Effect of shading on the physiological and reproductive parameters in Nelore cows.

This study aimed to evaluate the physiological and reproductive parameters of Nelore cows under various microclimatic conditions. The experiment was performed in Central Brazil, which has a tropical climate with dry winters and rainy summers. The experimental groups were divided into an area with shading (5.8 trees/ha; n = 42) and an area with little shading (0.4 trees/ha; n = 42). The physiological (heart rate, respiratory rate, rectal temperature, surface body temperature, and vaginal temperature) and reproductive (estrus detection, conception rate, and rate of pregnancy loss) parameters were then assessed. The rectal temperature (p = 0.002); surface body temperature on the flanks, forehead, and shoulder (p < 0.001); and vaginal temperature (p < 0.001) of cows in the group with shading were significantly lower than those of cows in the group without shading. Estrus was higher (p = 0.08) in the shaded group; however, no effect was observed on conception and pregnancy loss rates. In conclusion, shading (5.8 trees/ha) provided better thermal comfort for Nelore animals in the tropical climatic region. However, this did not affect their performance after fixed-time artificial insemination.

Cryopreservation of jaguar (Panthera onca) sperm cells using different cryoprotectants and different thawing temperatures.

The cryopreservation of jaguar semen must be improved to produce high-quality biobanking doses. Until now, the rare studies of semen freezing in the species have only evaluated glycerol, always with a significant reduction in sperm quality in thawed semen. The purpose of this study was to assess the efficacy of three cryoprotectants, dimethylsulfoxide (DMSO), glycerol (GLY), and methanol (MET), in the cryopreservation of jaguar semen in an LDL-based extender, as well as the effect of thawing temperature on dosage quality. Five mature males with a history of reproduction were used. On the males, an infrared thermal image (IRT) was captured, the spicules and testes were analyzed, and the CASA system was used to evaluate the quality of fresh and thawed sperm. The superficial IRT was 4.6 ± 1.2 °C cooler than the anal sphincter, and the semen measured between 27.3 and 28.7 °C shortly after exiting the urethra. The total motility of fresh sperm was 55.3 ± 22.6%, and progressive motility was 36.3 ± 18%. The total motility of thawed sperm was 5.28 ± 2.51%, 4.49 ± %2.49, and 0.51 ± 0.62% for DMSO, GLY, and MET, respectively. DMSO and GLY performed better than MET, and there was no difference in thawing temperature (37°C 30 s vs. 50°C 12 s). All animals exhibit a considerable level of morphological changes in sperm. Low amounts of total and progressive motility were found in the thawed sperm. Males with a high level of sperm morphological changes were found to be fertile, but the lone male with normospermia was infertile. Thus, we contest the applicability of the commonly used morphological classification for bovines to felid species.

Impact of quercetin, carnosine, and ozone in the cryopreservation on Nellore (Bos indicus) semen.

The objective of this study was to reduce the effects of cryoinjury caused in bovine semen by cryopreservation. Ejaculates were collected from Nellore bulls and subjected to freezing in C (control), ozone (15, 30, and 60 µg mL-1 of ozone), quercetin (25, 50, and 100 µg mL-1 of quercetin), and carnosine groups (100, 200, and 300 ng mL-1 of carnosine). Samples were evaluated post-thaw (M0) and post-rapid thermoresistance test (M30) for sperm kinetics (total motility, progressive motility, curvilinear speed, linearity and amplitude of lateral head displacement) and cell structure viability (plasma membrane integrity, acrosomal integrity, mitochondrial potential, membrane fluidity, and lipid peroxidation). There were no differences (P > 0.05) between the control, quercetin, and carnosine-treated groups for the parameters evaluated at M0 and M30. In turn, supplementation with ozone resulted in lower values for sperm kinetics (P < 0.05) and lower mitochondrial potential at M30 (P < 0.05). Quercetin and carnosine at the concentrations used did not promote significant gains in frozen semen, nor did they demonstrate cytotoxicity. We expected to obtain positive results with the use of ozone. Nonetheless, the addition was harmful to the parameters of sperm kinetics, and its effect was not observed as a possible pro-antioxidant. We believe that the fact that the gas did not harm the sperm structure opens avenues for tests with lower dosages, since, by reducing its concentration, we could minimize the damage to sperm kinetics.

