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Sheep pain is an animal welfare issue monitored based on behavioral responses, including appetite. Dominant (alpha) males have priority for accessing limited feed resources, however, the effects of pain on feed interest in members of a group with defined social hierarchy are unknown. Our objective was to investigate effects of acute post-orchiectomy pain on alpha rams' interest in accessing a limited feed resource. Eighteen rams were randomly housed in pens of 3 rams. After acclimation, the first 5-d (consecutive) battery of a behavior test was performed. In this test, 180 g of the regular diet concentrate was placed in a portable trough in the center of the pen; this feed was supplemental to the diet and represented a limited, albeit strongly preferable feed resource. Rams were filmed for 5 min after the feed introduction. Hierarchical levels (alpha, beta, and gamma) were defined based on the social hierarchical index according to higher initiator and lower receptor agonistic behaviors from the social network analyses. After 15 d, a second 5-d behavioral test battery was repeated. On the following day, alpha rams were castrated. Flunixin meglumine was given immediately before surgery and a final behavioral test was performed 8 h post-orchiectomy, concurrent with an expected peak in postoperative pain. For all recordings, the latency, frequency, and duration of time that each ram had its mouth inside the feed trough were recorded, and the Unesp-Botucatu sheep acute pain scale pain scale (USAPS) was applied. The social hierarchical index was highest in alpha rams, followed by beta and gamma. The pain scores were statistically equivalent across the 11 evaluation days for beta and gamma rams, whereas there was an increase in the final evaluation for alpha. There was no difference in latency, frequency, and duration between alpha, beta, and gamma rams across evaluations. We concluded that acute post-orchiectomy pain did not decrease alpha rams' interest in accessing limited feed. Routine feeding offers a valuable chance to detect pain-related behavior using the USAPS in rams. However, dominance may confound appetite-related behaviors in assessing acute pain, as alpha rams' interest in limited feed remained unaffected by the pain.

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BACKGROUND: Confinement of cattle imposes spatial restrictions and predisposes to aversive social encounters that can lead to contusions, wounds, pain, stress, fright, and reduced productivity. Although endogenous testosterone concentrations are linked to agonistic dominance behaviors in males, it is unknown whether decreased blood testosterone concentrations after castration alter social hierarchy rank in Nelore bulls. Therefore, in this study, we investigated the impact of the surgical would inflammation post-orchiectomy on social dynamics in a group of Nelore bulls (Bos indicus). Fourteen Nelore (Bos indicus) bulls were castrated and assessed pre- and post-surgically. Parameters evaluated were agonistic (mounting, headbutting, and fighting) and affiliative (head-play) behavior, plasma testosterone concentrations, average daily weight gain (ADG), and a score for severity of post-surgical infection. Exploratory statistics included social network analysis (SNA), hierarchy rank delta (Δ), and principal component analysis (PCA). Furthermore, statistical inferences included the Wilcoxon test, multiple logistic regression models, and Spearman's correlation. RESULTS: The social dynamic of Nelore bulls was modified after castration based on the findings of the SNA and the PCA. The moderate correlation between the postoperative inflammation level with the Δ, and the significant effect of this level in the logistic model post-castration were partially attributed to effects of pain on social relations. CONCLUSIONS: Our findings suggest the severity of post-surgical inflammation, which has an association with pain intensity, was closely associated with changes in the social hierarchy.

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Canids occupy the top of the food chain and are fundamental in sustaining a wild animal/environmental balance. South America, the most biodiverse continent, has 11 species of canids inhabiting diverse biomes, with or without overlapping territories. Although several species are threatened, little is known about their reproductive biology. Remarkably, basic knowledge regarding ejaculate characteristics, sexual behavior, female reproductive cycles, pregnancy and management, and parturition are scarce or absent. These gaps complicate or preclude development of conservation programs. This review compiles the current knowledge of the reproductive biology of South American canids and discusses implications of this scenario.

