Nutrient digestibilities of a corn-soybean meal diet as influenced by Bacillus products fed to finishing swine.

Twelve crossbred barrows (initial BW of 59.7 kg) were used in nutrient balance trials to investigate the influence of adding two Bacillus products (Biomate 2B and Pelletmate Livestock, Chr. Hansen's Biosytems) to a 14% CP corn-soybean meal diet (.64% lysine, .6% Ca and .5% P). A 3 x 3 Latin-square design with an extra period was used. Treatments were as follows: 1) basal diet; 2) basal + Biomate 2B (BAC1); and 3) basal + Pelletmate Livestock (BAC2). After a 7-d adaptation to metabolism crates, each 10-d period consisted of 5 d of diet adjustment followed by 4 d of total collection and 1 d for change-over. Both BAC1 and BAC2 were added at a level of .05% to supply approximately 3 million colony forming units per gram of diet. Pigs were fed twice daily at a daily rate of 3.2 to 3.5% of BW. Feeding BAC1 or BAC2 elevated (P < .001) fecal Bacillus spore counts at the end of each collection period, but the effect on number of coliforms and lactic acid bacteria was not as consistent; coliform counts tended to be decreased (P < .10) when BAC2 was fed, but not (P > .10) when BAC1 was fed. The number of lactic acid bacteria was increased (P < .05) when BAC1 was fed, but not (P > .10) when BAC2 was fed. Body weights were similar among all treatments for all periods. There was no carry-over or pretreatment effect (P = .50). Digestibility coefficients of DM, neutral detergent fiber, acid detergent fiber, ash, and N and retention of N were not affected (P = .40) by feeding Bacillus products.

Effect of feeding organic acids on selected intestinal content measurements at varying times postweaning in pigs.

Pigs weaned at 21 d of age (n = 72) were fed a 20% CP corn-soybean meal-based diet (control) with 1.5% fumaric or 1.5% citric acid added to observe the effect of these acids on the pH, chloride ion concentration (Cl-), VFA profile, and microflora population in the stomach, jejunum, cecum, and lower colon contents at -2, 0, 3, 7, 14, and 21 d postweaning. Feeding organic acids had no appreciable effect (P greater than .10) on stomach jejunum, cecum, or lower colon pH, Cl-, VFA profile, or microflora populations, except for increasing the concentration of fumaric acid in the stomachs of pigs fed fumaric acid. The pH of the gastrointestinal tract generally decreased from -2 to 21 d postweaning with no corresponding change in Cl- over time. No age effects on total anaerobic culture counts were observed except in the stomach, where counts decreased from -2 to 3 d postweaning. Clostridia counts generally decreased after weaning in all intestinal sections. Lactobacillus counts were usually lower at d 0 and 3 and greatest at d 7 postweaning in the stomach, jejunum, and lower colon, but no age effect was observed for concentration of cecum lactobacilli. Escherichia coli counts generally increased after weaning to 3 and 7 d postweaning. Intestinal content measurements were affected by postweaning age but were not affected by feeding organic acids.

Characterization of creep feed consumption and its subsequent effects on immune response, scouring index and performance of weanling pigs.

Four trials were conducted to characterize the consumption of creep feed by nursing pigs and the effects of creep feeding (from 10 d to weaning at 28 d) on the immune response, scouring index and subsequent performance of weanling pigs. Pigs were fed a ground 20% CP corn-soybean meal-whey diet with 1.0% chromic oxide (control, 9 litters), this diet with 2.7% ovalbumin added as a dietary antigen (ovalbumin, 14 litters), or no creep feed (unexposed, 11 litters). At weaning, pigs within a litter were fed a 20% CP corn-soybean meal diet either with or without 2.7% ovalbumin. Creep-fed litters began eating at 11 d of age and disappearance of creep feed increased linearly until weaning (P less than .01). However, based on the chronic oxide coloring of the feces, total creep feed consumption was quite variable from pig to pig (13 to 194 g) and from litter to litter (107 to 1,550 g). Preweaning daily gain was similar between creep-fed and noncreep-fed litters; larger litters generally had lower daily gains (P less than .09) and less feed disappearance per pig (P less than .02). Weekly blood sampling showed that pigs fed the antigen diet had a higher (P less than .001) antibody titer to ovalbumin at 14, 21 and 28 d of age than did pigs fed the control diet or pigs unexposed to creep feed. At 56 and 63 d of age, all pigs given an ovalbumin injection at 49 d (1 ml containing 3 mg of ovalbumin) had responded (P less than .001) to injection, with the lowest titers for pigs fed the control creep diet and the highest titers for pigs fed the ovalbumin creep diet; titers were intermediate for pigs not fed creep. Regardless of preweaning or postweaning treatment, most pigs began scouring 4 to 5 d postweaning; scouring peaked at d 10 and returned to normal after d 15. Although the magnitude of difference was small, creep-fed pigs tended to scour more than pigs not fed creep (P less than .01). Postweaning performance was not influenced by preweaning treatments.

Effects of water supplementation with selenium and vitamin E on growth performance and blood selenium and serum vitamin E concentrations in weanling pigs.

OBJECTIVE: To determine effects of supplementation of drinking water with selenium and vitamin E on blood selenium and serum vitamin E concentrations, growth performance, and water intake of pigs. DESIGN: Prospective controlled study. ANIMALS: 228 weanling pigs. PROCEDURE: In experiments 1 and 2, pigs were given drinking water supplemented with selenium and vitamin E, and blood selenium and serum vitamin E concentrations were measured. In experiment 3, growth performance and water intake were measured in pigs that received supplemented water for 2 or 5 weeks and in control pigs. RESULTS: In experiment 1, blood selenium concentrations were significantly increased after 7 days of supplementation, and serum vitamin E concentrations were significantly increased after 1 and 7 days of supplementation, compared with baseline concentrations. In experiment 2, blood selenium concentrations were not significantly different between treated and control pigs, and serum vitamin E concentrations were significantly increased on day 7. In experiment 3, gain-to-feed ratios were significantly higher for pigs supplemented with selenium and vitamin E for 5 weeks, but other differences were not detected. CLINICAL IMPLICATIONS: Supplementation of drinking water with selenium and vitamin E may improve the selenium and vitamin E status of weanling pigs by increasing selenium and vitamin E intake.

Modelling the extinction of Steller's sea cow.

Steller's sea cow, a giant sirenian discovered in 1741 and extinct by 1768, is one of the few megafaunal mammal species to have died out during the historical period. The species is traditionally considered to have been exterminated by 'blitzkrieg'-style direct overharvesting for food, but it has also been proposed that its extinction resulted from a sea urchin population explosion triggered by extirpation of local sea otter populations that eliminated the shallow-water kelps on which sea cows fed. Hunting records from eighteenth century Russian expeditions to the Commander Islands, in conjunction with life-history data extrapolated from dugongs, permit modelling of sea cow extinction dynamics. Sea cows were massively and wastefully overexploited, being hunted at over seven times the sustainable limit, and suggesting that the initial Bering Island sea cow population must have been higher than suggested by previous researchers to allow the species to survive even until 1768. Environmental changes caused by sea otter declines are unlikely to have contributed to this extinction event. This indicates that megafaunal extinctions can be effected by small bands of hunters using pre-industrial technologies, and highlights the catastrophic impact of wastefulness when overexploiting resources mistakenly perceived as 'infinite'.