Anthelmintic usage on the Reproductive Parameters in Captive reared Agoutis (Dasyprocta leporina) in Trinidad and Tobago, West Indies

Abstract The agouti (Dasyprocta leporina) is a rodent that is found in the Neo-tropical region. This animal is hunted for its meat but has recently been reared in captivity as a source of meat protein in rural communities. A 20-month experiment was carried out to evaluate the effect of an anthelmintic on the reproductive performance of the agouti (Dasyprocta leporina) reared in captivity. This experiment was conducted in the humid tropics of Trinidad and Tobago. Sixteen animals (15 females, 1 male) placed in each of the two treatment groups in a completely randomized study design. In treatment 1 (T1) animals were given subcutaneous injections of Endovet Ces® (Ivermectin/Praziquantel) at 0.2 mg/kg every three months. Treatment 2 (T2) was the negative control group where animals were not exposed to an anthelmintic. Reproductive data were collected at parturition which included birth weight, litter weight, litter size and gender of offspring. The results showed that there was no statistical difference (p > 0.05) between the treatment groups with respect to birth weight, litter weight, litter size and gender. However, agoutis that were dewormed had a higher birth weight (220.24 g vs 209.1 g) and litter weight (369.8 g vs 343 g). The same values were obtained for the litter size (1.7 vs 1.7) and animals that were dewormed had a higher female offspring to male offspring (2.41:1 vs 1.11:1). This experiment demonstrated that the use of an anthelmintic strategically in the management of captive reared agoutis had no statistical effect (p > 0.05) on the reproductive parameters. Therefore, these animals can be kept in captive conditions without being dewormed and produce efficiently with proper feeding and housing management.

Resumo A cutia (Dasyprocta leporina) é um roedor que se encontra na região neo-tropical. Esse animal é caçado por sua carne, mas recentemente foi criado em cativeiro como fonte de proteína de carne em comunidades rurais. Um experimento de 20 meses foi realizado para avaliar o efeito de um anti-helmíntico no desempenho reprodutivo de cutias (Dasyprocta leporina) criadas em cativeiro. Esse experimento foi conduzido nos trópicos úmidos de Trinidad e Tobago. Dezesseis animais (15 fêmeas, 1 macho) colocados em cada um dos dois grupos de tratamento em um desenho de estudo completamente randomizado. No tratamento 1 (T1) os animais receberam injeções subcutâneas de Endovet Ces® (Ivermectina / Praziquantel) na dose de 0,2 mg / kg a cada três meses. O tratamento 2 (T2) foi o grupo de controle negativo onde os animais não foram expostos a um anti-helmíntico. Os dados reprodutivos foram coletados no parto, incluindo peso ao nascer, peso da ninhada, tamanho da ninhada e sexo da prole. Os resultados mostraram que não houve diferença estatística (p > 0,05) entre os grupos de tratamento com relação ao peso ao nascer, peso da ninhada, tamanho da ninhada e sexo. No entanto, cutias desparasitadas tiveram maior peso ao nascer (220,24 g vs. 209,1 g) e peso da ninhada (369,8 g vs. 343 g). Os mesmos valores foram obtidos para o tamanho da ninhada (1,7 vs. 1,7) e os animais que foram desparasitados tiveram uma prole feminina maior do que a prole masculina (2,41: 1 vs. 1,11: 1). Esse experimento demonstrou que o uso de anti-helmíntico estrategicamente no manejo de cutias criadas em cativeiro não teve efeito estatístico (p > 0,05) sobre os parâmetros reprodutivos. Portanto, esses animais podem ser mantidos em cativeiro sem serem vermifugados e produzir de forma eficiente com alimentação adequada e manejo do alojamento.

Dr Association of bone morphogenetic protein 15 and growth differentiation factor 9 with litter size in livestock: a review study

Litter size is one of the crucial factors in livestock production and is of high economic value, which is affected by ovulation rate, hormones, and growth factors.Growth factors play a multifaceted role in reproductive physiology. This review aims to investigate the association of bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9)with litter size in livestock.The transforming growth factor ß(TGF-ß) superfamily includes more than 34 members; GDF9 and BMP15 are among the most significantfactors for regulating fertility and litter size in most livestock species. Ovarian follicles release BMP15 and GDF9 that are involved in the maturation of primary follicles into the basal form, proliferation of granulosa and theca cells, steroidogenesis, ovulation, and formation of the corpus luteum. Besides, these factors are highly expressed in oocytes and are necessary for female fertility and multiple ovulation in several livestock species. Animals with two inactive copies of these factors are sterile, while those with one inactive copy are fertile. Thus, the present reviewprovides valuable information on the association of BMP15 and GDF9with litter size in livestock that can be used as biological markers of multiple ovulation or for improving fertility in livestock.(AU)

