Breeding and reproductive behaviour of the neo-tropical opossum, Didelphis marsupialis insularis, Allen 1902 under captive conditions / Reprodução e comportamento reprodutivo do gambá neotropical, Didelphis marsupialis insularis, Allen 1902, em condições de cativeiro

Developing a captive breeding system for the widely hunted Caribbean species of opossum Didelphis marsupialis insularis can greatly aide in the management and conservation of this species in the neo-tropics. Although this species possesses ideal traits for captive breeding in this region (tolerance to high heat and humidity, high reproductive rate, and resistance to disease), challenges due to its aggressive behaviour and limited information on its breeding behaviour have prevented a system from being developed for this species. The present study describes a breeding system, and the reproductive behaviour of this species under captive conditions. Six (1 male; 5 females) adult opossums were maintained and managed for breeding over a ten (10) month period. Pouch litter sizes averaged 5±2.5 with a range of 2 to 8. Gestation length was found to be 13.25±0.96 days and 4 litters (n=23) were successfully weaned at 11-13 weeks. It was found that the male D. m. insularis exhibits behaviours of interest that can serve as indicators for receptivity of the female, and overall, that this species can be successfully reared and bred under captive conditions in the neo-tropics.

O desenvolvimento de um sistema de criação em cativeiro para as espécies de gambá do Caribe amplamente caçadas, Didelphis marsupialis insularis, pode auxiliar bastante no manejo e conservação dessa espécie nos neotrópicos. Embora essa espécie possua características ideais para a criação em cativeiro nessa região (tolerância a altas temperaturas e umidade, alta taxa de reprodução e resistência a doenças), alguns fatores, como o seu comportamento agressivo e informações limitadas sobre seu comportamento reprodutivo, impediram o desenvolvimento de um sistema para D. m. insularis. O presente estudo descreve um sistema de criação e o comportamento reprodutivo dessa espécie em condições de cativeiro. Seis gambás adultos (1 macho e 5 fêmeas) foram mantidos para reprodução durante um período de 10 meses. O tamanho da ninhada em bolsa foi em média de 5 ± 2,5 com um intervalo de 2 a 8. A duração da gestação foi de 13,25 ± 0,96 dias, e 4 ninhadas (n = 23) foram desmamadas com sucesso de 11 a 13 semanas. Verificou-se que o macho D. m. insularis exibe comportamentos de interesse que podem servir como indicadores de receptividade da fêmea, e, em geral, essa espécie pode ser criada com sucesso em condições de cativeiro nos neotrópicos.

Genetic parameter and genetic trend estimates for reproductive traits in Wistar rats / [Estimativas de parâmetros genéticos e tendências genéticas de características reprodutivas em ratos Wistar]

The aim of this study was to estimate genetic parameters and genetic trends for reproductive traits in Wistar rats. A total of 1,167 data records from 283 females over six generations of monogamous mating pairs was used. Heritability and genetic correlation were estimated through Bayesian inference and genetic trends were calculated by linear regression of breeding values over generations. Heritability estimates for litter size at birth (LS), calving interval (CI), pup mortality (PM) and maternal cannibalism (CAN) presented low magnitude, ranging from 0.01 to 0.13. CAN presented high and positive genetic correlation with LS and PM (0.77 and 0.78, respectively). On the other hand, all the other estimated genetic correlations were not significant. Genetic trend was positive for LS (+0.0900 pups per generation), and negative for PM and CAN (-1.0085 and -0.5217 pups per generation, respectively). For CI the genetic trend was not significant. It is recommended to increase selection intensity on dams in this Wistar rat population in order to accelerate the genetic progress.(AU)

O objetivo deste estudo foi estimar os parâmetros genéticos e as tendências genéticas de características reprodutivas em ratos Wistar. Foram analisados 1.167 registros coletados em 283 fêmeas ao longo de seis gerações de pares de acasalamentos monogâmicos. Herdabilidade e correlação genética foram estimadas por meio de inferência bayesiana, e as tendências genéticas foram calculadas pela regressão linear dos valores genéticos em função das gerações. As estimativas de herdabilidades para as características número de filhotes nascidos (LS), intervalo de parto (CI), mortalidade de filhotes (PM) e canibalismo materno (CAN) foram de baixa magnitude (0,01 a 0,13). CAN apresentou correlação genética alta e positiva com LS e PM, 0,77 e 0,78, respectivamente. As demais correlações genéticas estimadas foram não significativas. A tendência genética foi positiva para LS (+0,0900 filhote por geração) e negativa para PM e CAN (-1,0085 e -0,5217 filhote por geração, respectivamente). A tendência genética não foi significativa para CI. Recomenda-se aumentar a intensidade de seleção nas fêmeas nessa população de ratos Wistar, a,fim de acelerar o progresso genético.(AU)

Phenotypic correlation of characteristics in the gilt performance test with an average number of live-born piglets through all achieved births, during the reproductive exploitation / Ligação fenotípica de características no teste de desempenho de leitões com um número médio de leitões nascidos vivos durante todos os nascimentos realizados, durante a exploração reprodutiva

Reproductive efficacy of sows dictates the level of profitability of the production itself, and the moment of testing and selection of gilts for breeding (as the parents of a future generation), represents a very important moment. Given the fact that the selection of gilts for breeding is partly based on the weight-gain in the test, in this study we examined the influence of a daily weight-gain of gilts in the test of the manifestation of important reproductive characteristics - the size of the litter of the first and the other parities, as well as the percentage of sows that gave birth in relation to previous breeding process. Data of the 11637 tested gilts that completed the performance test have been used for the test. The studied characteristics were: the weight-gain at the end of the test, the number of live-born piglets, the number of stillborn piglets and the number of grown-weaned piglets in the first litter and the total number of live-born piglets, the total number of stillborn piglets and the total number of grown-weaned piglets. The results obtained in this study showed the effect of weight-gain in the reproductive efficacy test in the number of the live-born piglets in the first and from the 2nd to the 9th parity, as well as the percentage of the sows included in the next breeding process. By including all selected independent variables that showed the adequate statistical significance in correlation with the dependent variable, the determination coefficient rises to a value of 0.098 which represents 9.80% of the influence on the dependent variable, that can be explained by the independent variable, which leads to the conclusion that the binding strength between the variable "average live" and all the independent variables: "the number of litters", the MLD depth" and "the back-fat thickness", is very weak, which is not a rare case in multiple regression.(AU)

