Biostimulation is a non-hormonal and practical technique that has not yet been widely utilised when applied immediately before insemination to improve reproductive efficiency in livestock species. This study was conducted to determine the influence of short-term male biostimulation on behavioural and reproductive performance of inseminated rabbit does. A total of 142 female New Zealand White rabbits were randomly assigned to 3 groups. Females were either exposed to male odour (Odour group) or an adult aproned male (Male group), while the remaining does that were neither exposed to the male odour nor the adult male are considered the control group. All females were inseminated after the 2 h exposure session. Conception rates were determined by abdominal palpation 12 d after insemination. The results showed that conception rate of the male odour group (79.59%) was greater than that of male presence group (76.09%) and that of the control group (68.09%). Moreover, biostimulated does showed significant behavioural activities during the 2 h exposure session compared to the control group. Although no significant differences were recognised, litter size at birth and at weaning was slightly increased in biostimulated compared to control females. Nor were there any significant difference in serum oestradiol concentrations between treated groups. Conclusively, short-term 2 h biostimulation of rabbit does resulted in the appearance of various behavioural responses followed by differences in conception rates between groups after routine artificial insemination.

The effect of two kinds of probiotics different in their mode of actions was tested on rabbits' performance grew under hot summer conditions. Fiftysix New Zealand White rabbits (5-weeks-old) were fed on growing diet and orally supplemented with Saccharomyces cerevisiae (S. cerevisiae) 0.5, 1 and 1.5 g., Lactobacillus acidophilus (L. acidophilus) 1, 2 and 3×10 9 CFU/kg body weight or distilled water as a control. Calculated temperature humidity index was classified as severe heat stress. Significant improvements in productive parameters, (average daily gain and feed conversion ratio) were detected in the high-dose group (3×10 9 CFU/kg) of L. acidophilus. Similarly, the haemoglobin concentration, red blood cell count and fT3 serum levels were considerably higher in the L. acidophilus groups, with significantly lower cortisol levels. The mean duration of anxiety-related behavioural responses in the open field test showed significant improvements in treated groups. Also, microbiological investigation showed an absence of some pathogenic bacterial species (Salmonella spp, Clostridium spp and Enterobacteria spp) in treated groups and the presence of beneficial yeast species (Yarrowia lipolytica) in the L. acidophilus-supplemented groups. Conclusively, administration of S. cerevisiae and L. acidophilus for consecutive 8 weeks may counteract the consequences of chronic heat stress in growing rabbits.

There is wide gap between the available feedstuffs and the requirements of animal feeding in Egypt and especially in Sinai. The present study was carried out to investigate the effect of feeding agro-industrial by-products like olive cake (OC) or crushed date stone (DS), as partial replacement of ratio yellow corn, on growth performances, carcass traits and some physiological status of New Zealand White rabbits (NZW). Thirty growing NZW weighed about 465g were divided into three similar and equal groups, six males and four females each. The 1 st group was fed on commercial diet as control (C);2 nd and 3 rd group was fed on 6.25% OC or 6.25% DS. At the end of experiment (after 12 weeks) 3 males and 4 females were slaughtered to study the carcass traits and blood constituents. The results concluded that feeding NZW on diet containing 6.25% OC or SD has beneficial effects. The final body weight averaged 2.14, 2.49 and 2.44 kg. in C, OC and DS groups, respectively. The corresponding values of daily body gain averaged 18.3, 22.1 and21.6 g. Feed conversion (feed intake/ body gain) averaged 4.7, 4.2 and 3.9. Moreover, these substitutions hadn't any bad effects on peripheral signs of health (rectal temperature or respiration rate) or internal signs, kidney, liver, adrenal, thyroid functions or blood characteristics of NZW rabbit. Furthermore, there was an improvement in dressing percentage and total edible meat. The percentages of carcass weight and total edible parts averaged 48.6 and 57.9 respectively, in C group, 53.9 and 62.8 in OC group, 51.1 and 60.8 % in DS group.

The present work was designed to study the effect of feeding crushed date stone (DS) or olive cake (OC) as partial replacement of yellow corn on reproductive performance and milk yield of New Zealand White (NZW) does and bucks. Three experiments were conducted. The first experiment was conducted to determine the suitable amount of OC or DS in rabbit diet by digestibility trial. The digestibility trial indicated that substitution of 6.25 % of OC or DS by the same ratio of yellow corn in the commercial diets gave better digestion coefficients than 12.5%. In the second experiment, 21 NZW doe rabbits aged 4-5 months and weighed about 3.1 kg were divided to three equal groups. The first group was considered as control group and fed commercial diet, the second and third groups were fed diets containing 6.25% OC and 6.25% DS, respectively. This experiment continued for two consecutive parities. The obtained results revealed that, conception rate, number of services per pregnancy and litter size at birth and at weaning were improved insignificantly in DS and OC fed groups compared to control. However, litter weight at birth and weaning and average bunny weight at birth increased (P<0.05) in OC group. While, feeding DS did not affect litter weight and bunny weight appreciably. Bunny weight at weaning, bunny daily gain and viability rates did not differ due to different diets. Total milk yield (4 weeks) was better (P<0.05) in OC and DS groups than control. The total milk yield averaged 109.55, 133.93 and 129.64 g/day/doe in control, DS and OC fed groups respectively. In the third experiment, three males produced from litters of each group of the second experiment were randomly chosen after 2 months of semen was collected twice-weekly for 6 weeks. The results revealed that, bucks fed OC or DS showed quiet improvement (P<0.05) in sexual desire, sperm motility, sperm cell concentration and semen ejaculate volume compared to control. Total motile sperm output averaged 329.21, 295.63 and 243.65 X10 6 /ml in OC, DS and control groups, respectively. Conclusively, it could be concluded that feeding 6.25% crushed date stone or olive cake as partial replacement of yellow corn in commercial diets of New Zealand White rabbits gave better reproductive performance of does and bucks and milk yield of does.

The current study aimed to evaluate the impact of soy lecithin, instead of egg yolk, in extenders on quality and fertility of rabbit semen preserved at 4°C. Six mature New Zealand White rabbits were used for semen collection. Two different concentrations of soybean lecithin; L1 (1% lecithin and 10% egg yolk) and L2 (only 2% lecithin) were compared with L0 (free lecithin Tris-Yolk extender) as a control. Good quality ejaculates (initial motility ≥ 70%) were diluted to four fold with specified extender and preserved for three days at 4°C. Progressive motility and viability were examined in pooled and diluted semen samples. In addition, fertility test was carried out on 98 multiparous rabbit does using one day preserved (4°C) extended semen. Results showed that both lecithin-containing extenders slightly improved rabbit sperm motility. The decline rate in sperm motility by progress of preservation time was decreased in lecithin-based extenders compared to egg-yolk extenders. After one day of storage, the best progressive motility was observed in L1, but with nonsignificant differences. Both 48h and 72h of preservation at 4ºC showed better results (P<0.05) which were obtained for L1 and L2 as compared to L0. Sperm viability did not differ significantly all over the total periods of cold storage. There were no significant differences in pregnancy rates for artificially inseminated does with lecithin supplemented extenders (L1: 61.8% and L2: 60.0%) compared to control (L0: 58.8%). Conclusively, soybean lecithin could be included in rabbit semen extenders as a non-animal origin instead of egg yolk. It maintained motility, viability values of chilled-stored spermatozoa and preserved their fertilizing capacity.