Effects of vaccination against reproductive diseases on reproductive performance of lactating dairy cows submitted to AI

Four experiments evaluated the effects of vaccination against bovine herpesvirus-1 (BoHV-1), bovine viral diarrhea virus (BVDV), and Leptospira spp. on reproductive performance of lactating dairy cows without (experiments 1, 2, and 3) or with previous vaccination against these diseases (experiment 4). Cows were assigned to a fixed-time AI protocol (FTAI; d -11 to 0) in all experiments, as well as AI 12. h upon estrus detection in experiment 3. Pregnancy status was determined with transrectal ultrasonography on d 30 and 71 (d 60 for experiment 3) after AI. Pregnancy loss was considered in cows pregnant on d 30 but non-pregnant on the subsequent evaluation. In experiment 1, 853 cows received (VAC) or not (CON) vaccination against BoHV-1, BVDV, and Leptospira spp. at the beginning of the FTAI (d -11) and 30. d after AI. Pregnancy loss was reduced (P=0.03) in VAC cows compared with CON. In experiment 2, 287 cows received VAC or CON 30. d prior to (d -41) and at the beginning (d -11) of the FTAI. Pregnancy rates on d 30 and 71 were greater (P≤0.03) in VAC cows compared with CON. In experiment 3, 1680 cows with more than 28. d in milk were randomly assigned to receive VAC or CON with doses administered 14. d apart, and inseminated within 15-135. d after the second dose. Pregnancy rates on d 30 and 60 were greater (P≤0.02) in VAC cows compared with CON. In experiment 4, 820 cows received (REVAC) or not (CON) revaccination against BoHV-1, BVDV, and Leptospira spp. at the beginning of the FTAI protocol (d -11). Pregnancy rates and loss were similar (P≥0.54) between treatments. Hence, vaccinating naïve cows against BoHV-1, BVDV, and Leptospira spp. improved reproductive efficiency in dairy production systems, particularly when both doses were administered prior to AI. © 2013 Elsevier B.V.

Long-term effects of perinatal androgenization on reproductive parameters of male rat offspring androgenization and male rat reproduction

It is known that during sex differentiation, fetal androgens are critical determinants of the male phenotype. Although testosterone is necessary for normal development of male sexual behavior, perinatal androgen treatment can result in disruption of normal male sexual reproduction. Pregnant Wistar rats were administered either corn oil (vehicle) or testosterone propionate at 0.2 mg/kg from gestational day 12 until the end of lactation and the reproductive function of male offspring was evaluated at 90 (adulthood) and 270 (middle age) days of age. Perinatal androgenization in the rat provoked a reduction in sperm production and reserves in adulthood that did not affect fertility and did not persist at more advanced ages, as shown by the results at post-natal day 270. If perinatal androgenization promotes similar effects in humans of reproductive age, the results of the present work can impact male reproduction health, given the less efficient spermatogenesis and lower sperm reserves in the human epididymis, compared to rodents. © Georg Thieme Verlag KG Stuttgart. New York.

Effects of bovine somatotropin administration on growth, physiological, and reproductive responses of replacement beef heifers

This experiment compared growth, body composition, plasma IGF-I and leptin, and reproductive development of beef heifers receiving or not recombinant bovine ST (BST) beginning after weaning until the first breeding season. Fifty Angus × Hereford heifers (initial BW = 219 ± 2 kg; initial age = 208 ± 2 d), weaned at approximately 6 mo of age, were assigned to the experiment (d 0 to 210). On d 0, heifers were ranked by initial BW and age and assigned to 1) treatment with BST or 2) saline control. Heifers assigned to the BST treatment received subcutaneous (s.c.) injections containing 250 mg of sometribove zinc whereas control heifers received a 5-mL s.c. injection of 0.9% saline every 14 d. Treatments were initiated on d 14 and last administered on d 196. Heifers were maintained on separate pastures harvested for hay the previous summer according to treatment and received grass and alfalfa hay at a rate to provide a daily amount of 7.0 and 1.0 kg of DM per heifer, respectively. Heifer shrunk BW was collected on d 1 and 211 for heifer ADG calculation. Blood samples were collected weekly from d 0 to 210 for determination of plasma progesterone to estimate puberty attainment as well as plasma concentrations of IGF-I and leptin in selected samples. On d 0, 63, 133, and 189, heifers were evaluated for intramuscular marbling, LM depth, and backfat thickness via real-time ultrasonography. No treatment effects were detected (P = 0.27) for heifer ADG (0.49 vs. 0.51 kg/d for control and BST heifers, respectively; SEM = 0.02). Mean backfat thickness was lesser (P < 0.01) in BST heifers compared with control cohorts (3.56 vs. 3.92 mm, respectively; SEM = 0.08). Heifers receiving BST had greater plasma IGF-I concentrations compared with control cohorts 7 d after treatment administration (treatment × day interaction; P < 0.01). Mean plasma leptin concentrations were lesser (P = 0.05) in BST heifers compared with control cohorts (1.82 vs. 2.03 ng/mL, respectively; SEM = 0.07). Onset of puberty was hastened in BST heifers compared with control cohorts (treatment x day interaction; P = 0.04). In summary, a greater proportion of BST heifers reached puberty during the experiment compared with control cohorts, despite lesser plasma leptin concentrations, backfat thickness, and similar ADG. Hence, circulating IGF-I was positively associated with hastened puberty attainment independently of growth rate, circulating leptin concentrations, and body fat content of replacement beef heifers. © 2013 American Society of Animal Science. All rights reserved.