A eficácia reprodutiva das porcas dita o nível de rentabilidade da própria produção, e o momento do teste e seleção de leitoas para reprodução (como os pais de uma geração futura) representa um momento muito importante. Dado o fato de que a seleção de leitoas para criação é parcialmente baseada no ganho de peso no teste, neste estudo examinamos a influência de um ganho de peso diário de leitoas no teste da manifestação de importantes características reprodutivas - o tamanho da ninhada da primeira e das outras paridades, assim como a porcentagem de porcas que deram à luz em relação ao processo de criação anterior. Os dados das 11637 leitoas testadas que completaram o teste de desempenho foram utilizados para o teste. As características estudadas foram: o ganho de peso ao final do teste, o número de leitões nascidos vivos, o número de leitões natimortos e o número de leitões desmamados na primeira ninhada e o número total de leitões nascidos vivos , o número total de leitões natimortos e o número total de leitões desmamados. Os resultados obtidos neste estudo mostraram o efeito do ganho de peso no teste de eficácia reprodutiva no número de leitões nascidos vivos na primeira e da segunda à nona paridade, bem como a porcentagem de porcas incluídas na próximo processo de criação. Ao incluir todas as variáveis independentes selecionadas que mostraram a significância estatística adequada em correlação com a variável dependente, o coeficiente de determinação sobe para um valor de 0.098 que representa 9.80% da influência sobre a variável dependente, que pode ser explicada pela variável independente, que leva à conclusão de que a força de ligação entre a variável "média viva" e todas as variáveis independentes: "o número de ninhadas", a profundidade MLD "e" a espessura de gordura "é muito fraca, o que não é raro caso em regressão múltipla.(AU)

Understanding mammary activity in red-rumped agouti and implications for management and conservation of this Neotropical game species / Compreendendo a atividade mamária na cutia e as implicações para o manejo e a conservação desta espécie cinegética Neotropical

Abstract The red-rumped agouti (Dasyprocta leporina) produces precocial young and is the most hunted and farmed game species in several Neotropical countries. An understanding of the reproductive biology, including the relationship between litter size and teat functionality is crucial for conservation management of this animal. In precocial mammals, as the red-rumped agouti, maintaining maternal contact to learn foraging patterns may be more important than the energy demands and nutritional constraints during lactation and suckling may not play important roles when compared to altricial mammals. Therefore, in this study we evaluated the relationship between mammary functionality with litter size, litter birth weight, and parturition number in captive red-rumped agouti. Functionality was assessed by manual palpation of teats from un-sedated females (N=43). We compared the average birth weight of all newborns, male newborns and female newborns among agoutis with different litter sizes and different parturitions by one way ANOVA's, while Pearson's Chi-squared tests were used to detect relationships between teat functionality, litter size, and parturition number. Parturition number had no effect on the mean birth weight of all young (F0.822, P > 0.05), male young (F0.80, P > 0.05) or female young (F0.66, P > 0.05) in the litters. We found (i) no significant correlations (P > 0.05) between teat functionality and litter size and (ii) no significant correlations (P > 0.05) between teat functionality and parturition number. This suggests that whilst all teat pairs were functional, functionality was a poor indicator of litter size; suggesting that female agouti young may not have a high dependency on maternal nutrition; an possible evolutionary strategy resulting in large wild populations; hence its popularity as a game species.

Resumo A cutia (Dasyprocta leporina) produz filhotes precoces, e é a espécie cinegética mais caçada e criada em muitos países neotropicais. O entendimento da biologia reprodutiva, incluindo a relação entre o tamanho da ninhada e a funcionalidade das glândulas mamárias é crucial para o manejo conservacionista deste animal. Nos mamíferos precoces, como a cutia, manter o contato materno para a aprendizagem de padrões de forrageamento pode ser mais importante do que a demanda energética e de restrição nutricional durante a lactação, e a amamentação pode não desempenhar um papel importante quando comparado aos mamíferos altriciais. Portanto, neste estudo nós avaliamos a relação entre a funcionalidade mamária com o tamanho da ninhada, peso ao nascer da ninhada, e o número de partos em cutias cativas. A funcionalidade foi avaliada por meio de palpação manual das glândulas mamárias em fêmeas não sedadas (N=43). Nós comparamos a média do peso ao nascer de todos os recém-nascidos, macho e fêmeas recém-nascidos entre cutias com diferentes tamanhos de ninhadas e diferentes parturições, por meio da análise one-way ANOVA unifatorial; enquanto o teste do chi-quadrado de Pearson foi utilizado para detectar as relações entre a funcionalidade da glândula mamária, o tamanho da ninhada e o número de partos. O número de partos teve efeito na média de peso ao nascer dos filhotes (F0,822, P > 0,05), filhotes machos (F0,80, P > 0,05) ou filhotes fêmeas (F0,66, P > 0,05) nas ninhadas. A análise bivariada de Pearson (i) não mostrou correlação (P > 0,05) entre a funcionalidade da glândula mamária e o tamanho da ninhada e (ii) nenhuma correlação significativa (P > 0,05) entre a funcionalidade da glândula mamária e o número de parições. Os resultados sugerem que, embora todos os pares de tetas fossem funcionais, as cutias recém-nascidas podem não depender da nutrição materna para sobreviver; .embora todos os pares de tetas sejam funcionais, as cutias recém nascidas aparentemente não dependem da nutrição materna para sua sobrevivência; esta é, provavelmente, uma estratégia evolutiva que resulta em grandes populações da cutia em vida livre; e que pode explicar sua popularidade como espécie cinegética

Evaluation of prooxidant-antioxidant balance in in vitro fertilization-conceived mice / 대한생식의학회지

