Reproductive performance of single fixed-time inseminated sows with semen doses submitted to different semen storage times

This study aimed to evaluate the reproductive performance of sows submitted to single fixed-time insemination (SFTAI) using boars according to capacity for liquid in vitro semen preservation, type of extender, and storage time. Boars (n = 12) were classified into two groups based on progressive motility (PM) at 120 h of semen storage: low (PM - 64.5%) - and high-preservation (PM - 83.9%) capacity for semen storage. Weaned sows (n = 397, parity - 1 to 7) were inseminated (1.5×109 sperm cells) in a factorial design: two classes of boars (low- or high-preservation), two types of extenders (short- or long-term), and two semen storage times at insemination (24 or 72 h). An adapted triptorelin acetate protocol was used for SFTAI. Total sperm motility (TM) and PM at insemination were greater in high-preservation boars at 72 h compared with low-preservation boars at 24 or 72 h (P < 0.01). Short- or long-term extender did not affect (P ≥ 0.68) TM and PM in high-preservation boars; however, long-term extender improved these parameters in low-preservation boars (P < 0.01). Pregnancy and farrowing rates were not affected by groups (P > 0.05). Total piglets born (TPB) was reduced (P = 0.05) in low-preservation boars with 72 h of storage (13.6 ± 0.5) compared to high-preservation boars with semen stored for 24 or 72 h (15.2 ± 0.5 and 15.5 ± 0.5, respectively). The low-preservation boars reduced the TPB in sows submitted to SFTAI, and this reduction was greater using semen stored for 72 h.(AU)

Perspectives of intrauterine artificial insemination applicability in gilts / Perspectivas de aplicabilidade da inseminação artificial intrauterina em leitoas

The application of the intrauterine artificial insemination (IUAI) technique allows optimization of a swine production system due to the reductions in volume and number of sperm cells in the insemination dose, and by reducing the time taken to perform the insemination. However, IUAI is not recommended for gilts due to the difficulty of intrauterine cannula passage through the cervix. This difficulty is associated mainly with the fact that the reproductive tract is smaller in gilts than in pluriparous females. However, few studies have evaluated the application of IUAI in gilts. In these studies, there are variations in approach concerning the definition of the success rate for cannula passage through the cervix, the type of cannula and the body characteristics of the gilts used, making it difficult to extrapolate the recommendation for the use of IUAI in gilts. Considering the evidence that such characteristics influence or even determine the success of the application of IUAI, there is a necessity for an understanding of the influence of these factors in the improvement and later application of the technique. Gilts represent about 15-20% of the breeding group, and the use of IUAI could optimize the processes of insemination on farms. The approach used in this review highlights the aspects that could aid in structuring further studies for improving IUAI in gilts, allowing its use on commercial farms.(AU)

A aplicação da técnica de inseminação artificial intrauterina (IAU) permitiu uma otimização do sistema de produção de suínos por possibilitar a redução do volume e número de células espermáticas na dose inseminante e, também, por diminuir o tempo de execução da inseminação. Porém, a IAU não tem sido recomendada para leitoas devido à dificuldade de passagem do cateter intrauterino através da cérvix. Essa dificuldade é associada principalmente ao menor tamanho do trato reprodutivo de leitoas se comparado ao das fêmeas pluríparas. Entretanto, ainda são poucos os estudos que avaliaram a aplicação de IAU em leitoas. Nesses estudos, existem variações quanto à definição da taxa de sucesso na inserção do cateter através da cérvix, ao tipo de cateter e, também, quanto às características corporais das matrizes utilizadas, dificultando extrapolações de recomendação do uso da IAU em leitoas. Considerando os indícios de que tais características podem influenciar ou, até mesmo, determinar o sucesso de aplicação da técnica, ainda há necessidade de compreender a influência desses fatores para que a técnica possa ser aprimorada e posteriormente aplicada. Leitoas representam cerca de 15 a 20% do grupo de cobertura e viabilizar a IAU nessa categoria pode otimizar os processos de inseminação nas granjas. A abordagem realizada nessa revisão traz aspectos que podem auxiliar na estruturação de futuros estudos para aprimorar a IAU em leitoas e permitir seu emprego em granjas comerciais.(AU)

Reproductive performance of fixed-time artificial insemination in swine and factors for the technology success / Desempenho reprodutivo da inseminação artificial em tempo fixo em suínos e fatores para o sucesso da tecnologia