Effects of macrocyclic lactones on the reproductive parameters of engorged Rhipicephalus (Boophilus) microplus females detached from experimentally infested cattle

The present study therefore assessed the deleterious effects of MLs (ivermectin, abamectin, doramectin and moxidectin) on the reproductive parameters of engorged Rhipicephalus (Boophilus) microplus females that naturally detached from experimentally infested cattle in two experiments. The following reproductive parameters of engorged female ticks were analyzed: female weight, egg mass weight, percentage of hatchability, percentage of reduction in oviposition, percentage of reduction in hatchability, reproductive efficiency and percent control/efficacy of formulations with respect to reproductive parameters. In the experiment I, statistical analysis of the data grouped into 5-days intervals revealed that pour-on application of abamectin (500. mcg/kg) had significantly (p≤. 0.05) reduced engorged female weight, egg mass weight and percent hatchability on days 6-15, 6-20 and 11-20 post-treatment (p. t.) compared to the respective data for detached and pre-selected engorged females in the control group. The abamectin, demonstrated 33.41% of reduction in oviposition, 6.77% in hatchability and abamectin efficacy was of 13.99%. In the experiment II, statistically significant reductions (p≥. 0.05) were observed in animals treated subcutaneous with ivermectin (630. mcg/kg), doramectin (700. mcg/kg) and moxidectin (1000. mcg/kg) relative to the control for days 6-40, 6-48 and 6-40 p. t., respectively. Ivermectin reduced hatchability only on days 16-20 p. t., whereas doramectin significantly reduced (p≤. 0.05) hatchability on days 6-10 and 16-35 p. t. For moxidectin, deleterious effects on hatchability were observed on days 16-35 p. t. The percent reductions in oviposition of engorged female ticks were 46.31%, 62.17% and 61.02% with ivermectin, doramectin and moxidectin treatments, respectively. The percent efficacy of the formulations on the reproductive parameters of engorged female ticks was 21.22% for ivermectin, 36.03% for doramectin and 35.45% for moxidectin. Among the MLs assessed, doramectin and moxidectin had the highest acaricidal efficacies and the most deleterious effects on the reproductive parameters of engorged R. (B.) microplus females. However, future studies will be necessary to assess the extent to which these effects, along with acaricidal activity, can be used to control the ectoparasite in cattle. © 2013 Elsevier Inc..

Effects of β-glucan polysaccharide revealed by the dominant lethal assay and micronucleus assays, and reproductive performance of male mice exposed to cyclophosphamide

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Perinatal Androgenic Exposure and Reproductive Health Effects Female Rat Offspring

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Polymorphisms in the MTRN1A gene and their effects on the productive and reproductive traits in buffaloes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Phytoremediation Potential of Mana-Cubiu (Solanum sessiliflorum Dunal) for the Deleterious Effects of Methylmercury on the Reproductive System of Rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Population differentiation and speciation in the genus Characidium (Characiformes: Crenuchidae): effects of reproductive and chromosomal barriers

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Incidence of subclinical endometritis and its effects on reproductive performance of crossbred dairy cows