OBJECTIVE: Concerns about the safety of assisted reproductive technology (ART) have been raised, as some studies have shown elevated incidence rates of childhood cancer, asthma, allergies, and other diseases in ART-conceived babies. Findings regarding the health of ART-conceived babies are controversial. The present study was conducted to evaluate the prooxidant-antioxidant balance (PAB) in in vitro fertilization (IVF)-conceived mice in comparison to naturally conceived offspring. METHODS: Mice (6–8 weeks) were divided into two groups (IVF-conceived and naturally conceived) matched by sex, age, weight, and litter size. A 1-mL blood sample was taken and the sera were separated. The oxidant-antioxidant balance was evaluated using a fast and reliable PAB assay. The results were expressed as mean±standard deviation. RESULTS: The mean PAB values (HK units) in the IVF-conceived and naturally conceived groups were 59.70±22.30 and 54.70±18.22, respectively (p=0.82). CONCLUSION: Since free radicals contribute to several pathological conditions and antioxidants play an important protective role against oxidative stress, evaluating the oxidant-antioxidant balance is very important. Although the results of this study showed that the quality of the defense mechanism against free radicals was not significantly different between the IVF-conceived and naturally conceived mice, other parameters of metabolic dysfunction need to be measured.

Cytogenetics and Molecular Genetic Analysis of Chimerism in Marmosets (Callithrix: Primates)

ABSTRACT The birth of fraternal twins is a characteristic frequently observed in callitrichids. Cytogenetic studies have demonstrated hematopoietic chimerism in marmosets with the occurrence of two cell lines 2n=46,XX/46,XY in females and males co-twins, without phenotypic changes. Amplification by PCR have also been used to verify the presence of the SRY gene in female chimaeras. Our aim was to verify the occurrence of chimerism in Callithrix sp. individuals considered as hybrids according to their intermediate phenotypes between C. jacchus and C. penicillata. Blood samples from 37 Callithrix sp. individuals were collected. Hematopoietic chimerism 2n=46,XX/46,XY was detected by cytogenetic analysis in five individuals, three males and two females. A fragment of approximately 200bp of the SRY gene was amplified in seven females with normal external genitalia. The percentage of 32% of chimeric individuals detected in the present study is similar to that observed for pure specimens of Callithrix. These data suggests that hybridization probably does not interfere with the occurrence of twin gestation, nor of chimerism. Although cytogenetics is the main tool to identify the two cell lineages present in cases of chimerism, the amplification of the SRY gene by PCR has proved to be more efficient to identify the Y chromosome in cases of chimeric female marmoset.

Productive response of hair ewes crossed with Damara and Dorper and growth of their lambs / Resposta produtiva de ovelhas de cabelo cruzado com Damara e Dorper e crescimento de seus cordeiros

Profitability of sheep production depends on the reproductive response of ewes and growth of their lambs, which can be improved through the ram genotype. The aim of this study was to evaluate the reproductive response of Blackbelly (Bb), Pelibuey (Pb), Katahdin (Kat) and Dorper (Dor) ewes crossed with Damara (Dam) and Dor rams and the growth of their offspring. To measure percentage of single and multiple lambings (MLP), 234 Bb, Pb, Kat and Dor ewes were used. To measure lamb growth, the offspring of 86 Bb x Pb (BbPb) ewes and 73 Kat x Dor (KatDOR) ewes were used. Four Dor x BbPb, six Dam x BbPb and six Dam x KatDor lambs were slaughtered for carcass assessment. MLP was analyzed with the CATMOD procedure considering the factors age and breed. Lamb growth data were analyzed with the MIXED procedure, and those of carcass characteristics with the GLM procedure of SAS, using weight at slaughter as covariable. MLP was higher (P0.05) by effect of ram breed. It is concluded that Bb ewes are more prolific than Dor ewes; male lambs of Dam rams had post-weaning growth response and carcass yield similar to those of Dor rams, although the female lambs of Dor rams were heavier than those of Dam rams.

Rentabilidade da produção de ovinos depende da resposta reprodutiva de ovelhas e do crescimento de seus cordeiros, o que pode ser melhorado por meio do genótipo masculino. O objetivo deste estudo foi avaliar o desempenho reprodutivo de ovinos Blackbelly (Bb), Pelibuey (Pb), Katadin (Kat) e Dorper (Dor) e o crescimento de cordeiros com carneiros Damara (Dam) e Dor. Para medir a porcentagem de partos simples e múltiplas (MLP), foram utilizados 234 ovelhas Bb, PB, Kat e Dor. Para medir o crescimento dos cordeiros, foram utilizadas 86 ovelhas Bb x Pb (BbPb) e 73 Kat x Dor (KatDOR). Quatro cordeiros Dor x BbPb, seis Dam x BbPb e seis Dam x KatDor foram sacrificados para avaliação de carcaça. MLP foi analisada com o procedimento CATMOD, considerando-se fatores como idade e raça. Dados de crescimento do cordeiro foram analisados com o procedimento MIXED, e as de características de carcaça com o procedimento GLM do SAS, utilizando-se peso ao sacrifício como covariável. MLP foi maior (P<0.05) em Bb do que em Dor. Os cordeiros Dor x BbPb foram mais pesados (P<0.05) no nascimento do que Dam x BbPb. Em partos simples e múltiplos, os cordeiros de ovelhas KatDor foram mais pesados (P<0.05) no momento do nascimento de cordeiros BbPb. As cordeiras de carneiros Dor apresentaram maior (P<0.05) ganho de peso após o desmame do que as de carneiros Dam. O rendimento de carcaça, a espessura da gordura subcutânea e o rendimento de corte primal não foram diferentes por efeito da raça de carneiro. Conclui-se que as ovelhas Bb são mais prolíficas do que as ovelhas Dor; cordeiros de carneiros Damara tiveram resposta de crescimento pós-desmame e rendimento de carcaça semelhantes aos dos carneiros Dor, embora Dorper cordeiras fossem mais pesadas do que as de Damara.