Fixed-time artificial insemination (FTAI) is a reproductive technology that aids in obtaining an appropriate time to perform single artificial insemination (AI), thus reducing the number of inseminations per sow bred. FTAI protocols can either be based on estrus detection or day of weaning, aiming to synchronize ovulation using ovulation inducers. The protocols involving estrus detection usually employ porcine luteinizing hormone (pLH) as an inducer and, in general, satisfactory reproductive performance is observed. For protocols based on weaning day, the main hormone used is analog of gonadotropin-releasing hormone such as triptorelin and buserelin. Regardless of the protocol, the number of piglets born is usually not affected by FTAI. However, a possible compromise in the farrowing rate should be considered. The FTAI in gilts requires progestogen treatment for estrus synchronization, increasing the labor requirement and cost of protocol. Some of the benefits of FTAI are a reduced number of semen doses required, advantage of planning the breeding time and; consequently, optimizing labor involved. However, the limitations include a slight reduction in the fertility index due to the compromised farrowing rate in some cases, costs incurred by following the protocol, and difficulty in measuring all the conceptual benefits under commercial conditions. The aim of this review is to approach the reproductive performance of the current protocols of FTAI, considering the benefits and limitations of this technology in swine production.(AU)

A inseminação artificial em tempo fixo (IATF) surge como uma biotecnologia para definir o melhor momento para realizar uma única IA, reduzindo o número de células espermáticas por fêmea inseminada. Os protocolos de IATF podem se basear na detecção do estro ou na data de desmame e têm como objetivo sincronizar a ovulação a partir do uso de indutores da ovulação. Protocolos baseados na detecção de estro comumente utilizam o hormônio luteinizante suíno (pLH) como indutor e, de maneira geral, resultados satisfatórios têm sido observados quanto à performance reprodutiva. No caso dos protocolos baseados na data de desmame, os principais hormônios utilizados são os análogos do hormônio liberador de gonadotrofina: triptorelina e buserelina. Independentemente do protocolo, o número de nascidos totais normalmente não é afetado pelo uso da IATF. Porém, um possível comprometimento na taxa de parto deve ser considerado. Já a aplicação da IATF em leitoas requer o fornecimento de um progestágeno, para sincronização do estro, aumentando o manejo e o custo do protocolo. A IATF pode proporcionar diversos benefícios para a indústria suinícola, uma vez que é possível reduzir o número de doses de sêmen produzidas, melhorar o planejamento de coberturas e, consequentemente, otimizar a mão de obra. No entanto, essa biotecnologia apresenta limitações devendo ser considerado a redução nos dados de fertilidade, uma vez que a taxa de parto pode ser comprometida em alguns casos e, o custo do protocolo e a dificuldade de estimar todos os benefícios conceituais da IATF quando aplicada sob condições comerciais. O objetivo dessa revisão é abordar o desempenho reprodutivo dos mais recentes protocolos de IATF, considerando os benefícios e as limitações dessa tecnologia na produção de suínos.(AU)

Atualizações na avaliação andrológica em suínos / Updates in breeding soundness evaluation in swine

O exame andrológico é uma ferramenta importante para o manejo reprodutivo do rebanho, uma vez que compreende etapas como, anamnese, exame clínico geral e dos órgãos genitais, avaliação do comportamento sexual, além da avaliação da produção, motilidade e morfologia espermática. Apesar de apresentar uma estrutura simples, o exame andrológico deve ser bem executado em cada uma de suas etapas, pois por meio desse procedimento é possível identificar precocemente e remover do rebanho machos inaptos à reprodução. Sendo assim, é fundamental ter conhecimento sobre as características anatômicas e fisiológicas básicas da espécie, e sobre os avanços obtidos em andrologia suína nos últimos anos para realizar adequadamente o exame e, consequentemente, beneficiar toda a cadeia produtiva de suínos.

Breeding soundness evaluation is a valuable tool for herd management, since the exam includes anamnesis, general and physical exams, boar sexual behavior, and the traditional exams such as sperm production, sperm motility and sperm morphology evaluations. Regardless of its easy execution, examinations must be well performed, considering every step, since this procedure allows the early identification of boars unsuitable for reproduction and their removal from a herd. Thus, it is essential to know about anatomic and physiologic aspects of this species and the updates in swine breeding soundness over the last years, in order to perform this exam properly and, consequently, bringing benefits for whole swine production.

