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In a factorial design, animal fat was added incrementally (0, 35, 70 and 105 g/kg) to maize starch (M) or to two sources of fermentable carbohydrates (260 g purified cellulose (C) per kg or 270 g soya-bean hulls (S) per kg). The 12 experimental diets were formulated by replacing maize starch in the control diet with fat, cellulose and soya-bean hulls of equivalent estimated net energy. Ninety-six castrated males were given these diets according to net energy. Apparent digestibilities of crude protein, crude lipid, crude fibre and nitrogen-free extract were measured and were compared with those expected from the separate ingredients. Net energy conversion ratio (nECR) was also measured. Results showed that in the C and the S diets prediction of the apparent digestibility of nutrients was worse than in the M diets (significant effect of source of carbohydrate). Prediction of apparent digestibility of crude protein and crude lipid improved as the added fat increased (significant effect of amount of fat), except in the C and S diets where for digestible crude lipid the 70 g added fat per kg gave the worst prediction (significant effect of the interaction). The net energy calculated from the experimental data on apparent digestibility was proportionately between 0·83 and 0·98 of that calculated from the expected data. The pigs on the C and S treatments showed a significant lower nECR when calculated from the expected apparent digestibility coefficients, but not when calculated from those which were measured. At the highest fat addition, the nECR was poorest. It is concluded that the amounts of digestible components in compound foods cannot always be obtained from those in the separate ingredients.

Zusammenfassung Variationen in der Verdauungskapazitat von genetisch unterschiedlich Schweinepopulationen: eine Ubersicht In der Literaturubersicht werden Unterschiede in der Verdauungskapazitat von verschiedenen Rassen und Genotypen bei Schweinen aufgezeigt. Danach finden sich signifikante Unterschiede zwischen Schweinerassen mit groseren genetischen Unterschieden und zwar verursacht durch Verschiedenheiten der Morphologie des Dickdarms und damit der Rohfaserverdaulichkeit. Das sollte bei der Formulierung von Diaten fur unterschiedliche Schweinerassen berucksichtigt werden.

In the first of 3 experiments, requirement for total and digestible sulphur amino acids (SAA) was estimated in 240 pigs, 14 to 40 kg. A diet with low digestible amino acids content (digestible sulphur amino acids (SAA) 0.37%) was supplemented with all essential amino acids except methionine and 0, 0.05, 0.1, 0.1 or 0.2% synthetic DL-methionine added, providing diets with 0.42, 0.47, 0.52 and 0.57% digestible SAA. A control diet contained 0.52% digestible SAA. At similar levels of digestible SAA, there was no difference in performance between the experimental and the control diet, showing that optimum performance can be obtained with a less digestible diet supplemented with essential amino acids. Optimum performance was at 0.52% digestible SAA content in the diet, corresponding to about 0.65% total SAA. In experiment 2, 360 pigs 15 to 40 kg, were used to study SAA requirement at sub-optimal (0.60%) and optimal (0.70%) dietary threonine levels. Increasing threonine from 0.60 to 0.70%, increased (P

An in vivo experiment was conducted to monitor the changes in fermentation end products in the feces of weaning piglets due to the inclusion of selected fermentable carbohydrates in the diet. The experiment involved 3 groups of 16 piglets each. Specially raised piglets (neither antibiotics nor creep feeding) were weaned abruptly at 4 wk of age. The piglets were offered 1 of 2 dietary treatments [a control diet (CON), or a fermentable carbohydrate-enriched diet (CHO)] and were subjected to 1 of the 2 fasting treatments (fasting for 2 d at the beginning of the experimental period or nonfasting). Fecal samples were collected per rectum every day during the experimental period. Piglets were slaughtered at the end of the 10-d experimental period, and digesta samples were collected from different parts of the gastrointestinal tract (GIT): the first half of the small intestine, the second half of the small intestine, the cecum, and colon. The DM, VFA profile, and ammonia concentrations were analyzed from the fecal and digesta samples. Daily feed intake was also recorded. There was no difference in concentrations of VFA in feces between the treatment groups. Ammonia concentration was lower (P0.05) in piglets fed the CHO diet compared with those fed the CON diet in both feces and digesta from different parts of GIT. Fasting had no effect on fermentation end products in feces. This study demonstrated that the inclusion of fermentable carbohydrates in weanling diets reduces protein fermentation along the GIT and also reduced the fecal concentration of ammonia.