Seleção de touros para reprodução baseada no fenótipo e DEPs / Selection of bulls for reproduction based on EPD and phenotype

A fertilidade pode ser definida como a capacidade de gerar filhos normais, o que é essencial para o progresso genético, desde que os ascendentes tenham capacidade de transmitir características que venham impactar positivamente os índices zootécnicos e econômicos. Apesar do aumento expressivo do uso de biotécnicas reprodutivas, a maior parte das fêmeas bovinas aptas à reprodução no Brasil ainda são acasaladas por meio da monta natural. Torna-se importante então, não somente, a estimativa da saúde reprodutiva do touro, mas também a avaliação da sua qualidade genética que pode ser feita, por exemplo, pelo acesso os índices dos reprodutores nos diversos programas de melhoramento genético nacional ou pela utilização de escores de avaliação visual.(AU)

Fertility can be defined as the ability to generate normal descendants, which is essential for genetic progress, as long as the ancestors have the ability to transmit characteristics that will positively impact zootechnical and economic indices. Despite the significant increase in the use of reproduction biotechniques, most bovine females capable of reproduction in Brazil are still mated through natural mating. Therefore, it becomes important not only to estimate the reproductive health of the bull, but also to evaluate its genetic quality, which can be done, for example, by accessing the indices of the bulls in the various national genetic improvement programs or by using visual assessment scores.(AU)

Anthelmintic usage on the Reproductive Parameters in Captive reared Agoutis (Dasyprocta leporina) in Trinidad and Tobago, West Indies / Uso de anti-helmíntico nos parâmetros reprodutivos em cutias criadas em cativeiro (Dasyprocta leporina) em Trinidad e Tobago, Índias Ocidentais

Abstract The agouti (Dasyprocta leporina) is a rodent that is found in the Neo-tropical region. This animal is hunted for its meat but has recently been reared in captivity as a source of meat protein in rural communities. A 20-month experiment was carried out to evaluate the effect of an anthelmintic on the reproductive performance of the agouti (Dasyprocta leporina) reared in captivity. This experiment was conducted in the humid tropics of Trinidad and Tobago. Sixteen animals (15 females, 1 male) placed in each of the two treatment groups in a completely randomized study design. In treatment 1 (T1) animals were given subcutaneous injections of Endovet Ces® (Ivermectin/Praziquantel) at 0.2 mg/kg every three months. Treatment 2 (T2) was the negative control group where animals were not exposed to an anthelmintic. Reproductive data were collected at parturition which included birth weight, litter weight, litter size and gender of offspring. The results showed that there was no statistical difference (p > 0.05) between the treatment groups with respect to birth weight, litter weight, litter size and gender. However, agoutis that were dewormed had a higher birth weight (220.24 g vs 209.1 g) and litter weight (369.8 g vs 343 g). The same values were obtained for the litter size (1.7 vs 1.7) and animals that were dewormed had a higher female offspring to male offspring (2.41:1 vs 1.11:1). This experiment demonstrated that the use of an anthelmintic strategically in the management of captive reared agoutis had no statistical effect (p > 0.05) on the reproductive parameters. Therefore, these animals can be kept in captive conditions without being dewormed and produce efficiently with proper feeding and housing management.

Resumo A cutia (Dasyprocta leporina) é um roedor que se encontra na região neo-tropical. Esse animal é caçado por sua carne, mas recentemente foi criado em cativeiro como fonte de proteína de carne em comunidades rurais. Um experimento de 20 meses foi realizado para avaliar o efeito de um anti-helmíntico no desempenho reprodutivo de cutias (Dasyprocta leporina) criadas em cativeiro. Esse experimento foi conduzido nos trópicos úmidos de Trinidad e Tobago. Dezesseis animais (15 fêmeas, 1 macho) colocados em cada um dos dois grupos de tratamento em um desenho de estudo completamente randomizado. No tratamento 1 (T1) os animais receberam injeções subcutâneas de Endovet Ces® (Ivermectina / Praziquantel) na dose de 0,2 mg / kg a cada três meses. O tratamento 2 (T2) foi o grupo de controle negativo onde os animais não foram expostos a um anti-helmíntico. Os dados reprodutivos foram coletados no parto, incluindo peso ao nascer, peso da ninhada, tamanho da ninhada e sexo da prole. Os resultados mostraram que não houve diferença estatística (p > 0,05) entre os grupos de tratamento com relação ao peso ao nascer, peso da ninhada, tamanho da ninhada e sexo. No entanto, cutias desparasitadas tiveram maior peso ao nascer (220,24 g vs. 209,1 g) e peso da ninhada (369,8 g vs. 343 g). Os mesmos valores foram obtidos para o tamanho da ninhada (1,7 vs. 1,7) e os animais que foram desparasitados tiveram uma prole feminina maior do que a prole masculina (2,41: 1 vs. 1,11: 1). Esse experimento demonstrou que o uso de anti-helmíntico estrategicamente no manejo de cutias criadas em cativeiro não teve efeito estatístico (p > 0,05) sobre os parâmetros reprodutivos. Portanto, esses animais podem ser mantidos em cativeiro sem serem vermifugados e produzir de forma eficiente com alimentação adequada e manejo do alojamento.