Atualizações na avaliação andrológica em suínos / Updates in breeding soundness evaluation in swine

O exame andrológico é uma ferramenta importante para o manejo reprodutivo do rebanho, uma vez que compreende etapas como, anamnese, exame clínico geral e dos órgãos genitais, avaliação do comportamento sexual, além da avaliação da produção, motilidade e morfologia espermática. Apesar de apresentar uma estrutura simples, o exame andrológico deve ser bem executado em cada uma de suas etapas, pois por meio desse procedimento é possível identificar precocemente e remover do rebanho machos inaptos à reprodução. Sendo assim, é fundamental ter conhecimento sobre as características anatômicas e fisiológicas básicas da espécie, e sobre os avanços obtidos em andrologia suína nos últimos anos para realizar adequadamente o exame e, consequentemente, beneficiar toda a cadeia produtiva de suínos.(AU)

Breeding soundness evaluation is a valuable tool for herd management, since the exam includes anamnesis, general and physical exams, boar sexual behavior, and the traditional exams such as sperm production, sperm motility and sperm morphology evaluations. Regardless of its easy execution, examinations must be well performed, considering every step, since this procedure allows the early identification of boars unsuitable for reproduction and their removal from a herd. Thus, it is essential to know about anatomic and physiologic aspects of this species and the updates in swine breeding soundness over the last years, in order to perform this exam properly and, consequently, bringing benefits for whole swine production.(AU)

Métodos de avaliação de reprodutores em centrais de inseminação artificial de suínos: foco no exame clínico / Evaluation methods of boars in artificial insemination studs: focus on clinical examination

O exame andrológico de reprodutores suínos tem grande importância no que se refere a características dos animais e qualidade dos ejaculados por esses produzidos. Este exame compreende a avaliação da saúde geral do plantel, com foco principal nas características reprodutivas, sendo indicada a sua realização a cada 30-50 dias. Dentre as avaliações realizadas no exame andrológico, incluem-se a anamnese, o exame físico e o comportamento sexual dos reprodutores. A anamnese é definida como a obtenção do histórico dos animais e de informações sobre as condições de criação dos mesmos. O exame físico consiste na inspeção e palpação de diferentes estruturas, incluindo a avaliação do animal como um todo, de membros locomotores, cascos e órgãos reprodutivos. A avaliação do comportamento sexual dos reprodutores inclui o acompanhamento dos animais no momento da monta no manequim. Vale ressaltar que um único exame andrológico não é suficiente para determinar a capacidade produtiva e fecundante do reprodutor e que a periodicidade da realização das avaliações é o ponto chave para manter a alta qualidade nas centrais de inseminação artificial.

Breeding soundness is important regarding boar characteristics and quality of their ejaculates. This exam includes herd general health evaluation focusing mainly on reproductive aspects, and it is indicated to perform it every 30-50 days. Breeding soundness evaluation comprises anamnesis, physical exam and boar sexual behavior. Anamnesis is defined as the obtaining history of the animals and information about housing conditions. Physical examination consists in inspection and palpation of different structures, including evaluation of whole animal, legs, feet and reproductive organs. Sexual behavior evaluation includes monitoring the animals at the time they are mounting a collection dummy. It is important to note that a single breeding soundness examination is not sufficient to determine boar productive and reproductive capacity and, the periodicity of the evaluation is the key to maintain high quality in boar studs.

Métodos de avaliação de reprodutores em centrais de inseminação artificial de suínos: foco no exame clínico / Evaluation methods of boars in artificial insemination studs: focus on clinical examination

O exame andrológico de reprodutores suínos tem grande importância no que se refere a características dos animais e qualidade dos ejaculados por esses produzidos. Este exame compreende a avaliação da saúde geral do plantel, com foco principal nas características reprodutivas, sendo indicada a sua realização a cada 30-50 dias. Dentre as avaliações realizadas no exame andrológico, incluem-se a anamnese, o exame físico e o comportamento sexual dos reprodutores. A anamnese é definida como a obtenção do histórico dos animais e de informações sobre as condições de criação dos mesmos. O exame físico consiste na inspeção e palpação de diferentes estruturas, incluindo a avaliação do animal como um todo, de membros locomotores, cascos e órgãos reprodutivos. A avaliação do comportamento sexual dos reprodutores inclui o acompanhamento dos animais no momento da monta no manequim. Vale ressaltar que um único exame andrológico não é suficiente para determinar a capacidade produtiva e fecundante do reprodutor e que a periodicidade da realização das avaliações é o ponto chave para manter a alta qualidade nas centrais de inseminação artificial.(AU)