Effects of supplementation on production and age anticipation at first mating of ewe lambs in tropical pastures.

Studies on the rearing of ewe lambs in the Cerrado are scarce, so the objective was to evaluate the effects of protein-energy supplementation with 1.6 and 2.4% BW on the productive and reproductive performance of ewe lambs raised on pastures of Brachiaria brizantha cv. Marandu. Twenty-four Texel ewe lambs, with a mean age of 5 months, were distributed in two treatments with provision of energy protein supplementation at levels of 1.6 and 2.4% BW, formulated for average daily gains of 150 and 200 g/day for ewe lambs weighing 20 kg, respectively. The experimental delineation adopted was the completely randomized design, with fifteen repetitions per treatment. The performance of the ewe lambs was evaluated by weight at the beginning and end of the breeding season (BS), average daily gain (ADG), and total weight gain (TWG). The count of fecal eggs was performed monthly. The evaluation of the ewe lambs reproductive organs took place at 8 months of age. The fertility of the ewe lambs was detected by transrectal ultrasonography at the end of the BS. The supplementation level of 2.4% BW was higher for ADG and TWG; however, it did not influence the other performance characteristics. There was no effect of supplementation on the reproductive characteristics, parasite load, and nutrients of the pasture. Pasture nutrients were influenced by the month of use. Supplementation levels were not effective to ensure the reproductive success of 8-month-old ewe lambs.

Shading effect on physiological parameters and in vitro embryo production of tropical adapted Nellore heifers in integrated crop-livestock-forest systems.

The aim of this study was to evaluate the impact of increased shadow supply in integrated crop-livestock-forest systems on in vitro embryonic development and physiological parameters related to stress response in Nellore heifers (Bos indicus). For the study, animals (n = 16) were randomly divided into two groups and kept in areas with different afforestation systems, the integrated crop-livestock-forest (ICLF) and the integrated crop-livestock (ICL) system. The microclimate of the ICLF system provided better comfort conditions than ICL. No differences of respiratory rate, rectal temperature, cortisol, T3, T4, oocyte quality, and cleavage rate between the systems were verified. A higher blastocyst rate was observed in the ICLF (p < 0.05). The results demonstrate that Nellore heifers managed in ICLF during summer in Midwest of Brazil showed higher production of in vitro embryos, without typical changes in its physiological parameters. The results observed in the present study indicate that zebu females are able to respond satisfactorily to the intense heat conditions; however, we believe that the long period to which these animals are exposed to these conditions interferes in the oocyte competence and embryo development.

Comparison between in vitro embryo production using Y-sorted sperm and timed artificial insemination with non-sorted sperm to produce crossbred calves.

Due to the increasing use of in vitro embryo production (IVEP) and the importance of crossbreeding for beef production, pregnancy rates of Nelore recipients were evaluated following Fixed Time Embryo Transfer with fresh or vitrified IVEP embryos produced with Y-sorted sperm of Angus bulls (B. taurus) or Fixed Time Artificial Insemination using non-sorted sperm. For IVEP in Experiment 1, oocytes were obtained using Ovum Pick Up (OPU) (n = 84 embryos) or from ovaries from a slaughterhouse (SLAUGHTER, n = 66 embryos). In Experiment 2, with oocytes obtained by OPU, IVEP embryos were fresh (FRESH, n = 271) or after vitrification/warming (VITRIFIED, n = 79) and PR was compared with FTAI (n = 239). In Experiment 1, cleavage rates were 63.8% and 39.1% for OPU and SLAUGHTER groups, respectively (P = 0.02), and blastocyst rates were 30.5% and 14.7%, respectively (P = 0.09). The PR was similar when considering the source of oocytes (OPU = 35.7%; SLAUGHTER = 25.8%; P = 0.17). In Experiment 2, there was no difference in PR for FRESH or VITRIFIED embryos (34.3% and 30.4%, respectively, P = 0.72), but lesser than FTAI (47.7, P = 0.002). It is concluded that the IVEP with Y-sorted sperm associated with vitrification or embryos produced with oocytes from different sources did not affect PR when there was transfer of crossbred embryos into recipients, and can optimize large-scale application of IVEP technology; however, FTAI pregnancy rates with non-sex sorted sperm were greater.

