.027). Meanwhile, the concentration of brain nitric oxide did not differ between the experimental groups (p = 0.080). In conclusion, the dietary supplementation of GA may improve the carcass yield and levels of essential amino acids in the breast muscles, as well as the brain neurotransmitters in aged laying hens.

Effects of Chronic Thermal Stress on Performance, Energy Metabolism, Antioxidant Activity, Brain Serotonin, and Blood Biochemical Indices of Broiler Chickens.

The aim of this paper was to investigate the effects of chronic thermal stress on the performance, energy metabolism, liver CoQ10, brain serotonin, and blood parameters of broiler chickens. In total, 100 one-day-old chicks were divided into two equal groups of five replicates. At 22 days of age and thereafter, the first group (TN) was maintained at a thermoneutral condition (23 ± 1 °C), while the second group (TS) was subjected to 8 h of thermal stress (34 °C). The heat-stressed group showed significantly lower ADFI but higher FCR than the thermoneutral group (p = 0.030 and 0.041, respectively). The TS group showed significantly higher serum cholesterol, ALT, and AST (p = 0.033, 0.024, and 0.010, respectively). Meanwhile, the TS group showed lower serum total proteins, albumin, globulin, and Na+ than the TN group (p = 0.001, 0.025, 0.032, and 0.002, respectively). Furthermore, the TS group showed significantly lower SOD and catalase in heart tissues (p = 0.005 and 0.001, respectively). The TS group showed significantly lower liver ATP than the TN group (p = 0.005). Meanwhile, chronic thermal stress significantly increased the levels of ADP and AMP in the liver tissues of broiler chickens (p = 0.004 and 0.029, respectively). The TS group showed significantly lower brain serotonin (p = 0.004) and liver CoQ10 (p = 0.001) than the TN group. It could be concluded that thermal stress disturbed the antioxidant defense system and energy metabolism and exhausted ATP levels in the liver tissues of broiler chickens. Interestingly, chronic thermal stress reduced the level of brain serotonin and the activity of CoQ10 in liver tissues.

Dietary Curcumin Improves Energy Metabolism, Brain Monoamines, Carcass Traits, Muscle Oxidative Stability and Fatty Acid Profile in Heat-Stressed Broiler Chickens.

The aim of the present study was to elucidate the impacts of dietary curcumin supplementation on energy metabolism, brain monoamines and muscle oxidative stability in heat-stressed broilers. In total, 120 day-old chicks were allocated into three equal groups of four replicates. The first group (T1) was maintained on a thermoneutral condition, while the second group (T2) was subjected to 8 h of thermal stress (34 °C), and both groups fed the basal diet with no supplement. The third group (T3) was exposed to the same thermal stress conditions and fed the basal diet supplemented with curcumin (100 mg kg-1 diet). The dietary curcumin supplementation significantly increased the breast yield (p = 0.004), but reduced the percentage of abdominal fat (p = 0.017) compared with the T2 group. The addition of curcumin to broiler diets significantly improved the levels of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) in breast and thigh muscles compared with the T2 group (p < 0.05). The curcumin-supplemented group showed significantly lower levels of malondialdehyde in the breast and thigh muscles than that of the T2 group (p = 0.001 and 0.015, respectively). The dietary curcumin supplementation significantly improved the levels of ATP and CoQ10 in liver tissues (p = 0.012 and 0.001, respectively) and brain serotonin (p = 0.006) as compared to the T2 group. Meanwhile, the heat-stressed group showed significantly higher levels of ADP and Na,K-ATPase in the liver tissues than that of the other experimental groups (p = 0.011 and 0.027, respectively). It could be concluded that dietary curcumin supplementation may improve carcass yield, energy biomarkers, brain serotonin and muscle oxidative stability of heat-stressed broiler chickens.

Royal Jelly Improves the Morphology of the Reproductive Tract, Internal Egg Quality, and Blood Biochemical Parameters in Laying Hens at the Late Stage of Production.

