MALE EFFECT: SUSTAINABILITY AND EFFECTIVENESS IN INDUCING ESTRUS IN GOATS/EFECTO MACHO: SOSTENIBILIDAD Y EFICIENCIA EN LA INDUCCIÓN DEL CELO EN CABRAS

The male effect is a strategy used in reproductive management of herds for the induction and synchronization of estrus, consisting of the reintroduction of males into a group of previously separated females. This interaction induces an increase in LH pulses followed by ovulation. In all species, there are communication mechanisms, many involving the use of chemoreceptor organs that enable the perception of pheromones, mediators in intraspecies interaction related to recognition for mating. Synchronization of female estrus by the male effect has many advantages reported by several authors, such as the reduction of costs, the absence of undesirable immune response by the use of chorionic gonadotropin, the decrease of hormonal residues in treated females, thus complying with ecological and sustainable production principles in animal production. El efecto macho es una estrategia usada en el manejo reproductivo de los rebaños para la inducción y sincronización del celo, consistiendo en la reintroducción de machos en un grupo de hembras previamente separadas. Esta interacción induce un incremento en los pulsos de LH seguidos por la ovulación. En todas las especies, existen unos mecanismos de comunicación, algunos involucran el uso de órganos quimiorreceptores que permiten la percepción de feromonas, mediadores en las interacciones intraespecíes relacionados con el reconocimiento para el apareamiento. La sincronización del celo en las hembras por el efecto macho tiene varias ventajas reportadas por diversos autores, tales como la reducción de costos, la ausencia de una respuesta inmune indeseada por el uso de gonadotropina coriónica, la disminución de residuos hormonales en las hembras tratadas, cumpliendo con los principios de una producción ecológica y sostenible en la producción animal.

CONSEQUÊNCIAS DA DEGENERAÇÃO TESTICULAR POR ESTRESSE TÉRMICO SOBRE A QUALIDADE DO EJACULADO DE PEQUENOS RUMINANTES DOMÉSTICOS

Animal production depends on the reproduction of domestic males and females. In ruminant breeding, heat stress is the main reason of testicular degeneration, causing anatomical changes in the male gonad even microscopic changes, from the seminiferous epithelium until the spermatozoa in transit in the male reproductive tract. These microscopic changes occur simultaneously to several changes in the protein composition of the seminal plasma of the reproductive tract, which is related to higher sperm defects (of primarily testicular origin) or minor defects (that arise during epididymal transit) and, consequently, to the parameters of sperm kinetics and ejaculate fecundity. Thus, this review aims to describe the changes that occur when domestic ruminants are affected by testicular degeneration due to failure in thermoregulation, correlating them to the changes found in seminal plasma, sperm morphology in parallel to sperm motility parameters.A produção animal depende da reprodução de machos e fêmeas domésticas. Em reprodutores ruminantes, o estresse térmico é a principal causa de degeneração testicular e, nesta, ocorrem desde mudanças anatômicas na gônada masculina até alterações microscópicas, do epitélio seminífero aos espermatozoides em trânsito no trato reprodutor masculino. Essas alterações microscópicas são simultâneas a diversas mudanças na composição proteica do plasma seminal dos reprodutores, o que está ligado a defeitos espermáticos de ordem maior (de origem primariamente testicular) ou menor (que surgem durante o trânsito epididimário) e, consequentemente, aos parâmetros de cinética espermática e à fecundidade do ejaculado. Assim, esta revisão objetiva descrever as alterações que ocorrem quando reprodutores ruminantes domésticos são acometidos de degeneração testicular por falha na termorregulação, correlacionando-as às mudanças encontradas no plasma seminal, na morfologia espermática e, paralelamente, aos parâmetros de motilidade espermática

Thermal comfort of female buffaloes in a silvipasture system in the eastern Amazon