An experiment was conducted to examine changes in VFA and ammonia concentrations at different time points using 4 fermentable carbohydrate-rich feed ingredients as substrates and feces of unweaned piglets as inoculum. Fecal inoculum was collected, pooled, and mixed from 9 specially raised (no creep feed or antibiotics) crossbred piglets at 3 wk of age. Inulin, lactulose, molasses-free sugar beet pulp, and wheat starch were used as substrates and were fermented in vitro for 72 h (3 replicates per substrate). Cumulative gas production was measured as an indicator of the kinetics of fermentation. In addition, 3 bottles of substrate per time point with similar contents (amounts of substrate, inoculum, and media) were incubated but were allowed to release their gas throughout incubation. For these latter bottles, fermentation fluid was sampled at incubation time points including every hour between 1 and 24 h and at 48 h, and fermentation end products (VFA, lactate, and ammonia) and OM disappearance were measured. Dry matter and ash were analyzed from the postfermentative samples. The pH of the contents from these bottles was also recorded. The correlation in time between fermentation end products and cumulative gas produced was determined. The results showed that the prolongation of fermentation to 72 h, especially in the case of fast-fermenting inulin and lactulose, may lead to a different end product profile (P0.001) compared with the profile observed at the time at which most of the substrate has disappeared. Therefore, we concluded that the fermentation product profile at the end of in vitro fermentation at a specific time point cannot be used to compare fermentability of carbohydrate sources with different fermentation kinetics in terms of gas production.

In 6 trials with 460 pigs, initially about 19 kg the threonine requirement for growth between about 20 to 40 kg was investigated. To a negative control diet, containing crude protein 160 g and threonine 5.6 g/kg. L-threonine 0.0, 0.6, 1.2 and 1.8 g/kg, was added and compared with a positive control diet with crude protein 185 g/kg and threonine 6.8 g/kg. The negative control diet was supplemented with lysine, methionine, tryptophan, isoleucine, histidine and valine so that no other amino acids than threonine were limiting. The positive control diet was supplemented with lysine and methionine. The experimental diets were fed ad libitum as pellets. In 2 separate trials, the apparent faecal and ileal digestibility of the amino acids of the 2 control diets was estimated. The requirement for total threonine was 7.1 g/kg for maximum weight gain, and 7.4 g/kg for maximum efficiency of feed utilization in a diet containing net energy 2290 kcal/kg. These results correspond with 6.2 and 6.5 g/kg faecal digestible and 5.7 and 6.0 g/kg ileal digestible threonine, respectively. Pig performance on the negative control diet supplemented with the first limiting amino acids, was similar to that of the positive control diet. (Abstract retrieved from CAB Abstracts by CABI’s permission)

An improved method is described for the determination of oestriol concentrations in urines of pregnant women. Oestriol is detected as a derivate of 1-dimethylaminonaphtalene-5-sulphonylchloride (DANSYLchloride). The method has the following characteristics: 1. The recovery of oestriol-16-glucuronide is 94%. 2. For the interpretation of the results obtained with this method mean values and 95% probability bounds of urinary oestriol excretion for each week of the last three months of pregnancy are given. (e.g. 49--125 mumol/24 h at 32 weeks of gestation, 108--238 mumol/24 h at 40 weeks). 3. The coefficient of variation of the method is 4% (from day to day). 4. The lowest detectable concentration is 3 mumol/l. 5. Influence of glucose can be eliminated. 6. Other urinary compounds have no influence on the determination.