Productive response of hair ewes crossed with Damara and Dorper and growth of their lambs / Resposta produtiva de ovelhas de cabelo cruzado com Damara e Dorper e crescimento de seus cordeiros

Profitability of sheep production depends on the reproductive response of ewes and growth of their lambs, which can be improved through the ram genotype. The aim of this study was to evaluate the reproductive response of Blackbelly (Bb), Pelibuey (Pb), Katahdin (Kat) and Dorper (Dor) ewes crossed with Damara (Dam) and Dor rams and the growth of their offspring. To measure percentage of single and multiple lambings (MLP), 234 Bb, Pb, Kat and Dor ewes were used. To measure lamb growth, the offspring of 86 Bb x Pb (BbPb) ewes and 73 Kat x Dor (KatDOR) ewes were used. Four Dor x BbPb, six Dam x BbPb and six Dam x KatDor lambs were slaughtered for carcass assessment. MLP was analyzed with the CATMOD procedure considering the factors age and breed. Lamb growth data were analyzed with the MIXED procedure, and those of carcass characteristics with the GLM procedure of SAS, using weight at slaughter as covariable. MLP was higher (P<0.05) in Bb than in Dor. The Dor x BbPb lambs were heavier (P<0.05) at birth than Dam x BbPb. Of the lambs from single and multiple births, the KatDor lambs were heavier (P<0.05) at birth than BbPb lambs. The female lambs of Dor rams had higher (P<0.05) weight gain after weaning than those of Dam rams. Carcass dressing, subcutaneous fat, and primal cut yield were not different (P>0.05) by effect of ram breed. It is concluded that Bb ewes are more prolific than Dor ewes; male lambs of Dam rams had post-weaning growth response and carcass yield similar to those of Dor rams, although the female lambs of Dor rams were heavier than those of Dam rams.(AU)

Rentabilidade da produção de ovinos depende da resposta reprodutiva de ovelhas e do crescimento de seus cordeiros, o que pode ser melhorado por meio do genótipo masculino. O objetivo deste estudo foi avaliar o desempenho reprodutivo de ovinos Blackbelly (Bb), Pelibuey (Pb), Katadin (Kat) e Dorper (Dor) e o crescimento de cordeiros com carneiros Damara (Dam) e Dor. Para medir a porcentagem de partos simples e múltiplas (MLP), foram utilizados 234 ovelhas Bb, PB, Kat e Dor. Para medir o crescimento dos cordeiros, foram utilizadas 86 ovelhas Bb x Pb (BbPb) e 73 Kat x Dor (KatDOR). Quatro cordeiros Dor x BbPb, seis Dam x BbPb e seis Dam x KatDor foram sacrificados para avaliação de carcaça. MLP foi analisada com o procedimento CATMOD, considerando-se fatores como idade e raça. Dados de crescimento do cordeiro foram analisados com o procedimento MIXED, e as de características de carcaça com o procedimento GLM do SAS, utilizando-se peso ao sacrifício como covariável. MLP foi maior (P<0.05) em Bb do que em Dor. Os cordeiros Dor x BbPb foram mais pesados (P<0.05) no nascimento do que Dam x BbPb. Em partos simples e múltiplos, os cordeiros de ovelhas KatDor foram mais pesados (P<0.05) no momento do nascimento de cordeiros BbPb. As cordeiras de carneiros Dor apresentaram maior (P<0.05) ganho de peso após o desmame do que as de carneiros Dam. O rendimento de carcaça, a espessura da gordura subcutânea e o rendimento de corte primal não foram diferentes por efeito da raça de carneiro. Conclui-se que as ovelhas Bb são mais prolíficas do que as ovelhas Dor; cordeiros de carneiros Damara tiveram resposta de crescimento pós-desmame e rendimento de carcaça semelhantes aos dos carneiros Dor, embora Dorper cordeiras fossem mais pesadas do que as de Damara.(AU)

Comparison of commonly used ICR stocks and the characterization of Korl:ICR / 한국실험동물학회지

Mouse is a commonly used animal in life science studies and is classified as outbred if genetically diverse and inbred if genetically homogeneous. Outbred mouse stocks, are used in toxicology, oncology, infection and pharmacology research. The National Institute of Food and Drug Safety Evaluation (NIFDS; former the Korea National Institute of Health) have bred ICR mice for more than 50 years. We investigated to provide users with information and promote accountability to the Korl:ICR. To secure the indigenous data, biological characteristics of Korl:ICR were identified by comparing with other ICR stocks. This domestic ICR stock was denominated as ‘Korl:ICR’. Phylogenetic analysis using SNPs indicated that the population stratification of the Korl:ICR was allocated different area with other ICR. In addition, we measured litter size, body weight, body length, various organ weight, hematology and clinical blood chemistry of the Korl:ICR compared to other ICR. Otherwise, there are no significant differences among the biological phenotypes of Korl:ICR and other ICR. These results suggest that as a genetically indigenous source colony, the Korl:ICR is seperated (or independent) stock with other ICR. Also, we confirmed that there is no difference among the Korl:ICR and other ICR on biological phenotypes. Therefore, the Korl:ICR source colony might be a new stock in distinction from other ICR, it is a good milestone in securing ownership of the national laboratory animal resource. The NIFDS expects that the Korl:ICR mice will be useful animal resource for our domestic researchers.

Synchronization of estrus in paca (Cuniculus paca L. ): possible impacts on reproductive and productive parameters / Sincronização do estro em pacas (Cuniculus paca L. ): possíveis impactos sobre parâmetros reprodutivos e produtivos

Estrus synchronization is a reproductive biotechnology used to improve artificial insemination or pairing through the manipulation of the estrous cycle at a desirable time. Employing this technique in captive pacas (Cuniculus paca L.) is important because it creates expectation of meeting the demand for paca meat and, consequently, reduces poaching. Thus, this research aims to verify the effect of a progestogen implant associated with two doses of eCG on the synchronization and induction of fertile estrus. Twenty-seven adult pacas were used, 18 non-pregnant females and nine males, divided into three groups. G1 and G2 females groups (treatments) received 1.5 mg Norgestomet and were injected intramuscularly, seven days later, with 0.13 mg of prostaglandin. After 24 hours the implants were removed and the animals immediately received 25 IU and 50 IU of ECG intramuscularly, respectively. The mating of the three groups took place on the same days. G3 females' group (control) showed estrus on different days after D0. Females under treatment displayed estrus only after removing the implant (D8). G1, G2, and G3 pregnancy rates were 100%, 66%, and 50%, respectively. Regarding births per parturition, 100% of G1 and G3 produced one offspring, while 50% of G2 produced two. Progestogen in the form of subcutaneous implants was effective in mimicking the luteal phase of the estrous cycle. After removal, implants favored the occurrence of a fertile estrus. As a conclusion, further studies must be conducted in order to establish in-depth possible association between 50 IU of eCG, and the occurrence of twin pregnancies.(AU)

