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

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. Keywords: Dairy goat, Lactation stage, Biochemical trait

Genetic Polymorphism of Prolactin, Bone Morphogenetic Protein Receptor 1B and Insulin-like Growth Factor 1 Genes in Two Selected Lines of Japanese Quail

Abstract: Quail is the smallest avian species raised for meat and egg production. It has several advantages as a laboratory bird for biological and biomedical investigations. In this study, we performed single nucleotide polymorphism (SNP) . DNA was extracted from blood samples using commercial kits and amplified using polymerase chain reaction (PCR). Nucleotide polymorphisms between two selected lines were detected by DNA sequencing. Five nucleotide changes in PRL and BMPR-1B genes were identified and there was no nucleotide difference in IGF-1 gene between egg and meat selected lines. The further study was required to find mutation in other site of IGF-1 and the SNPs discovered in this study provided suitable markers for association studies of candidate genes with important economic traits in Japanese quail

Effects on some immunological traits after crossing three rabbit breeds in Egypt

The authors evaluate the effect of crossing three purebred rabbit breeds in a complete 3 × 3 diallel crossbreeding experiment (New Zealand White, V-line and Gabali) on certain immunological traits, including IgG titre. Sheep red blood cells (SRBCs) were administered at 8 weeks of age and boosted at 10 weeks of age. V-line/Gabali crossbreeds gave the highest significant (p<0.05) level of serum total protein at 8 and 12 weeks of age (4.71 and 7.70 g/dl, respectively). Its reciprocal crossbreed Gabali/V-line resulted in the highest estimate of serum globulin at 8 weeks of age (2.07 g/dl). V-line/Gabali crossbreeds showed the highest positive heterosis percentage (H%) of total protein, albumin and globulin at 8 weeks of age (27.98, 30.28 and 25.00, respectively). However, its reciprocal crossbreeds, Gabali/V-line, revealed negative estimates for total protein and albumin at the same age (–4.07 and –29.80). V-line/Gabali crossbreeds gave the highest titre (3.167) and positive H% (0.69) of IgG to the second dose of SRBCs. On the contrary, the highest negative estimate to the second dose was recorded in Gabali/New Zealand White crossbreeds (–2.49). Using the Gabali breed as the female line gave superior results for most immunological parameters

Detection of SNPs in growth hormone and insulin like growth factor -1 genes in two divergently selected lines of Japanese quail

The Japanese quail (Coturnix japonica) is used for producing both meat and egg in many countries and as a model for animal research purposes. Two lines of Japanese quail that were differentiated by high body weight (HBW) and low body weight (LBW) had been improved by selection for body weight at four weeks of age. The objective of this study was to detect single nucleotide polymorphism (SNP) in Growth hormone (GH) and Insulin like Growth Factor -1 (IGF-1) genes in the two Japanese quails selected lines which based on the weight of the body at four weeks of age. DNA has been extracted from fifty blood samples by commercial kits and amplified by polymerase chain reaction (PCR). DNA sequencing revealed nucleotide polymorphisms between the two Japanese quails selected lines. The results of this investigation revealed that, one nucleotide change (T/C) in the intron 2 of GH gene. However, there were no nucleotide differences in IGF-1gene between the two selected lines. It concluded that, the SNP discovered in the GH gene may provide appropriate markers for associating researches of candidate genes with imperative economic measurements in Japanese quail. However, further studies are necessitating detecting mutation in another region of IGF-1

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

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

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 &times; female brown), and reciprocal crossbred line (BWQ: male brown &times; 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 &lt; 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 &lt; 0.001). Both crossbred lines (WBQ and BWQ) exhibited negative heterosis percentages for body weight (&minus;4.39 and &minus;3.90%, respectively) and feed intake (&minus;10.87 and &minus;14.59%, respectively). Meanwhile, heterosis percentages for FCR (&minus;6.46 and &minus;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