An experiment using 81 crossbred swine was conducted to evaluate quantitative and percentage chemical compositional changes of swine from 1.5 kg (birth) to 145 kg body weight. Groups of eight pigs were sacrificed at 1.5, 6.4 and 18 kg, and then at 18 kg increments to 145 kg. Body composition was determined by grinding the entire body, minus digesta, partitioning the carcass from other body components and chemically analyzing each subsample. Results indicated that weight of the carcass increased linearly with live weight, while the total weight of the other body components increased quadratically. Percentage fat in the empty body (ingesta-free) increased rapidly from birth to weaning (6.4 kg), plateaued until 36 kg and then increased, while water percentage declined dramatically from 1.5 to 6.4 kg, but then declined more gradually to 145 kg. Percentage protein increased from birth to 18 kg, plateaued and declined after 54 kg. When expressed on a fat-free basis, the percentage water decreased in a curvilinear manner with increasing animal weight while protein increased curvilinearly inverse to the change in water. Constancy of composition ("chemical maturity") between protein and water in the fat-free body was not attained by 145 kg. When expressed on an absolute empty body basis, water, protein and fat weight increased curvilinearly with increasing empty body weight; the rate of fat deposition increased faster during the latter growth stages while water and protein had declining deposition rates. Logarithmic and quadratic equations relating body composition to animal weight had similar R2 and lower coefficients of variation than linear or semilog functions. Gilts contained more water and less fat than barrows at similar slaughter weights, but sex differences were not apparent when expressed on a fat-free basis. The growth and fattening process was reflected in several carcass measurements. Backfat thickness, longissimus muscle area and body length increased as pig weight increased.

The amino acid composition of the body components (carcass, hair, whole blood, and a composite of the other body tissues) were determined from a total of 81 crossbred pigs at 10 weight intervals from birth to 145 kg body weight. Body component amino acid compositions (g/100 g protein) were multiplied by their respective protein contents, resulting in calculated whole-body amino acid compositions. From 8.5 to 145 kg body weight, the amino acid compositions were similar within each body component but differed between body components. There was a higher concentration of carcass lysine, arginine, and histidine (P < .01) in the carcass, and isoleucine (P < .12), threonine (P < .15), and methionine (P < .08) tended to be higher than in the composite of the other body tissue. Whole blood was, however, higher in leucine, valine, and lysine, and hair was higher in cystine than the carcass. The relative concentration of lysine in the whole body increased to about 37 kg body weight and reached a plateau, whereas the other essential amino acids increased to 8.5 kg and then reached a plateau. Tryptophan, however, decreased from birth to 8.5 kg and then remained at a similar concentration to 145 kg body weight. Whole-body amino acid composition of pigs in our study was generally similar to that noted in other scientific reports, but there was a wide variation in amino acid values between studies.

Body mineral composition was determined in 81 pigs killed at birth, weaning (28 d), and at approximately 15-kg intervals to 145 kg of BW. Total body components, including internal tissue, whole blood, and hair, were wet-ashed and analyzed for their mineral contents with the inductive coupled plasma method, except for Se, which was determined by fluorometric analysis. The results demonstrated that the body protein:ash ratio increased from birth to 20 kg BW, remained constant to 125 kg, but then declined to 145 kg BW (P < .01). The K:Na ratio increased from birth to 105 kg BW and then reached a plateau (P < .01). The Ca:P ratio decreased from birth to 20 kg then remained relatively constant to 90 kg BW, whereupon it increased (P < .01). These ratios reflected the rate of development of muscle and bone tissue and the higher soft tissue requirement for P and K during early growth. When expressed on a fat-free tissue basis, body Na was higher than K at birth, but thereafter body K increased linearly (P < .01) and Na content declined (P < .01). When Mg, Mn, Mo, and Cr were expressed on a fat-free empty body weight basis, each increased from birth but they maintained the same relative concentrations from 20 to 145 kg BW (P < .01). Body Fe increased from birth to 20 kg BW but then gradually declined to 145 kg BW (P < .01), whereas Zn increased to 145 kg BW (P < .01). Selenium increased from birth to weaning and again after 105 kg BW (P < .01). The amount of Co in the fat-free empty body increased linearly (P < .01) with increasing pig weight, and body Cu decreased to 75 kg BW and then reached a plateau (P < .01). The nonessential elements Al, Sr, and Sn increased dramatically from birth to weaning with a low rate of increase from 8.5 to 145 kg BW (P < .01), but Sn decreased after weaning (P < .01). The nonessential elements generally had a more variable concentration than the dietary essential trace minerals. There was a quantitative increase (P < .01) in all macro- and microelements from birth to 145 kg BW.