A sincronização é uma biotécnica reprodutiva que melhora a porcentagem de cobertura por meio da manipulação do ciclo estral. Empregar esta biotécnica em pacas de cativeiro (Cuniculus paca L.) é importante, pois cria-se a expectativa de que a demanda pela carne seja atendida e a caça ilegal diminua. O objetivo da pesquisa foi verificar o efeito de implantes de progestágenos associados a duas doses de gonadotrofina coriônica equina (eCG) na sincronização e indução de cios férteis de pacas. Foram utilizadas 18 fêmeas não prenhas e nove machos, divididos em três grupos. Fêmeas do G1 e G2 receberam implantes com 1,5mg de Norgestomet e, sete dias depois, 0,13mg de prostaglandina via intramuscular (IM). No dia 8 (D8), foram retirados os implantes e G1 e G2 receberam 25 UI e 50 UI de eCG, IM, respectivamente; G3 foi o controle. O pareamento nos três grupos aconteceu nos mesmos dias. As fêmeas do G3 apresentaram cio alguns dias após o dia zero (D0). Fêmeas que receberam tratamento apresentaram cio só após a retirada do implante no dia 8 (D8). As taxas de prenhez de G1, G2 e G3 atingiram 100%, 66% e 50%, respectivamente. Em relação a filhotes por parto, 100% do G1 e G3 produziram uma cria, enquanto 50% do G2 produziram duas crias. O progestágeno do implante foi eficaz em mimetizar a fase lútea do ciclo estral. Após a remoção, o tratamento hormonal favoreceu a ocorrência de cio fértil. Outros estudos devem ser realizados a fim de estabelecer uma possível associação entre 50 UI de eCG e a ocorrência de gestações gemelares.(AU)

Influence of gender on carcass yield of twin lambs Blackbelly x Pelibuey at 56 days of age / Influência do gênero no rendimento de carcaça em cordeiros gêmeos Blackbelly x Pelibuey aos 56 días de idade

The aim of this study was to determine the influence of gender on pre-weaning growth, yield and weight of primal cuts of the carcass of Blackbelly x Pelibuey lambs. 16 twin lambs were used. The lamb gender was the fixed factor. The variables evaluated were: body weight at birth and at weaning, average daily weight gain, weight and yield of carcass and primal cuts: neck, arm, thorax, abdomen and leg. Gender did not affect (P>0.05) body weight at birth. However, the pre-weaning average daily weight gain and body weight at weaning were affected (P<0.05) by the gender. Hot carcass yield and weight and primal cuts were not affected (P>0.05) by the gender of the lamb. Nevertheless, the area of the Longissimus dorsi muscle and cavity fat were different between males and females (P<0.05) 11.5±0.73cm2 and 198±0.05 g vs 9.3±0.73cm2 and 282±0.05g, respectively. In conclusion, in twin lambs Blackbelly x Pelibuey males had greater average daily weight gain and body weight at weaning than females. Carcass yield and weight and primal cuts were not affected by the gender of the lamb. However, males had greater area of the L. dorsi muscle than females and these in turn had a greater amount of cavity fat than males.(AU)

Objetivou-se determinar a influência do gênero no crescimento pré-desmame, no rendimento e no peso dos cortes primários de carcaça de cordeiros Blackbelly x Pelibuey. Utilizaram-se 16 cordeiros gêmeos. Os dados foram analisados em um desenho completamente ao acaso, em que o gênero dos corderos foi o fator fixo. As variáveis avaliadas foram: peso vivo ao nascimento e ao desmame, ganho diário de peso, peso e rendimento de carcaças e dos cortes primários: pescoço, braço, tórax, abdômen e perna. O gênero não afetou (P>0,05) o peso vivo ao nascimento. No entanto, o ganho diário de peso e o peso vivo ao desmame foram afetados, sendo esses valores superiores nos machos (P<0,05). O peso e o rendimento das carcaças quentes e dos cortes primários não foram afetados (P>0,05) pelo gênero do cordeiro. Entretanto, a área do músculo Longissimus dorsi e a gordura cavitária foram diferentes entre machos e fêmeas (P<0,05): 11.5±0.73cm2 e 198±0.05g vs. 9.3±0.73cm2 e 282±0.05g, respectivamente. Em conclusão, nos cordeiros gêmeos Blackbelly x Pelibuey, os machos tiveram maior ganho diário de peso e maior peso vivo ao desmame do que as fêmeas. O peso e o rendimento da carcaça bem como os cortes primários não foram afetados pelo gênero do cordeiro. Todavia, os machos tiveram maior área do músculo L. dorsi que as fêmeas e estas tiveram maior quantidade de gordura cavitária que os machos.(AU)

Effect of environmental factor on some litter traits of sows in the tropics Mexican / Efecto de factores ambientales sobre algunas características de la camada de cerdas en el trópico de México

Objective. To determine the effect of environmental factors on litter traits at birth and weaning, and their repeatabilities in four farms in the sub-humid tropics of Mexico. Materials and methods. Data from 46.249 to 50.316 litters for litter size at birth (LSB), number of piglets born alive (NBA), litter weight at birth (LWB), number of piglets weaned (NPW) and litter weight at weaning (LWW) were used. The statistical model for LSB, NBA and LWB included the effects of farm, farrowing year, farrowing season, parity number, simple interactions, random effects of sow and the error term. NPW and LWW were analyzed using the previous model plus the linear and quadratic effects of lactation length (LL). Results. The means for LSB, NBA, LWB, NPW and LWW were 11.7 piglets, 11.0 piglets, 16.1 kg, 10.3 piglets and 61.3 kg, respectively. All effects in the model affected the litter traits. Farrowing year x season interaction was significant for NPW, LWB and LWW. The dry season had the highest LSB, NBA y NPW. First parity sows had higher LSB and NBA means than for second parity sows. Parity increase until parity 4 to decrease thereafter. LL had a quadratic effect on NPW and LWW. Repeatability estimates for LSB, NBA, and LWB were 0.12, 0.12 and 0.14, respectively. Conclusions. All traits studied were influenced by the environmental factors studied. Repeatabilities for LSB, NBA and LWB were low.

