Antibiotics for bull semen frozen in milk and egg yolk extenders

Antibiotics in semen extenders - a multiplicity of paradoxes

Addition of antibiotics to semen extenders was taken for granted for many years, from the time that commercial artificial insemination in livestock first began many decades ago. However, there is now a growing realisation that this non-therapeutic utilisation of antibacterial agents is contrary to current recommendations for prudent use that medical and veterinary professionals are advised to follow. Furthermore, antibiotics are not benign, having negative effects on sperm samples, the inseminated female, personnel and potentially the environment. The purpose of this review is three-fold: to highlight the fact that antibiotics are used in semen extenders, with the result that considerable amounts are used globally in animal breeding, to review recent studies on the negative aspects of using antibiotics for this purpose, and to look at possible alternatives. Recent changes in the legislation regarding semen extenders occurred in some, but not all, countries, leaving question marks for semen producers as to whether antibiotics should be added to semen extenders or not.

Zamzam Water Ameliorates Gentamicin-Induced Testicular Toxicity in a Rat Model via Targeting Sperm Parameters, Testicular Tissue Oxidative Insult, Inflammation, Apoptosis, and Pituitary-Gonadal Axis

Gentamicin is considered one of the most typical causes of testicular damage. Oxidative stress is a significant contributor to testicular tissue damage. Zamzam water (alkaline in nature) has an antioxidant effect. The purpose of this study was to assess the potential palliative effect of Zamzam water against gentamicin-induced testicular damage. Thirty Rats were separated into three groups, each with ten rats, as follows: The Control received only normal saline. The gentamicin group received 100 mg/kg/day of gentamicin intraperitoneally for six days from day 15 to the end of the experiment. The gentamicin +Zamzam Water group received a dose of gentamicin 100 mg/kg/day intraperitoneally with Zamzam water as their sole source of drinking from day one to day 21. Hormonal assay in serum, histological, immunohistochemical, and ultrastructural examination of testicular tissue with a molecular study were obtained. Pretreatment with Zamzam water significantly p < 0.001 increased serum levels of testosterone, FSH, and LH, as well as the percentage of sperm motility and progressive motility. It also upregulated SOD, CAT, GPx enzymatic activity, gene expression of Nrf2/HO-1, and immunoexpression of PCNA. While the percentage of dead sperm and abnormal sperm, immunoexpression of NFκB, Caspase 3, inflammatory cytokines TNFα, IL-1β, IL-6, and MDA levels significantly (p < 0.001) declined with histological improvement. It was concluded that Zamzam water as alkaline water possesses antioxidant, anti-inflammatory, and antiapoptotic effects against gentamicin-induced testicular toxicity in vivo.

Iron Oxide Nanoparticles as an Alternative to Antibiotics Additive on Extended Boar Semen

This study examined the effect of Fe₃O₄ nanoparticles on boar semen. Beltsville thawing solution without antibiotics was used to extend ejaculates from 5 boars (4 ejaculates/boar). Semen samples of control group (C) and group with Fe₃O₄ (Fe; 0.192 mg/mL semen) were incubated under routine boar semen storage temperature (17 °C) for 0.5 h and nanoparticles were removed by a magnetic field. Before and after treatment, aliquots of all groups were cultured using standard microbiological methods. The samples after treatment were stored (17 °C) for 48 h and sperm parameters (computer-assisted sperm analyzer (CASA) variables; morphology; viability; hypo-osmotic swelling test (HOST); DNA integrity) were evaluated at storage times 0, 24, 48 h. Semen data were analyzed by a repeated measures mixed model and microbial data with Student’s t-test for paired samples. Regarding CASA parameters, Fe group did not differ from C at any time point. In group C, total motility after 24 h and progressive motility after 48 h of storage decreased significantly compared to 0 h. In group Fe, linearity (LIN) after 48 h and head abnormalities after 24 h of storage increased significantly compared to 0 h. The microbiological results revealed a significant reduction of the bacterial load in group Fe compared to control at both 24 and 48 h. In conclusion, the use of Fe₃O₄ nanoparticles during semen processing provided a slight anti-microbiological effect with no adverse effects on sperm characteristics.

Melatonin prevents gentamicin-induced testicular toxicity and oxidative stress in rats

This study investigated the protective effects of melatonin (MT) against gentamicin (GM)-induced testicular toxicity and oxidative damage in rats. GM (100 mg kg(-1) ) was injected intraperitoneally (i.p.) to rats for 6 days. MT (15 mg kg(-1) ) was administered i.p. to rats for 6 days at 1 hr after the GM treatment. GM caused a decrease in prostate and seminal vesicle weights, sperm count and sperm motility. Histopathological examination showed various morphological alterations in the testis, characterised by degeneration of spermatogonia/spermatocytes, decrease in the number of early spermatogenic cells and vacuolisation. In addition, an increased malondialdehyde concentration and decreased glutathione content and glutathione reductase, catalase and glutathione-S-transferase activities were found in the testis. In contrast, MT treatment significantly attenuated the testicular toxicity of GM, including decreased reproductive organ weights, sperm count, and sperm motility and increased histopathological alterations. MT also had an antioxidant benefit by decreasing the lipid peroxidative product malondialdehyde and increasing the level of the antioxidant glutathione and the activities of antioxidant enzymes in the testis. These results indicate that MT prevents testicular toxicity induced by GM in rats, presumably due to its potent antioxidant activity, and its ability to inhibit lipid peroxidation, and restore antioxidant enzyme activity.

Effect of semen thaw method on conception rate in four large commercial dairy heifer herds

Semen processed with procedures intended to permit a flexible thaw method is used to breed millions of cows yearly. One method of thawing straws, the "pocket thaw" is used extensively with semen prepared with these procedures. Published field data is lacking for thaw method comparisons with semen processed to permit flexible-thawing. The objective of the present study was to measure the effect of semen thaw method (warm-water or pocket thaw) over all seasons and its interaction with herds, inseminators, straw package size, and sperm number on conception rate in commercial dairy heifer herds using semen processed with procedures historically optimized for success with flexible-thawing. Professional inseminators performed 11,215 services over a 16-month period in four large herds, achieving a 67.6% conception rate. Thaw method was alternated weekly. Thaw effect on conception status, determined by 70 days non-return rate, was estimated by a generalized linear mixed model. Neither thaw method nor number of sperm per straw significantly affected probability of conception (P=0.658 and 0.769, respectively). No interactions of thaw method with herd, sperm number, season, straw size, and straw size by season were detected (P=0.297, 0.526, 0.365, 0.723, and 0.824, respectively). Bull, herd, inseminator within herd, year, season, and straw size affected conception rate (P=0.002, 0.000, 0.000, 0.000, 0.000, and 0.014, respectively). In conclusion, for semen processed with procedures that permit flexible-thawing, thaw method (pocket thaw versus warm-water thaw) did not affect conception rate under commercial conditions and with routine semen handling methods.

Bovine spermatozoa in vitro: A review of storage, fertility estimation and manipulation

In vitro storage of bovine spermatozoa virtually indefinitely has provided the opportunity to distribute conveniently and widely germ plasm from superior sires and benefit the productivity of cattle around the world. Techniques developed in our laboratories are well on their way to being able to predict accurately the fertility of young, prospective sires without the inconvenience and expense of large field trials. Manipulation of spermatozoa provides opportunities for the predetermination of sex of resulting offspring, the introduction of foreign DNA into oocytes, and the formation of transgenic individuals. Many other possibilities are limited only by the ingenuity of those conducting research in this exciting field.