Risk factors associated with stillbirth in sows / Fatores de risco associados à natimortalidade em fêmeas suínas

In this study, the risk factors associated with stillbirth in sows were identified and their odds ratio assessed. For this purpose, 587 farrowings on Farm A and 929 on Farm B were monitored, and the sow parity, body condition score, farrowing duration, total number of piglets born, numbers of live births, stillbirths, and mummified piglets, obstetric interventions, and piglet sex and weight were recorded. At the end of farrowing, piglets classified as stillborn were necropsied to confirm the diagnosis. Consequently, 5.49% of the piglets on Farm A and 5.10% of those on Farm B were stillborn. On both farms, sows with a high parity, prolonged farrowing, and a large litter size had the highest odds ratio of stillbirths. On Farm B, farrowing intervention through the use of vaginal palpation and oxytocin increased the odds of stillbirth by 1.7 and 2.5 times, respectively. Heavy litters increased the odds of stillbirth by 1.4 times. Additionally, low-birth-weight piglets were 2.3 and 3.1 times more likely than their medium-birth-weight and high-birth-weight counterparts, respectively, to be stillborn. In conclusion, on both farms, the risk factors associated with stillbirth were a high parity, a large litter size, and prolonged farrowing.

O objetivo deste estudo foi avaliar os fatores de risco associados ao nascimento de natimortos em fêmeas suínas e a razão de chance para a sua ocorrência. Foram acompanhados 587 partos na granja A e 929 na granja B onde foram registrados: ordem de parto, escore de condição corporal, duração do parto, total de nascidos, nascidos vivos, natimortos, mumificados, intervenções ao parto, peso e o sexo dos leitões. Ao final do parto foi realizada necropsia dos leitões classificados como natimortos a fim de confirmar o diagnóstico. A ocorrência de leitões natimortos foi de 5,49% e 5,10% na granja A e B, respectivamente. Fêmeas de maior ordem de parto, com partos prolongados e leitegadas mais numerosas apresentaram maior chance da ocorrência de leitões natimortos em ambas as granjas. Na granja B a necessidade de intervenção ao parto através do uso de ocitocina e palpação vaginal aumentaram a chance da presença de leitões natimortos em 1,7 e 2,5 vezes, respectivamente. Leitegadas pesadas aumentaram em 1,4 vezes as chances de ocorrência de leitões natimortos. No entanto, leitões com menor peso ao nascer aumentam em 2,3 vezes as chances de natimortos, quando comparadas a leitões de peso intermediário, e 3,1 vezes em relação a leitões com maior peso de nascimento. Os fatores de risco associados à ocorrência de natimortos nas duas granjas foram a ordem de parto elevada, leitegadas numerosas e partos prolongados.

Anthelmintic usage on the Reproductive Parameters in Captive reared Agoutis (Dasyprocta leporina) in Trinidad and Tobago, West Indies / Uso de anti-helmíntico nos parâmetros reprodutivos em cutias criadas em cativeiro (Dasyprocta leporina) em Trinidad e Tobago, Índias Ocidentais

The agouti (Dasyprocta leporina) is a rodent that is found in the Neo-tropical region. This animal is hunted for its meat but has recently been reared in captivity as a source of meat protein in rural communities. A 20-month experiment was carried out to evaluate the effect of an anthelmintic on the reproductive performance of the agouti (Dasyprocta leporina) reared in captivity. This experiment was conducted in the humid tropics of Trinidad and Tobago. Sixteen animals (15 females, 1 male) placed in each of the two treatment groups in a completely randomized study design. In treatment 1 (T1) animals were given subcutaneous injections of Endovet Ces® (Ivermectin/Praziquantel) at 0.2 mg/kg every three months. Treatment 2 (T2) was the negative control group where animals were not exposed to an anthelmintic. Reproductive data were collected at parturition which included birth weight, litter weight, litter size and gender of offspring. The results showed that there was no statistical difference (p > 0.05) between the treatment groups with respect to birth weight, litter weight, litter size and gender. However, agoutis that were dewormed had a higher birth weight (220.24 g vs 209.1 g) and litter weight (369.8 g vs 343 g). The same values were obtained for the litter size (1.7 vs 1.7) and animals that were dewormed had a higher female offspring to male offspring (2.41:1 vs 1.11:1). This experiment demonstrated that the use of an anthelmintic strategically in the management of captive reared agoutis had no statistical effect (p > 0.05) on the reproductive parameters. Therefore, these animals can be kept in captive conditions without being dewormed and produce efficiently with proper feeding and housing management.