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Os testículos, são mantidos no escroto a uma temperatura ~3-5°C abaixo da corporal. Quando a temperatura das gônadas se eleva, instala-se um quadro de estresse térmico (ET) testicular. O ET afeta a espermatogênese, e observam-se, já na primeira semana pós-ET, impactos na cinética, concentração e morfologia espermática. Classicamente, tais efeitos eram creditados à incapacidade da circulação local de atender ao aumento do metabolismo testicular devido ao aumento da temperatura local. Contudo, estudos recentes demonstraram que a hipóxia não era a causa da degeneração testicular. Atualmente, credita-se os efeitos deletérios do ET ao aumento local das espécies reativas de O2. Nesta situação, apesar da ativação de mecanismos antioxidantes (aumento das HSP e GPX1) e de proteção do DNA (aumento da P53), estes não são suficientes, sendo desencadeada a apoptose. Os efeitos deletérios do ET testicular podem ser mitigados pela melatonina, que pode ser tanto administrada aos animais ou adicionada ao sêmen para que desencadeie seus efeitos protetores.(AU)

The testes are kept in the scrotum at a ~3-5°C below body core temperature. When the temperature of the gonads increases, a process called heat stress (HS) takes place. The HS impairs spermatogenesis, and in the first week post-HS, impacts in sperm kinetics, concentration, and morphology are observed. Classically, such effects were credited to the incapacity of the local circulation to sustain the higher testicular metabolism due to the increased temperature. However, recent studies demonstrated that it was not the cause of testicular degeneration. The novel perspective credits the deleterious impacts of the HS to the local increase of the reactive oxygen species. Importantly, although there's an activation of antioxidant defenses (increase in HSP and GPX1) and DNA protection (increase in P53), such mechanisms are not sufficient, unfolding the apoptotic cascade. Lastly, some of the negative effects of HS can be mitigated by melatonin, which can either be given to the animals or added to the sperm to exert its protective effects.(AU)

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The objective was to compare effects of immunological, chemical and surgical castrations on testicular characteristics, scrotal surface temperatures, sperm quality, and serum testosterone concentrations in Bos indicus bulls. Eighty Nelore bulls (∼20 mo) were grazed on pasture, fed a supplement and slaughtered at ∼480 kg. Bulls were allocated into four groups (n = 20/group). The control group (CON) was non-castrated and there were three castration methods: immune (IMM - Bopriva®), injected on D-30, D30 and D60; chemical (CHE), an intratesticular injection of 40% CaCl2 + 0.5% dimethylsulfoxide on D0; and surgical (SUR) on D0. The CHE group were surgically castrated on D60, due to testicular swelling and necrosis of scrotal skin. Most scrotal surface temperatures (infrared thermography) were significantly higher on D15 in CHE and SUR compared to CON, due to inflammation. All bulls were subjected to a breeding soundness evaluation on D-7 and slaughtered on D220. Scrotal circumference and testicular volume did not differ among groups (P > 0.05) at D0, but at D15, both end points were highest (P < 0.05) in the CHE group (due to swelling), although both end points were smaller for IMM versus CON (P < 0.05) at D60 and D150. Sperm motility in the IMM group was ∼50 and 10% of that in the CON group on D60 and D150, respectively. For the IMM group, serum testosterone concentrations were similar on D0 and D15 (but ∼50% of CHE or SUR on D0, attributed to the first treatment on D-30), and had decreased ∼70% on D60 and D150, whereas in the CHE and SUR groups, there were ∼80-90% decreases in testosterone after D0. In conclusion, immunological castration was a viable alternative to surgical castration, as it supressed testosterone production and spermatogenesis, with the benefits of being much less invasive, with better animal welfare and less stress.

