ABSTRACT The objective of this study was to identify and quantify, through mathematical models, the main factors of production in growing and finishing pig units linked to three Brazilian cooperatives located in Western Region of Paraná State that influence the parameters of daily feed intake and feed conversion ratio. The records of 216 growing and finishing farms from 2010 to 2013, representing 1,533 batches, and totaling approximately 1,025,000 pigs, were evaluated. Thirty production factors related to the management, health, installations and equipment, nutrition, genetics, and environment were considered. The number of pigs per pen, the feeder model, the origin and sex of the animals, and the initial and final body weights were the factors included in the final models for both dependent variables (daily feed intake and feed conversion ratio) and had a significant impact on these ratios. Approximately, 41 and 55% of the total variance found for daily feed intake and feed conversion ratio, respectively, were explained by the variables included in the final models. Mathematical models could serve as important tools to aid the decision-making in pig production systems.

Resumo: O objetivo deste trabalho foi identificar e quantificar, por meio de modelos de regressão linear múltipla, os fatores de produção que afetam o consumo diário de ração e a conversão alimentar de suínos nas fases de crescimento e terminação, em granjas integradas a uma cooperativa. Foram avaliados os históricos produtivos de 690 lotes, que representavam aproximadamente 363 mil animais alojados entre 2010 e 2013 em 118 granjas vinculadas a uma cooperativa do Estado do Paraná. Foram considerados 44 fatores de produção relacionados a instalações, manejo, sanidade, genética e alimentação. O consumo diário de ração (CDR) foi menor nos lotes oriundos de granjas com árvores nas laterais dos galpões e naqueles formados apenas por fêmeas. Já a conversão alimentar (CA) foi melhor para os lotes provenientes de granjas com árvores nas laterais dos galpões, alojados no verão/outono, oriundos de granjas edificadas em alvenaria e que apresentavam composteira e unidades especializadas produtoras de leitões. Os pesos de entrada e de saída dos lotes influenciaram o CDR, e o peso de entrada e a duração do período de engorda, a CA. Os modelos de regressão linear múltipla possibilitam identificar variáveis de importância e estimar seus efeitos sobre a conversão alimentar e o consumo diário de ração de suínos nas fases de crescimento e terminação.

Abstract: The objective of this work was to identify and quantify, through multiple linear regression models, the factors of production that affect the daily feed intake and feed conversion ratio of pigs in the growing and finishing phases, in farms linked to a company. The production records of 690 batches were evaluated, representing approximately 363 thousand animals housed between 2010 and 2013 in 118 commercial farms linked to a company in the state of Paraná, Brazil. Forty-four factors of production related to facilities, management, health status, genetics, and feeding were considered. Daily feed intake (DFI) was lower in batches from farms that had trees planted on the sides of the barns and in those formed only by females. The feed conversion ratio (FCR) was better in batches from farms with trees on the sides of the barns, housed during summer/fall, originated from farms with barns built of masonry and that had compost bins and specialized units for producing piglets. The initial and final weights of the batches affected DFI, and the initial weight and duration of the growing and finishing phases, the FCR. The multiple linear regression models allow identifying important variables and estimating their effects on FCR and DFI of pigs in the growing and finishing phases.

ABSTRACT The objective of this study was to evaluate the effect of chelated iron supplementation on gestating and lactating sows and on their suckling and weaned piglets. Reproductive traits, piglet performance, hematological parameters, and the iron concentrations in colostrum, milk, and stillborn livers were measured. Ninety-six sows were subjected to one of three treatment groups. Group T1 comprised pregnant and lactating sows treated with diets supplemented with inorganic iron (551 mg Fe/kg) and suckling piglets administered 200 mg of injectable iron dextran. Group T2 was the same as T1, except that sows after 84 days of gestation, lactating sows, and suckling piglets were fed a diet supplemented with 150 mg Fe/kg of chelated iron, and suckling piglets were administered injectable iron dextran. Group T3 was the same as T2 but without injectable iron dextran for suckling piglets. During the nursery phase, all of the weaned piglets were penned with their original groups or treatments and received isonutritive and isocaloric feeds. Piglets from the T2 and T3 groups also received an additional 150 mg Fe/kg of chelated iron via their feed. There were no differences among the treatments for reproductive traits or the iron concentrations in the colostrum, milk, or liver. The piglets that did not receive the injectable iron dextran showed the poorest performance during the pre-and post-weaning phases and showed the poorest hematological parameters of the suckling piglets. The chelated iron supplementation is insufficient to meet piglet demand. The iron dextran supply is necessary for suckling and weaned piglets.