A cutia (Dasyprocta leporina) é um roedor que se encontra na região neo-tropical. Esse animal é caçado por sua carne, mas recentemente foi criado em cativeiro como fonte de proteína de carne em comunidades rurais. Um experimento de 20 meses foi realizado para avaliar o efeito de um anti-helmíntico no desempenho reprodutivo de cutias (Dasyprocta leporina) criadas em cativeiro. Esse experimento foi conduzido nos trópicos úmidos de Trinidad e Tobago. Dezesseis animais (15 fêmeas, 1 macho) colocados em cada um dos dois grupos de tratamento em um desenho de estudo completamente randomizado. No tratamento 1 (T1) os animais receberam injeções subcutâneas de Endovet Ces® (Ivermectina / Praziquantel) na dose de 0,2 mg / kg a cada três meses. O tratamento 2 (T2) foi o grupo de controle negativo onde os animais não foram expostos a um anti-helmíntico. Os dados reprodutivos foram coletados no parto, incluindo peso ao nascer, peso da ninhada, tamanho da ninhada e sexo da prole. Os resultados mostraram que não houve diferença estatística (p > 0,05) entre os grupos de tratamento com relação ao peso ao nascer, peso da ninhada, tamanho da ninhada e sexo. No entanto, cutias desparasitadas tiveram maior peso ao nascer (220,24 g vs. 209,1 g) e peso da ninhada (369,8 g vs. 343 g). Os mesmos valores foram obtidos para o tamanho da ninhada (1,7 vs. 1,7) e os animais que foram desparasitados tiveram uma prole feminina maior do que a prole masculina (2,41: 1 vs. 1,11: 1). Esse experimento demonstrou que o uso de anti-helmíntico estrategicamente no manejo de cutias criadas em cativeiro não teve efeito estatístico (p > 0,05) sobre os parâmetros reprodutivos. Portanto, esses animais podem ser mantidos em cativeiro sem serem vermifugados e produzir de forma eficiente com alimentação adequada e manejo do alojamento.

Anthelmintic usage on the Reproductive Parameters in Captive reared Agoutis (Dasyprocta leporina) in Trinidad and Tobago, West Indies / Uso de anti-helmíntico nos parâmetros reprodutivos em cutias criadas em cativeiro (Dasyprocta leporina) em Trinidad e Tobago, Índias Ocidentais

The agouti (Dasyprocta leporina) is a rodent that is found in the Neo-tropical region. This animal is hunted for its meat but has recently been reared in captivity as a source of meat protein in rural communities. A 20-month experiment was carried out to evaluate the effect of an anthelmintic on the reproductive performance of the agouti (Dasyprocta leporina) reared in captivity. This experiment was conducted in the humid tropics of Trinidad and Tobago. Sixteen animals (15 females, 1 male) placed in each of the two treatment groups in a completely randomized study design. In treatment 1 (T1) animals were given subcutaneous injections of Endovet Ces® (Ivermectin/Praziquantel) at 0.2 mg/kg every three months. Treatment 2 (T2) was the negative control group where animals were not exposed to an anthelmintic. Reproductive data were collected at parturition which included birth weight, litter weight, litter size and gender of offspring. The results showed that there was no statistical difference (p > 0.05) between the treatment groups with respect to birth weight, litter weight, litter size and gender. However, agoutis that were dewormed had a higher birth weight (220.24 g vs 209.1 g) and litter weight (369.8 g vs 343 g). The same values were obtained for the litter size (1.7 vs 1.7) and animals that were dewormed had a higher female offspring to male offspring (2.41:1 vs 1.11:1). This experiment demonstrated that the use of an anthelmintic strategically in the management of captive reared agoutis had no statistical effect (p > 0.05) on the reproductive parameters. Therefore, these animals can be kept in captive conditions without being dewormed and produce efficiently with proper feeding and housing management.(AU)

