Energy expenditure is a physiological process that may be closely associated with residual feed intake (RFI). The maintenance energy (ME(M)) EPD was developed by the Red Angus Association of America (RAAA) and is used as an indicator of energy expenditure. The objectives of this study were to evaluate and quantify the following relationships using progeny of Red Angus (RA) sires divergent for M...

Research emphasis has been placed on heifer development strategies in recent years, comparing traditional, more intensive systems to more extensive systems using less feed and relying on compensatory gain to reach a target BW. Recent research has indicated that developing heifers to a lighter target BW at breeding (i.e., 50 to 57% of mature BW compared with 60 to 65% BW) reduced development cos...

Performance records on 41,184 Red Angus cattle were analyzed and estimates of parameters calculated for absolute growth rate, relative growth rate and restricted selection indices. Heritability estimates for birth weight, 205-d weight, 365-d weight and postweaning gain were .46 +/- .02, .39 +/- .02, .40 +/- .02 and .36 +/- .02, respectively. Heritability estimates for preweaning, postweaning an...

To examine the effects of exogenous porcine (p) ST on measures of stress and immune function in weaned pigs with or without transport, pigs (20 +/- 1 d of age) received daily injections of pST (0.5 mg/kg; n = 16) or saline (n = 16) for 5 d. On d 5, a blood sample was collected immediately before injection. At 4 h postinjection, pigs were weighed, sampled for blood, injected with di-nitrophenyl-...

A total of 191 crossbred sows were used to determine the effect of energy intake during one lactation on (1) sow and pig performance and (2) the percentage of sows in estrus by 7, 14, 21 and 70 d postweaning. Sows received 8 (Lo) or 16 (Hi) Mcal of metabolizable energy (ME)/d (Exp. 1 and 2) and 8 (Lo), 12 (Md) or 16 (Hi) Mcal of Me/d (Exp. 3) during a 28-d lactation period. All sows were fed an...

Although weaning stress has been reported to impair intestinal barrier function, the mechanisms have not yet been elucidated. In the present study, the intestinal morphology and permeability and mRNA expressions of tight junction proteins and cytokines in the intestine of piglets during the 2 wk after weaning were assessed. The phosphorylated (activated) ratios of p38, c-Jun NH(2)-terminal kina...

The effectiveness of carbohydrase enzymes has been inconsistent in corn-based swine diets; however, the increased substrate of nonstarch polysaccharides in drought-affected corn may provide an economic model for enzyme inclusion, but this has not been evaluated. A total of 360 barrows (PIC 1050 × 337, initially 5.85 kg BW) were used to determine the effects of drought-affected corn inclusion wi...

Research emphasis has been placed on heifer development strategies in recent years, comparing traditional, more intensive systems to more extensive systems using less feed and relying on compensatory gain to reach a target BW. Recent research has indicated that developing heifers to a lighter target BW at breeding (i.e., 50 to 57% of mature BW compared with 60 to 65% BW) reduced development cos...

In phocid seals, the transition to nutritional independence is abrupt, with females abandoning their offspring after weaning and returning to sea. We hypothesized that body size at weaning may play an important role in the nature of this transition. We studied the changes in body composition and water flux of newly weaning harbour seals over the first 4-6 wk postweaning. Thirty-three pups were ...

Our earlier studies have shown that the artificial rearing of newborn rat pups [first generation high carbohydrate (1-HC)] on an HC milk formula resulted in chronic hyperinsulinemia and adult-onset obesity (HC phenotype). Offspring [second-generation HC (2-HC)] of 1-HC female rats spontaneously acquired the HC phenotype in the postweaning period. In this study, we have characterized the develop...