Breeding soundness is important regarding boar characteristics and quality of their ejaculates. This exam includes herd general health evaluation focusing mainly on reproductive aspects, and it is indicated to perform it every 30-50 days. Breeding soundness evaluation comprises anamnesis, physical exam and boar sexual behavior. Anamnesis is defined as the obtaining history of the animals and information about housing conditions. Physical examination consists in inspection and palpation of different structures, including evaluation of whole animal, legs, feet and reproductive organs. Sexual behavior evaluation includes monitoring the animals at the time they are mounting a collection dummy. It is important to note that a single breeding soundness examination is not sufficient to determine boar productive and reproductive capacity and, the periodicity of the evaluation is the key to maintain high quality in boar studs.(AU)

Insertion of an intrauterine catheter for post-cervical artificial insemination in gilts: a case report / Introdução do cateter intrauterino para inseminação artificial pós-cervical em leitoas: um relato de caso

The aim of this case report was to characterize the insertion of an intrauterine catheter (IC) in gilts to perform post-cervical artificial insemination (PCAI). Attempts to insert ICs through the cervixes of gilts were performed using either a standard sow foam tip catheter (SFC; n = 25) or a standard gilt foam tip catheter (GFC; n = 25). The percentage of passage, depth and degree of difficulty for insertion were evaluated. The average depth of IC insertion was 10.1 ± 1.3 cm for SFC and 10.0 ± 1.2 cm for GFC. For both catheters, insertion depths of greater than 10 cm were achieved in the first insemination in 44% of gilts. Insertion depths of greater than 6 cm were observed in 72% and 60% of attempts using SFC and GFC, respectively. A high level of difficulty for IC insertion was observed, mainly while using GFC. In conclusion, the routine application of PCAI in gilts on swine farms remains limited by the low success rate for intrauterine catheter insertion. In further studies, we suggest evaluating reproductive performance using low insertion depths for PCAI in gilts, and assessing the use of sow foam tip catheter as a guide to introduce the IC.(AU)

O objetivo deste relato de caso foi caracterizar a inserção de um cateter intrauterino (IC) em leitoas para realização da inseminação pós-cervical (PCAI). Tentativas de inserir o IC através da cérvix em leitoas foram realizadas usando um cateter de ponta de espuma padrão utilizado para porcas (SFC; n=25) e um cateter de ponta de espuma padrão utilizado para leitoas (GFC; n=25). O percentual de passagem, profundidade e grau de dificuldade para a inserção do IC através da cérvix foram avaliados. A profundidade média de inserção do IC foi 10,1 ± 1,3 cm para SFC e 10,0 ± 1,2 cm para GFC. Para ambos cateteres, profundidades maiores que 10 cm para a inserção do IC na primeira inseminação foram possíveis em 44% das leitoas. Inserções maiores que 6 cm foram observadas em 72% e 60% das tentativas utilizando SFC e GFC, respectivamente. Alto nível de dificuldade para a inserção do IC foi observada, principalmente para GFC. A aplicação da PCAI em leitoas, na rotina prática em granjas de suínos, permanece limitada pela baixa taxa de sucesso para a inserção do IC. Em estudos futuros, sugerimos o uso de menor profundidade de inserção para realizar a PCAI em leitoas e o uso de cateteres de porcas como guia para introduzir o cateter intrauterino.(AU)

Proposal of equations for predicting post-farrowing sow weigh

Background: Body condition score is used widely in swine production to ensure adequate nutritional levels in sows during gestation and lactation. However, body condition score is not a gold standard for the estimation of nutritional requirements in sows. Post-farrowing sow body weight assessment might serve as a useful approach for the better adjustment of the nutritional requirements during lactation; however, this approach is time-consuming, requires labor, and might result in detrimental effects on the sow behavior and welfare. The objective of the present study, therefore, was to formulate prediction equations for the estimation of post-farrowing sow weight.Materials, Methods & Results: Seven equations were formulated for predicting the post-farrowing sow body weight, by using the data from three databases, which comprised a total 522 sows (434 gilts and 88 multiparous). The sows were weighed on Day 112 of gestation and after farrowing within 12 h. The piglets birth weight was recorded within 24 h after farrowing. The equations were formulated considering all the parity orders. While formulating the equations, the following five variables were used: pre-farrowing body weight, piglets born, litter weight, the interval between pre-farrowing weighing and farrowing (in days), and the total feed intake between pre-farrowing and post-farrowing weighing. The seven models were compared using the sets of possible predictors through regression with the best subsets procedure (Minitab for Windows, v. 18). Equations (EQ) 1, 2, and 4 were validated with a database comprising 732 sows (parity orders: 1-5). The females were weighed on Day 107 of gestation and within 24 h after farrowing. The predicted weights estimated by EQ 2 and 4 (215.4 ± 34.3 kg and 216.7 ± 34.4 kg, respectively) did not significantly differ from the observed weight (216.8 ± 34.6 kg) [P > 0.05].[...](AU)