Objetivo. Determinar el efecto de factores ambientales sobre características de la camada al nacer y al destete, y sus repetibilidades en cuatro granjas en el trópico sub-húmedo de México. Materiales y métodos. Se utilizaron los datos de 50.316 a 46.249 camadas para el total de lechones nacidos (LSB), lechones nacidos vivos (NBA) y peso de la camada al nacimiento (LWB), lechones destetados (NPW) y peso de la camada al destete (LWW). El modelo estadístico para LSB, NBA y LWB incluyen los efectos de granja, año, época, número de parto, interacciones simples, efecto aleatorio de cerda y error. El modelo para NPW y LWW incluyó los factores anteriores y además, los efectos lineal y cuadrático de largo de lactación (LL). Resultados. Las medias para LSB, NBA, LWB, NPW y LWW fueron 11.7 lechones, 11.0 lechones, 16.1 kg, 10.3 lechones y 61.3 kg, respectivamente. Todos los factores estudiados afectaron las características de la camada. La interacción de año x época fue significativa para NPW, LWB y LWW. La época seca presentó las mayores medias de LSB, NBA y NPW. Las cerdas primer parto obtuvieron medias de LSB y NBA superiores que las cerdas del segundo parto. Las medias por número de parto incrementaron hasta el cuarto, para después disminuir. La LL obtuvo un efecto cuadrático sobre NPW y LWW. Las repetibilidades estimadas para LSB, NBA, y LWW fueron 0.12, 0.12 y 0.14, respectivamente. Conclusiones. Todos los factores ambientales estudiados afectaron las características de la camada al nacer y al destete. Las repetibilidades estimadas fueron bajas.

Physiological and biochemical measurements before, during and after pregnancy of healthy rats

PURPOSE:To analyze the physiological and biochemical measurements before, during and after pregnancy of healthy rats.METHODS:Wistar adult females rats (n=8) were weighed and blood samples were obtained before, during and after pregnancy for biochemical determinations, chow intake, water consumption and milk production were evaluated. At day 10 postpartum, the rats were killed for weighing of organs and adipose tissues.RESULTS: The results showed increase in body weight, serum insulin and ingestion of water and chow. At day 17 pregnancy, presented normal values in the OGTT. At days 7, 14 and 20 of pregnancy, there was increase in triglyceride levels. At term pregnancy, there was weight gain due to fetal growth. In the postpartum period presented reduced blood glucose levels. The glycemic means were reduced during and after pregnancy compared to after pregnancy. The triglyceride concentrations were increased before and during pregnancy in relation to after pregnancy. The total cholesterol levels presented no changes.CONCLUSION: The use of experimental animals is suitable for evaluation of metabolic changes because the profile of answers found in this study was similar to human profile, showing the relevance of translational research to better understand the pathophysiological mechanisms and possible treatment for diseases.

Sows' parity and coconut oil postnatal supplement on piglets performance / Número de partos y la suplementación de aceite de coco para lechones recién nacidos

Objective. The study aimed to evaluate the effect of sows' of different parities and the supplement of coconut oil for piglets, on the development of litter. Materials and methods. A total of 51 sows of different parities and their 642 piglets were used in the trial. Each piglet was weighed and identified at birth in a sequential order. They were randomly distributed in two treatments (CG=control group and TG=test group). TG piglets had the first access to a dosage of 3.0 ml of coconut oil 12 hours after birth, and the second at 36 h after the first. Piglets were weighed at 21 days. In order to analyze the effect of the coconut oil supplement as a function of the weight at birth, piglets were grouped according to their weight (0.600 to 0.900 kg; 1.000 to 1.499kg; 1.500 to 1.999 kg; and 2.000 to 2.499 kg). Results. Sows parity affected the number and weight of born piglets. Sows in 4th, 5th and 7th parity had a larger litter than those from the 2nd parity. Sows from 2nd and 3rd parity had a lower number of piglets but heavier litter. No effect of the coconut oil supplement on neonatal piglets' performance was found. Conclusions. The coconut meal was neither beneficial to neonatal piglets nor to those with low weight at birth, which usually present low body energy.

El objetivo del estudio fue evaluar el efecto del número de partos y el suplemento de aceite de coco en lechones recien nacidos. Materiales y métodos. Se utilizaron 51 cerdas de diferentes partos y sus 642 lechones. Cada lechón se pesó y se identificó al nacer en orden secuencial. Fueron distribuidos aleatoriamente en dos grupos (CG = control y TG=tratamiento). Lechones TG tenían el primer acceso a una dosis de 3.0 ml de aceite de coco 12 horas después del nacimiento, y el segunda a las 36 h después de la primera. Los lechones fueron pesados a los 21 días. Con el fin de analizar el efecto de los suplementos de aceite de coco con relación al peso al nacer. Los lechones fueron agrupados de acuerdo con su peso (0.600 a 0.900 kg; 1.000 a 1.499 kg; 1.500 a 1.999 kg y 2.000 a 2.499 kg). Resultados. El número de partos afectó el peso y el número de lechones nacidos. Cerdas en cuarto, quinto y séptimo parto, tuvieron una camada mayor que las de segundo parto. Las cerdas de segundo y tercer parto tuvieron menor número de lechones y con peso mayor. No se encontró efecto del suplemento de aceite de coco en el desarrollo de los lechones recién nacidos. Conclusiones. Lo aceite de coco no es favorable para los lechones recién nacidos, tampoco para aquellos con el bajo peso al nacer, que normalmente presentan la energía corporal baja.

