The neurotrophin b-nerve growth factor (NGF) has been described as an important mediator of seminal plasma-induced ovulation in reflexive ovulators like camelids, but this action has not been evidenced in rabbits. In this study, the mRNA expression of NGF was analysed in rabbit male organs by PCR and in a purified basic fraction of seminal plasma by liquid chromatography mass spectrometry. Besides, the ovulatory response [ovulation rate (OR), corpora lutea number, LH peak and progesterone profile] of 27 rabbit does was recorded after injection with murine NGF, gonadoreline (GnRH) or saline solution (SS). An empty catheter was introduced through the vagina (n ¼ 4 animals per group) to simulate the nervous/mechanical stimulus of coitus. Molecular studies confirmed the expression of b-NGF mRNA in the prostate, seminal gland and testicles of male adult rabbits, and the presence of the protein in seminal plasma. For the in vivo experiment, all GnRH-group does exhibited a significantly higher OR (100%) compared to females treated with NGF (30%) and SS (25%), who showed significantly lower LH and progesterone concentrations at 120 min. However, in the non-vaginally stimulated animals, only the gonadoreline group ovulated properly, since no ovulation was recorded in the SS group, and only 17% of the NGF does ovulated; this was associated to a tendency to a higher rate of anovulatory haemorrhagic follicles. mRNA expression of NGF and its presence in seminal plasma evidence a role in rabbit reproduction. Nevertheless, murine NGF triggered some stimulatory effect in the females but not enough to elicit a significant ovulatory response.

The present work was carried out to investigate the effects of dietary propolis supplementation to laying Japanese quail ( Coturnix coturnix japonica ) on egg production, egg quality, physiological and immunological aspects under heat stress conditions. A total of 200, 21-day-old, Japanese quail females were distributed equally into standard wired cages in two identical environmentally-controlled rooms (10 cages per room, 10 birds per cage). From 29–70 d of age, the quail birds in the first room remained at a normal temperature of 24°C (C group), whereas the quail birds in the second room were kept under heat stress at 35°C (HS group). Each group was further assigned to 2 propolis subgroups (5 cages per subgroup); one of them received a basal diet without propolis supplementation (-PR subgroup), while, the other received 1 g propolis/ kg basal diet (+PR subgroup). In the present study, performance and egg production of laying quail were significantly (P<0.001) impaired by HS treatment and improved by the PR treatment. Similarly, the negative and positive effects of HS and PR, respectively, were appeared on the egg shell thickness and yolk index. Stress indicators in laying quail were significantly (P<0.001) increased by HS, while, PR significantly (P<0.05) moderated these levels in the HS+PR group when compared to the HS-PR quail group. In addition to the positive impact of PR on the plasma levels of calcium, phosphorus, and albumin, it also normalized the plasma levels of alanine aminotransferase and cholesterol in the heat-stressed quail birds. Moreover, the quail birds in the HS groups expressed lower immunological aspects than those in the C group, while, the addition of propolis to the diets enhanced the immune status of laying quail birds under HS conditions. These results strongly suggest that dietary propolis supplementation could be a successful attempt to maintain the performance and egg production of laying Japanese quail at convenient levels under heat stress conditions.

The interest in biodiesel production from oil-bearing seeds rather than soybean necessitates the scientific validation of other good quality protein sources that could substitute soybean meal in animal diets, particularly, broiler chickens where soybean meal constitutes a large portion of their diet. Therefore, the present study was conducted to investigate the effect of sun-dried Azolla leaf meal (ALM) as an unconventional dietary protein source in broiler chicken diet on growth performance, meat quality, skeletal muscle cell growth and protein synthesis through regulation of ribosomal protein S6 kinase (p70S6 kinase α). A total of 120 male Ross 308 broiler chicks were randomly allocated to three dietary treatments. Each treatment had four cages (i.e. replicates) with 10 birds/cage. The control group was fed with a corn–soy-based diet, the AZ5 group was supplemented with 5% ALM and the AZ10 group was supplemented with 10% ALM for 37 days. A 5-day trial was also conducted to measure the apparent nutrient digestibility. Growth performance parameters were measured weekly. At the end of the experiment, 12 birds from each group (3/cage) were euthanized and used for samplings. Inclusion of ALM tended to improve BW gain (P = 0.06) and increased feed intake (P < 0.01). Additionally, ALM decreased the percentage of breast meat cooking loss linearly (P < 0.01). In addition, ALM at a dose of 5% increased the production of propionate in the cecum (P = 0.01). Activation of breast muscle p70S6 kinase was higher when ALM was included in a dose-dependent manner (P < 0.01). The inclusion of ALM increased breast meat redness (P < 0.01); however, the lightness was within the normal range in all groups. Findings from our study suggest that ALM could be included in a broiler chicken diet up to 5% without any major negative effect on meat quality or performance, and it regulates muscle protein synthesis through activation of mammalian target of rapamycin/6S kinase signaling.

