This study aimed to investigate the effect of different cryoprotectants, glycerol (GLY) or ethylene glycol (EG) or dimethyl sulfoxide (DMSO) on sperm characteristics, and in vivo fertility of frozen-thawed buffalo-bull semen. A total of 85 ejaculates collected by artificial vagina from buffalo-bulls of proven fertility were used in this study. The collected ejaculates were examined for volume, motility, viability, morphology, and sperm cell concentration. The qualifying ejaculates (≥ 3 mass motion, > 70% progressive motility and viability, < 15% abnormal morphology and > 1 x 10 9 sperm cells/mL) were pooled and diluted with Tris-based diluent containing either 7% GLY or 5% EG or 5% DMSO. After 4 h equilibration time, the diluted semen was loaded in 0.5 mL straws, labeled, sealed and frozen stored until analysis. Frozen straws were thawed and evaluated for progressive motility, viability, hypo-osmotic swelling test (HOST), acrosomal membrane integrity, and acrosome reaction (AR) in response to calcium ionophore A23187. Moreover, in vivo fertility was calculated after artificial insemination (AI) of 75 buffalo-cows (25 female/cryoprotectant) treated with double doses of prostaglandin F2α (PGF2α) 11 days interval. The proportions of progressive motility, viability and intact-acrosome were higher (p < 0.05) in extender containing 7% GLY compared to 5% EG and 5% DMSO. The proportion of intact-plasma membrane was comparable (p ≥ 0.05) between GLY and EG but higher than that of DMSO. A time-dependent increase in the % AR and % relative AR was recorded in the three cryoprotectants with clear significant (p < 0.01) difference among them at 30 and 60 min incubation, respectively. Moreover, GLY yielded higher pregnancy rate (52%) than EG (32%) and DMSO (16%). In conclusion, GLY is recommended for preservation of buffalo-bull semen in order to maintain sperm plasma membrane integrity and improve in vivo fertility of frozen-thawed buffalo-bull semen.

he study was performed to evaluate the effect of organic chromium (Cr), organic selenium (Se) or vitamin C (vit. C) alone or in combination on reproductive performance, and egg quality of Dokki-4 laying hens under hot summer conditions of Egypt. A total number of 240 hens plus 48 cocks from Dokki-4 strain at 30 weeks of age were randomly selected and distributed into eight groups with 3 replicates (10 hens + 1 cock) each. The remaining 24 cocks were also divided into 8 groups of 3 cocks each and housed separately for semen evaluation experiment. Treatments groups were fed a basal diet (control group) or the basal diet supplemented with either 400 µg Cr/kg diet (Cr group), 250 mg of L-ascorpic acid /kg diet (vit. C. group), 0.2 mg Se/kg diet (Se group), 400 µg Cr plus 250 mg of L-ascorpic acid/ kg diet (Cr + vit. C group), 400 µg Cr plus 0.2 mg Se/kg diet (Cr + Se group), 2 mg Se plus 250 mg L-ascorbic acid/kg diet (Se + vit. C. group) and 400 µ Cr plus 0.2 mg Se plus 250 mg ascorbic acid /Kg diet (Cr + Se + vit.C group). All groups were put under observation for 12 weeks. Results obtained can be summarized as follows: Supplementation of Cr, Se or vitamin C alone or in combinations significantly increased (P < 0.05) shell thickness, haugh units, albumin and shell to egg weight, sperm motility, ejaculate volume, sperm concentration, total sperm output, total motile sperm, live spermatozoa, semen quality factor and significantly decreased (P < 0.05) dead spermatozoa and seminal malondialdehyde (MDA) as compared with control group. The best result was obtained for layers fed diet containing the combinations of the three supplements (Cr, Se or vitamin C) as compared to other groups. In conclusion, combinations of Cr, Se and vitamin C improved the most reproductive traits and egg quality of Dokki-4 strain under Egyptian hot summer.