Juvenile Obesity Aggravates Disease Severity in a Rat Model of Atopic Dermatitis

PURPOSE: There is increasing epidemiological evidence of an association between childhood obesity and atopic dermatitis, but little is known about the underlying mechanism(s). In the present study, we used a rat model of atopic dermatitis to assess whether juvenile obesity, induced by reduction of litter size, aggravated the signs of atopic dermatitis and, if so, whether this aggravation was associated with changes in plasma concentration of adipokines, such as leptin and adiponectin. METHODS: Dermatitis was induced by neonatal capsaicin treatment. Body weight, dermatitis score, serum IgE, skin nerve growth factor (NGF), serum leptin and adiponectin, and cytokine mRNA expression in the skin lesion were compared between small (SL, 5 pups) and large litters (LL, 15 pups). RESULTS: The body weight of juvenile rats up to 6 weeks of age was significantly heavier in the SL group, compared with those in the LL group. The SL group showed more robust development of dermatitis, and higher levels of serum IgE and skin NGF than the LL group. Additionally, the SL group demonstrated higher levels of leptin and pro-inflammatory cytokine mRNA but lower levels of adiponectin than the LL group. CONCLUSIONS: These results suggest a causal link between a decrease in immunological tolerance, induced by juvenile obesity, and aggravation of atopic dermatitis.

Behaviour and growth performance of low-birth-weight piglets cross-fostered in multiparous sows with piglets of higher birth weights / Comportamento e desempenho de crescimento de leitões com baixo peso ao nascer uniformizados com leitões de maior peso em fêmeas suínas multíparas

The aim of the study was to evaluate the behaviour, pre-weaning survival rate and growth performance of low birth weight (BW) piglets cross-fostered with piglets of higher weights. Piglets were transferred to 60 foster sows, and divided in three groups (G; n=20): G1- 12 low BW piglets (0.80 - 1.25kg); G2- six low BW piglets and six intermediate BW piglets (1.40 - 1.60kg), and G3- six low BW piglets and six high BW piglets (>1.70kg). For the analysis, groups G2 and G3 were subdivided in LG2 (six G2 light piglets); IG2 (six G2 intermediate piglets), LG3 (six G3 light piglets), and HG3 (six G3 heavy piglets). Behavioural observations were carried out on days 1, 2, 4 and 6 (visual direct observation) and on days 3 and 5 (video recording) after birth. The percentage of missed nursings was higher in LG3 piglets than in LG1, IG2 and HG3 piglets, on days 1 and 2. On day 4, light piglets (LG1, LG2 and LG3) missed more nursings than IG2 and HG3 piglets. On day 3, video recording showed a higher percentage of missed nursings in LG1, LG2, and LG3 piglets as compared to HG3 piglets. On day 1, the number of fights during nursing was higher in IG2 than in LG1 and LG3 piglets. Also on day 1, number of fights and percentage of piglets engaged in fights, during 15min after nursing, were higher in LG1, LG3 and HG3 than in LG2 piglets. More playful behaviours were observed on day 2 in IG2 and HG3 piglets compared to LG1, LG2 and LG3 piglets. Light piglets (LG1, LG2, and LG3) presented similar body weight on days 4, 8, 12 and 16 after birth, regardless of being mixed with piglets of higher weights or not; however, the survival rate until day 16 was most compromised in LG3 piglets compared to the other groups. Despite the lack of influence of littermates' weight on the growth of low BW piglets, their survival rate indicates that they should not be mixed with high BW piglets...

O objetivo do estudo foi avaliar o comportamento, a taxa de sobrevivência pré-desmame e o desempenho de crescimento de leitões leves ao nascer uniformizados com leitões de maior peso ao nascer (PN). Os leitões foram transferidos para 60 fêmeas e divididos em três grupos (G; n=20): G1 - 12 leitões de baixo PN (0,80-1,25kg); G2 - seis leitões de baixo PN e seis com PN intermediário (1,40-1,60kg); e G3 - seis leitões de baixo PN e seis leitões pesados (>1,70kg). Para a análise, os grupos G2 e G3 foram subdivididos em LG2 (seis G2 leitões leves); IG2 (seis G2 leitões de peso intermediário); LG3 (seis G3 leitões leves) e HG3 (seis G3 leitões pesados). Observações de comportamento foram realizadas nos dias 1, 2, 4 e 6 (observações visuais diretas) e nos dias 3 e 5 (gravações) após o nascimento. A porcentagem de mamadas perdidas foi maior no grupo LG3 quando comparado aos grupos LG1, IG2 e HG3, nos dias 1 e 2. No dia 4, leitões leves (LG1, LG2 e LG3) perderam maior número de mamadas do que os grupos IG2 e HG3. No dia 3, a gravação mostrou maior porcentagem de perda de mamadas nos grupos LG1, LG2 e LG3 do que no grupo HG3. No dia 1, o número de brigas durante a mamada foi maior nos grupos IG2 do que nos grupos LG1 e LG3. Também no dia 1, o número de brigas e porcentagem de leitões envolvidos em brigas, durante 15 minutos após a mamada, foi maior nos grupos LG1, LG3 e HG3 do que no grupo LG2. Brincadeiras foram mais observadas no dia 2 nos grupos IG2 e HG3 quando comparado aos grupos LG1, LG2 e LG3. Leitões leves (LG1, LG2 e LG3) apresentaram peso semelhante nos dias 4, 8, 12 e 16 após o nascimento, independentemente de serem misturados ou não com leitões pesados. No entanto, a taxa de sobrevivência até o dia 16 foi mais comprometida nos leitões do grupo LG3 do que nos outros grupos. Apesar da falta de influência do peso das leitegadas no crescimento de leitões de baixo PN, a taxa de sobrevivência indicou que estes não devem ser misturados com leitões de maior PN...