A cutia (Dasyprocta leporina) é um roedor que se encontra na região neo-tropical. Esse animal é caçado por sua carne, mas recentemente foi criado em cativeiro como fonte de proteína de carne em comunidades rurais. Um experimento de 20 meses foi realizado para avaliar o efeito de um anti-helmíntico no desempenho reprodutivo de cutias (Dasyprocta leporina) criadas em cativeiro. Esse experimento foi conduzido nos trópicos úmidos de Trinidad e Tobago. Dezesseis animais (15 fêmeas, 1 macho) colocados em cada um dos dois grupos de tratamento em um desenho de estudo completamente randomizado. No tratamento 1 (T1) os animais receberam injeções subcutâneas de Endovet Ces® (Ivermectina / Praziquantel) na dose de 0,2 mg / kg a cada três meses. O tratamento 2 (T2) foi o grupo de controle negativo onde os animais não foram expostos a um anti-helmíntico. Os dados reprodutivos foram coletados no parto, incluindo peso ao nascer, peso da ninhada, tamanho da ninhada e sexo da prole. Os resultados mostraram que não houve diferença estatística (p > 0,05) entre os grupos de tratamento com relação ao peso ao nascer, peso da ninhada, tamanho da ninhada e sexo. No entanto, cutias desparasitadas tiveram maior peso ao nascer (220,24 g vs. 209,1 g) e peso da ninhada (369,8 g vs. 343 g). Os mesmos valores foram obtidos para o tamanho da ninhada (1,7 vs. 1,7) e os animais que foram desparasitados tiveram uma prole feminina maior do que a prole masculina (2,41: 1 vs. 1,11: 1). Esse experimento demonstrou que o uso de anti-helmíntico estrategicamente no manejo de cutias criadas em cativeiro não teve efeito estatístico (p > 0,05) sobre os parâmetros reprodutivos. Portanto, esses animais podem ser mantidos em cativeiro sem serem vermifugados e produzir de forma eficiente com alimentação adequada e manejo do alojamento.(AU)

Comparison of efficiency between two artificial insemination methods using fresh semen in domestic cat (Felis Catus) / Comparação da eficiência entre dois métodos de inseminação artificial utilizando sêmen fresco em gata doméstica (Felis Catus)

This study aimed to compare domestic cats' pregnancy rates using fresh semen for the bilateral intrauterine insemination (BIUI) method and the novel uterine body insemination (UBI) method. Queens received a single injection of equine chorionic gonadotropin (eCG) (200 IU; IM) to induce ovarian follicular development and, after 83 h, an injection of human chorionic gonadotropin (hCG) (100 IU; IM) for final oocyte maturation and ovulation induction. Thirty-four hours after hCG administration, 3 × 106fresh spermatozoa were used for insemination by the BIUI (n = 8 queens) or by the UBI (n = 7 queens) techniques,respectively. Pregnancy rates were 75.00% (6/8) by BIUI and 42.85% (3/7) by the UBI method. Themean litter size was 3.0 ± 0.86 for the BIUI, and 2.0 ± 1.0 for the UBI method. Spontaneous abortion occurred on day 35 of pregnancy in one queen following the UBI method. Our findings showed that the BIUI of queens with fresh semen resulted in higher pregnancy rates than the novel UBI method; also, acceptable pregnancy rates were achieved following BIUI with fresh semen in the domestic cat.(AU)

O objetivo deste estudo foi comparar as taxas de prenhez em gatas domésticas usando sêmen fresco para o método de inseminação intrauterina bilateral (BIUI) e o novo método de inseminação do corpo uterino (UBI). As gatas receberam uma única injeção de gonadotrofina coriônica equina (eCG) (200 UI; IM) para induzir o desenvolvimento folicular ovariano e, após 83 h, uma injeção de gonadotrofina coriônica humana (hCG) (100 UI; IM) para maturação final do oócito e ovulação indução. Trinta e quatro horas após a administração de hCG, 3 × 106 espermatozoides frescos foram utilizados para inseminação pelas técnicas de BIUI (n = 8 gatas) ou UBI (n = 7 gatas), respectivamente. As taxas de gravidez foram de 75,00% (6/8) pela BIUI e 42,85% (3/7) pelo método UBI. O tamanho médio da ninhada foi de 3,0 ± 0,86 para o método BIUI e 2,0 ± 1,0 para o método UBI. Aborto espontâneo ocorreu no dia 35 de gestação em uma gata seguindo o método UBI. Nossos achados mostraram que a BIUI de gatas com sêmen fresco resultou em maiores taxas de prenhez do que o novo método UBI; também, taxas de prenhez aceitáveis foram alcançadas após BIUI com sêmen fresco no gato doméstico.(AU)

Efficacy of Aluminum Sulfate Addition to Poultry Litter on Productive Performance of Laying Hens, Ammonia Emissions, and Litter Quality

