Comparison of different cryoprotectants for freezing donkey (Equus asinus) semen.

The aim of this study was to evaluate two cryoprotectants, dimethylformamide (DMF) and methylformamide (MF) in two concentrations (5 and 7 %) in vitro in donkey semen using a rapid freezing technique and the effect on pregnancy rates in mares. Twenty-four ejaculates from 8 jacks (n = 8; r = 3) were divided into 4 extenders: BotuSemen Gold with 5 % or 7 % MF and 5 % or 7 % DMF, all containing 11 % lactose, 20 % egg-yolk and 0.5 % Equex. Post-thaw evaluations included: sperm motility, membrane function and acrosome status. A linear mixed effect model was used to test the effect of different freezing media on semen parameters. No differences were observed between the 4 freezing media used, for any of the seminal parameters (P > 0.05). However, samples with 5 % DMF showed the highest percentages of sperm with acrosomes and functional membranes (DMF: 5 %: 53.67 ± 22.01; 7 %: 33.92 ± 23.4; MF: 5 %: 44.5 ± 20.46; 7 %: 38.75 ± 27.4) (Data: mean ± SD; P > 0.05). Hence, thirty mares were inseminated: 15 with 5 % DMF and 15 with 7 % DMF. The pregnancy rate was 46 % (7/15) and 0 % (0/15) using the extender with 5 % or 7 % DMF, respectively (P = 0.003). To conclude, the use of 5 % or 7 % of MF or DMF did not affect the in vitro parameters. Despite the lack of differences in vitro with the two DMF concentrations, in vivo results only showed pregnancies when using 5 % DMF. Thus, the results of this study demonstrate the importance of accompanying in vitro semen evaluations with studies that evaluate post-insemination pregnancy rates.

Hematological parameters of a Neotropical wild frog population, with a phylogenetic perspective on blood cell composition in Anura.

Hematological parameters can provide key information to an animal health status. However, this information is usually hard to obtain. Here, we described the hematological parameters of Leptodactylus podicipinus in the Brazilian Pantanal. We measured red blood cell morphometrics, erythrogram, and leukogram. We also tested for phylogenetic signal in the erythrogram and leukogram of 48 frog species from 15 families, testing if body size explains their variation. Lymphocytes were the most abundant leukocytes (>60%) in L. podicipinus, followed by neutrophils (∼10%). Given that L. podicipinus is an abundant and widely distributed species in central Brazil, knowing its hematological pattern can help establish a baseline and improve its use as a bioindicator of environmental degradation. Mean corpuscular hemoglobin and value contributed more to the phylomorphospace of erythrogram, in which Leptodactylus spp. and Hypsiboas raniceps had lower values of these variables, whereas Bufotes viridis and Hyla arborea had high values. The phylogenetic signal was spread throughout the dimensions of the leukogram phylomorphospace. The variables that most contributed to it were total leukocytes counts, lymphocytes, and neutrophils. We also found a moderate phylogenetic signal for both the erythrogram and leukogram. Accordingly, body size accounted for a low proportion of variation in both the leukogram (4.7%) and erythrogram (0.57%). By applying phylogenetic comparative methods to hematological parameters, our results add a new perspective on the evolution of blood cell physiology in frogs.

Genotoxic and melanic alterations in Lithobates catesbeianus (anura) tadpoles exposed to fipronil insecticide.

The aim of this study was to evaluate the genotoxic and morphological systemic effects of both an acute and a chronic exposure of bullfrog tadpoles to fipronil. Lithobates catesbeianus tadpoles had morphological biomarkers (skin, liver, and blood) analyzed at Gosner stages 36-38, when exposed to four different concentrations of Regent® 800 WG (80% fipronil): 0.00 (control), 0.04, 0.08, 0.4 mg/L, and four experimental times: 4, 8, 12, and 16 days. Body darkness responded directly to the treatment and exposure time. There was a treatment-dependent decrease in darkness of heads and tails. In relation to the biometric analysis, fipronil induced a decrease in the individual weight and liver mass at the end of the experiments, whereas the hepatosomatic index did not vary according to the treatment. For the exposed animals and for the control group, the area of hepatic melanin increased as exposure time increased. Fipronil has genotoxic effects on L. catesbeianus tadpoles even after short exposure times (e.g., 4 and 8 days), and the main nuclear abnormality is in the anucleate cells. A relevant correlation was observed between genotoxic biomarkers and cutaneous and internal melanin. The frequency of nuclear abnormalities is inversely correlated both with the hepatic melanin area and with the cutaneous melanin of animals. Fipronil has distinct systemic effects on tadpoles based on its concentration, as well as on its exposure time. Such alterations (pigmentation level and rate of erythrocyte abnormality) result in morphological and physiological effects, which may compromise the behavior and survival of the anurans.

Effect of allogeneic mesenchymal stem cells (MSCs) on corneal wound healing in dogs.

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Effect of transportation distances, seasons and crate microclimate on broiler chicken production losses.

The goal of this research was to evaluate the microclimate (temperature, relative humidity and ECI-enthalpy comfort index) of commercial loads of broiler chickens at different transport distances: Dist15 (15 km on average) and Dist90 (90 km on average) in the summer and winter seasons and their effects on the production parameters body weight difference (BWD), mortality (%) and bruising prevalence (%). Twelve broiler loads were monitored using dataloggers to record temperature and humidity, with a total of 24 target crates per load. The experiment followed a factorial design [2 seasons (rainy and dry) × 2 distances (Dist15 and Dist90)] with a randomized complete block arrangement, 3 sexes (all males, all females, or mixed shipments) and one shipment per combination. BWD had a heterogeneous distribution throughout the load, and this distribution was not significantly correlated with the mean ECI measured during transport at 12 positions along the load. In terms of comfort, summer is the most critical period for broiler transport. In the interaction between rainy season and Dist90, the highest ECI was scored in the lethal zone (where physiological mechanisms are not enough to control body temperature). Mortality during the rainy season was not significantly different between distances. However, during the dry season, mortality was twice as high as broilers that travelled for 15 km. The prevalence of bruising on carcasses was not affected by the interaction between season and distance. As we know, broiler chicken performance, during transport, can be also related to road conditions, being hard to evaluate the real impact of seasons and distances on animal welfare. Load microclimate can compromise broiler chicken welfare during transport and it does not necessary reflect significant losses pre and post-slaughter.