O objetivo deste trabalho foi avaliar o efeito de um sistema silvipastoril no conforto térmico de 20 búfalas Murrah, das quais 10 criadas em piquetes sem sombra (SS) e 10 com sombreamento (CS) de Racosperma mangium, em Belém, PA. Os animais foram alimentados em pasto, com Urochloa humidicola, com acesso livre à água para beber e sal mineral. A cada três dias, foram mensuradas: temperatura do ar (TA), umidade relativa do ar (UR), temperatura de globo negro (TGN), temperatura retal (TR), frequências respiratória (FR) e cardíaca (FC), e a temperatura da superfície corporal (TSC), pela manhã (7h) e à tarde (13h). Os valores de TR, TSC, FR e FC foram maiores à tarde, especialmente no grupo SS. Mais altas no período menos chuvoso, a TR, TSC e FR apresentaram correlação linear positiva com a TA e o índice de temperatura e umidade (ITGU) e negativa com a UR. Tanto na estação mais chuvosa quanto na menos chuvosa, a FC apresentou correlações significativas positivas com a TA e ITGU e negativas com a UR, apenas no período mais chuvoso. A arborização da pastagem é eficiente para melhorar o conforto térmico das búfalas Murrah, principalmente à tarde.The objective of this work was to evaluate the effects of a silvipasture system on the thermal comfort of 20 female buffaloes, from which 10 raised in under nonshaded paddocks (SS) and 10 in paddocks shaded by Racosperma mangium (CS), in Belém county, PA, Brazil. All animals were fed in pastures with Urochloa humidicola, and had free access to drinking water and mineral salt. Every three days, measurements were made for air temperature (TA), relative humidity (UR), black globe temperature (TGN), rectal temperature (TR), respiratory rate (FR), heart rate (FC), and body surface temperature (TSC), in the morning (7 AM) and in the afternoon (1 PM). The values of TR, TSC, RR and FR, mainly for the SS group, were higher in the afternoon. The TR, TSC and FR showed a significant and positive correlation with TA and the temperature and humidity index (ITGU), and a negative correlation with UR. These correlations were higher for the less rainy period. The FR showed significant and positive correlations with TA and ITGU, during both the most and the less rainy seasons, and negative correlations with UR only in the rainy season. The forestation of pasture areas is efficient to increase the thermal comfort for Murrah females, especially in the afternoon

Heat Stress and Body Temperature in Brown Swiss Cows Raised in Semi-Arid Climate of Ceará State, Brazil

Background: In tropical countries like Brazil, air temperature and relative humidity have a significant effect on animal physiology; there is a great impact of solar radiation on physiological parameters, especially on body temperature. This study evaluated the occurrence of heat stress in Brown Swiss cows in a tropical semi-arid climate, and checked for the correlation between internal body temperatures [rectal temperature (RT) and vaginal temperature (VT)] with surface temperature (ST) to determine if these variables are associated.Materials, Methods & Results: Twenty-eight Brown Swiss cows at three stages of the lactation cycle were used in this study: 10 nonpregant lactating (NPL) cows, 8 dry pregnant (DP) cows, and 10 pregnant lactating (PL) cows. These animals were between the second and third calving, weighed between 346 and 720 kg, and had ages between 2 and 13 years. During the experimental period, air temperature and relative humidity (RH) at the experimental site were measured using a digital thermohygrometer. The temperature and humidity index (THI) was calculated according to methodology described by Thom (1958), and was used as an environmental comfort parameter. For the evaluation of RT and VT, two digital clinical thermometers, one inserted in the vagina and the other in the rectum, were used simultaneously to minimize stress. Surface temperature (ST) was assessed using a digital infrared laser thermometer at a distance of 50 cm from the animal. Surface temperature was measured in the forehead (FST), thorax (TST), flank (FLST), and legs (LST). During the study period, the ambient temperature (AT) was significantly higher outside (in the sun) than inside of the facilities (in the shade) (P < 0.05). RH was inversely proportional to AT, and was significantly higher inside than outside the facilities (P < 0.05). Like AT, THI was significantly higher outside (in the sun) than inside the facilities (in the shade), with significant differences between these locations (P < 0.05). The amplitudes of the differences between the locations were as follows: 3.8°C for AT, 6.2% for RH, and 2.6 for THI. Mean values of rectal and vaginal temperatures were not significantly different from each other independent of lactation cycle stage, and were almost always significantly higher than the measured surface temperatures (P < 0.05). The maximum values obtained for each lactation cycle stage in this study were higher when compared to the mean values, showing that they are more representative of the occurrence of heat stress. Correlations between internal temperatures (RT and VT) and surface temperatures (TSF, TST, TSFL, and TSP) were weak and non-significant. ST values exhibited mostly weak, non-significant correlations, with the exception of FST with FLST and LST, which had moderate, significant correlations, as shown by the following coefficient factors: FST x FLST, 0.34; LST x FST, 0.415; and LST x FLST, 0.37.Discussion: A temperature of 34°C with RH ranging from 46% to 80% (i.e., a THI between 83 and 89) has been reported to have a significant thermal impact on dairy Brown Swiss cows; the THI values found in the present experiment were close to those. Body temperatures exhibited significant variations depending on the lactation cycle stage of the cows. Lactation concomitant with pregnancy significantly increases internal temperatures (RT and VT) in DP and NPL cows. This finding may be explained by the fact that pregnancy concomitant with lactation accelerates the metabolism, which results in higher food intake and increased production of body heat with consequent increase in internal body temperature. The maximum values of internal body temperatures (RT and TV) at all stages of the lactation cycle were higher than their corresponding average values, which indicates that some cows exhibited, at given moments, hyperthermia

