Intervenção manual ao parto em suínos: estudo comparativo do desempenho reprodutivo, longevidade e produção de leite

O experimento 1 caracterizou as fêmeas com intervenção manual no parto, além de avaliar os efeitos que podem ocorrer na sua vida reprodutiva ao longo de 1 ano. Foram coletados dados do parto de 4.121 fêmeas, informações anteriores ao parto e registrados os motivos e momentos de remoção. Os animais foram divididos em grupo Controle (n=3.271) e Intervenção (n=850). O percentual de fêmeas submetidas à intervenção manual no parto foi de 20,6%. Houve aumento na distribuição de intervenções na ordem de parto (OP) acima de 5 e no verão (P0,05). Foi verificada diferença na média de OP (3,6 e 4,7), duração do parto (208,3 e 224,6 min), leitões nascidos vivos (11,9 e 11,6), natimortos (0,3 e 0,6) e no percentual de fêmeas com natimortos (28,6 e 38,8%) nos grupos Controle e Intervenção, respectivamente. A remoção geral foi maior no grupo Intervenção (P=0,001) e antes da IA por motivos não reprodutivos (

Managing reproduction in hyperprolific sow herds

The rearing of large litters from hyperprolific sows is a characteristic of modern genotypes. However, these sows have body and reproductive characteristics that differentiate them from the genotypes of the past decades, making it necessary to adopt different management strategies. This review describes the main care and challenges associated with the hyperprolificity of sows during the period in which replacement gilts are selected, along with gestation, parturition, lactation, and the weaning-estrus interval. It describes the challenges that these sows’ piglets will face during the lactation period and includes some strategies adopted to develop these surplus piglets. In addition, it identifies areas where more research is needed to understand the reproductive management of modern genotypes

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.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

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.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

Uso de tônus e ecogenicidade testiculares na identificação de reprodutores suínos com baixa qualidade espermática

This study aimed to evaluate the use of some testicular traits to identify boars with low sperm morphological quality. The consistency (scores from 1 to 5), tone with tonometry (mm), parenchyma echogenicity and heterogeneity with ultrasound (pixel) were assessed in 402 mature boars (18.5 months on average). Sperm abnormality thresholds (≤ 25% of total sperm abnormalities, ≤ 5% of heads, acrosome, neck or midpiece defects, ≤ 10% tail defects, and 15% cytoplasmic droplets) were used to classify boars as approved or disapproved. Three classes of testicular traits were formed (extremely low and high values, approximately 15% each, were kept in separated classes). When the traits were individually evaluated, fewer boars were approved if the echogenicity or heterogeneity were high, or if the tone was rigid. When evaluated in combination, the interaction between heterogeneity and tone, and between heterogeneity and echogenicity were significant. The high heterogeneity combined with soft tone or with hypo-echogenicity resulted in lower approval of boars. Tonometry and ultrasonography have a moderate potential to be included in breeding soundness examination of boars. When combined, they provide more reliable information about the impact of testicular parenchymal alterations on morphology of sperm cells.O estudo objetivou avaliar o uso de características testiculares para identificar reprodutores com baixa qualidade de morfologia espermática. A consistência (escore de 1 a 5), o tônus por tonometria (mm), a ecogenicidade e a heterogeneidade do parênquima testicular por ultrassonografia (pixel) foram avaliados em 402 machos suínos maduros (18,5 meses, em média). Limiares máximos de anormalidades espermáticas (≤ 25% de defeitos totais, ≤ 5% de defeitos de cabeça, acrossoma, colo e peça intermediária, ≤ 10% de defeitos de cauda e 15% de gota citoplasmática) foram utilizados para classificar os machos como aprovados ou reprovados. Três classes de características testiculares foram formadas (valores extremamente baixos e altos, aproximadamente 15% em cada, foram mantidos em classes separadas). Quando as características testiculares foram avaliadas individualmente, menos machos foram aprovados se a ecogenicidade ou a heterogeneidade foram altas, ou se o tônus era rígido. Quando avaliadas em combinação, a interação entre heterogeneidade e tônus e a interação entre heterogeneidade e ecogenicidade foram significativas. A alta heterogeneidade combinada com testículos flácidos ou com testículos hipoecogênicos resultou em menor aprovação de cachaços. A tonometria e a ultrassonografia possuem potencial moderado para serem incluídas no exame andrológico de cachaços. Quando combinadas, as técnicas fornecem uma informação mais consistente do impacto das alterações do parênquima testicular na morfologia das células espermáticas

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 0.05). 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

Reflexo do período de lactação na produtividade de porcas primíparas e multíparas

O período de lactação é um importante aspecto na produtividade de granjas suínas, já que influencia diretamente os dias do ciclo produtivo e a fisiologia da reprodução das matrizes. O objetivo deste trabalho foi verificar o efeito do período de lactação (PL) no intervalo desmame-estro (IDE), taxa de parição ajustada (TPA) e tamanho da leitegada subseqüente (TLS) em um rebanho comercial. Dados referentes a 19.846 desmames realizados em 2002 e 2003 foram coletados a partir do programa de gerenciamento de dados PigCHAMP  ®. Para multíparas, PL de 15 dias foram suficientes para a estabilização do IDE (4,8 ± 2,8 dias). As primíparas apresentaram IDE mais curto com PL de 20-24 dias (4,7 ± 2,5 dias). Houve redução na TPA somente em PL inferiores a 10 dias, tanto em primíparas como em multíparas. Para primíparas, períodos de lactação a partir de 17 dias resultaram em estabilização do TLS. As porcas multíparas apresentaram aumento gradativo do TLS até 15-16 dias de lactação, quando houve estabilização. A duração da lactação influencia o desempenho reprodutivo subseqüente em primíparas e multíparas suínas. Períodos de lactação de duas semanas podem ser adequados para multíparas, mas três semanas seriam necessárias para melhor desempenho das primíparas

