Pregnancy success in bitches - evaluation of interactions between artificial insemination method, serum progesterone concentration and vaginal cytology parameters

Background: The artificial insemination has become a well-established method in the breeding of bitches, and evaluation of the factors that may potentially affect pregnancy success is essential. For this reason, it is essential to evaluate the factors that may affect fertility of the bitch when artificial insemination is performed. Serum progesterone concentrations and vaginal cytology have been used to determine the time of ovulation and stage of the estrus cycle. This study aimed to evaluate the artificial insemination method, the serum progesterone concentration, the breed size, age, the whelping number, vaginal cytology parameters, and their interactions on pregnancy success in bitches. Materials, Methods & Results: A total of 607 bitches that had undergone reproductive consultation with the Mexican Canine Federation from January to December 2016 were enrolled in the present study and assigned to one of 2 artificial insemination methods (intravaginal and transcervical) using fresh semen. Determination of the estrus cycle phase and the time of Artificial insemination was based on vaginal cytology and serum progesterone concentrations. Bitches inseminated by the transcervical technique had a higher pregnancy rate with respect to females inseminated by the intravaginal technique (P < 0.05). Moreover, females with a serum progesterone concentration of 5-10 ng/mL had a greater probability (> 4 times) of getting pregnant than animals with lower or higher progesterone concentrations (P < 0.05). Bitches inseminated by the intravaginal technique and with serum progesterone concentrations >10 ng/mL had a considerable reduction in pregnancy (P < 0.05) compared with females with < 10 ng/mL serum progesterone or with bitches inseminated by the transcervical technique. Discusion: Serum progesterone concentration, the artificial insemination method, and superficial cells without a nucleus modified the pregnancy rate in bitches. Females inseminated by transcervical semen deposition had a higher pregnancy rate than females inseminated by the intravaginal technique. Using fresh or frozen-thawed semen produced a higher pregnancy rate in bitches inseminated by transcervical semen deposition than females inseminated by the intravaginal technique. Differences in the pregnancy rate between transcervical and intravaginal insemination could be associated with the correct semen disposition, the distance that the sperm must travel to reach the oocyte, as well as the number of sperm that reach the oviduct ampulla. Exist evidences that after ovulation, as progesterone rises, the cervix is closed, which may compromise the passage of the sperm deposited into the vagina. Therefore, it is likely that in females with a serum progesterone concentration > 10 ng/mL, the cervix was closed, compromising the ability of the sperm to access the oviduct. Thus, the use of intravaginal insemination should be done in bitches with a serum progesterone concentrations < 11 ng/mL to reduce the possibility of cervical closure and to increase the odds of pregnancy. It is well documented that the serum progesterone concentration and vaginal cytology parameters have a great influence on pregnancy success, and the results confirm these findings. In the present study, 96% of the bitches inseminated with a serum progesterone concentration of 5-10 ng/mL got pregnant and had higher odds of pregnancy than bitches with lower or higher serum progesterone concentrations.

Gestational follow-up in ewes - placentome size and fecal progesterone metabolite levels