Hermafroditismo verdadeiro na espécie canina

Background: Hermaphroditism or intersex is a general term that includes various congenital anomalies of the genital system which is used to define animals with ambiguous sexual characteristics. It occurs in domestic animals, more commonly in pigs and goats, and rarely in horses, dogs, sheep, and cattle. The prevalence of hermaphroditism varies a lot among breeds and species and is higher in groups with a high degree of consanguinity. Therefore, the objective of this report is to describe a case of canine hermaphroditism in a dog with male phenotype, as well as the anatomical and hormonal findings, and classification of the hermaphroditism exhibited by the animal studied.Case: A 1-year-old, mongrel, 5 kg dog was referred to the UHV-UECE due to the presence of a slit on the lower quadrant of the abdomen, caudal to the umbilical scar. At examination, the animal exhibited normal rectal temperature, no alterations of palpable lymph nodes, and a satisfactory body condition score. The pubic area had 2 testicles, each one in a different scrotum, 1 to the right and 1 to the left of the slit. A prepuce with no apparent function was present cranially to the slit, closer to the umbilical scar. At the other extremity of the slit, on the pubic region, there was a flaccid structure similar to a penis (micropenis) with no penile bone and no function. The slit was open until the area ventral to the anus, where the urethra was detected. The animal exhibited a behavior of territory demarcation with urine typically seen in male dogs. Orchiectomy and slit correction surgery were performed. Pre-surgical exams included: complete blood count and hormonal doses of estradiol, testosterone, and progesterone. Abdominal ultrasound was performed to assess presence of sexual glands and gonads. The hormonal exam revealed: estradiol 56.39 pg/mL; testosterone 127.9 ng/mL; progesterone 0.892 ng/mL. A uterus was not detected on ultrasound examination. Ovaries were seen on their typical anatomical position; they were symmetrical and had normal sizes. There was a normal size prostate in the pelvic area, exhibiting normal texture and echogenicity. No other abnormalities were seen and the owner opted for no further surgical intervention.Discussion: Testosterone predominance explains the male behavior and appearance, demonstrating that the testis were prevalent over the ovaries. The occurrence of XX males has been reported. The genetic cause is the absence of the SRY chromosome, which has a fundamental role on activation of the SOX gene, which is responsible for sex determination. Clinically, a true hermaphrodite can exhibit different degrees of genital ambiguity; they can be diagnosed during puberty with the emergence of heterosexual characteristics, or as an adult, with infertility or gonadal neoplasia. True hermaphrodites are individuals with testicular and ovarian tissues, either combined in one gonad (ovotestis) or present as two separate gonads. The presence of ovaries and testicles can be confirmed by histology, which was not performed in this study. However, ultrasound findings (prostate and ovaries), and the presence of normal testis and external genitalia without a defined penis or vulva are in accordance with the description of a true hermaphrodite

Fertilidade após a inseminação artificial intra-cervical ou laparoscópica intra-uterina de ovelhas utilizando diluidores à base de água de coco

