Reproductive performance of gilts and weaned sows grouped at different days after insemination.

The objective of the study was to compare the reproductive performances of gilts and weaned sows grouped at different days after insemination. The study was conducted on a sow farm in the Midwest of Paraná State, Brazil, using animals from the Camborough genetic line (PIC®, Patos de Minas, Brazil, Landrace × Large White crossbred). The groups of comparison have considered the distribution of gilts (n = 407) and sows (parity 1 to 5; n = 843) according to the day of group housing in collective pens in relation to the day of last insemination (AI). Thus, gilts were distributed in four groups of comparison: group housing on days 1, 2, 3, or 4 after the last AI (AI). Sows were distributed in three groups of comparison: group housing on the day after the last AI (0), at day 1 or 2 after the last AI. Farrowing rate (FR), the total number of piglets born (TB), and return to estrus (RE) were recorded. In a subsample (254 gilts and 622 sows), the presence and the score of skin lesions (0, no lesions; 1, low; 2, moderate; or 3, high) were evaluated 24 and 48 h after mixing. Statistical analysis was performed using the SAS® 9.4 software using the GLIMMIX procedure. Comparisons of means were performed using the Tukey-Kramer test and frequencies by logistic regression. Group housing gilts on different days after insemination did not affect FR, TB, and RE (P ≥ 0.79). However, sows mixed 2 days after AI had a reduction in TB compared to those mixed on day 1 (P = 0.05), without differences from sows mixed on the day of the last AI. All the females had low (score 1; 60.5%) or moderate (score 2; 39.5%) skin lesions. For both female categories, the presence of low or moderate lesion scores did not affect ER, FR, and TB (P ≥ 0.25). Fights within 48 h were not severe enough to compromise reproductive performance (P ≥ 0.25). In conclusion, group housing gestating sows 2 days after breeding compromised litter size; however, mixing gilts on days 1 to 4 after breeding did not impair reproductive performance.

Additional feeding during late gestation improves initial litter weight of lactating sows exposed to high ambient temperature

The present study investigated the impacts of additional feeding (AF; containing 16% excess feed than control diet in the last two weeks of gestation) during late gestation period and different backfat thickness (BFT) including low (<20 mm) and high (≥20 mm) backfat on reproductive performance, litter size, blood metabolites, hormonal profiles, colostrum, and milk composition of sows from day 90 of gestation to farrowing, and from farrowing to weaning during summer (average 28.3 °C). Fifty-four crossbred sows (Yorkshire × Landrace) were allotted to one of four treatments according to a 2×2 factorial arrangement. There was no AF×BFT interaction for any of the measured variables. The body weight change of sows was decreased for <20 mm in BFT and AF treatments during late gestation and farrowing to weaning periods. The BFT change of sows was higher in AF during late gestation and higher in ≥20 mm BFT during late gestation and farrowing to weaning periods. There were no effects of AF and BFT on the average daily feed intake and weaning-to-oestrus interval; however, sows in AF groups had a greater litter uniformity at birth and initial litter weight. Hormone profiles, colostrum, and milk composition of sows were not different among the treatments. Additional feeding during the last two weeks of gestation increases initial litter size in summer; however, final litter weight is not affected.(AU)

Physiological and productive responses of environmental control on housed sows

Swine housing must promote an adjusted environment for thermal comfort and high animal productivity without negatively affecting the sow performance and reproductive response. This study evaluated the use of distinct environmental cooling equipments on sow performance, both on the gestation and on nursing in open sided housing. Two treatments were tested in the gestation building: natural ventilation and mechanical ventilation associated to fogging; while in the nursing rooms three treatments were tested: natural ventilation; mechanical ventilation; and evaporative cooling with forced ventilation. Sows were randomly chosen from the same genetic lot form six combined treatments. The evaporative cooling system in the farrowing room differed for piglet performances, at birth (4% higher) and on daily weight gain (15% higher), and also for sow physiological response improving the respiratory rate (8%) and back fat thickness (3%), without influencing skin temperature. The use of evaporative cooling directed to the sow head during nursing improved the physiological and productive results.

As instalações suínicolas devem promover um ambiente adequado para o conforto térmico, sem afetar negativamente o desempenho produtivo e reprodutivo das porcas. O presente trabalho avaliou a influência do uso de diferentes equipamentos de climatização, em ambas as instalações abertas de gestação e maternidade, no desempenho das matrizes suínas. Na instalação de gestação foram testados dois tratamentos: ventilação natural e resfriamento; enquanto nas salas de maternidade foram aplicados três tratamentos: ventilação natural, ventilação mecânica e resfriamento adiabático com ventilação forçada. Matrizes escolhidas aleatoriamente, com a mesma genética, foram expostas a seis tratamentos combinados. O sistema de resfriamento adiabático na maternidade foi diferencial para o desempenho dos leitões ao nascer (4% superior) e no ganho de peso diário (15% superior), e também para as respostas fisiológicas das porcas com melhorias nos resultados de freqüência respiratória (8%) e espessura de toucinho (3%). Não houve influência na temperatura de pele dos animais. O uso de resfriamento evaporativo direcionado para a cabeça das porcas na maternidade demonstrou ser um procedimento positivo com melhorias nos resultados fisiológicos e produtivos.

Physiological and productive responses of environmental control on housed sows

Swine housing must promote an adjusted environment for thermal comfort and high animal productivity without negatively affecting the sow performance and reproductive response. This study evaluated the use of distinct environmental cooling equipments on sow performance, both on the gestation and on nursing in open sided housing. Two treatments were tested in the gestation building: natural ventilation and mechanical ventilation associated to fogging; while in the nursing rooms three treatments were tested: natural ventilation; mechanical ventilation; and evaporative cooling with forced ventilation. Sows were randomly chosen from the same genetic lot form six combined treatments. The evaporative cooling system in the farrowing room differed for piglet performances, at birth (4% higher) and on daily weight gain (15% higher), and also for sow physiological response improving the respiratory rate (8%) and back fat thickness (3%), without influencing skin temperature. The use of evaporative cooling directed to the sow head during nursing improved the physiological and productive results.

As instalações suínicolas devem promover um ambiente adequado para o conforto térmico, sem afetar negativamente o desempenho produtivo e reprodutivo das porcas. O presente trabalho avaliou a influência do uso de diferentes equipamentos de climatização, em ambas as instalações abertas de gestação e maternidade, no desempenho das matrizes suínas. Na instalação de gestação foram testados dois tratamentos: ventilação natural e resfriamento; enquanto nas salas de maternidade foram aplicados três tratamentos: ventilação natural, ventilação mecânica e resfriamento adiabático com ventilação forçada. Matrizes escolhidas aleatoriamente, com a mesma genética, foram expostas a seis tratamentos combinados. O sistema de resfriamento adiabático na maternidade foi diferencial para o desempenho dos leitões ao nascer (4% superior) e no ganho de peso diário (15% superior), e também para as respostas fisiológicas das porcas com melhorias nos resultados de freqüência respiratória (8%) e espessura de toucinho (3%). Não houve influência na temperatura de pele dos animais. O uso de resfriamento evaporativo direcionado para a cabeça das porcas na maternidade demonstrou ser um procedimento positivo com melhorias nos resultados fisiológicos e produtivos.