Conjugated linoleic acid (CLA) is known for its multiple benefits including improvement of growth, increasing lean mass, and anti-carcinogenic effects. However, when used in longterm supplementations CLA does not improve semen parameters in boar and bull and reduces fertility in Japanese quails. The content of unsaturated fatty acids in dietary lipids plays a significant role in spermatogenesis owning the high proportion of unsaturated fatty acids in plasma membrane of sperms. Whether CLA plays a role in testicular tissue and epididymal fat is still unknown. Therefore, in this study we hypothesize that long-term supplementation of equal proportion of CLA isomer mix (c9,t11-CLA and t10,c12-CLA) in rabbit bucks might alter male reproductive potentials. Twelve V-Line weaned male rabbits were used in 26 weeks trial, rabbits were individually raised and randomly allocated into three dietary groups. Control group (CON) received a basal diet, a group received 0.5% CLA (CLA 0.5%), and a group received 1% CLA (CLA 1%). Rabbits were euthanized at the end of the trial and several parameters were evaluated related to growth, semen quality, and testicular and epididymal tissue histopathology and transcriptome. The long-term supplementation of CLA increased feed intake by 5% and body weight by 2-3%. CLA 1% decreased sperm progressive motility. In testicular tissue L-carnitine and α-tocopherol were decreased by CLA supplementation. In epididymal fat, CLA tended to decrease concentration of polyunsaturated fatty acids, the expression of SCD5 gene was upregulated by CLA 1% and CASP3 gene was upregulated by CLA 0.5%. Transcription of PPARG was downregulated by CLA. Feeding 1% CLA also decreased testicular epithelial thickness. Long-term supplementation

Food deprivation affects female reproduction. The goal of the present study was to elucidate in the rabbit model the effects of acute energy restriction on ovarian function (follicle development, atresia rate and in vitro oocyte maturation) and embryonic development and gene expression of some candidate genes. Serum metabolic parameters (non-esterified fatty acids (NEFA), triglycerides, glucose, insulin and leptin concentrations) and endocrine markers (oestradiol-17β and progesterone concentrations) were also studied. A control group of nulliparous does fed ad libitum and a 72-h fasted group were used. At the end of the nutritional treatment, the ovaries of half of the animals were retrieved while the other animals were re-fed and artificially inseminated to recover embryos at 84 h after insemination, during the luteal phase. At the end of fasting, increased serum NEFA and decreased leptin concentrations were observed in the fasted group, but no differences appeared in serum steroid concentrations, follicle population and atresia rate or nuclear and cytoplasmic oocyte maturation. In the luteal phase, insulin concentrations increased notably in the fasted group. The number of recovered embryos per female and the speed of embryo development were reduced in the food-deprived group. Acute fasting altered both metabolic and endocrine markers and embryo development, but follicle and oocyte development and embryo gene expression were not affected.

This study aimed to apply early heat shock exposure programs for releasing HSP70 gene expression to improve production of rabbits reared under hot desert conditions at Egypt. 120 Hi-Plus rabbits, one-day old were randomly divided into six equal treatments (20 rabbits/ treatment), namely T1, T2, T3, T4, T5 and T6. T1 served as control. The rabbits of second, third, fourth, fifth and sixth treatments were exposed to heat shock (36±1 °C for 3 hours from 12:00 -15:00 for three successive days). Rabbits of T2, T3, T4, T5 and T6 were exposed to heat shock at 3, 25, 60, 3+25 and 3+25+60 days of age, respectively. HSP70 expression and tri-iodothyronine hormone in the rabbits of T2, T3, T4, T5 and T6 were significantly increased. Rectal and fur temperatures, respiration rate, alanine transaminase, corticosterone hormone levels and overall mortality rate significantly decreased in the rabbits exposed to heat shock programs. Red blood cells count, packed cell volume and hemoglobin concentration increased in the rabbits of T2, T3 and T4. Total protein and globulin concentrations increased in the rabbits of T5 when compared to the rabbits of T1, T2 and T6. However, rabbits of T2 and T4 showed an increase in total antioxidant capacity when compared to the rabbits of T1. Conception rate was higher in the does of T5 than that in T3, T4 and T6. Litter traits, productive efficiency index, feed conversion and cost of feeding improved in the rabbits exposed to heat shock programs. In conclusion, applying heat shock exposure programs of rabbits especially T3 treatment, might increase HSP70 gene expression, this led to enhance immunity responses and production under severe heat stress conditions.

This study was carried out to monitor the fertilizing ability of rabbit semen frozen in the presence of melatonin as antioxidant. Semen from 10 mature Egyptian Baladi red bucks was pooled, extended with Tris-glucose-citric extender (1:1 v/v) supplemented by three concentrations of melatonin (10 -9 , 10 -6 and 10 -3 M) in addition to control, and finally cryopreserved at -196°C. After thawing, sperm kinetics, antioxidant capacity and fertility traits were evaluated. The results showed that total and progressive motility percentages were higher significantly in samples cryopreserved by melatonin (10 -6 M) as compared to control group. Curvilinear and average path sperm velocities were significantly higher in melatonin groups of 10 -9 and 10 -6 M than in the control group. Supplementation of melatonin at 10 -9 M and 10 -6 M groups decreased (P < 0.05) malondialdehyde activity when compared to the control one. In contrast, the total antioxidant capacity and catalase activity were significantly (P < 0.05) elevated at concentration of 10 -6 M melatonin as compared to the control group. In addition, transcript abundance of NFE2L2 and SOD1 genes increased in groups supplemented with melatonin compared to the control group. The fertility trial indicated that pregnancy rate, and the total and live born increased significantly (P < 0.05) in rabbit does inseminated with semen of 10 -6 M melatonin group in compared to the control samples. Conclusively, these results concluded that using melatonin with 10 -6 M level in rabbit freezing extenders could be recommended to improve semen quality and fertilizing ability of buck sperm post-thawing.

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