In dairy cattle, uterine infections are not life threatening and often unavoidable; however, they reduce fertility and increase the production costs of properties. The aim of this study was to evaluate the incidence of subclinical endometritis from 32 to 70 days in milk (DIM) and its effects on the reproductive performance of crossbred dairy cows. Lactating cows (Holstein/Gir; n = 172), with no history of retained placenta, without clinical signs of uterine infection were used. The body condition score (BCS) was evaluated on a scale from 1 to 5. Ultrasound examination was performed to evaluate uterine lining and ovarian activity, while vaginal mucus was analyzed by gloved hand. The diagnosis of subclinical endometritis was performed by endometrial cytobrush technique. The samples were collected, stained, and examined microscopically; positive cases for subclinical endometritis were considered with the presence of a parts per thousand yen5 % of neutrophils. Later, the cows were submitted to conventional artificial insemination or timed artificial insemination. The incidence of subclinical endometritis in the herd was 26 %, and this was not affected by the season of calving, presence of corpus luteum, DIM, and parity. Cows with a BCS a parts per thousand currency sign2.50 had a higher incidence of subclinical endometritis. The conception rate to first insemination and pregnancy rate at 150 days postpartum were not influenced by the presence of subclinical endometritis in crossbred dairy cows.

Effects of fluazuron (2.5 mg/kg) and a combination of fluazuron (3.0 mg/kg) + abamectin (0.5 mg/kg) on the reproductive parameters of a field population of Rhipicephalus (Boophilus) microplus on experimentally infested cattle

The current study assessed the deleterious effects of two formulations of fluazuron (2.5 mg/kg fluazuron and a combination of 3.0 mg/kg fluazuron + 0.5 mg/kg abamectin) on the reproductive parameters of engorged Rhipicephalus (Boophilus) micro plus females that naturally detached from experimentally infested cattle in two experiments. Based on the obtained results, it can be concluded that fluazuron (2.5 mg/ kg) showed deleterious effects only on the hatchability percentage in the period of 2-7 post-treatment days of this ectoparasite's engorged females. On the other hand, the fluazuron (3.0 mg/kg) + abamectin (0.5 mg/kg) combination presented harmful effects over reproductive parameters of this tick species. Further studies should be performed with a known tick population (reference susceptible strain) to determine the effect of these formulations on the reproductive parameters and to elucidate if this field population is fluazuron resistant. (C) 2014 Elsevier Ltd. All rights reserved.

Effects of a Mixture of Pesticides on the Adult Female Reproductive System of Sprague-Dawley, Wistar, and Lewis Rats

The Brazilian federal government Agency for Health Surveillance detected pesticide residues in fresh food available for consumers all over the country. The current study investigated the effects of a mixture of some of those pesticides (dichlorvos, dicofol, dieldrin, endosulfan, and permethrin) on the reproductive system of Sprague-Dawley (SD), Wistar (WT), and Lewis (LEW) rats. Female rats from each strain were randomized into three experimental groups and were fed a control diet or diets added with pesticides mixture at their respective no-observed-effect level (NOEL)/no-observed-adverse-effect level (NOAEL) (low dose) (mg/kg/d): dichlorvos (0.23), dicofol (0.5), dieldrin (0.025), endosulfan (0.7), permethrin (5), or lowest-observed-effect level (LOEL)/lowest-effect level (LEL)/ lowest-observed-adverse-effect level (LOAEL) (toxically effective dose) (mg/kg/d): dichlorvos (2.3), dicofol (2.1), dieldrin (0.05), endosulfan (3.8), and permethrin (25) as reported in the literature. Euthanasia was performed between wk 10 and 12, during the estrous stage. Decreased body weights gain (SD and WT) and increased liver weights (SD, WT, and LEW) were observed in each strain fed the pesticides mixture at the higher levels. At that dose level, rat strains also varied in their responses regarding the estrous cycle, hormonal levels, and number of developing ovarian follicles. The studied mixture of pesticides was found to interfere with the female reproductive system when individual pesticides were mixed above a certain level, indicating a threshold exists for each of the strains studied.

Effects of maternal exposure to the galactagogue Sulpiride on reproductive parameters in female rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Some effects of cimetidine on the reproductive organs of rats

1. The development of genital organs of rats chronically treated with cimetidine showed that the drug may present anti-androgenic activity. 2. This treatment did not alter the sensitivity of vas deferens to noradrenaline, but increased their sensitivity to BaCl2. 3. In the male reproductive system, cimetidine must have peripheral actions apart from the central ones observed after chronic treatment.