Características da carcaça e dos componentes não carcaça de cordeiros oriundos de parto simples ou duplo / Carcass and non-carcass traits of single and twin lambs

Um experimento foi conduzido com o objetivo de avaliar as características da carcaça e dos componentes não carcaça de cordeiros nascidos de parto simples ou duplo. Dezesseis cordeiros mestiços Texel × Ile de France, machos não castrados, foram desmamados aos 56 dias de idade e abatidos com aproximadamente 28kg de peso corporal. Imediatamente após o abate, cada componente corporal foi pesado separadamente, sendo as carcaças avaliadas após 24 horas de refrigeração a 2°C. Os cordeiros oriundos de parto simples apresentaram superioridade no peso e nos rendimentos da carcaça, além de maior área de olho de lombo. Por outro lado, proporcionalmente ao peso de corpo vazio, o rúmen é maior em cordeiros nascidos de parto duplo, o que resulta incremento da proporção de conteúdo gastrintestinal ao abate. Os resultados deste estudo indicam que, quando abatidos a um mesmo peso, cordeiros oriundos de parto simples possuem carcaças de melhor qualidade, em comparação a cordeiros nascidos de parto gemelar...

An experiment was conducted to evaluate the carcass and non-carcass traits of single and twin lambs. Sixteen Texel × Ile de France crossbred, non-castrated male lambs were weaned at 56 days of age and slaughtered at 28kg of body weight. Immediately after the slaughter each body component was individually weighed, while carcasses were evaluated after a 24h period of refrigeration at 2°C. Single lambs presented higher values of carcass weight and carcass dressing percentage. Moreover, the Longissimus muscle area was also greater for single lambs. On the other hand, as a proportion of empty body weight, rumen was greater for twin lambs, increasing their gastrointestinal content at slaughter. The results of this study indicated that at a same slaughter weight single lambs have better quality carcasses in comparison with those from twin lambs...

Polymorphism of bone morphogenetic protein receptor-IB [BMPR-IB] gene with litter size and kids growth of some goat breeds in Egypt

Polymerase Chain Reaction-Restriction Fragment Length Polymorphisms [PCR-RFLP] and Single Nucleotide polymorphism [SNP] techniques were used to study the association between bone morphogenetic protein receptor IB [BMPR IB] gene polymorphism with litter size trait and kids growth. Forty four Female goats were precisely selected according to their litter size and kids growth. PCR amplification of 190 bp of the BMPR-IB gene was genotyped in all goats and sequenced only in those produced the highest and lowest litter size and kids growth. Restriction analysis of PCR-RFLP using Ava II and Hind III of the BMPRIB gene [190-bp] do not produce restriction fragments. By DNA sequencing, eight single nucleotide polymorphisms [SNP's] at seven different positions were obtained. Furthermore, with translation of SNPs to corresponding amino acids, change of six amino acids in three female goats were obtained as the following, Baladi goat with high litter size, glutamic acid [E] changed to aspartic acid [P] and isoleucine [I] changed to valine [V]. In high litter size, Zaraibi goat, valine [V] changed to leucine acid [L] and glutamine [Q] changed to histidine [H] and threonine [T] changed to proline [P]. These findings can be used in a marker-assisted selection [MAS] for selection for high litter size trait in goats. There are negative relationships in most goats between SNPs in BMPR IB gene and relative growth gain [RGG]

Polymorphism of four microsatellites and their polymerisation effect on litter size in Boer goats

Background: Finding molecular markers linked to quantitative trait loci is the first step in marker-assisted selection (MAS). Microsatellites are excellent molecular markers because of their large numbers, even distribution in the genome, and high polymorphism. In this study, the polymerisation effect of four microsatellites (OarAE101, BM1329, BM143, and LSCV043) on litter size was analysed using microsatellite markers and pedigrees. Results: The results indicate that the polymerisation effect of four microsatellite loci significantly affected the litter size. E5E10F2F6G1G5H6H11 and E3E8F5F7G1G5H3H9 had the highest and lowest litter sizes in the F2 generation, respectively. The polymerisation effect value (v) of the E5E10 genotype was 3.18% higher than that of the E2E7 genotype. The v of genotype F2F6 was 14.47% higher than that of the F5F7 genotype. The v of genotype G1G5 was 58.99% higher than that of the G2G7 genotype. The v of the H6H11 genotype was 5.60% to 49.74% higher than those of the H4H10 and H1H7 genotypes. The v of the H3H9 genotype was 17.22% higher than that of the H1H7 genotype. Conclusions: The results of the present study are vital to improving the reproductive performance in goat breeds MAS.

Circadian clock gene Rev-erb-α deficiency prolongs female estrous cyclicity / 生理学报

The circadian clock has been linked to female reproductive physiology and endocrine in mammals. Epidemiological studies of female shift workers have shown increased rates of abnormal reproduction and adverse pregnancy. But little is known how the circadian rhythms affect reproduction. The aim of the present study was to investigate the influences of circadian rhythms on estrous cycle in female mice using clock gene Rev-erb-α knock out (Rev-erb-α(-/-)) mice. To test the fertility of Rev-erb-α(-/-) mice, litter sizes were counted after mating with C57BL/6J male mice. HE staining was used to observe the change of follicle development. The number of embryos of Rev-erb-α(+/+) and Rev-erb-α(-/-) female mice was compared 1.5 d after mating with C57BL/6J male mice. Then Rev-erb-α(+/+) and Rev-erb-α(-/-) female mice were housed to adult, and daily vaginal lavage with 0.9% saline was used to monitor estrous cycle for at least 30 days. Quantity of various cells was counted on specified smears views after staining. We observed estrous cycles of Rev-erb-α(+/+) and Rev-erb-α(-/-) female mice using line plots and periodic spectrograms. The results showed that the Rev-erb-α(-/-) female mice were infertility, and the number of embryos of Rev-erb-α(-/-) females was less than that of Rev-erb-α(+/+) females. However, the follicle development of Rev-erb-α(-/-) female mice was normal. The estrous cycle of Rev-erb-α(-/-) female mice was 3.22 days longer than that of Rev-erb-α(+/+) female mice. The results suggest that loss of Rev-erb-α prolongs estrous cycle, which is probably one of the reasons for female mice infertility, and circadian rhythm is important for mammalian estrous cycle.