Impact of environmental variables on some reproductive metrics of white-lipped peccaries (Tayassu pecari) raised in Atlantic Forest of Brazil.

Knowledge on male reproductive physiology is essential for the development of effective conservation strategies. This study investigated the influence of environmental variables on certain reproductive metrics in white-lipped peccaries (Tayassu pecari) raised in the Atlantic Forest. After anesthetization, testicular and cauda epididymis biometry were evaluated in nine adult male individuals subjected to electroejaculation. Semen was evaluated for volume, pH, concentration, total number of sperm, sperm morphology, membrane integrity, and kinematic parameters. Concurrently, environmental variables were collected from the day before, for the previous 14 days (estimated for sperm maturation in epididymis), and the period of 51-55 days (corresponding to the spermatogenic cycle) before semen collection. Overall, it was observed that rainfall is the most important environmental variable influencing the reproductive parameters of white-lipped peccaries, being positively correlated with the amplitude of lateral sperm head displacement (ρ = 0.62, P < 0.05) and the appearance of proximal cytoplasmic droplets in sperm (ρ = 0.62, P < 0.05). In addition, the testicular biometry of the species is influenced by the set of environmental variables of air temperature, rainfall, and relative humidity (ρ ≥ 0.60, P < 0.05). On the other hand, epididymal biometric data showed numerous correlations between cauda epididymis metrics and sperm parameters (ρ = 0.68, P < 0.05). This information will be useful to improving conservation strategies for these animals, contributing to their management in captivity and to reintroduction programs, especially in the Atlantic Forest where the species is declining.

Effect of Detergents Based on Sodium Dodecyl Sulfate on Functional Metrics of Frozen-Thawed Collared Peccary (Pecari tajacu) Semen.

We evaluated the effects of detergents based on sodium dodecyl sulfoxide (SDS) on the functional parameters of collared peccary frozen-thawed sperm. Semen aliquots from ten individuals were diluted in a Tris-egg yolk-glycerol extender alone or with 0.5% Equex STM® paste or SDS (at 0.1%, 0.3% or 0.5% (v/v) concentration). Samples were fast frozen in liquid nitrogen with a post-thaw evaluation of motility, membrane functionality and integrity, mitochondrial activity, sperm binding ability and thermal resistance. The treatments without SDS (41.8 ± 3.5%) and those containing Equex (41.8 ± 4.4%) or 0.1% SDS (41.2 ± 5.5%) provided greater sperm motility (p < 0.05) than those containing SDS 0.3% (30.5 ± 4.7%) and 0.5% (31.2 ± 6.3%). Immediately after thawing, only treatments containing 0.1% SDS effectively preserved sperm straightness (STR) when compared to the negative control. All treatments preserved the amplitude of lateral head (ALH) and straightness (STR) during a thermal resistance test (p > 0.05), but SDS 0.5% impaired the membrane functionality and mitochondrial activity after thawing (p < 0.05). All treatments provided a similar recovery of sperm binding ability after thawing (p < 0.05). Our results showed that the addition of 0.1% SDS to the Tris-yolk-glycerol extender optimized the freeze-thaw recovery of peccary semen.

Investigating the need for antibiotic supplementation to the extender used for semen cryopreservation in collared peccaries.

The objective was to investigate the effects of semen freezing extender supplementation with antibiotics on bacterial load of semen samples, sperm functional and morphological metrics in the collared peccary. Fresh ejaculates from 10 males were extended in Tris-egg yolk-glycerol supplemented or not (control) with gentamicin (70 µg/mL) streptomycin-penicillin (SP; 1 mg/mL-1000 IU/mL) or and cryopreserved in liquid nitrogen. Bacterial load, sperm motility patterns, morphology, membrane functionality and integrity, mitochondrial activity, chromatin integrity and sperm-binding ability were evaluated in fresh and frozen-thawed samples. Regardless of the use of antibiotics, the sole cryopreservation provoked a significant decrease (P < 0.05) in bacterial load compared to fresh samples (from average values > 1 x 106 CFU/mL to <0.4 × 106 CFU/mL). Post-thawing sperm kinetic parameters were not affected by the absence or presence of different antibiotics, except for beat cross frequency that was significantly (P < 0.05) impaired by SP supplementation compared to the group without antibiotics. After thawing, sperm morphology, membrane functionality and integrity, and mitochondrial activity were also not affected by the presence or absence of antibiotics; however, a significant decrease was observed in the group without antibiotics (P < 0.05) in comparison to fresh samples. Regarding sperm-binding ability, there were no differences among the different groups. While collared peccary semen could be efficiently cryopreserved in the absence of antibiotics in the extender, the use of both gentamicin or the streptomycin-penicillin combination is recommended as effective antibiotic supplementation for a further control of bacterial loads without affecting sperm parameters.

Morphological, morphometric, ultrastructural, and functional evaluation of red-rumped agouti (Dasyprocta leporina) sperm during epididymal transit.