Proposal of equations for predicting post-farrowing sow weigh

Background: Body condition score is used widely in swine production to ensure adequate nutritional levels in sows during gestation and lactation. However, body condition score is not a gold standard for the estimation of nutritional requirements in sows. Post-farrowing sow body weight assessment might serve as a useful approach for the better adjustment of the nutritional requirements during lactation; however, this approach is time-consuming, requires labor, and might result in detrimental effects on the sow behavior and welfare. The objective of the present study, therefore, was to formulate prediction equations for the estimation of post-farrowing sow weight.Materials, Methods & Results: Seven equations were formulated for predicting the post-farrowing sow body weight, by using the data from three databases, which comprised a total 522 sows (434 gilts and 88 multiparous). The sows were weighed on Day 112 of gestation and after farrowing within 12 h. The piglets birth weight was recorded within 24 h after farrowing. The equations were formulated considering all the parity orders. While formulating the equations, the following five variables were used: pre-farrowing body weight, piglets born, litter weight, the interval between pre-farrowing weighing and farrowing (in days), and the total feed intake between pre-farrowing and post-farrowing weighing. The seven models were compared using the sets of possible predictors through regression with the best subsets procedure (Minitab for Windows, v. 18). Equations (EQ) 1, 2, and 4 were validated with a database comprising 732 sows (parity orders: 1-5). The females were weighed on Day 107 of gestation and within 24 h after farrowing. The predicted weights estimated by EQ 2 and 4 (215.4 ± 34.3 kg and 216.7 ± 34.4 kg, respectively) did not significantly differ from the observed weight (216.8 ± 34.6 kg) [P > 0.05].[...]

Reproductive performance, retention rate, and age at the third parity according to growth rate and age at first mating in the gilts with a modern genotype

Background: Gilts represent the largest category (18-20%) of female pigs in a breeding herd. Under field conditions, the amplitude of growth rate and age at the first mating of gilts are remarkably higher than the recommendations made by the genetic companies. There are several studies that have considered the management of these animals starting from their introduction to the herd till the mating. It has been noted that the genetic selection constantly promotes evolution that may change certain traits of these animals. However, there is a lack of the studies that evaluate the management strategies suitable for the modern sows. This study, therefore, aimed to evaluate the effect of age and growth rate of gilts at the first mating on productive performance and retention rate until the third farrowing. Materials, Methods & Results: The study was performed in a gilt development unit (GDU) with a breeding stock capacity of 1000 females and a goal of 90 gilts mating per week. The groups were retrospectively created according to age ( 0.05) on farrowing rate after first, second, and third mating. The total number of piglets born in the three first farrowing and over three parities were not affected (P > 0.05) by the age and GR at first mating. The retention rate until the third farrowing of gilts inseminated with more than 210 days of age was approximately 7% greater than in the gilts mated younger; however, no statistical difference (P > 0.05) was detected. An effect of the age at the first mating was observed in the age to reach the third farrowing. Gilts mated with less than 210 and more than 210 days reached the third farrowing, respectively, at 604.5 ±1.9 and 625.1 ± 2.7 days of age (P < 0.001). Discussion: With a minimum GR of 550 g/d, 180 days of age, and at least 130 kg of weight, gilts are eligible to be inseminated without impairing their litter size, farrowing, and retention rate until the third parity. [...]

Reproductive performance, retention rate, and age at the third parity according to growth rate and age at first mating in the gilts with a modern genotype

Background: Gilts represent the largest category (18-20%) of female pigs in a breeding herd. Under field conditions, the amplitude of growth rate and age at the first mating of gilts are remarkably higher than the recommendations made by the genetic companies. There are several studies that have considered the management of these animals starting from their introduction to the herd till the mating. It has been noted that the genetic selection constantly promotes evolution that may change certain traits of these animals. However, there is a lack of the studies that evaluate the management strategies suitable for the modern sows. This study, therefore, aimed to evaluate the effect of age and growth rate of gilts at the first mating on productive performance and retention rate until the third farrowing. Materials, Methods & Results: The study was performed in a gilt development unit (GDU) with a breeding stock capacity of 1000 females and a goal of 90 gilts mating per week. The groups were retrospectively created according to age ( 0.05) on farrowing rate after first, second, and third mating. The total number of piglets born in the three first farrowing and over three parities were not affected (P > 0.05) by the age and GR at first mating. The retention rate until the third farrowing of gilts inseminated with more than 210 days of age was approximately 7% greater than in the gilts mated younger; however, no statistical difference (P > 0.05) was detected. An effect of the age at the first mating was observed in the age to reach the third farrowing. Gilts mated with less than 210 and more than 210 days reached the third farrowing, respectively, at 604.5 ±1.9 and 625.1 ± 2.7 days of age (P < 0.001). Discussion: With a minimum GR of 550 g/d, 180 days of age, and at least 130 kg of weight, gilts are eligible to be inseminated without impairing their litter size, farrowing, and retention rate until the third parity. [...](AU)

