The effect of diet on fecal moisture, osmolarity of fecal extracts, products of bacterial fermentation and loss of minerals in feces of weaned pigs.

Litters of pigs were allotted to one of three dietary treatments. Treatment 1 (T1) consisted of a corn-soybean meal starter diet. Pigs fed treatment 2 (T2) received a steamed, rolled oat groats-casein diet and pigs in treatment 3 (T3) remained with the sow. Four pigs/treatment were used to investigate the difference in performance and the cause of post-weaning diarrhea associated with early weaning of pigs at 4 wk of age to a starter diet. Fecal moisture, osmolarity, acetic acid, lactic acid and glucose contents were all good indicators of dietary differences because of treatment X age interactions. These variables increased faster in fecal extracts from pigs fed the corn-soybean meal diet. Lactic acid, volatile fatty acid (VFA) levels, glucose and pH values were indicative of a more active bacterial fermentation in pigs receiving T1 than in those receiving T2 or pigs remaining with the sow (T3). Excess minerals appear to contribute significantly to the osmolarity of fecal material. Of the anions, lactate was the main contributor to the osmolarity of feces of T1 pigs, followed by P, VFA, of which acetic acid contributed 70%, and Cl. The main cations were K, Na and Ca. In T2, P was the main anion, followed by lactate, VFA and Cl, while the main cations were Na, K and Ca. Minerals seemed to be the major osmotic particles in fecal extracts of pigs remaining with the sow. Phosphorus was the major anionic contributor to osmolarity, followed by VFA, Cl and lactic acid. Potassium was the major cation, followed by Na and Ca.(ABSTRACT TRUNCATED AT 250 WORDS)