The effects of alfalfa-based molt diets on skeletal integrity of white leghorns.

Sixty White Leghorn hens were assigned to 1 of 6 treatments: pretrial control (PC), full fed (FF), 9-d feed withdrawal (FW), 90% alfalfa-10% layer ration (A90), 80% alfalfa-20% layer ration (A80), and 70% alfalfa/30% layer ration (A70). For the PC, hens were killed and bones collected immediately before light restriction. The FF hens were also subjected to light restriction. After hens were fasted or fed different molting treatment diets for 9 d, they were fed a maintenance diet for 14 d. At 23 d postmolt, hens were killed and bones collected. Feed intakes per hen of the FF, A90, A80, and A70 treatments during a 9-d molting period were 97, 17, 44, and 46 g, respectively. Tibia dry weight of the PC was greater than the FF group. The PC group had significantly greater tibia ash weight than the FF, FW, A90, and A80 groups. Tibia ash concentration of the PC group was significantly greater than the FF, A90, and A80 groups. Humerus dry weights of the PC group were greater than the other groups except for hens on FW. Humerus ash weight was lower for FF hens as compared with PC hens, but other molting treatments had humerus ash weights similar to PC hens. Tibia mineral content and density of the PC were significantly greater than the other treatments. The FF group exhibited significantly lower humerus mineral content and density compared with those of the PC group. The PC and A70 hens exhibited significantly greater ultimate bending moment and ultimate stress compared with the FF and A90 hens. The modulus of elasticity of the PC hens was greater than that of the FF and A90. There were no significant differences in modulus of elasticity among the PC, FW, A80, and A70 hens. In conclusion, hens at 23 d postmolt experienced deterioration in skeletal integrity. This decrease in bone quality occurred in all molted hens. However, A70 and A80 alfalfa-fed hens retained mechanical properties of bones compared with the pretrial control.

Stabilized rice bran improves weaning pig performance via a prebiotic mechanism.

Stabilized rice bran (SRB) is classified as a "functional food" because of its prebiotic characteristics. With increasing grain prices and the pressure to remove antibiotics from swine diets because of concern over antibiotic resistance, SRB was investigated as a nursery diet ingredient with and without the addition of antibiotics (ANT). Two hundred pigs were weaned at 21 d of age, blocked by BW, and allotted to diets containing 0 or 10% SRB ± ANT according to a 2 × 2 factorial arrangement of treatments. Five animals were housed per pen throughout a 28-d growth period. At the end of the trial, 1 pig from each pen was euthanized for measurement of intestinal morphology. Antibiotic supplementation improved ADG by 6.4% during Phase 2 (d 14 to 28; P = 0.02), but other production variables were unaffected by ANT. During Phase 2 and cumulatively (d 0 to 28), the supplementation of SRB improved G:F by 10% in ANT-free pigs but not in pigs fed ANT (ANT × SRB, P < 0.03). Ileal histology revealed an increase in crypt depth of pigs fed the diet containing ANT plus SRB and corresponding decreases in villi:crypt associated with both ANT and SRB supplementation (P < 0.05). Intraepithelial lymphocytes were increased by 15% in pigs fed SRB without ANT, but were unaffected by SRB in pigs fed ANT (ANT x SRB, P = 0.003). Colonic bifidobacteria tended to increase with SRB supplementation (P < 0.10). Differences in ileal and cecal digesta short-chain fatty acid concentrations were not detected. In summary, SRB improved the efficiency of nutrient utilization in nursery diets lacking antibiotics and tended to increase intestinal bifidobacteria concentrations, indicating that SRB may exert beneficial prebiotic effects in weanling pigs.

Safety evaluation of polydextrose in infant formula using a suckling piglet model.

Oligosaccharides, the third largest component in human milk, are virtually absent from cow's milk and most infant formula. Prebiotic carbohydrates like polydextrose (PDX) have been proposed as surrogates for human milk oligosaccharides. Safety assessments of novel infant formula ingredients include dose-response experiments in appropriate neonatal animal models such as the suckling pig. To further substantiate the safety of the ingredient, one-day old pigs were fed a cow's milk-based formula supplemented with PDX (1.7, 4.3, 8.5 or 17 g/L) for 18 days (n=13/dose) and compared to appropriate control (unsupplemented formula; n=13) and reference groups (day 0 pigs, and sow-reared pigs; n=13). Growth rate, formula intake, stool consistency, behavior score, blood chemistry and hematology, relative organ weights (% of body weight), tissue morphology (i.e. liver, kidney and pancreas) and pancreas biochemistry did not differ among formula-fed pigs (P>0.1). Polydextrose mimicked other prebiotic carbohydrates and had no adverse effect at the highest tested level 17.0 g PDX/L, equivalent to a dose of 8.35 g/kg of body weight per day.