Prepartum progestagen supplementation in swine: a strategy to facilitate piglet care and prevent early parturition / Suplementação de progestágenos no pré-parto em suínos: estratégia para facilitar assistência aos leitões e evitar partos precoces

Gestation length in swine has a considerable amplitude and both early and delayed parturition are common. This variation increases the occurrence of unassisted farrowing and could lead to a wide-ranging age at weaning for piglets born from one batch. Supervision of sow parturition is crucial to reduce mortality of neonate piglets. To facilitate assistance, induction of farrowing using prostaglandin F2α (PGF) has been widely used in batch farrowing systems, whereby synchronization would concentrate the time of farrowing, allowing for better organization of employees. However, a viable alternative method that can be implemented to manage farrowing is to sustain high progestagen levels in the final days of gestation and, consequently, prevent early parturition. Efficient techniques to delay farrowing such as using oral progestagen supplementation have been previously described, but are only recently being considered for commercial use. The present manuscript reviews publications regarding delaying parturition and discusses the use of intravaginal devices (IVDs) containing progestagen. There is limited data addressing the effect of progestagen treatment during gestation on productive and reproductive performance. Therefore, future studies should focus on improving synchronization protocols following progestagen supplementation and evaluating piglet viability and sow fertility, before widely using progestagen supplementation to manipulate parturition.(AU)

Como a duração da gestação de suínos pode ter ampla variação, é comum a ocorrência de partos antecipados ou gestações prolongadas. Isso aumenta as chances de partos sem assistência e leva a uma grande variação de idade dos leitões dentro do lote de produção. Portanto, a supervisão do parto é indispensável para reduzir as perdas neonatais. Para facilitar o auxílio aos leitões, a indução do parto com prostaglandina F2α (PGF) é eficaz e amplamente utilizada, sendo indicada para concentrar os partos em momentos mais adequados, preferencialmente durante o horário com maior disponibilidade de colaboradores. Uma alternativa viável é manipular o momento do parto, através da manutenção de níveis plasmáticos elevados de progestágeno durante o final da gestação, a fim de evitar partos antecipados. Formas eficientes de evitar o parto através de suplementação oral de progestágenos foram descritas há décadas, mas apenas recentemente tem sido cogitada a utilização comercial. A presente revisão aborda estudos disponíveis na literatura relacionados ao protelamento do parto, incluindo a utilização de dispositivos intravaginais (DIVs) impregnados com progestágeno. São poucos os dados disponíveis relacionados ao uso de progestágenos na gestação com índices produtivos e reprodutivos. Portanto, alguns pontos ainda devem ser melhor avaliados, especialmente com relação à determinação da sincronia dos partos após o fim da suplementação com progestágenos, à viabilidade dos neonatos e à fertilidade subsequente das fêmeas antes da ampla adoção desta técnica.(AU)

The influence of air contact on the quality of extended boar semen

Background: The extensive use of artificial insemination in the swine industry emphasizes the need for distribution of good quality semen doses by the artificial insemination centers. A factor that could modify seminal quality is the contact of extended semen with environmental air. However, only few studies have investigated the effects of air presence on semen parameters. Thus, the aim of the present study was to evaluate the influence of different amounts of air on porcine semen quality during the storage period. Materials, Methods & Results: Four ejaculates from five sexually mature boars were used. Each ejaculate (n = 20) was isothermically diluted (30 x 106 /mL) in a BTS-extender and assigned to three groups differing on the amount of air entrapped within the polystyrene tubes (100 mL). In group AIR-0 the tubes were completely filled with extended semen (0% air); in group AIR-25, 75% of the tube volume was filled with extended semen and 25% with air; in group AIR-50, 50% of the tube volume was filled with extended semen. The semen doses were stored at 17.3 ± 0.5ºC for 120 h. The motility parameters were assessed at 24, 72 and 120 h of storage using a CASA system. The evaluation of acrosomal integrity was performed by examining formalin-fixed samples under phase-contrast microscopy (1000 x) at 72 and 120 h of storage. The pH was measured at 24, 48, 72, and 120 h of [...](AU)