The objective of this research was to examine whether different types of litter (New, used, and mixed) and alum could interfere in litter quality, thereby also influencing the productive performance of laying hens. A total number of 450 Inshas chickens aged 24 weeks were randomly distributed into six groups (5 replicates, each with 15 hens) of floor litter. The groups included (G1) new wheat straw litter, (G2) used wheat straw litter, (G3) mixed wheat straw litter (50% new+50% used) and (4, 5 and 6) the same litter types in groups 1, 2 and 3 supplied with 500g of alum /m2 litter. The experiment lasted 16 weeks. Laying hens productive parameters, blood parameters, carcass parameters, respiratory rate, coliform count and pH, as well as ammonia emission, litter quality were assessed.The results showed that the litter type significantly affects the level of ammonia emission, litter characteristics, carcass characteristics, intestinal pH and coliform count, blood characteristics (T3, cholesterol, uric acid, total protein, albumin, globulin, hemoglobin, and PCV), as well as the body weight gain. In general, we found that reused litter followed by the mixed litter without added alum resulted in the lowest efficiency on the studied traits, as compared to the same types of litter treated with alum and the new litter. We therefore conclude that the addition of alum reduces ammonia emission and improves the characteristics of the litter, which is reflected in enhancement of productive performance and properties of blood and carcass.(AU)

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.

A new species of Megaspira (Stylommatophora: Megaspiridae) from Ilha Grande, Southeast Brazil

Megaspiridae include land snails with a tall spire. They occur in Brazil, New Guinea and Australia. Megaspira Lea, 1839 is distributed through the central and southeast regions of Brazil There is controversy regarding the number of species in the genus, and their taxonomic status. The characters used to identify Megaspira include a large cylindrical shell and internal armature in the columella. The goal of the present study is to describe a new species for the genus, based on shell morphology, microsculpture and the inner anatomy. These anatomic characters had not been described before for any of the included species. The material was collected at the Jararaca trail, Ilha Grande (Angra dos Reis, state of Rio de Janeiro). Seven linear measurements were taken from the shells. Megaspira adenticulata sp. nov. differs from the other species of the genus by not having apertural lamella in the shell aperture or in the columella in adult specimens. Also, the shell does not have light brown spots, as observed in other species of Megaspira. The shell has a mean of 16 whorls and height of 27 mm. It is smaller in average size than the shell of other described species. The new species was found under leaf litter, especially near rocks and in shallow soil.(AU)

Inbreeding on litter size of German Spitz dogs

The objective of the present study was to assess the association between the inbreeding coefficient (F) of German Spitz dogs (litter, sires, and dams) and number of live newborn dogs for this breed. Records of dams and sires of a breeding system were used to calculate the F of 105 litters and their sires and dams and the number of live newborn dogs. The analysis performed through the GLM procedure showed a negative influence of F of litter and mother on litter size. This influence was investigated through models that considered linear and quadratic influences. Although the model that considered quadratic effect of F of the litter achieved the best adjustment, only linear coefficients were significant in both analyses. According to these results, the studied sample of German Spitz dogs exhibits inbreeding depression for litter size, which is an important information for breeders and professionals that assist in dog breeding. In addition to all the known effects of inbreeding on canine health, the results indicate that monitoring inbreeding through F is important for the reproductive success of the breed.

Environmental influence on the reproductive strategy of Helogenes marmoratus (Siluriformes: Cetopsidae) in the Amazonian streams

RESUMEN La estrategia reproductiva de una especie debe ajustarse a las variaciones de las condiciones ambientales para garantizar el equilibrio poblacional. En los riachos amazónicos de tierra firme las fluctuaciones hidrológicas están controladas principalmente por las lluvias locales, predominando especies de peces de pequeño porte. Investigamos la estrategia reproductiva de Helogenes marmoratus y la influencia de variables ambientales (e.g., lluvia, conductividad, descriptores del hábitat) en su actividad reproductiva. Colectamos mensualmente entre marzo de 2019 y marzo de 2020 en una microcuenca del río Guamá, en la Amazonia oriental brasileña. Identificamos un período reproductivo prolongado entre julio de 2019 y marzo de 2020. Los machos comienzan a reproducirse con un menor tamaño ( = 27.41; = 31.36 mm). Confirmamos desove parcial, baja fecundidad (59.55 ± 22.76 ovócitos) y ovócitos grandes (1.24 ± 0.15 mm). La estrategia reproductiva de H. marmoratus ocupa un lugar intermedio entre el gradiente oportunista y de equilibrio. Regresiones múltiples destacan la importancia de la profundidad, la conductividad eléctrica, los bancos de hojas y la lluvia como reguladores de la actividad reproductiva de las hembras, explicando 32% de la variación del IGS. Nuestro estudio proporciona evidencia de una respuesta reproductiva diferenciada entre los sexos a las variables ambientales.