The purpose of this study was to evaluate the effects of royal jelly (RJ) on the morphology of the reproductive tract, egg production, and blood biochemical indices of aged laying hens. In total, 120 Lohman Brown laying hens at week 58 of age were randomly assigned into three equal groups. Pure RJ was dissolved in distilled water and injected subcutaneously as follows: the first treatment (R1; 100 mg RJ kg-1); the second treatment (R2; 200 mg RJ kg-1); the control treatment (CON; 1 mL distilled water). Both RJ-treated groups exhibited a significantly higher number of large yellow follicles (LYFs), small yellow follicles (SYFs), and large white follicles (LWFs) (p ˂ 0.05). Furthermore, RJ treatment significantly increased the diameter and weight of the F1 follicles. However, only the R2 group exhibited significantly greater ovary and uterus weights. RJ treatment did not affect the percentage of oviduct and weight of ovarian stroma. In addition, RJ increased the hen-day egg production rate compared with the CON group; however, only the R2 group showed greater egg weight (p = 0.032). RJ treatment also improved the albumen height, Haugh units, and yolk index. The administration of RJ significantly decreased the serum glucose, but increased the levels of serum albumen and cholesterol. In conclusion, RJ treatment may improve the morphology of the reproductive tract (including follicular growth and oviduct morphology), egg production rate, and internal egg quality traits of aged laying hens.

Effect of cage density on growth rate, carcass traits, muscle amino acid profile, and antioxidant biomarkers of commercial rabbits.

The objective of this work was to elucidate the impact of cage density on growth efficiency, carcass yield, and muscle amino acid profile of fattening rabbits. In total, 96 weaned rabbits were assigned into three cage densities: low cage density (LCD) = 1425 cm2/rabbit; medium cage density (MCD) = 850 cm2/rabbit; high cage density (HCD) = 625 cm2/rabbit. Compared with the HCD, the body gain and feed conversion ratio were better in the LCD and MCD groups (P = 0.003 and 0.004, respectively). The MCD and HCD groups had lower hot carcass weight (P = 0.012) and dressing percentage (P = 0.022) than the LCD group. Compared with the HCD group, the LCD and MCD groups exhibited greater serum GSH (P = 0.029) and SOD (P = 0.032), but significantly lower levels of serum cortisol and cholesterol (P = 0.001 and 0.026, respectively). Regarding the amino acid profile of longissimus dorsi and leg muscles, the LCD group had significantly higher levels of muscle lysine and threonine than the HCD and MCD groups (P˂0.05). The current study indicates that the MCD (850 cm2/rabbit) could maintain an acceptable growth performance, carcass traits, and welfare-related parameters. Furthermore, only the low cage density (1425 cm2/rabbit) may preserve the levels of essential (lysine, isoleucine, and threonine) and nonessential (histidine, proline, and glysein) amino acids in the longissimus dorsi and leg muscles of growing rabbits.

Folic acid and flaxseed oil supplements in Ossimi ewes: effect on body weight changes, progesterone profile, blood chemistry, and litter traits.

The aim was to explore the impact of periconceptional folic acid or flaxseed oil (FXO) supplementation on fertility, progesterone profile, and blood chemistry in pregnant ewes during the breeding season. In total, 54 Ossimi ewes were divided into three groups (18 animals each). The control treatment (CON) fed a basal diet only, while the others fed the basal diet and supplemented every other day with a single bolus of folic acid (FO 500 µg/head) or flaxseed oil (FX 50 ml/head). During the early stage of pregnancy, the FO and FX groups showed significantly higher serum antioxidant activity (glutathione and superoxide dismutase) as compared with the control CON group (P = 0.012 and 0.007, respectively). Although no significant variations were detected in the serum nitric oxide levels during the early stage and mid-stage of pregnancy, the FO and FX groups showed significantly lower serum nitric oxide concentration in the late stage of pregnancy (P = 0.001). The FO and FX groups showed significantly higher serum progesterone concentrations during the early stage (10.9 and 11.4 ng/ml, respectively) and mid-stage (22.2 and 23.4 ng/ml, respectively) of pregnancy as compared with the CON group (7.72 and 13.9 ng/ml, respectively). The FX group exhibited a significantly higher lambing rate (P = 0.034), as well as the proportion of female lambs (P = 0.029) as compared with the CON group. In conclusion, supplementing Ossimi ewes with folic acid or FXO significantly improved the progesterone profile during pregnancy. Moreover, the FXO supplementation significantly increased the lambing rate and the female lamb rate as compared with the control group.

Effects of dietary curcumin and acetylsalicylic acid supplements on performance, muscle amino acid and fatty acid profiles, antioxidant biomarkers and blood chemistry of heat-stressed broiler chickens.