In vitro performance and in vivo fertility of antibiotic-free preserved boar semen stored at 5 °C

Background: Hypothermic preservation of boar semen is considered a potential method for omitting antibiotics from insemination doses, thereby contributing to the global antibiotic resistance defence strategy. The main challenges are chilling injury to spermatozoa and bacterial growth during semen storage leading to reduced fertility. Objectives: To examine chilling injury and the number and type of bacteria in boar semen stored at 5 °C in the absence of antibiotics, and to assess the applicability of hypothermic semen storage under field conditions. Material and methods: Boar ejaculates were extended with AndroStar® Premium, stored at 17 °C with and at 5 °C without antibiotics and tested for functional sperm parameters by flow cytometry. Raw semen and extended samples were investigated bacteriologically. Fertility was evaluated after once-daily inseminations of 194 sows in a field study. Results: Lethal sperm damage assessed by motility and membrane integrity was low throughout storage in both experimental groups. Sublethal chilling effects based on the decrease of viable spermatozoa with low membrane fluidity were higher (P 0.05) between sow groups inseminated with semen stored antibiotic-free at 5 °C and semen stored at 17 °C with antibiotics. Conclusion: Despite subtle chilling effects and low bacterial numbers, antibiotic-free hypothermic storage of boar semen offers the possibility to reduce the use of antibiotics in pig insemination. However, strict sanitary guidelines must be maintained and further evidence of efficiency under field conditions is considered desirable

Weight gain of pregnant sows associated with their behavior in pens and to the uniformity of piglets

O objetivo deste trabalho foi avaliar a associação do comportamento de fêmeas suínas mantidas em baias coletivas, durante a alimentação, com o ganho de peso no último mês de gestação, e determinar se a uniformidade de peso das leitegadas é influenciada pelo ganho de peso das fêmeas. As fêmeas (n = 699) foram separadas em três grupos de ordem de parto (OP): 2, 3–5 e 6–9. Cada grupo de OP foi dividido em três subgrupos com percentual de ganho de peso: baixo, médio e alto. Fêmeas de OP 6–9 tiveram mais leitões com peso menor que 1.200 g e maior coeficiente de variação desse peso, em comparação às de OP 2. O menor peso de leitões e o maior número de leitões com peso<1.200 g foram observados no subgrupo de peso baixo. Houve correlação do percentual de ganho de peso na gestação com o número de vezes que a fêmea esteve em pé no cocho (r = 0,669) e com o número de vezes que a fêmea agrediu outras fêmeas (r = 0,451). A variação do ganho de peso das fêmeas, durante o último mês de gestação, em baias coletivas é influenciada pela competição durante a alimentação, e o menor ganho de peso no último mês de gestação reduz o peso dos leitões ao nascimento.The objective of this work was to evaluate the association between the behavior of group-housed sows during feeding time, with weight gain during the last month of gestation and to determine if piglet birth weight uniformity is influenced by sow weight gain. Sows (n = 699) were separated into three parity groups (P): 2, 3–5, and 6–9. Each parity group was divided in three subgroups according to the percentage of weight gain: low, medium, and high. Sows from P 6–9 showed higher number of piglet birth weight below 1,200 g and higher birth weight coefficient of variation, in comparison to P 2 sows. Lower birth weight piglets and higher number of piglets weighing <1,200 g were observed in the low weight subgroup. There was a correlation of weight gain percentage during gestation with the number of visits to the feeder (r = 0.669) and with the number of aggressive encounters (r = 0.451). Variation in weight gain during the last month of gestation in group-housed sows is influenced by competition at feeding time, and the lower weight gain during the last month of gestation reduces the birth weight of piglets

Proposal of Equations for Predicting Post-Farrowing Sow Weight

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 &amp; 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 &gt; 0.05].Discussion: Pre-farrowing sow body weight was identified as the main input variable required for the estimation of the post-farrowing sow body weight. Thus, even EQ 1, which contained only this variable, exhibited a high coefficient of determination (R2 = 0.8707). However, the R2 value kept increasing as more input variables were included in the equation. Equation 2, 4, and 6 included the litter weight variable, and the addition of this variable increased the numerical value of R2 from 0.8707 in EQ 1 to 0.8975 in EQ 2. The EQ 3, 5, and 7 considered the piglets born variable as well, which increased the R2 value from 0.8707 in EQ 1 to 0.9119 in EQ 3. The coefficient of determination did not vary much among the equations; therefore, the selection of the prediction equations depended on data availability, feed management, facility, and the reliability of data collection in each farm. Although EQ 1 demonstrated a greater correlation between the predicted and the observed post-farrowing weight compared to the other equations, the values of error in central tendency and the errors due to disturbances were numerically higher for EQ 1 in comparison to the other two equations (EQ 2 and 4). Therefore, it is suggested that EQ 1 should be used as the last choice for the estimation of post-farrowing sow weight as it presented low trueness and precision, and also because the predicted weight estimated by EQ 1 was statistically lower than the observed weight (211.67 ± 33.33 kg vs. 216.84 ± 34.62 kg; P = 0.012). EQ 4 emonstrated higher trueness and precision; however, it did not differ significantly from EQ 2 and 1. Further analyses are required in order to validate EQ 3, 5, 6, and 7. Among the equations that were predicted as well as validated, the simplest and the easiest equation with satisfactory results for trueness and precision was EQ 2, which is as follows:Post-farrowing sow weight (kg) = 13.03 + (0.93 × pre-farrowing body weight, kg) + (–1.23 × piglets born, n