The objectives of this study were to use transgenic sows that overexpress IGF-I in milk to investigate the effect of a short-term fast on piglet intestinal morphology and disaccharidase activity and to determine how milk-borne IGF-I influences the response to fasting. After farrowing, litters were normalized to 10 piglets. On d 6, piglets (n = 30) suckling IGF-I transgenic (TG) sows and piglets (n = 30) suckling nontransgenic sows (control) were assigned randomly to three treatments: fed piglets (0 h), which remained with the sow until euthanized on d 7, or fasted piglets, which were removed from the sow at either 6 or 12 h before euthanasia on d 7. Serum IGF-I and IGFBP, intestinal weight and length, jejunal protein and DNA content, disaccharidase activity, and villus morphology were measured. Fasting for 12 h resulted in a negative weight change between d 6 and 7 (quadratic response to fasting; P < 0.001). Piglets suckling TG sows tended to have greater intestinal length (P = 0.068), but no effect of IGF-I overexpression was noted for intestinal weight. Fasting, however, resulted in linear (P < 0.001) and quadratic (P = 0.002) decreases in intestinal weight. Serum IGF-I did not differ between control and TG sows, but decreased linearly (P = 0.003) with fasting. Serum IGFBP-4 decreased (linear and quadratic; P < or = 0.02) with fasting, whereas IGFBP-1 increased quadratically (P < 0.001) with fasting. Jejunal villus height, width, and crypt depth were all increased with fasting (linear and quadratic; P < 0.04). Disaccharidase activity was not affected by fed state; however, piglets suckling TG sows had greater jejunal lactase-phlorhizin hydrolase (P < 0.01) and sucrase-isomaltase (P = 0.02) activities than control piglets. In summary, intestinal weight, villus morphology, serum IGF-I, serum IGFBP-1 and -4, and piglet BW change were altered (P < or = 0.02) in response to fasting. Thus, the duration of food deprivation before euthanization should be considered when designing experiments to assess intestinal development or the IGF axis, as the magnitude of differences between the fed and fasted state may exceed those expected as a result of experimental treatment.

"Your Guide to Diet and Diabetes" filled a need for an easy-to-use website that addressed the issues of diet and diabetes. Based on the number of visits to the login page (n = 6,124) and number of individuals who answered demographic questions, the site was well received. While a smaller group of participants elected to complete the interactive knowledge and skills questions, responses to these questions demonstrated that participants obtained knowledge from the website. In particular, participants increased their knowledge of food sources and appropriate serving sizes of carbohydrate. The "making a plate" skill activity was used with much greater frequency than the more conceptually complex carbohydrate counting skill activity.

Porcine milk contains hormones and growth factors that stimulate piglet intestinal growth and development. Milk-borne insulin-like growth-factor-I (IGF-I) has received considerable attention. In swine, IGF-I concentrations range from 0.10 to 0.4 mg/L in colostrum and approximately 0.01 to 0.04 mg/L in mature milk. Two experimental approaches have been utilized to investigate the role of orally administered IGF-I in neonatal intestinal development. In the first approach, piglets were reared on sow milk replacer formulas containing recombinant human IGF-I (rhIGF-I) at concentrations of 0.1 to 12 mg/L. The advantage of this approach is that specific effects of IGF-I can be assessed in the absence of other bioactive components, changes in milk composition, and other environmental factors. However, the applicability to swine production is limited. A second approach has been to develop transgenic mice or swine that overexpress IGF-I in milk under the direction of promoter regulatory elements of milk proteins to result in animals experiencing mammary specific overexpression of IGF-I during lactation. Herein, the effect of orally administered IGF-I on neonatal intestinal development in artificial rearing studies, as well as studies utilizing transgenic overexpression of IGF-I in milk, was reviewed. Both rhIGF-I in formula or transgenic IGF-I overexpression increased villus growth and disaccharidase activity; however, these effects were primarily observed late in the suckling period (d 21 postpartum) in piglets suckling IGF-I transgenic sows. We speculate that piglets suckling IGF-I transgenic sows may have improved intestinal health during the weaning transition.

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