Sexual behaviour response, testicular development and semen quality of New Zealand white rabbit bucks as influenced by dietary chitosan.

The present study was conducted to determine the effects of dietary chitosan supplementation on sexual behaviour responses, testicular development, and semen quality traits of New Zealand White (NZW) rabbit bucks. Twenty-four 5-week-old rabbit bucks were used in this experiment. Animals were grouped into four equal experimental groups: the control group was fed only on a basal diet, whereas the other groups were fed the basal diet supplemented with three levels of chitosan at 0.2, 0.4, or 0.6 g/kg, respectively. Also, bucks that received chitosan at 0.2 and 0.4 g/kg had a significantly earlier time of sexual libido (p ≤ .05) and had significantly higher ejaculate volume and sperm concentration than other groups (p ≤ .001). Furthermore, basic and sexual behaviours were significantly improved in bucks fed chitosan at 0.2 and 0.4 g/kg compared with other groups. Therefore, it could be concluded that using chitosan at 0.2 and 0.4 g/kg enhanced sexual behaviour, improved semen quality, and reproductive efficiency in the NZW rabbit bucks.

The role of different dietary Zn sources in modulating heat stress-related effects on some thermoregulatory parameters of New Zealand white rabbit bucks.

The present work was conducted to assess the effect of diets supplementation to heat-stressed buck rabbits with different zinc (Zn) sources on the thermoregulatory and hematobiochemical parameters, and antioxidant status. A total of 24 mature buck rabbits (32-36 weeks of age) were randomly distributed into four groups (6 each). Group 1, non-heat-stressed control (NHSC), was reared in the absence of heat stress (HS) conditions and received the basal diet only. The other three groups (groups 2, 3 and 4) were kept in HS conditions. Group 2, heat-stressed control (HSC), received the basal diet only. The diet supplemented with 75 mg Zn/kg diet either in the inorganic form (Zn sulfate) or in the organic form (Zn picolinate) for groups 3 and 4, respectively. Zn supplementation to rabbits' diets lowered the heat stress-related increase of serum urea, alanine transaminase and malondialdehyde (MDA) concentration. These supplementations also increased the concentration of testosterone under HS conditions. Zn picolinate was more effective than Zn sulfate in restoring serum concentrations of urea, testosterone, and MDA. In conclusion, Zn addition to rabbits' diets from different sources, especially Zn picolinate, exhibits an ameliorative effect against the harmful impact of HS on hematobiochemical parameters and antioxidant status.

Amelioration of sperm fertilizability, thyroid activity, oxidative stress, and inflammatory cytokines in rabbit bucks treated with phytogenic extracts.

This study investigated the beneficial effect of phytogenic extracts on semen quality, reproductive hormones, thyroid activity, immunity, hepatic antioxidant activity, and fertility in rabbit bucks. We divided 70 bucks into seven groups (10 in each). Group 1 was fed a basal diet (control); groups 2, 3, and 4 were fed the control diet with 30, 60, and 90 mg/kg of turmeric, respectively; and groups 5, 6, and 7 were fed the control diet with 50, 75, and 100 mg/kg of garlic extract, respectively, for 8 weeks. Rectal and skin temperatures decreased, while follicle-stimulating hormone, luteinizing hormone, triiodothyronine, thyroxine, testosterone, immunoglobulin M, tumor necrosis factor-alpha, and interleukin-6 in blood serum and glutathione peroxidase in the liver increased in all groups (p < .05). Garlic extract (100 mg/kg diet) increased adenosine triphosphate and glutathione in the liver tissues. All treatments significantly increased net semen volume, percentages of progressive motility, livability, curled tail, and intact acrosomes of spermatozoa, sperm cell concentration, and outputs of total and motile spermatozoa, while significantly decreased percentage of sperm abnormality. In conclusion, dietary supplementation of turmeric or garlic extract can be used as a suitable tool for enhancing the hepatic antioxidant activity, immunity, and semen quality in rabbit bucks.