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Bull testes must be 2 to 6 0C below body temperature for morphologically normal, motile and fertile sperm. Scrotal/testicular thermoregulation is complex, including a coiled testicular artery, surrounded by the venous pampiniform plexus comprising the testicular vascular cone, a counter-current heat exchanger. In addition, heat radiation from the scrotum, sweating, complementary arterial blood supplies, and temperature gradients in the scrotum and testes all contribute to testicular cooling. Despite a long-standing paradigm that mammalian testes are close to hypoxia and blood flow does not increase in response to testicular heating, in recent studies in mice, rams and bulls, warming the testes stimulated increased blood flow, with no indications of testicular hypoxia. Furthermore, hypoxia did not replicate the changes and hyperoxia did not provide protection. Therefore, we concluded that testicular hyperthermia and not secondary hypoxia affects spermatogenesis and sperm quality. Increasing testicular temperature causes many cellular and subcellular changes. As testicular temperature increases, the proportion of defective sperm increases; recovery is dependent upon the nature and duration of the thermal insult. Environmental control of temperature (shade, sprinklers, air conditioning) and some chemical approaches (e.g., melatonin and L-arginine) have promise in reducing the effects of heat stress on bull reproduction.

Os testículos dos bovinos devem permanecer 2 a 6 ºC abaixo da temperatura corporal para produzirem espermatozoides morfologicamente normais, móveis e férteis. A termorregulação escrotal/testicular é complexa e envolve a enovelada artéria testicular circundada pelo plexo venoso pampiniforme, que constituem o cone vascular, um sistema contracorrente de troca de calor. Adicionalmente, a perda de calor por radiação pelo escroto, sudorese, suprimento sanguíneo arterial complementar, e os gradientes de temperatura no escroto e testículos contribuem para o resfriamento testicular. A despeito do duradouro paradigma de que os testículos estão em uma situação de quase hipóxia e que o fluxo sanguíneo não aumenta em resposta ao aquecimento testicular, em recentes estudos em camundongos, carneiros e touros, o aquecimento testicular estimulou o fluxo sanguíneo sem serem observados sinais de hipóxia. Além disso, a hipóxia não afetou os testículos e a hiperóxia não conferiu proteção. Portanto, concluímos que é a hipertermia testicular, e não a hipóxia secundária, que afeta a espermatogênese e a qualidade seminal. O aumento da temperatura testicular causa muitas mudanças celulares e subcelulares. À medida que a temperatura aumenta, a proporção de espermatozoides defeituosos aumenta. A recuperação depende da natureza e duração do insulto térmico. O controle ambiental (sombra, aspersores de água e ar condicionado) e algumas abordagens químicas (ex., melatonina e L-arginina) são medidas promissoras de redução dos efeitos do estresse térmico na reprodução de touros

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O estresse por calor (ET) ocorre quando a temperatura ambiente excede a zona de conforto térmico animal. Várias respostas corporais inespecíficas, capitaneadas pelos sistemas nervoso, neuroendócrino e imunológico são acionadas para manter a homeostase e resfriar o animal. O ET afeta o eixo hipotálamo-hipofisário-gonadal, comprometendo a liberação de gonadotrofinas, e promove o acúmulo de espécies reativas de oxigênio e proteínas anormais nas células ovarianas. Em resposta, as células ativam mecanismos antioxidantes e de reparação do DNA, que reduzem o metabolismo celular e aumentam as chances de sobrevivência; quando a reparação não é possível, acontece a apoptose. O ET impacta negativamente a produção de estradiol ovariano, o comportamento do estro, o desenvolvimento folicular, a competência dos oócitos e do embrião, as taxas de concepção, o estabelecimento e a manutenção da gravidez e até mesmo a eficiência reprodutiva da progênie. O combate ao ET inclui estratégias de combate ao aquecimento global progressivo e de manejo para resfriar os animais, e diminuir a produção de calor metabólico. O uso de biotecnologia reprodutiva e estratégias genéticas para gerar animais termotolerantes são também essenciais

