Experiments were conducted to evaluate the effect of restricted feeding of a starter diet to suckling pigs (creep feeding) in a model of postweaning colibacillosis. The hypothesis that restricted creep feeding primes an intestinal allergic reaction to starter diet ingested after weaning was tested. Twenty-eight suckling pigs were fed a starter diet for 3 h/d on days 7, 8, and 9 after birth (creep-fed). Twenty-six suckling pigs were not fed the diet until 3 weeks of age (not creep-fed), when all pigs were weaned and given the starter diet. One day after weaning, 24 creep-fed and 22 not creep-fed pigs were inoculated with K88+ enterotoxigenic Escherichia coli, and 4 pigs in each group were kept as noninoculated controls. Among inoculated pigs (principals), 10 creep-fed and 12 not creep-fed pigs were found to be genetically resistant to K88+ E coli and remained healthy during the 6-day postinoculation period, as did the noninoculated controls. Eighteen (10 creep-fed and 8 not creep-fed) of the 24 genetically susceptible principals developed diarrhea after inoculation. There were no significant differences in the incidence and severity of diarrhea, amount of body weight loss, and mortality between creep-fed and not creep-fed susceptible principal pigs. Histologic examination of intestine from control pigs and principals that survived for 6 days after infection did not reveal any substantial morphologic difference between creep-fed and not creep-fed groups. In conclusion, creep feeding was not required for the production of diarrhea in this model. Creep feeding did not induce morphologic changes characteristic of an allergic reaction in the small intestine.

Due to the high value of land in Brazil, it is necessary to conduct studies about the economic feasibility of the choice of production strategy. The soil expectation value determines the maximum purchase price of the bare land, considering the horizon of infinite time. Therefore, this methodology was used to assess the financial-economic feasibility of sheep production systems in pasture with either creep feeding or creep grazing termination of unweaned lambs. Six scenarios were proposed to evaluate the economic feasibility, according to the finishing strategy, the dry matter (DM) offer per kg of body weight (BW) per day (12% or 8%) and the corresponding percentage of white clover supplementary pasture area (30% to 50% - relative to the main pasture area). The soil expectation value was positive in all of the evaluated systems Creep grazing finishing system with 8% DM offer per kg BW and with 30% of reduction on the white glover area resulted in the largest financial return (R$ 289,043.71) and the highest internal return rate (1.74%). The most economically attractive scenario, however, was the creep feeding finishing system with 8% DM offer per kg of BW, which allowed expenses with the land as high as R$ 22,950.68 per hectare. Adjustments in the main pasture offer, which do not compromise animal performance, can enable economic improvement on the feasibility of grazing sheep production systems. The soil expectation value can be used as an economic indicator in the choice of location or expansion of grazing sheep farms. | Devido ao valor elevado da terra no Brasil, é necessária a realização de estudos de viabilidade econômica durante a escolha da estratégia de produção. O valor esperado da terra determina o preço máximo de compra da terra nua, considerando o horizonte de tempo infinito. Portanto, essa metodologia foi utilizada para avaliar a viabilidade econômico-financeira de sistemas de produção de ovinos em pastagem com terminação em creep feeding ou creep grazing de cordeiros não desmamados. Seis cenários foram propostos para avaliar a viabilidade econômica de acordo com a estratégia de terminação, a oferta de matéria seca (MS) por kg de peso vivo (PV) por dia (12% ou 8%) e a área de pastagem suplementar correspondente de trevo branco (30% a 50% – em relação à área de pastagem principal). O valor esperado da terra foi positivo em todos os sistemas avaliados. O sistema com terminação em creep grazing com 8% de oferta de MS/PV e com redução da área suplementar para 30% apresentou o maior retorno financeiro (R$ 289.043,71) e a maior taxa interna de retorno (1,74%). No entanto, o cenário economicamente mais atraente foi o sistema de creep feeding com 8% de oferta de MS/PV, permitindo despesas de até R$ 22.950,68 por hectare. Ajustes na oferta da pastagem principal, que não comprometam o desempenho do animal, podem permitir melhores resultados econômicos de sistemas de produção de ovinos em pastagem. O valor esperado da terra pode ser usado como um indicador econômico na escolha da localização ou ampliação de sistemas de produção de ovinos em pastejo.