ABSTRACT The objective of this study was to evaluate the behavior of immunocastrated male pigs compared with females and castrated males during the period before and after full immunization. A total of 30 animals were divided into three treatments, with ten animals in each (females, barrows, and immunocastrated males). The experiment was divided into three periods: 70 to 80 days of age (period 1), 81 to 110 days of age (period 2), and 111 to 140 days of age (period 3). The behavior of animals during these stages was evaluated. Immunocastrated males showed a higher rate of aggressive and sexual behavior during period 2, which decreased after the second vaccine dose. Both barrows and immunocastrated males presented high locomotion in period 1, reducing the frequency of this activity in period 3. All analyzed animals had a higher level of activities such as drinking, playing, and sexual behavior in period 1 than in the other periods, decreasing during the experiment. The remaining behavioral responses did not differ between the studied categories. Immunocastrated males had higher proportions of undesirable behaviors (aggressive and sexual) related to the surgically castrated males and females, and these were reduced after the second vaccine dose. Immunocastration is effective in the reduction of behaviors such as agonistic and sexual at the same levels observed in females and surgically castrated males. However, immunocastrated pigs are more subject to these undesirable behaviors before full immunization.

O estudo foi conduzido com o objetivo de avaliar o desenvolvimento microbiológico em carne suína PSE em comparação à carne normal e o efeito da época do ano sobre a velocidade de proliferação dos mesmos. Amostras do músculo Longissimus dorsi de carcaças classificadas ao abate como PSE (pH45<5,8) e normais (pH45>5,8), foram coletadas após 24 horas de refrigeração, no momento da desossa, em um abatedouro comercial, com serviço de inspeção federal, situado na região da Grande Dourados (MS). As amostras (12 normais e 12 PSE) foram coletadas em duas épocas distintas do ano (outono e inverno) para as análises de coliformes totais, coliformes a 45ºC, mesófilos, psicotróficos, pseudômonas, bolores e leveduras aos 0, 5, 10 e 15 dias de armazenamento por refrigeração. O crescimento microbiano comportou-se de maneira semelhante entre os dois tipos de carne ao longo do período de armazenamento, exceto para a contagem de microorganismos aeróbios mesófilos totais, cujo desenvolvimento foi superior em carnes PSE até o 5º dia de armazenamento, igualando-se entre os dois tipos de carne posteriormente. Houve efeito da época do ano sobre a contagem de coliformes totais e a 45ºC, sendo sua velocidade de proliferação superior em carnes provenientes dos animais abatidos na época mais quente (outono).

The study was conducted to evaluate the microbiological development in PSE pork compared with normal meat and the effect of season of the year on the rate of proliferation of the same. Longissimus dorsi muscle samples from carcasses classified as PSE slaughter (pH45 <5.8) and normal (pH45 > 5.8) were collected after 24 hours of refrigeration, at the time of deboning, in a commercial slaughterhouse, with service federal inspection, located in the Grande Dourados region (MS). The samples (12 normal and 12 PSE) were collected at two different times of the year (fall and winter) for analysis of total and 45ºC coliforms, mesophylls, psychotropic, pseudomonas, yeasts and molds at 0, 5, 10 and 15 days of storage under refrigeration. Microbial growth behaved similarly between the two types of meat throughout the storage period, except for the count of mesophilic aerobic microorganisms, whose development was superior in PSE meat until the 5th day storage, matching between both types of meat later. Was no effect of season on the count of total coliforms and 45ºC, and their proliferation rate higher in meat from the slaughtered animals the warmer season (autumn).