Heat stress (HS), a harmful condition affecting animal production, reproduction, and welfare, occurs when an animal is exposed to temperatures that exceed its thermal comfort zone. Several nonspecific body responses involving neural, neuroendocrine, and immune systems are triggered to keep homeostasis in such conditions. These responses, primarily directed to cooling the body, also impact the hypothalamic-pituitary-gonadal axis, compromising the bovine female’s release of gonadotropins. Heat stress also promotes reactive oxygen species accumulation in ovarian cells, impairing protein folding and refolding, triggering antioxidant and DNA protection mechanisms. These mechanisms, directed to reduce cell metabolism and increase survival chances, are not always sufficient to protect the cell and result in apoptosis. Heat stress’s systemic and cellular consequences impact ovarian estradiol production, estrous behaviors, follicular development, oocytes and embryo competence, conception rates, pregnancy establishment and maintenance, and even the future reproductive efficiency of the progenies of cows exposed to HS during pregnancy. The combat of heat stress includes strategies to alleviate the effect of progressive global warming, management strategies to cool the animals, reduced metabolic heat, and methane production dietary approaches. The use of reproductive biotechs and genetic strategies to increase thermotolerant animals are also critical to overcoming the harmful effect of HS.

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Our objective was to condition adult male crab-eating fox (Cerdocyon thous) to allow semen collection by digital manipulation of the penis, assess sperm characteristics, and use ultrasonography to assess and measure testes and prostate and determine echotexture, as well as hemodynamics of testicular and spermatic cord arteries. Five captive C. thous (2-5 y, ∼7 kg) were used. After conditioning for digital sperm collection, 13 ejaculates were obtained from two males. Ejaculate characteristics (mean ± SD) were volume (393.2 ± 178.0 µL), concentration (463.7 ± 594.4 × 106 sperm/mL), total sperm number (217.4 ± 304.0 × 106 sperm), total motility (68.0 ± 6.1%), progressive motility (48.8 ± 5.1%) and rapid sperm (57.2 ± 6.8%). The most prevalent sperm morphological defects were abnormal acrosome, small abnormal head, and diadem defect. Under chemical restraint, testes and prostate were evaluated with B-mode and spectral Doppler ultrasonography. Based on ultrasonography, testicular volumes were (2.2 ± 0.7 and 2.1 ± 0.7 cm3 for left and right testes, respectively), whereas prostate dimensions were 2.3 ± 0.4 cm long and 1.5 ± 0.3 cm thick. Lastly, using triplex Doppler, peak systolic velocity (PSV) was higher in testicular versus intratesticular arteries. In conclusion, adult male C. thous were conditioned to allow sperm collection by digital manipulation without urine contamination, enabling evaluation of sperm characteristics. Furthermore, B-mode ultrasound facilitated evaluation of testes and prostate morphometry and echotexture, whereas Doppler was used to characterize testicular blood flow. This was proof of concept for semen collection and baseline data for future male reproductive soundness examinations and development of assisted reproductive techniques in this species.

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Although equine blastocysts ≤ 300 µm in diameter can be successfully vitrified, larger equine blastocysts are not good candidates for cryopreservation. As Na+, K+-ATPase is involved in maintaining blastocyst expansion, perhaps inhibition of this enzyme would be a viable method of reducing blastocyst diameter prior to cryopreservation. Objectives were to evaluate effects of ouabain-induced inhibition of Na+, K+-ATPase in equine blastocysts. Sixteen mares were ultrasonographically monitored, given deslorelin acetate to induce ovulation, and inseminated. Embryos (D7 and D9) were harvested and Na+, K+-ATPase inhibited for 1 or 6 h by exposure to 10-6 M ouabain, either natural ouabain or conjugated to fluorescein (OuabainFL), during incubation at 37° C. Evaluations included morphometric characteristics (bright field microscopy) and viability (Hoescht 33342 + propidium iodide). Blastocysts incubated for 6 h in Holding medium + ouabain (n=3) had, on average, a 45.7% reduction in diameter, with adverse morphologic features and no re-expansion after subsequent incubation in Holding medium for 12 h. In subsequent studies, even a 1-h exposure to Ouabain or OuabainFL, caused similar reductions, namely 38.7 ± 6.7% (n=5) and 33.6 ± 3.3% (n=7) for D7 and D9 blastocysts, respectively. Ouabain binding was confirmed after OuabainFL exposition and all embryos (n=12) lost viability. We concluded that Na+, K+-ATPase inhibition with ouabain caused death of equine blastocysts and therefore was not a viable method of reducing blastocyst size prior to cryopreservation.