The influence of air contact on the quality of extended boar semen

Background: The extensive use of artificial insemination in the swine industry emphasizes the need for distribution of good quality semen doses by the artificial insemination centers. A factor that could modify seminal quality is the contact of extended semen with environmental air. However, only few studies have investigated the effects of air presence on semen parameters. Thus, the aim of the present study was to evaluate the influence of different amounts of air on porcine semen quality during the storage period. Materials, Methods & Results: Four ejaculates from five sexually mature boars were used. Each ejaculate (n = 20) was isothermically diluted (30 x 106 /mL) in a BTS-extender and assigned to three groups differing on the amount of air entrapped within the polystyrene tubes (100 mL). In group AIR-0 the tubes were completely filled with extended semen (0% air); in group AIR-25, 75% of the tube volume was filled with extended semen and 25% with air; in group AIR-50, 50% of the tube volume was filled with extended semen. The semen doses were stored at 17.3 ± 0.5ºC for 120 h. The motility parameters were assessed at 24, 72 and 120 h of storage using a CASA system. The evaluation of acrosomal integrity was performed by examining formalin-fixed samples under phase-contrast microscopy (1000 x) at 72 and 120 h of storage. The pH was measured at 24, 48, 72, and 120 h of [...]

Influência do peso ao nascimento e de lesões orais, umbilicais ou locomotoras no desempenho de leitões lactentes / Influence of birth weight and of oral, umbilical or limb lesions on performance of suckling piglets

Background: Several factors influence the survival and performance of piglets during lactation. Birth weight appears as one of the most important factors affecting the survival of piglets, mainly during the first week after birth. There is also a positive correlation between birth weight and weaning weight. In addition to the birth weight, the presence of oral, umbilical or limb lesions can compromise the performance of suckling piglets, affecting their weaning weight. Although limb lesions are common among suckling piglets, there is little information associating these lesions with piglet performance. The aim of this study was to evaluate the influence of birth weight as well as of oral, umbilical or limb lesions on mortality and performance of piglets at 7, 14 and 21 days of age. Materials, Methods & Results: The study was performed in a pig farm located in Rio Grande do Sul State, Brazil. A total of 2004 piglets were evaluated for the presence of oral (at the first day of life), umbilical and limb lesions (at the end of first and second weeks of life). Piglets were weighed at birth and at 7, 14 and 21 of age. Overall, birth and weaning weights were respectively 1546 ± 8.2 g and 5837 ± 32.0 g (means ± SEM). Mortality rate from birth to weaning was 4.7% and 79.0% of deaths occurred during the first week of life. Piglets with birth weight until 1200g showed pre-weaning mortality higher (P < 0.05) than heavier piglets (13.0% - 47/362 vs 2.9% - 48/1642). The occurrence of oral lesions at the first day of life did not affect the survival of piglets until weaning. Birth weight was positively correlated with weaning weight (r = 0.515; P < 0.001). The difference between lighter (> 600 g - 900 g) and heavier piglets (> 2100 g) was 1477 g at birth and 3229 g at weaning. Occurrence of oral or umbilical lesions did not compromise the piglet performance. The presence of limb lesions affected negatively the weaning weight (P < 0.05), mainly when lesions were present in the second week of life. Body weight at 21 d of age was higher (P < 0.05) in piglets without lesions (5957 ± 30.4 g) than in piglets with lesions at the second week (5417 ± 125.9 g) or in those with lesions at both first and second weeks of life (5218 ± 104.2 g). Discussion: The mortality rate of 4.7% observed during lactation is lower than that observed in other reports. The occurrence of a low mortality rate in this study may refl ect the continuing presence of employees in facilities and intensive care provided to the piglets at farrowing and during the suckling period. In agreement with other studies, lighter piglets presented higher pre-weaning mortality than heavier piglets, and 70.5% of deaths occurred in piglets weighing between 600 g and 1500 g. Birth weight was also shown to be a determinant factor for weight gain until weaning, confirming the results of previous studies. Piglets with a low body weight at birth have low body energy reserves and a reduced ability to maintain their body temperature. These aspects result in a lower colostrum and milk intake, a reduction of passive immunity and undernourishment, resulting in a lower survival and pre-weaning performance. It has been shown that most of limb lesions may cause only discomfort to piglets, but can also act as a gateway to infectious pathogens which result in relevant lesions. The reduction of body weight observed in piglets which had limb lesions during the second week of life may be associated with the fact that from this week onwards there is an increase in daily weight gain of piglets, then limiting their potential body weight gain if lesions are present during this phase.