Background: Transabdominal ultrasonography in sheep allows real-time diagnosis and monitoring of pregnancy as well as measurement of the size of placentomes, which are structures that connect the fetal and maternal portions, that increase as pregnancy progresses. Progesterone is involved in the maintenance of gestation, with high levels noted during pregnancy. In this context, it is hypothesized that measurements of placentome and progesterone could help in monitoring pregnancy in sheep. Therefore, the main objectives of this study included evaluating whether placentome size and fecal progesterone levels are associated with gestational age in ewes and whether measurement of the placentome and progesterone could be used as an estimate of gestational age. Materials, Methods & Results: A total of 63 pregnant adult (between 2 and 5 years of age) Santa Inês ewes were monitored in the city of Boa Vista, Roraima. All ewes were kept in the paddock with Panicum maximun cv. tanzania, mineral salt, and water ad libitum, supplemented with 200 g/animal/day of soybean residue. Ewes were subjected to ultrasonography every 21 days from day 42 of pregancy until term to monitor pregnancy. Ultrasonography was performed using a linear probe to measure the placentome, including length × width in centimeters. Also every 21 days, fecal samples were collected for measurement of progesterone level. Feces were collected directly from the rectal ampulla, stored individually in plastic bags, and frozen at -20ºC until processing. In the laboratory, these feces samples were freeze-dried and subjected to hormonal extraction with 80% methanol. Then, the levels of fecal progesterone metabolites were measured by enzyme immunoassay. Data was tabulated and submitted to statistical analyses, including descriptive stastistic, correlation, KruskalWallis test and Tukey's test. The levels of fecal progesterone metabolites increased significantly between the 3rd and 4th months of pregnancy, with a decrease close to delivery. Placentome size increased significantly between the 2nd and 3rd months of pregnancy. Placentome measurements did not correlate with progesterone levels and showed a weak correlation with gestational age. Therefore, we concluded that the measurements of placentome size and a single evaluation of fecal progesterone metabolites were not considered efficient methods for estimating gestational age. Discussion: Measurement of progesterone level in fecal samples is a non-invasive hormone monitoring method that provides values like that of blood levels and is less stressful for the animals at the time of sample collection. The wide physiological variation makes it difficult or even useless to use fecal progesterone, when is measured only once per animal, as an indicator of the presence of pregnancy. Despite this limitation, serial sampling is useful for monitoring of hormones during the pregnancy period and is an important tool for research purposes. Placentome size measurements correlated weakly with gestational age and did not correlate with progesterone level. Thus, the presence of placentomes is indicative of the presence of pregnancy but was considered inefficient for determining gestational age in sheep.

Efeito da progesterona na sincronização de vacas de leite / Effect of progesterone on synchronization of dairy cows

Diversos fatores impactam os índices reprodutivos em vacas leiteiras, como a produção de leite, o manejo nutricional e o programa reprodutivo implementado. Em vacas leiteiras de alta produção, o maior catabolismo de esteróides, como a progesterona, devem ser levados em consideração ao escolher o tratamento hormonal a ser realizado. Assim, estratégias com a suplementação de progesterona previamente e ao início do protocolo foram desenvolvidas e descritas.(AU)

Milk production, nutritional management and the implemented reproductive program impact reproductive rates in dairy cows. The greater catabolism of steroids such as progesterone in high producing dairy cows must be considered when choosing the hormonal treatment to be used. Thus, strategies with progesterone supplementation before and at the beginning of the protocol were developed and described.(AU)

In vivo embryo development in bitches inseminated laparoscopically after ovulation time estimated based on a single progesterone determination

Logistic and economical limitations are often the causes of dog owners not accurately monitoring the estrous cycle and the optimal insemination time. The aim of this study was to evaluate in vivo early embryonic development in bitches, after the analysis of sequential vaginal cytologies associated to single progesterone measurement and single laparoscopic insemination with high quality semen (fresh and with high spermatozoa concentration) or low-quality semen (frozen/thawed and with low spermatozoa concentration) at 48 h post- ovulation time predicted on a single progesterone measurement. Ten bitches were inseminated with 250 x 106 fresh spermatozoa (80% motility), and ten with 80 x 106 frozen/thawed spermatozoa (60% motility) in the cranial part of each uterine horn. Seven days later, ovariohysterectomy was performed and the oviducts and uterine horns and body were flushed to recover embryos and unfertilized oocytes. In 80% of the bitches inseminated with fresh and 50% of bitches inseminated with frozen/thawed semen, embryos at 2 to 8 cells stage were recovered mostly from the, oviducts. This study indicates that pregnancies can be obtained with a single laparoscopic intrauterine insemination after single serum progesterone measurement, although with a low number of embryos. This result should be taken into account in case economic or logistic restrictions that affect the possibility of owners to plan an accurate monitoring of the optimal breeding time using fresh and frozen semen.(AU)

Relationships between follicle and corpus luteum size and vascularization with ovulation, progesterone production, and pregnancy in Nellore beef cattle