Effect of dietary pomegranate peel (Punica granatum L.) and Aloe vera gel (Aloe barbadensis miller) supplementation on testicular antioxidant biomarkers and spermatogenesis enzymes in mature V-Line rabbit bucks.

Rabbit meat is considered as an economic source of white meat, increasing its production is limited by the buck fertility, since one rabbit can be used to inseminate up to 15 female. The aim of the current study is to enhance male rabbit fertility by using dietary antioxidants including Aloe vera gel (AVG) and pomegranate peels (PP). In a 60 days experiment, 48 V-Line 5-month-old rabbit bucks of average body weight (2,300 ± 20) kg were allocated into four dietary treatments (n = 12/group) as follow: CON (fed on control diet), ALOE (received AVG in drinking water; 500 mg/L drinking water), POM3 (fed on basal diet + 3% of pomegranate) and POM5 (fed on basal diet + 5% of pomegranate). Semen samples were collected at d30 and d60 of the experiment and used for analysis of semen quality. Sexual behaviour was reported in terms of latency to first mating and ejaculation interval. At the end of the experiment, six bucks were euthanized from each group, blood samples were collected and used for testosterone level determination and testicular tissue samples were collected and used for key antioxidant and spermatogenesis enzymes assessment, and testes histopathological evaluation. The UNIVARIATE procedures of SAS 9.4 were used to analyse the data, significance was declared at p ≤.05. PP supplementation improved percentage of progressive motile sperms while AVG negatively impacted it (p = .04), sperm concentration and metabolically active sperm cells were the highest in PP and lowest in ALOE supplemented bucks (p = .01 and .01; respectively). Testicular alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) decreased in AVG supplemented group (p = .01 and .02; respectively). From our findings, AVG in its fresh form decreased fertility of rabbit bucks, while PP is potent fertility boosting for rabbit bucks.

Physiological response and semen quality of rabbit bucks supplemented with Moringa leaves ethanolic extract during summer season.

Exposure of rabbit bucks to summer heat stress reduces their homeostasis and semen quality leading to a temporal subfertility. The potentiality of ethanolic extract of Moringa oleifera leaves (M. oleifera ethanolic extract (MLEE)) to reduce negative impacts of heat stress on physiological and semen quality traits was investigated. A total of 28 adult V-line rabbit bucks were randomly distributed among four experimental groups of seven rabbits each. The first group received water (placebo) and served as a control (M0). The other three groups were given orally MLEE at levels of 50 (M50), 100 (M100) and 150 (M150) mg/kg BW every other day for 12 consecutive weeks during the summer season. Chemical constituents of MLEE were detected by gas chromatography/MS. During the experimental period, ambient temperature and relative humidity were recorded daily and were used to estimate temperature and humidity index. Feed intake, BW, rectal temperature were recorded and blood serum biochemical attributes were determined. Semen samples were collected weekly and were analyzed for semen quality traits. Results showed that MLEE contained high percentages of long-chain fatty acids and antioxidant agents. Feed intake and BW were not affected significantly by the treatment, however rectal temperature was decreased significantly by 0.42°C, 0.24°C and 0.40°C in the M50, M100 and M150 groups, respectively, compared with the M0 group. Treatment with 50 mg/kg BW increased concentration of serum albumin (115%; P<0.05), total antioxidant capacity (132%; P<0.05) and testosterone (160%; P=0.098) as well as seminal plasma initial fructose (127%; P=0.092) compared with the control group. Compared with the control, MLEE supplementation with 50, 100 and 150 mg/kg BW increased significantly sperm concentration by 118%, 151% and 158%, sperm progressive motility by 117%, 120% and 118%, sperm viability by 129%, 137% and 127%, sperm normal morphology by 114%, 113% and 114%, intact acrosome sperm by 109% (on average) and sperm with integrated cell membrane by 109%, 123% and 114%, respectively. In conclusion, MLEE supplementation at a level of 50 mg/kg BW could be effectively used to improve heat tolerance, oxidative status and semen quality of rabbit bucks during summer season.