The objective of this study was to assess fermentability by canine gut microflora to include shortchain fatty acid (SCFA) production, organic matter (OM) disappearance, and gas production of vegetable and fruit fiber sources compared to fiber standards (psyllium, citrus pectin, and Solka Floc). Fiber sources included apple pomace, carrot pomace, flaxseed, fruit blend (mixture of peach, almond, nectarine, and plum), grape pomace, pea hulls, pistachio, and tomato pomace. Substrates were fermented in vitro for 4, 12, and 24 h with fecal flora obtained from three healthy dogs. Citrus pectin had the highest OM disappearance, SCFA production, and gas production at all times of fermentation; psyllium was intermediate and Solka Floc was lowest. A wide variation in fermentability was noted among the vegetable and fruit fiber sources. Apple pomace, carrot pomace, and flaxseed had the greatest fermentability as assessed by OM disappearance. Pea hulls and tomato pomace had intermediate OM disappearances, and fruit blend, grape pomace, and pistachio were poorly fermented. Carrot pomace produced the largest amounts of gas and SCFA. Apple pomace produced high concentrations of gas but intermediate concentrations of SCFA. Pea hulls and tomato pomace produced intermediate concentrations of gas and SCFA, whereas flaxseed, fruit blend, grape pomace, and pistachio produced low amounts of these fermentation products. For all substrates collectively, OM disappearance was highly correlated with both gas production (r2 = 0.782 and 0.723 for 12- and 24-h values, respectively) and SCFA production (r2 = 0.737 and 0.738 for 12- and 24-h values, respectively). In general, OM disappearance, gas production, and SCFA production were related to the insoluble:soluble fiber ratio in the samples; as the insoluble:soluble ratio decreased (increased soluble fiber), the OM disappearance, gas production, and SCFA production increased.

A 2 X 3 factorial split-plot experiment was conducted to determine the effect of dietary protein on the performance and calculated body compositions of 45 first-litter sows using the D2O dilution technique at various reproductive stages. Animals were initially fed 1.82 kg daily of a 14% protein diet to 14 d post-coitum. Subsequently, two gestation protein levels (5 or 14%) were daily fed at 1.82 kg from 15 d postcoitum to parturition with three dietary lactation protein levels (5, 14 or 23%) fed from parturition to 28 d postpartum. Maternal body compositions were determined at 17, 35, 70, 85 and 105 d postcoitum and 7, 14 and 28 d postpartum using prediction equations reported previously. Gravid sows demonstrated higher maternal tissue accretion of all body chemical components from 14 to 70 d than from 70 to 105 d postcoitum. Sows fed the 5% protein gestation diet had more maternal fat but less protein accretion than those fed the 14% protein at each measurement interval. During the last trimester, those sows fed the 5% protein diet catabolized body protein reserves. Gravid sows fed the 14% protein gestation diet catabolized more maternal protein and water between 105 d postcoitum and 7 d postpartum than those fed the 5% protein diet. Litter and pig birth weights were lower and postpartum mortality higher for sows fed the 5% rather than the 14% protein gestation diet. Sows fed the 5% protein lactation diet mobilized more maternal tissue, particularly fat, between 7 and 28 d postpartum than those fed 14 or 23% protein lactation diets. These results suggest that labile maternal body protein reserves are used by gravid and nursing dams to fulfill reproductive needs and that dietary protein sequence affects the dam's performance and body composition.