The red-rumped agouti (Dasyprocta leporina) is a hystricognath rodent with reproductive anatomical peculiarities presenting as an intra-abdominal testes-epididymis complex. This study was carried out to describe, for the first time, details related to the morphological and functional changes in sperm along the epididymal transit in agoutis. The testes-epididymal complexes were sampled from seven sexually mature agoutis. Sperm from different epididymal regions (caput, corpus, and cauda) were collected using the floating technique, and their morphology, morphometry, ultrastructure, mitochondrial activity, membrane structural integrity, and kinetic parameters were determined. The number of sperm collected (823.5 ×106 sperm) was higher in the epididymis cauda. No significant differences in normal sperm morphology among the different epididymal regions (caput, 82.42%; corpus, 86.71%; and cauda, 88.86 %) were observed. The mean head length, head width, and tail length were highest in the caput (5.15 µm, 3.44 µm, and 32.04 µm, respectively), decreasing along the epididymal transit. Ultrastructure by scanning electron microscopy (SEM) revealed agglomeration of spermatozoa from caput and corpus, thus, enabling analysis of the gametes from only the epididymal cauda with clarity. Sperm from epididymis cauda showed the greatest proportion of membrane integrity and mitochondrial activity, followed by those from corpus and caput (79.71 %, 58.9 %, 47.7 %, respectively). Significant increase in total motility, progressive motility, velocity average pathway -VAP, velocity straightline - VSL, velocity curvilinear - VCL, and rapid sperm in the caput-corpus-cauda direction were observed. These novel data contribute to the knowledge of sperm maturation in the red-rumped agouti.

Identification of trailer heat zones and associated heat stress in weaner pigs transported by road in tropical climates.

Heat stress is major welfare concern during transport of pigs in tropical climates, which can also lead to direct production costs. This study evaluated the dynamics of heat zones through the load and their relationship with heat stress of weaner pigs during road transport in a tropical climate. Both environmental (e.g. temperature and relative humidity) and physiological (e.g. respiratory frequency and lactate) measures were recorded from four vehicle journeys (70 km distance, 216 weaner pigs within each trailer load) within Ceará, northeastern Brazil. Geostatistics and fluid dynamics simulation techniques were applied to understand the dynamics of heat zones and ventilation patterns the truckload. Statistics based on canonical discriminant analysis and ANOVA were performed to verify the relationship between heat zones and heat stress in pigs. The results showed that, during transport, the generation of heat zones occurred with different magnitudes along the load (P < 0.05), which was harmonized by the ventilation dynamics. There was a heat core with high energy content, in the front region of the lower deck (LD) of the trailer. In this zone, weaners pigs had higher rectal temperature (+1.8 °C temperature difference), respiratory frequency (LD = 94 ± 1.3 breaths/min; UD = 86 ± 1.3 breaths/min), and blood cortisol concentration (LD = 32.9 ± 0.8 ng/mL; UD = 30.18 ± 0.6 ng/mL) (all P < 0.05). Weaners pigs transported in the upper deck (UD) compartments had the highest skin temperature (LD = 38.13 ± 0.3 °C; UD = 38.9 ± 0.22 °C) and the highest mean values of blood lactate (LD = 65.5 ± 1.11 m/M; UD = 71.60 ± 1.19 m/M) and Creatine kinase (LD = 3891.23 ± 69U/L; UD = 4107.43 ± 62U/L) (P < 0.05). Weaners transported in compartments of the LD of trailer were more susceptible to heat stress, while weaners in the UD compartments were more susceptible to physical stress and muscle exhaustion. These results provide additional evidence of heat zones within trailer compartments and highlight the requirement for the planning of pig transport operations in tropical climates to mitigate risks of heat stress.

Composition of collared peccary seminal plasma and sperm motility kinetics in semen obtained during dry and rainy periods in a semiarid biome.

The aim of this study was to evaluate environmental effects in a semiarid region on collared peccary seminal plasma content and sperm motility. Ejaculates from 12 mature males were obtained during the peak of rainy and dry periods of the Caatinga biome. Samples were evaluated for semen volume, pH, as well as sperm concentration, morphology, osmotic response, membrane integrity, chromatin condensation, and kinetic motility. Seminal plasma was evaluated for ions and organic compounds. The values for chloride, iron, magnesium, phosphorus, citric acid, cholesterol, triglycerides, total proteins, albumin, and fructosamine were similar during the dry and rainy periods; however, concentrations of fructose (849.2 mg/dL compared with 119.4 mg/dL) and calcium (32.3 mg/dL compared with 15.6 mg/dL) were greater during the rainy compared with dry period (P < 0.05). There were correlations (P < 0.05) among values for semen variables and biochemical contents, particularly between fructose and sperm velocity average pathway (r = 0.65), velocity straight line (r = 0.78), velocity curvilinear (r = 0.57), amplitude lateral head (r = 0.62), linearity (r = 0.41), and subpopulation with a medium velocity (r = -0.75). Furthermore, values for relative humidity were positively correlated with concentrations of fructose (r = 0.49), while air temperature (r = -0.43) and wind velocity values (r = 0.66) were negatively affected by concentration of fructose (P < 0.05). There were novel results regarding collared peccary seminal plasma biochemistry indicating there are important correlations with values for semen variables that are affected by the environment in a semiarid climate.

Coarse corn particles cause a negative effect on eggshell quality of semi-heavy laying hens.

One of the possible ways to optimize the productive performance of poultry is through the physical processing of ingredients, which can improve the use of nutrients in these animals. In this context, this study was to evaluate the effects of different corn particle sizes in diets on the productive performance and egg quality of semi-heavy laying hens. Sixty naked neck laying hens were used from 24 weeks of age and distributed in a completely randomized design. Experimental diets in different treatments contained corn grain ground into sieves with a diameter of 2, 4, or 8 mm to provide corn particles with a geometric mean diameter (GMD) of 605 (fine), 1,030 (medium), and 2,280 µm (coarse), respectively. The feed and leftovers were weighed daily throughout the experimental period to determine the feed intake and feed conversion. Different corn particle sizes did not affect any aspect of the productive performance of hens, except for feed intake. Hens fed fine and medium corn particles exhibited higher values for egg yolk color, eggshell weight, and eggshell thickness. It is suggested that semi-heavy laying hens should be fed mash diets containing corn particles with GMD from 605 to 1,030 µm, because coarse corn particles cause a negative effect on eggshell quality.