The objective was to investigate the effects of dietary curcumin and acetylsalicylic acid (ASA) on the performance and physiological responses of broiler chickens under chronic thermal stress. One hundred and sixty day-old male chicks (Ross 308) were divided equally into 4 groups (each contained 4 replicates). On the day 22 of age and thereafter, the first group (TN) was raised in a thermoneutral condition (23 ±â€¯1 °C), while the second group (HS) was subjected to 8 h of thermal stress (34 °C) and both groups fed the basal diet with no supplements. The third (CR) and fourth (AS) groups were subjected to the same thermal stress conditions and fed curcumin-supplemented diet (100 mg curcumin kg-1 diet) and ASA-supplemented diet (1 g ASA kg-1 diet), respectively. Dietary treatment had a significant effect on ADFI (P = 0.041), average daily gain (P = 0.013) and final body weight (P = 0.001). The curcumin-supplemented had higher values for these measures compared with other experimental groups (P < 0.05). Also, the dietary curcumin supplement significantly increased the carcass yield as compared to the HS group (P < 0.05). Compared with the HS group, the dietary curcumin and ASA supplements decreased the concentration of malondialdehyde in the breast muscles (P = 0.014). Both dietary supplements exhibited a marked ability to restore the serum TAC, Na and K in heat-stressed broiler chickens. The current study reported a remarkable ability of curcumin supplement to restore the concentrations of polyunsaturated fatty acids (PUFA) in the breast muscles of heat-stressed broilers, including α-linolinec acid and Docosahexaenoic acid (P = 0.009 and 0.001, respectively). It could be concluded that supplemental dietary curcumin or ASA enhanced growth performance and antioxidant biomarkers of heat-stressed broilers. Moreover, curcumin might be an effective dietary supplement to alleviate the adverse effect of chronic thermal stress on carcass yield and meat quality.

Effect of bee pollen on growth performance, carcass traits, blood parameters, and the levels of metabolic hormones in New Zealand White and Rex rabbits.

The aim was to evaluate the effect of bee pollen (BP) on performance, blood parameters, and metabolic hormones in New Zealand White (NZW) and Rex (RX) rabbits. A total of 60 six-week-old rabbits were allotted into a completely randomized design in a 2 × 3 factorial arrangement (two breeds and three levels of BP: 0, 250, and 350 mg/kg body weight). The effects of breed × BP supplementation level were non-significant for all growth performance and carcass traits, as well as the concentrations of metabolic hormones in the plasma. Meanwhile, some blood parameters (hemoglobin, packed cell volume, alanine aminotransferase, aspartate aminotransferase, and urea) were significantly affected (P < 0.05). Regardless of the effect of breed, the supplementation of BP at a dose of 350 mg/kg BW increased the final body weight (P = 0.008), average daily gain (P < 0.001), and net profits (P = 0.006). However, the rabbits treated with BP at a dose of 250 mg/kg BW showed lower average daily feed intake (- 14.45 g/d; P = 0.049) and feed to gain ratio (- 0.48; P = 0.039). In both rabbit breeds, BP at a dose of 350 mg/kg increased the concentrations of insulin-like growth factor-1 (302.62 ng/ml, P < 0.001), insulin (16.63 ng/ml, P = 0.050), and triiodothyronine (158.50 ng/dl, P < 0.001) in plasma compared with other groups. It may be concluded that intake of BP supplementation can improve the feed to gain ratios, blood indices, and metabolic hormones in different rabbit breeds. However, the appropriate dosage and the route of supplementation of BP in broiler rabbits need further research.

Impact of space allowance on performance traits, brain neurotransmitters and blood antioxidant activity of New Zealand White rabbits.

The objective of this trial was to investigate the effect of space allowance on performance, welfare-related parameters and the levels of brain neurotransmitters in growing male rabbits. In a cage housing system, a total of 96 weaned rabbits were accommodated on three space allowance conditions (S1 = 1425 cm2/rabbit; S2 = 850 cm2/rabbit; S3 = 625 cm2/rabbit), with 8 replicate cages per each group. Rabbits in the S1 and S2 groups showed better daily feed intake and feed conversion ratio compared with the high stocking density group (p = 0.004 and 0.018, respectively). Compared to the highest stocking density group (S3), rabbits in the S1 and S2 groups showed significantly lower serum cortisol, MDA and GSSH level (p = 0.026, 0.018 and 0.009, respectively). The concentration of dopamine in brain tissues was significantly decreased in the S3 group compared with other experimental groups (P = 0.001). However, there was no significant effect of space allowance on the brain AChE level (P = 0.277). Brain serotonin and GABA levels showed a significant decrease in rabbits reared with a limited space allowance (S3) compared with S1 and S2 groups (P = 0.001 and 0.038, respectively). The level of brain MDA was significantly increased in the S3 group compared with the S1 group (P = 0.006). However, there were no detectable differences in the brain ATP level in rabbits reared with different space allowance (P = 0.693). In conclusion, the current study indicates that the 850 cm2/rabbit stocking density has resulted in a better feed intake, and welfare-related conditions compared with the 625 cm2/rabbit. Furthermore, the limited space allowance may impair the most important brain neurotransmitters in male rabbits.