ABSTRACT The reproductive strategy of a species must be adjusted to variations in environmental conditions to guarantee population balance. Hydrological fluctuations in Amazonian streams of terra firme (non-flooded) are controlled primarily by local rainfall. Fish assemblages are composed predominantly of species of small size. We investigated the reproductive strategy of the cryptic catfish Helogenes marmoratus and assessed the influence of environmental variables (e.g., rainfall, conductivity, habitat descriptors) on its reproductive activity in a catchment of the Guamá River in the eastern Brazilian Amazon. Through monthly collections between March 2019 and March 2020, we identified an extended reproductive period between July 2019 and March 2020. Males mature at smaller sizes than females ( = 27.41 mm; = 31.36 mm). We confirmed batch spawning, low fecundity (59.55 ± 22.76 stage IV oocytes), and large oocytes (1.24 ± 0.15 mm). Our results indicated that H. marmoratus strategy occupies an intermediate place between opportunistic and equilibrium gradient. Multiple regressions showed that thalweg depth, electrical conductivity, leaf litter, and rainfall are important drivers of reproductive activity of females of H. marmoratus, explaining 32% of the variation of the GSI. Our study provides evidence of differentiated reproductive response between the sexes to environmental variables.

Desenvolvimento embrionário: quando avaliar o fenótipo e sua relação com o genótipo / Embryonic development: when to evaluate its phenotype and its relationship with genotype

Durante as últimas décadas, a suinocultura vivencia um processo de intensa seleção genética. Dentre as características reprodutivas, a taxa ovulatória sofreu a avanços significativos e, como consequência, o aumento do tamanho da leitegada em fêmeas suínas contemporâneas é evidente. No entanto, essa pressão de seleção gerou também características indiretas indesejáveis, como o baixo peso ao nascimento e grande variabilidade de peso ao nascimento dentro de uma mesma leitegada. Desta forma, durante os últimos anos, inúmeros estudos buscaram entender os principais aspectos relacionados ao desenvolvimento embrionário e pré-natal em suínos. A capacidade de elucidar aspectos relacionados à regulação do desenvolvimento embrionário e placentário, aos genes centrais e marcadores moleculares que estão relacionados ao adequado desenvolvimento e qualidade embrionária contribuem para a compreensão da reprodução básica e facilitam o entendimento das relações materno-embrionárias no período gestacional.

During the last few decades, the swine industry has undergone an intense process of genetic selection. Among the reproductive characteristics, the ovulation rate has undertaken significant advances , and, consequently, the increase in litter size is evident in contemporaneous sows. However, the selection pressure also resulted in undesired indirect characteristics, as the low birth weight and birth weight variability within the litter. Therefore, during the last few years, many studies have shed light on the aspects related to embryonic and prenatal development in pigs. The ability to understand how embryonic development is regulated, the central genes and molecular markers that are related to appropriate development, and embryonic quality contribute to the understanding of basic reproduction and facilitates the understanding of embryo-maternal relationships.

Relationship between reproductive performance and meteorological variables in French Alpine goats in the northwestern part of Croatia

The study aimed to determine the relationship between reproductive performance, kidding distribution, and birth weight of French Alpine goats and meteorological variables in the northwestern part of Croatia throughout six consecutive years (from 2013 until 2018). During the study, French Alpine goats (n=948) on the 6 dairy goat farms, birthed 1025 goat kids after 893 successful matings (55 matings were unsuccessful) during six consecutive years. The average birth weight was 3.46±0.48 kg for females (n=478) and 3.71±0.51 kg for male kids (n=547). French Alpine does with single kids accounted for 85.89% (n=767), with twins 13.44% (n=120) and triplets 0.67% (n=6). The average litter size was 1.15, and the average parity was 2.95. The birth weight of goat kids in primiparous and pluriparous goats was not significantly different. Survival rate (until 1 month of age) was 93.66 % (n=960). French Alpine does fertility in northwestern Croatia, through six years was 94.18%. Seasonal kidding of French Alpine was distributed mostly on two seasons: winter (73.57%) and spring (24.52%) in the northwestern part of Croatia during six consecutive years 2013-2018. Observed differences in the kidding distribution per month during the years of observation were statistically significant (P = 0.018). The highest number of kidding was recorded in February in all years of observation. It can be concluded that there was not any relationship between monthly air temperature and precipitation amounts with tested reproductive performances in French Alpine dairy goats in the NW part of Croatia during the observed period.(AU)