RESUMO

Although equine blastocysts ≤ 300 µm in diameter can be successfully vitrified, larger equine blastocysts are not good candidates for cryopreservation. As Na+, K+-ATPase is involved in maintaining blastocyst expansion, perhaps inhibition of this enzyme would be a viable method of reducing blastocyst diameter prior to cryopreservation. Objectives were to evaluate effects of ouabain-induced inhibition of Na+, K+-ATPase in equine blastocysts. Sixteen mares were ultrasonographically monitored, given deslorelin acetate to induce ovulation, and inseminated. Embryos (D7 and D9) were harvested and Na+, K+-ATPase inhibited for 1 or 6 h by exposure to 10-6 M ouabain, either natural ouabain or conjugated to fluorescein (OuabainFL), during incubation at 37° C. Evaluations included morphometric characteristics (bright field microscopy) and viability (Hoescht 33342 + propidium iodide). Blastocysts incubated for 6 h in Holding medium + ouabain (n=3) had, on average, a 45.7% reduction in diameter, with adverse morphologic features and no re-expansion after subsequent incubation in Holding medium for 12 h. In subsequent studies, even a 1-h exposure to Ouabain or OuabainFL, caused similar reductions, namely 38.7 ± 6.7% (n=5) and 33.6 ± 3.3% (n=7) for D7 and D9 blastocysts, respectively. Ouabain binding was confirmed after OuabainFL exposition and all embryos (n=12) lost viability. We concluded that Na+, K+-ATPase inhibition with ouabain caused death of equine blastocysts and therefore was not a viable method of reducing blastocyst size prior to cryopreservation.(AU)

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Although equine blastocysts ≤ 300 µm in diameter can be successfully vitrified, larger equine blastocysts are not good candidates for cryopreservation. As Na+, K+-ATPase is involved in maintaining blastocyst expansion, perhaps inhibition of this enzyme would be a viable method of reducing blastocyst diameter prior to cryopreservation. Objectives were to evaluate effects of ouabain-induced inhibition of Na+, K+-ATPase in equine blastocysts. Sixteen mares were ultrasonographically monitored, given deslorelin acetate to induce ovulation, and inseminated. Embryos (D7 and D9) were harvested and Na+, K+-ATPase inhibited for 1 or 6 h by exposure to 10-6 M ouabain, either natural ouabain or conjugated to fluorescein (OuabainFL), during incubation at 37° C. Evaluations included morphometric characteristics (bright field microscopy) and viability (Hoescht 33342 + propidium iodide). Blastocysts incubated for 6 h in Holding medium + ouabain (n=3) had, on average, a 45.7% reduction in diameter, with adverse morphologic features and no re-expansion after subsequent incubation in Holding medium for 12 h. In subsequent studies, even a 1-h exposure to Ouabain or OuabainFL, caused similar reductions, namely 38.7 ± 6.7% (n=5) and 33.6 ± 3.3% (n=7) for D7 and D9 blastocysts, respectively. Ouabain binding was confirmed after OuabainFL exposition and all embryos (n=12) lost viability. We concluded that Na+, K+-ATPase inhibition with ouabain caused death of equine blastocysts and therefore was not a viable method of reducing blastocyst size prior to cryopreservation.

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