Reproductive effects of pyrethroid use in beef cattle

The effect of pyrethroid use in beef cattle on reproductive function and steroid biosynthesis was investigated. In the first study, BSEs were taken 5 d prior to and 14 d after treatment with label-dose of a commercial pyrethroid (permethrin)-based pour-on fly control product. Motility did not differ as a result of treatment. Although morphology improved across treatments between the first and second BSE, permethrin treated bulls had less improvement in percent of head sperm abnormalities and a tendency to have less improvement in midpiece sperm defects compared to control bulls, resulting in less improvement of primary abnormalities. Nonetheless, overall outcome for satisfactory breeder status was not impacted by treatment. In addition, there was no difference in the change of testosterone concentration as a result of treatment. Histopathological examination determined that testicular degeneration and tubule diameter did not differ as a result of treatment. However, it should be noted that regardless of treatment, degeneration score (higher score having more degeneration) was positively correlated with primary abnormalities and negatively correlated with normal sperm cells. In the second study, superovulated beef heifers were flushed at 17 and 51 days after treatment with label-dose pour-on pyrethroid (permethrin) or saline control. No differences were noted in total embryos recovered regardless of treatment. However, total embryos did decrease in the second flush compared to the first. Embryo quality grade, total transferrable quality embryos (TQE), and overall flush success did not differ due to treatment. However, TQE did decrease in flush 2 compared to flush 1 regardless of treatment. Estradiol per ovulated follicle and estradiol per total ovarian structure was greater in flush 2 but did not differ due to treatment. Furthermore, permethrin treated heifers tended to have reduced progesterone concentrations and lower progesterone per corpus luteum proportion at embryo recovery. In summary, the data from the two studies indicate that permethrin administration at one-time label-dose in yearling bulls and superovulated beef heifers has minimal effects on reproductive physiology, but not to a degree that would indicate compromised reproductive function or fertility

Effects of Injectable Trace Mineral Supplementation on Embryo Development and Quality in Superovulated Dairy Heifers—First Year Progress Report

Injectable supplementation of trace minerals is often used to combat the malabsorption of microminerals due to antagonists in feed and water. Previous research has shown that Multimin90, a commercial supplement containing copper, zinc, manganese, and selenium, has been shown to have a positive impact on reproductive efficiency and pregnancy rates in beef cattle. The objective of this study was to determine the effects of supplementation of MultiMin90 on embryo quality in superovulated heifers. This report includes the preliminary results of the first year of an ongoing study. Though there was no difference in overall embryo quality, supplementation of MultiMin90 tended to reduce the proportion of nonfertilized embryos per flush and resulted in one more embryo per flush when compared to a saline-treated control

Effects of Label-Dose Permethrin Administration on Reproductive Function and Embryo Quality on Superovulated Beef Heifers

Commercial pyrethroid pour-ons are commonly appliedin cow-calf operations to eliminate the potential for insectborne diseases and to improve productivity. However,recent literature has focused on potential negativereproductive effects in the bull after exposure to pyrethroids.While the female bovine has been primarily neglected fromthe debated pyrethroid concern on reproduction, literature inmice and rats have reported potential endocrine disruptionof sex steroids resulting from pyrethroid exposure, withpotential detrimental effects on female fertility. Theobjective was to study the effects of a commercialpyrethroid-based pour-on product, permethrin, onreproductive performance in superovulated beef heifers byassessing steroid biosynthesis and embryo quality. It washypothesized that exposure to pyrethroid pour-on at labeldose would cause minimal effects on embryoquantity/quality and steroidogenesis in the female bovine.Results from this study revealed pyrethroid-treated heifershad a tendency for reduced progesterone, but embryoquantity and quality were not affected compared to control

Climatic Factors Affecting Quantity and Quality Grade of in vivo Produced Bovine Embryos

The present study investigated the effects of climatic variables on the quality grade and quantity of in vivo produced bovine embryos. High temperature during the early embryonic development stage, one day after AI to flush, tended (P \u3c 0.10) to decrease the quality of embryos recovered. High Temperature-Humidity Index during the early antral follicular stage, 40 to 45 days prior to ovulation, tended to improve the total number of freezable and transferrable embryos recovered per flush (P \u3c 0.10). Increased wind speed at the early antral follicular phase was associated with a significant increase of the percentage of quality grade 1 embryos recovered (P \u3c 0.05). This implies that wind has a significant effect in the quality grade and quantity of in vivo produced bovine embryos that is rarely taken into consideration

Effects of Label Dose Permethrin Use in Yearling Angus Beef Bulls on Reproductive Function and Testicular Histopathology

To eliminate the potential for insect borne diseases and improve productivity in cow-calf operations, many producers use pour-on pyrethroids. However, popular press literature has identified potential links between use of pyrethroids and reproductive function failures in bulls. While literature in mice and rats have reported potential endocrine disruption of sex steroids resulting from pyrethroid exposure, effects of pyrethroid use on bull fertility is still questionable. The objective of this study was to measure reproductive parameters in peripubertal Angus bulls using a commonly used pyrethroid pour-on. We hypothesized that use of a pyrethroid pour-on at labeled dose would have limited effects on semen and testicular characteristics. Results from this study revealed pyrethroid-treated bulls had greater spermatozoa head and midpiece abnormalities compared to controls, resulting in higher primary morphological abnormalities. Although some morphological semen parameters appear to be negatively affected by use of pyrethroid administration in bulls, biological relevance of this result needs to be further elucidated as the ability to pass a breeding soundness exam was not affected. Moreover, further research should be conducted to determine the effects of pyrethroid pour-ons on fertility when used with other pyrethroids such fly tags or perimeter sprays. Based on these results, pour-on pyrethroid use in yearling bulls is still recommended for label dose administration