Relationship between reproductive performance and meteorological variables in French Alpine goats in the northwestern part of Croatia

The study aimed to determine the relationship between reproductive performance, kidding distribution, and birth weight of French Alpine goats and meteorological variables in the northwestern part of Croatia throughout six consecutive years (from 2013 until 2018). During the study, French Alpine goats (n=948) on the 6 dairy goat farms, birthed 1025 goat kids after 893 successful matings (55 matings were unsuccessful) during six consecutive years. The average birth weight was 3.46±0.48 kg for females (n=478) and 3.71±0.51 kg for male kids (n=547). French Alpine does with single kids accounted for 85.89% (n=767), with twins 13.44% (n=120) and triplets 0.67% (n=6). The average litter size was 1.15, and the average parity was 2.95. The birth weight of goat kids in primiparous and pluriparous goats was not significantly different. Survival rate (until 1 month of age) was 93.66 % (n=960). French Alpine does fertility in northwestern Croatia, through six years was 94.18%. Seasonal kidding of French Alpine was distributed mostly on two seasons: winter (73.57%) and spring (24.52%) in the northwestern part of Croatia during six consecutive years 2013-2018. Observed differences in the kidding distribution per month during the years of observation were statistically significant (P = 0.018). The highest number of kidding was recorded in February in all years of observation. It can be concluded that there was not any relationship between monthly air temperature and precipitation amounts with tested reproductive performances in French Alpine dairy goats in the NW part of Croatia during the observed period.

Genetic study of litter size and litter uniformity in Landrace pigs

We aimed to estimate litter size and litter uniformity genetic parameters and genetic trends of Landrace pigs at birth and at three weeks by using multitrait analyses for 2,787 litters. The following litter traits were evaluated: number of piglets born alive (NBA), within-litter weight mean at birth (MBW), within-litter weight standard deviation at birth (SDB), within-litter weight coefficient of variation at birth (CVB), number of piglets at three weeks (NT), within-litter weight mean at three weeks (MT), within-litter weight standard deviation at three weeks (SDT), and within-litter weight coefficient of variation at three weeks (CVT). Heritability estimates for NBA, MBW, SDB, and CVB were 0.09±0.04, 0.31±0.08, 0.01±0.04, and 0.07±0.05, respectively, greater than those obtained at three weeks (0.06±0.04, 0.10±0.06, 0.01±0.04, and 0.02±0.04 for NT, MT, SDT, and CVT, respectively). The genetic correlations between NBA and MBW and between MBW and CVB (−0.73±0.20 and −0.93±0.21, respectively) were of moderate to high magnitudes, as well as the genetic correlations between CVT and SDT (0.85±0.39). Genetic correlations between MBW and MT, SDB and SDT, CVB and CVT, and NBA and NT were 0.73±0.16, 0.69±0.54, 0.36±0.80, and 0.95±0.06, respectively. The genetic trends were linear for NBA and CVB and quadratic for MBW and SDB, whereas for all traits at three weeks, they were close to zero. Within-litter weight coefficient of variation (CV) may be the most appropriate variation measure for application in breeding programs, especially at birth, due to its greater heritability estimate and high and negative genetic correlation with MBW. The genetic trends show that NT does not follow the increase in NBA, emphasizing the need to review the breeding goals.(AU)

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)

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)

Genetic analysis of reproductive characteristics in Iran-Black sheep

This study was conducted to estimate genetic parameters and trends for reproduction traits using data collected at the breeding station of Iran-Black sheep during 1980 to 2004. The traits included in the analyses were litter size at birth (LSB) and weaning (LSW) and litter mean weight per lamb born (LMWLB) and weaned (LMWLW) as basic traits, and total litter weight at birth (TLWB) and weaning (TLWW) as composite traits. Direct heritability estimates for LSB, TLWB, LMWLB, LSW, TLWW and LMWLW were 0.11, 0.07, 0.33, 0.08, 0.09 and 0.11, respectively. The permanent environmental effects had significant impact on all traits and ranged from 0.05 to 0.16. Effect of service sire was highly significant (p < 0.01) for all traits except LMWLW. Estimates of genetic correlations ranged from -0.76 (LSB-LMWLB) to 0.98 (LSB-LSW). Phenotypic and environmental correlations were generally lower than those of genetic correlations. Environmental correlations ranged from -0.55 (LSW-LMWLW) to 0.99 (LSB-LSW). Also, the estimated correlation for the effect of service sire ranged from -0.77 (LMWLB-TLWW) to 0.96 (LSB-LSW and LSB-TLWW). The results suggest that selection based on TLWB could be more effective than the other traits to enhance reproductive performance in Iran-Black ewes.(AU)