ABSTRACT The objective of this study was to evaluate the relationships between preovulatory follicle (POF) and corpus luteum (CL) diameters, and POF and CL vascular perfusion with progesterone production, ovulation, and pregnancy in Nellore cows subjected to timed artificial insemination (TAI). Nellore cows (n = 201) were subjected to ovulation synchronization and later to ultrasound evaluation of POF and CL at the time of insemination (D0) and seven days later (D7), respectively. Females were divided into three categories according to the POF diameter assessed at the time of insemination: small (SF), medium (MF), and large (LF) follicles. The LF group had a greater number and intensity of pixels in the POF ultrasound exam compared with the SF group. The CL flow intensity and progesterone concentration were also higher in the LF group. The SF group showed lower flow intensity and lower ovulation rate compared with the others. When non-pregnant females were compared to pregnant ones, no difference was observed in any of the analyzed variables. The results show for the first time in Nellore cattle the relationship between the size of ovarian structures and blood flow (quantity and intensity) as well as the ability of the CL to produce progesterone. The intensity of the POF pixels proved to be relevant, demonstrating correlations with the size and flow of the CL, which were not found when evaluating only the number of pixels, thus revealing the importance of evaluating complementary characteristics of the flow.

Estratégias farmacológicas para a manipulação do ciclo estral de fêmeas bovinas de raças de corte taurinas / Pharmacological approaches to manipulate bovine estrous cycle in taurine beef breeds

Este texto discute as estratégias farmacológicas para a manipulação do ciclo estral de fêmeas taurinas de corte, com foco na inseminação artificial em tempo fixo (IATF). Os zebuínos, rebanho predominante no Brasil, apresentam características de ciclo estral diferentes das raças taurinas, o que justifica a busca por estratégias hormonais adaptadas para o controle do ciclo estral nas subespécies. O estradiol combinado com a progesterona (P4) e prostaglandina F2 alfa (PGF) é o esquema hormonal mais comumente utilizado para a manipulação do ciclo estral em protocolos de IATF. Porém, o uso de GnRH combinado ou em substituição aos ésteres de estradiol vem sendo considerado. Coletivamente, os dados do nosso grupo reforçam a necessidade de customizar as abordagens para o controle do ciclo estral de acordo com a composição genética das fêmeas bovinas.(AU)

This text discusses pharmacological strategies to manipulate the estrous cycle of taurine and synthetic females, with a focus on timed artificial insemination (TAI). Zebu cattle, the predominant herd in Brazil, have different estrous cycle characteristics than taurine breeds, requiring different synchronization hormonal strategies for each subspecies. Estradiol combined with progesterone (P4) and prostaglandin F2 alpha (PGF) is the most used hormonal scheme for estrous cycle manipulation in TAI protocols. But the use of GnRH instead of estradiol esters is being considered. Collectively, our group's data reinforce the need to customize approaches to estrous cycle control according to the genetic composition of bovine females.(AU)

Clinical and pathological aspects of progressive hyperphosphatasemia associated with vacuolar hepatopathy and hepatocellular carcinoma in a Scottish Terrier bitch / Aspectos clínicos e patológicos da hiperfosfatasemia progressiva associada à hepatopatia vacuolar e carcinoma hepatocelular em uma cadela da raça Scottish Terrier

ABSTRACT: Hyperphosphatasemia refers to an increase in alkaline phosphatase serum activity, and Scottish Terriers (STs) are predisposed to develop this condition of uncertain pathogenesis. This study describes a case of progressive hyperphosphatasemia with vacuolar hepatopathy and hepatocellular carcinoma (HCC) in a ST bitch. This dog had a five-year clinical follow-up with progressive hyperphosphatasemia (up to 5503 U/L) and with ultrasound findings and histologic diagnosis of vacuolar hepatopathy, in addition to posterior onset of HCC. A steroidogenic adrenal panel revealed an increase of adrenocortical hormones, especially progesterone and androstenedione, consistent with a subdiagnosed hypercortisolism. Euthanasia was elected and at necropsy, multinodular, yellow to red masses were observed in the liver, which were histologically and immunohistochemically defined as HCC. The association of the clinical, imaging, biochemical, adrenal panel and pathologic findings allowed to characterize and confirm a progressive disorder in this ST bitch associated with elevated adrenocortical hormones.