The objetive of this study was to evaluate pregnancy rates in ewes using extenders based on coconut water (in natura: NCW or in powder: PCW-102®) following intra - cervical (Trial 1) or intrauterine laparoscopic insemination (Trial 2). Trial 1. Semen from 4 Santa Inês rams were collected, diluted at 32°C (T1: NCW; T2: PCW-102®) and cooled to 4°C. 56 adult Santa Inês ewes were inseminated intra-cervically following syncronization, 31 using the extender NCW and 25 the extender PCW-102®. Trial 2. Semen from 5 rams (Santa Inês: n=04; Dorper n=01) were collected and processed as described. 64 adult crossbred multiparous ewes were inseminated intrauterine by laparoscopy following oestrus syncronization. 37 ewes using the extender NCW and 27 the extender PCW-102®. The pregnancy diagnosis was performed by ultrasonography. The fertility rates between treatments for each method of insemination and within each extender for both methods were analysed by Chi-square test (p<0,05). The pregnancy rates following intra-cervical (NCW: 25.8% vs PCW-102®: 48%) and intrauterine (NCW: 72.9% vs 70.3%) inseminations were not influenced by the extenders. The pregnancy rate was influenced by insemination method (intra-cervical: 35.7% vs laparoscopy: 71.8%; p<0,05). The extenders based coconut water as basis can be used following cervical or intra-uterine laparoscopic inseminations in ewes from Northeast of Brazil under field conditions.O objetivo deste estudo foi avaliar a taxa de prenhez em ovelhas utilizando diluidores à base de água de coco (in natura: ACN ou em pó: ACP-102®) após inseminação artificial intra-cervical (Experimento 1) ou laparoscópica intra-uterina (Experimento 2). Experimento 1. Sêmen de 4 carneiros Santa Inês foi coletado, diluído a 37°C (T1: ACN; T2: ACP-102®) e resfriado á 4°C. 56 ovelhas Santa Inês foram inseminadas cervicalmente após a sincronização, 31 utilizando o diluidor ACN e 25 o diluidor ACP-102®. Experimento 2. Sêmen de 5 carneiros adultos (Santa Inês: n=04; Dorper n=01) foi coletado e processado de acordo com o descrito. 64 ovelhas SRD foram inseminadas intra-uterina por laparoscopia após a sincronização do estro, 37 utilizando o diluidor ACN e 27 o diluidor ACP-102®. O diagnóstico de gestação foi realizado por ultra-sonografia. A taxa de prenhez entre os tratamentos, dentro de cada método de inseminação, entre cada diluidor para ambos métodos de inseminação foi analisada pelo teste do Qui-quadrado (p<0,05). A taxa de prenhez após IA intra-cervical (ACN: 25,8% vs. ACP-102®: 48%) e laparoscópica (ACN: 72,9% vs ACP-102®: 70,3%) não foi influenciada pelos diluidores. A taxa de prenhez foi influenciada pelo método de inseminação (intra-cervical: 35,7% vs. laparoscopia: 71,8%; p<0,05). Os diluidores a base de água de coco podem ser utilizados nas inseminações artificiais cervical ou laparoscopica em ovelhas do Nordeste do Brasil em condições de campo

Conforto térmico de búfalas em sistema silvipastoril na Amazônia Oriental

O objetivo deste trabalho foi avaliar o efeito de um sistema silvipastoril no conforto térmico de 20 búfalas Murrah, das quais 10 criadas em piquetes sem sombra (SS) e 10 com sombreamento (CS) de Racosperma mangium, em Belém, PA. Os animais foram alimentados em pasto, com Urochloa humidicola, com acesso livre à água para beber e sal mineral. A cada três dias, foram mensuradas: temperatura do ar (TA), umidade relativa do ar (UR), temperatura de globo negro (TGN), temperatura retal (TR), frequências respiratória (FR) e cardíaca (FC), e a temperatura da superfície corporal (TSC), pela manhã (7h) e à tarde (13h). Os valores de TR, TSC, FR e FC foram maiores à tarde, especialmente no grupo SS. Mais altas no período menos chuvoso, a TR, TSC e FR apresentaram correlação linear positiva com a TA e o índice de temperatura e umidade (ITGU) e negativa com a UR. Tanto na estação mais chuvosa quanto na menos chuvosa, a FC apresentou correlações significativas positivas com a TA e ITGU e negativas com a UR, apenas no período mais chuvoso. A arborização da pastagem é eficiente para melhorar o conforto térmico das búfalas Murrah, principalmente à tarde