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.