Desempenho de leitegadas após a uniformização cruzada de leitões entre fêmeas de ordem de parto 1 e 5 / Performance of litter after crossfostering of piglets between females of parity order 1 and 5

Crossfostering is the transference of piglets to either equalize litter size or to formation of homogeneous litters according to the birth weight. It is used in order to improve survival rate and weight gain of piglets during lactation. Several aspects influence the results of crossfostering, as the moment when this management is performed, size of the piglets and parity order (PO) of biological and adoptive dams. Crossfostering should be performed, preferably between six and 24 h after farrowing, before teat order has been established and so that piglets can absorb the maximum of colostrum immunoglobulins from their biological dams. Performance and viability of piglets during lactation depends on the quality of colostrum and milk production of biological and adoptive dam, which varies according to PO. The aim of the experiment was to assess the performance of biological and adopted piglets crossfostered in PO 1 and PO 5 females.[...](AU)

Desempenho de leitegadas após a uniformização cruzada de leitões entre fêmeas de ordem de parto 1 e 5 / Performance of litter after crossfostering of piglets between females of parity order 1 and 5

Crossfostering is the transference of piglets to either equalize litter size or to formation of homogeneous litters according to the birth weight. It is used in order to improve survival rate and weight gain of piglets during lactation. Several aspects influence the results of crossfostering, as the moment when this management is performed, size of the piglets and parity order (PO) of biological and adoptive dams. Crossfostering should be performed, preferably between six and 24 h after farrowing, before teat order has been established and so that piglets can absorb the maximum of colostrum immunoglobulins from their biological dams. Performance and viability of piglets during lactation depends on the quality of colostrum and milk production of biological and adoptive dam, which varies according to PO. The aim of the experiment was to assess the performance of biological and adopted piglets crossfostered in PO 1 and PO 5 females.[...]

Insertion of an intrauterine catheter for post-cervical artificial insemination in gilts: a case report / Introdução do cateter intrauterino para inseminação artificial pós-cervical em leitoas: um relato de caso

The aim of this case report was to characterize the insertion of an intrauterine catheter (IC) in gilts to perform post-cervical artificial insemination (PCAI). Attempts to insert ICs through the cervixes of gilts were performed using either a standard sow foam tip catheter (SFC; n = 25) or a standard gilt foam tip catheter (GFC; n = 25). The percentage of passage, depth and degree of difficulty for insertion were evaluated. The average depth of IC insertion was 10.1 ± 1.3 cm for SFC and 10.0 ± 1.2 cm for GFC. For both catheters, insertion depths of greater than 10 cm were achieved in the first insemination in 44% of gilts. Insertion depths of greater than 6 cm were observed in 72% and 60% of attempts using SFC and GFC, respectively. A high level of difficulty for IC insertion was observed, mainly while using GFC. In conclusion, the routine application of PCAI in gilts on swine farms remains limited by the low success rate for intrauterine catheter insertion. In further studies, we suggest evaluating reproductive performance using low insertion depths for PCAI in gilts, and assessing the use of sow foam tip catheter as a guide to introduce the IC.

O objetivo deste relato de caso foi caracterizar a inserção de um cateter intrauterino (IC) em leitoas para realização da inseminação pós-cervical (PCAI). Tentativas de inserir o IC através da cérvix em leitoas foram realizadas usando um cateter de ponta de espuma padrão utilizado para porcas (SFC; n=25) e um cateter de ponta de espuma padrão utilizado para leitoas (GFC; n=25). O percentual de passagem, profundidade e grau de dificuldade para a inserção do IC através da cérvix foram avaliados. A profundidade média de inserção do IC foi 10,1 ± 1,3 cm para SFC e 10,0 ± 1,2 cm para GFC. Para ambos cateteres, profundidades maiores que 10 cm para a inserção do IC na primeira inseminação foram possíveis em 44% das leitoas. Inserções maiores que 6 cm foram observadas em 72% e 60% das tentativas utilizando SFC e GFC, respectivamente. Alto nível de dificuldade para a inserção do IC foi observada, principalmente para GFC. A aplicação da PCAI em leitoas, na rotina prática em granjas de suínos, permanece limitada pela baixa taxa de sucesso para a inserção do IC. Em estudos futuros, sugerimos o uso de menor profundidade de inserção para realizar a PCAI em leitoas e o uso de cateteres de porcas como guia para introduzir o cateter intrauterino.