Carcass yields, muscle amino acid and fatty acid profiles, and antioxidant indices of broilers supplemented with synbiotic and/or organic acids.

The objective of the current research was to explore the possible impacts of dietary supplementation with synbiotic and/or organic acids (OA) on the performance traits, carcass yields and muscle amino acid and fatty acid (FA) profiles of broilers. Randomly, a total of 160 day-old chicks (Ross 308) were assigned into four equal groups (40 birds each), with each group subdivided into eight replicates (five birds/pen). The control group (CON) fed the basal diet with no supplements, while diets of the treated groups were supplemented with OA (Sodium butyrate 40%; 1 g/kg), synbiotic (comprised Bacillus subtilis, Saccharomyces cerivisiae, Streptococcus faecium, Mannan-Oligosaccharides and ß-Glucan; 1 g/kg) and equal mix of OA and synbiotic (2 g/kg). Broilers fed the diets supplemented with synbiotic or synbiotic plus OA produced a significantly higher feed utilization efficiency (p = 0.021) and carcass yields (p = 0.038) than the CON and OA-supplemented groups. The group fed the diet supplemented with the synbiotic showed lowered serum cholesterol (p = 0.049), triglycerides (p = 0.001) and very low density lipoprotein (p = 0.032) when compared with the CON group. Regarding the polyunsaturated FA (PUFA) of breast muscles, synbiotic-supplemented birds had significantly lower n-6:n-3 ratio (p = 0.047), however, a greater hypocholesterolaemic to hypercholesterolaemic FA (H/H) ratio was reported when compared with the CON group (p = 0.002). Among the essential amino acids, the contents of leucine and methionine in the breast (p = 0.032 and 0.007 respectively) and thigh (p = 0.023 and 0.003 respectively) muscles were greater in the synbiotic-supplemented birds compared with the CON group. In conclusion, the synbiotic-supplemented diet improved the PUFA:SFA, n-6:n-3 and H/H ratios by altering the FA composition of broiler muscles, which are important with regards to human health.

Impact of crossing Fayoumi and Leghorn chicken breeds on immune response against Newcastle disease virus vaccines.

This study was conducted to evaluate the immune response against Newcastle disease (ND) virus vaccines (live attenuated and inactivated) in purebred Lohman Selected Leghorn (LSL), Fayoumi, male Fayomi × female LSL (FL crossbred), male LSL × female Fayomi (LF reciprocal crossbred) chickens. One-hundred-day-old chicks of each genetic type were assigned to five equal replicates. The log geometric means of the hemagglutination inhibition (HI) antibody titers were calculated. The FL crossbred chickens had a significantly higher HI antibody titer at day 26 of age when compared with the LSL chickens (P = 0.039). The Fayoumi and FL crossbred chickens had significantly higher HI antibody titers at day 45 of age (2.35 and 2.23, respectively) when compared with the LSL chickens (P = 0.031). In the same way, the purebred Fayoumi and FL crossbred chickens had significantly higher HI antibody titers at 60 and 75 days of age (P = 0.009 and 0.041, respectively) when compared with the purebred LSL and LF crossbred chickens. The LSL chickens showed a significantly higher (P < 0.05) correlation estimate between HI titer to the ND vaccine on day 75 of age and body weight at week 12 of age. When challenged with the virulent ND virus, the hazard ratio (HR) for mortality rates in purebred LSL and LF crossbred chickens were significantly (HR = 3.52 and 2.07; P = 0.001 and 0.049, respectively) higher than the Fayoumi chickens. In conclusion, purebred Fayoumi and FL crossbred chickens showed superior antibody titers against live attenuated and inactivated ND virus vaccines. Hence, Fayoumi breed may be incorporated in the crossbreeding programs to improve the genetic resistance to ND.

Effect of synchronization protocols on reproductive indices, progesterone profile and fertility under subtropical environmental conditions in repeat breeder Holstein cows.