RESUMO: Hiperfosfatasemia é o aumento sérico de fosfatase alcalina, sendo que Scorrish Terriers estão predispostos a desenvolverem essa condição de patogênese desconhecida. Este trabalho descreve um caso de hiperfosfatasemia progressiva com hepatopatia vacuolar e carcinoma hepatocelular em um canino da raça Scottish Terrier. Uma cadela Scottish Terrier foi acompanhada clinicamente por cinco anos devido à hiperfosfatasemia persistente (até 5503 U/L), com achados ultrassonográficos e histológicos compatíveis com hepatopatia vacuolar, além de posterior desenvolvimento de carcinoma hepatocelular. O painel esteroidogênico realizado indicou aumento dos hormônios adrenocorticais, principalmente progesterona e androstenediona, consistente com diagnóstico de hipercortisolismo subdiagnosticado "atípico". Devido ao prognóstico desfavorável, a eutanásia foi realizada e na necropsia, massas amarelas a vermelhas e multinodulares foram observadas no fígado, com diagnóstico de carcinoma hepatocelular pela análise histológica e imuno-histoquímica. A associação dos achados clínicos, de imagem, bioquímicos, do painel androgênico e patológicos permitiram caracterizar e confirmar um distúrbio progressivo no canino da raça Scottish Terrier associado ao aumento dos hormônios adrenocorticais.

Reproductive and economic evaluation of sexual stimulation during the anestrous period in a commercial farm with neonatal lamb losses / Avaliação reprodutiva e econômica da estimulação sexual durante o período antrópico em uma fazenda comercial com perdas neonatais de cordeiros

This study was performed during the anestrous, involving 140 Akkaraman Kangal ewes whose lambs had died in the neonatal stage due to pneumonia and enteritis. Intravaginal sponge containing progesterone was placed to the animals (Group 1, n = 70) on day 0 and removed after 7 days, following which 263 µg PGF2α and 500 IU eCG were administered to the sheep. Ram introduction was performed for 7 days (days 8-14), starting from the day after the removal of the intravaginal sponge (day 8). The animals in Group 2 (n = 70) were not exposed to any treatment. Ram introduction was performed simultaneously in both the groups. To determine the reproductive response, reproductive parameters such as estrous, pregnancy, multiple pregnancy, and embryonic mortality rates, number of births, number of offspring, and fertility, as well as their economic implications, were compared between groups. Each reproductive parameter exhibited a statistical difference between groups. An economically positive trend was observed in the study group compared with the control group. It was concluded that in case of lamb losses in commercial farms that derive profit from lambing, pregnancy of ewes can be achieved via sexual stimulation without waiting for the next breeding season.

Este estudo foi realizado durante o anestrous, envolvendo 140 ovelhas Akkaraman Kangal cujos cordeiros haviam morrido no estágio neonatal devido a pneumonia e enterite. A esponja intragaginal contendo progesterona foi colocada aos animais (Grupo 1, n = 70) no dia 0 e removida após 7 dias, após os quais 263 µg PGF2α e 500 UI eCG foram administrados às ovelhas. A introdução do carneiro foi realizada por 7 dias (dias 8-14), a partir do dia seguinte à remoção da esponja intravaginal (dia 8). Os animais do Grupo 2 (n = 70) não foram expostos a nenhum tratamento. A introdução do carneiro foi realizada simultaneamente em ambos os grupos. Para determinar a resposta reprodutiva, foram comparados entre os grupos parâmetros reprodutivos, tais como estrogênio, gravidez, gravidez múltipla e taxas de mortalidade embrionária, número de nascimentos, número de descendentes e fertilidade, bem como suas implicações econômicas. Cada parâmetro reprodutivo exibia uma diferença estatística entre os grupos. Uma tendência economicamente positiva foi observada no grupo de estudo em comparação com o grupo de controle. Concluiu-se que no caso de perdas de cordeiros em fazendas comerciais que obtêm lucros com a parição, a gravidez de ovelhas pode ser obtida através de estimulação sexual sem esperar pela próxima estação de reprodução.