Homeopatia aplicada à reprodução animal / Homeopathy applied to animal reproduction / Homeopatía aplicada a la reproducción animal

A homeopatia é um sistema terapêutico que propõe abordagem clínica e terapêutica para o tratamento do indiví- duo doente, desenvolvida por Christian Friedrich Samuel Hahnemann no final do século XVIII. No Brasil, a homeopatia foi introduzida por Benoit Mure, em 1840, tornando-se uma nova opção de tratamento. Como princípio básico tem-se a utiliza- ção de medicamentos dinamizados, ou seja, preparados a partir de substâncias animais, vegetais, minerais ou tecidos doentes. Existem duas leis que sustentam a homeopatia como parte da medicina. A primeira é a Lei dos Semelhantes - “Similia simili buscurentur”- (os semelhantes que se curem pelos semelhantes) e, a segunda, a Lei do Vitalismo. O uso da homeopatia na reprodução se faz importante na busca de melhorias da fertilidade animal, tanto no diz respeito ao tratamento de patologias quanto na eficiência reprodutiva. Contudo, novos estudos devem ser desenvolvidos, uma vez que há divergências nos resultados encontrados na literatura...

Homeopathy is a therapeutic system proposing both clinical and therapeutic approaches to the treatment of the patient, developed by Christian Friedrich Samuel Hahnemann in the late eighteenth century. In Brazil, homeopathy was introduced by Benoit Mure in 1840, becoming a new treatment option. The use of dynamized medication, or prepared from animal, vegetable or mineral substances, or from diseased tissue is at the core of homeopathy. There are two laws that support homeopathy as part of medicine. The first one is the Law of Similars - “Similia simili buscurentur” - (like cures like). The second law is the Law of Vitalism. The use of homeopathy in reproduction is important in the search for improvement in animal fertility, both regarding the treatment of diseases and as in reproductive efficiency. However, further studies still need to be developed, since there are differences in the results found in literature...

La homeopatía es un sistema terapéutico que ofrece enfoque clínico y terapéutico para el tratamiento de la persona enferma, desarrollado por Christian Friedrich Samuel Hahnemann a finales del siglo XVIII. En Brasil, la homeopatía fue introducida por Benoit Mure en 1840, convirtiéndose en una nueva opción de tratamiento. Como principio básico se ha utilizado drogas energizadas, es decir, sustancias preparadas a partir de animales, vegetales, minerales o tejidos enfermos. Hay dos leyes que apoyan la homeopatía como parte de la medicina. La primera es la ley de los semejantes - “Similia simili buscurentur” - (los semejantes que se curen por los semejantes) y, la segunda, la Ley del Vitalismo. El uso de la homeopatía en la reproducción llega a ser importante en la búsqueda de la mejora de la fertilidad de los animales, tanto en lo que respecta al tratamiento de patologías como la eficiencia reproductiva. Sin embargo, nuevos estudios deben ser desarrollados, ya que hay divergencias en los resultados encontrados en la literatura...

Human-animal interaction, stress, and embryo production in Bos indicus embryo donors under tropical conditions.

This study investigated the effect of human-animal interaction (HAI) and the stress response on the quality of embryo production in superovulated Nelore (Bos indicus) cattle, under tropical conditions. Thirty-two females underwent a superovulation protocol for 5 days. Cortisol concentrations were determined in blood plasma collected on days 0, 4, and 5. Artificial insemination was performed on days 4 and 5, and nonsurgical embryo flushing on day 11. Embryo production and viability were determined. Human stimulation, animal behaviors, accidents, and handling time were recorded to assess HAI. Cattle age was negatively correlated with accidents, frequency of aversive behaviors, and negative stimuli by stockperson during transit through corral compartments to receive superovulation treatments. The factor analysis revealed two distinct groups. The first group was called stressed and had higher cortisol concentration than the nonstressed group, 16.0 ± 2.1 and 12.5 ± 1.0 ng/mL, respectively. Comparisons between these groups showed that the frequency of voice emissions by the stockperson and the number of accidents were higher in the stressed group, and also, the mean handling time was longer in the stressed group than for the nonstressed. As a result, viability rate of the embryos was 19% lower in the stressed group (P < 0.05). This indicates that intensive negative HAI is likely related to stress, which affects embryo production in a superovulation program.