The objectives were to evaluate the reproductive indices and survival analysis of pregnancy outcomes in multiparous repeat breeder Holstein cows (n = 557). The cows were synchronized to ovulate by Ovsynch, new controlled internal drug release device (N-CIDRsynch), and once-used CIDR device (U-CIDRsynch). The pregnancy per AI at 28 days post-insemination (P/AI 28) in the N-CIDRsynch group (28.75%) was significantly (COR = 1.49; p = 0.011) greater than that reported in the Ovsynch (23.46%) and U-CIDRsynch (21.73%) groups. Furthermore, the pregnancy per AI at day 75 post-insemination (P/AI 75) in the N-CIDRsynch group was significantly greater than the Ovysync group (COR = 1.35; p = 0.050). The repeat breeder cows received a N-CIDR device had a significantly higher progesterone level on day 2 and day 4 of CIDR insertion (1.38 and 1.67 ng/ml, respectively) than those received a U-CIDR device or the control group (p = 0.012 and 0.001, respectively). The Cox regression model recorded significant associations for synchronization protocols, THI at the TAI and season of calving with the hazard of P/AI 28 and P/AI 75 (p = 0.044 and 0.046; 0.001 and 0.005; 0.003 and 0.001, respectively). Multiparous repeat breeder cows (>3) had a lower hazard ratio (HR) of P/AI 28 than that reported in the reference (2nd parity) group (HR = 0.74, p = 0.050). The repeat breeder cows inseminated at 76-80 and >80 temperature-humidity index (THI) had significantly lower HR of P/AI 28 than those inseminated at the baseline (<70) THI value (HR = 0.73 and 0.30, p = 0.036 and 0.001, respectively). The current results indicate that the use of N-CIDR synch protocol may achieve satisfactory pregnancy outcomes in repeat breeder cows.

Impact of strain and duration of thermal stress on carcass yield, metabolic hormones, immunological indices and the expression of HSP90 and Myogenin genes in broilers.

The aim was to elucidate the effects of strain and the duration of thermal stress (36 °C) on the carcass yield, metabolic hormones, immunological parameters and the relative expression of liver heat shock protein 90 (HSP90) and Myogenin genes. Two hundred and seventy day-old chicks (135 of each breed; Ross 308 and Cobb 500) were used in this trial. The birds were divided into 3 equal groups (CON: thermoneutral condition; S1 and S2 groups were subjected to 4 and 6 h of daily thermal stress, respectively. The relative bursa weight in the thermonuteral Ross broilers, but not Cobb broilers was significantly greater than both heat-stressed groups (P = 0.001). The serum Na and phosphorus levels were significantly decreased when both broiler strains subjected to 6 h of thermals stress (P = 0.020 and 0.022, respectively). A linear decrease in the serum T3 level was recorded in both broiler strains as the duration of thermal stress increases (P = 0.001). In both broiler strains, heat stress up-regulate the expression of liver HSP90 gene compared with the thermoneutral group (P = 0.012). Meanwhile, the S2 group of Ross broilers showed a significantly lower IgG level (P = 0.027). Moreover, thermal stress for 6 h down-regulate the relative expression of Myogenin gene compared with the S1 and thermoneutral groups (P = 0.005). In conclusion, thermal stress for 6 h down-regulate the mRNA expression of liver Myogenin, concomitantly with an increase in the expression of HSP90 gene in both broiler strains. These results could be helpful in the markers assisted selection to develop more heat-tolerant broiler strains.

Impact of lactation stage on milk composition and blood biochemical and hematological parameters of dairy Baladi goats.

The objective of this study was to elucidate the impact of lactation stage on milk composition, hematological and biochemical parameters of dairy Baladi goats under Egyptian conditions. Forty-eight Baladi goats (32.8 ± 2.9 kg of BW) were enrolled in the current study. The lactation period has been divided into three stages; early (DIM less than 80 days), Mid (DIM 80-140 days), and Late (DIM over 140 days). Baladi goats had decreased daily-MY at a rate of 18.4% and 31.9% at mid and late stages of lactation, compared with early stage, respectively (p = 0.001). Furthermore, lactose% decreased significantly with progress of lactation (p = 0.017). Total solids%, however, decreased significantly at early stage of lactation in comparison with mid and late stages (p = 0.022). On the contrary, no significant differences were found in protein, fat and SNF percentages at different stages of lactation (p = 0.836, 0.625 and 0.281, respectively). Serum glucose and total protein were significantly reduced at late stage of lactation in comparison with early and mid stages (p = 0.001 and 0.001, respectively). On the contrary, no significant differences were found for erythrocytes count, hemoglobin, serum cholesterol, catalase and triiodothyronine at different stages of lactation. There were high and positive correlations between daily-MY and serum total protein (r = 0.87, P < 0.01) and triiodothyronine (r = 0.41, P < 0.01). However, negative estimates were reported between daily-MY and triglycerides (r = -0.55, P < 0.01) and cholesterol (r = -0.33, P < 0.05). Our results indicate that dairy Baladi goats produce milk with relatively stable protein, fat and solid not fat (SNF) contents at the different stages of lactation, encouraging the continuous utilization of their milk in processing. Also, dairy Baladi goats seem able to maintain the most vital biochemical parameters.