Atualizações no controle do ciclo estral em ovinos / Updates on the control of the estrous cycle in sheep

Nos últimos anos, observou-se um aumento no tamanho do rebanho ovino no país, indicando uma retomada na ovinocultura. Para melhorar a eficiência reprodutiva desses animais, a utilização de biotécnicas tem se mostrado uma ferramenta importante. Dentre essas biotécnicas, destacam-se os protocolos de sincronização do ciclo estral, os quais frequentemente utilizam progesterona associada a gonadotrofinas ou análogos da prostaglandina em duas aplicações. Este artigo tem como objetivo revisar os protocolos de sincronização utilizados em ovinos e apresentar atualizações relevantes sobre os mesmos.(AU)

In recent years, there has been an increase in the size of the sheep herd in the country, indicating a recovery in sheep farming. To improve the reproductive efficiency of these animals, the use of biotechniques has been shown to be an important tool. Among these biotechniques, estrous cycle synchronization protocols stand out, which frequently use progesterone associated with gonadotropins or prostaglandin analogues in two applications. This article aims to review the synchronization protocols used in sheep and present relevant updates about them.(AU)

Clinical and pathological aspects of progressive hyperphosphatasemia associated with vacuolar hepatopathy and hepatocellular carcinoma in a Scottish Terrier bitch / Aspectos clínicos e patológicos da hiperfosfatasemia progressiva associada à hepatopatia vacuolar e carcinoma hepatocelular em uma cadela da raça Scottish Terrier

Hyperphosphatasemia refers to an increase in alkaline phosphatase serum activity, and Scottish Terriers (STs) are predisposed to develop this condition of uncertain pathogenesis. This study describes a case of progressive hyperphosphatasemia with vacuolar hepatopathy and hepatocellular carcinoma (HCC) in a ST bitch. This dog had a five-year clinical follow-up with progressive hyperphosphatasemia (up to 5503 U/L) and with ultrasound findings and histologic diagnosis of vacuolar hepatopathy, in addition to posterior onset of HCC. A steroidogenic adrenal panel revealed an increase of adrenocortical hormones, especially progesterone and androstenedione, consistent with a subdiagnosed hypercortisolism. Euthanasia was elected and at necropsy, multinodular, yellow to red masses were observed in the liver, which were histologically and immunohistochemically defined as HCC. The association of the clinical, imaging, biochemical, adrenal panel and pathologic findings allowed to characterize and confirm a progressive disorder in this ST bitch associated with elevated adrenocortical hormones.

Hiperfosfatasemia é o aumento sérico de fosfatase alcalina, sendo que Scorrish Terriers estão predispostos a desenvolverem essa condição de patogênese desconhecida. Este trabalho descreve um caso de hiperfosfatasemia progressiva com hepatopatia vacuolar e carcinoma hepatocelular em um canino da raça Scottish Terrier. Uma cadela Scottish Terrier foi acompanhada clinicamente por cinco anos devido à hiperfosfatasemia persistente (até 5503 U/L), com achados ultrassonográficos e histológicos compatíveis com hepatopatia vacuolar, além de posterior desenvolvimento de carcinoma hepatocelular. O painel esteroidogênico realizado indicou aumento dos hormônios adrenocorticais, principalmente progesterona e androstenediona, consistente com diagnóstico de hipercortisolismo subdiagnosticado "atípico". Devido ao prognóstico desfavorável, a eutanásia foi realizada e na necropsia, massas amarelas a vermelhas e multinodulares foram observadas no fígado, com diagnóstico de carcinoma hepatocelular pela análise histológica e imuno-histoquímica. A associação dos achados clínicos, de imagem, bioquímicos, do painel androgênico e patológicos permitiram caracterizar e confirmar um distúrbio progressivo no canino da raça Scottish Terrier associado ao aumento dos hormônios adrenocorticais.