Electrosurgical bipolar vessel sealing for a standing flank ovariectomy in beef heifers

Traditional ovariectomy techniques for heifers (e.g. colpotomy) have adverse effects ranging from hemorrhage to mortality. Electrosurgical bipolar vessel sealing devices offer a superior ligation of ovarian pedicle and associated structures. In ruminants, standing flank laparotomy has been used for abdominal visibility. We performed ovariectomy in 2 companion beef heifers via a unilateral flank approach, combined with electrosurgical ligation. Surgeries were performed in standing animals, under local anesthesia, with no observed short- or long-term adverse effects. This technique is worth considering for cases where the security of electrosurgical ligation combined with the accessibility of a flank laparotomy are desired. Additional research is needed to determine the viability of the technique for cattle of various ages and breeds

Reproductive effects of pyrethroid use in beef cattle

The effect of pyrethroid use in beef cattle on reproductive function and steroid biosynthesis was investigated. In the first study, BSEs were taken 5 d prior to and 14 d after treatment with label-dose of a commercial pyrethroid (permethrin)-based pour-on fly control product. Motility did not differ as a result of treatment. Although morphology improved across treatments between the first and second BSE, permethrin treated bulls had less improvement in percent of head sperm abnormalities and a tendency to have less improvement in midpiece sperm defects compared to control bulls, resulting in less improvement of primary abnormalities. Nonetheless, overall outcome for satisfactory breeder status was not impacted by treatment. In addition, there was no difference in the change of testosterone concentration as a result of treatment. Histopathological examination determined that testicular degeneration and tubule diameter did not differ as a result of treatment. However, it should be noted that regardless of treatment, degeneration score (higher score having more degeneration) was positively correlated with primary abnormalities and negatively correlated with normal sperm cells. In the second study, superovulated beef heifers were flushed at 17 and 51 days after treatment with label-dose pour-on pyrethroid (permethrin) or saline control. No differences were noted in total embryos recovered regardless of treatment. However, total embryos did decrease in the second flush compared to the first. Embryo quality grade, total transferrable quality embryos (TQE), and overall flush success did not differ due to treatment. However, TQE did decrease in flush 2 compared to flush 1 regardless of treatment. Estradiol per ovulated follicle and estradiol per total ovarian structure was greater in flush 2 but did not differ due to treatment. Furthermore, permethrin treated heifers tended to have reduced progesterone concentrations and lower progesterone per corpus luteum proportion at embryo recovery. In summary, the data from the two studies indicate that permethrin administration at one-time label-dose in yearling bulls and superovulated beef heifers has minimal effects on reproductive physiology, but not to a degree that would indicate compromised reproductive function or fertility.</p

Effects of Label-Dose Permethrin Administration on Reproductive Function and Embryo Quality on Superovulated Beef Heifers

Commercial pyrethroid pour-ons are commonly appliedin cow-calf operations to eliminate the potential for insectborne diseases and to improve productivity. However,recent literature has focused on potential negativereproductive effects in the bull after exposure to pyrethroids.While the female bovine has been primarily neglected fromthe debated pyrethroid concern on reproduction, literature inmice and rats have reported potential endocrine disruptionof sex steroids resulting from pyrethroid exposure, withpotential detrimental effects on female fertility. Theobjective was to study the effects of a commercialpyrethroid-based pour-on product, permethrin, onreproductive performance in superovulated beef heifers byassessing steroid biosynthesis and embryo quality. It washypothesized that exposure to pyrethroid pour-on at labeldose would cause minimal effects on embryoquantity/quality and steroidogenesis in the female bovine.Results from this study revealed pyrethroid-treated heifershad a tendency for reduced progesterone, but embryoquantity and quality were not affected compared to controls</p

Effects of Label Dose Permethrin Use in Yearling Angus Beef Bulls on Reproductive Function and Testicular Histopathology

To eliminate the potential for insect borne diseases and improve productivity in cow-calf operations, many producers use pour-on pyrethroids. However, popular press literature has identified potential links between use of pyrethroids and reproductive function failures in bulls. While literature in mice and rats have reported potential endocrine disruption of sex steroids resulting from pyrethroid exposure, effects of pyrethroid use on bull fertility is still questionable. The objective of this study was to measure reproductive parameters in peripubertal Angus bulls using a commonly used pyrethroid pour-on. We hypothesized that use of a pyrethroid pour-on at labeled dose would have limited effects on semen and testicular characteristics. Results from this study revealed pyrethroid-treated bulls had greater spermatozoa head and midpiece abnormalities compared to controls, resulting in higher primary morphological abnormalities. Although some morphological semen parameters appear to be negatively affected by use of pyrethroid administration in bulls, biological relevance of this result needs to be further elucidated as the ability to pass a breeding soundness exam was not affected. Moreover, further research should be conducted to determine the effects of pyrethroid pour-ons on fertility when used with other pyrethroids such fly tags or perimeter sprays. Based on these results, pour-on pyrethroid use in yearling bulls is still recommended for label dose administration.</p