To investigate the effects of dietary charcoal powder including wood vinegar compound liquid (CWVC, 4 : 1) on intestinal villus histology, piglets were fed 0, 1, 3 and 5% dietary CWVC diets for 30 days. Feed intake and body weight gain were measured during the experimental period. At the end of the experiments, intestinal villus height, epithelial cell area and cell mitosis were examined using light microscopy (LM), and the duodenal villus tip surface was observed using scanning electron microscopy (SEM). Feed efficiency tended to be improved in the CWVC group. The 3% CWVC group showed the highest value, followed by 1% CWVC group of most LM parameters in most intestinal parts, but the 5% CWVC group showed the almost similar value compared with the control. In addition, on the duodenal villus tip surface, the 3% CWVC group showed a clearer cell outline, larger cells and cells protuberated further into the lumen than those of the 1% CWVC group. However, the 5% CWVC group showed faint SEM features than the 1% CWVC group. The present trend of improved feed efficiency after feedings of dietary CWVC demonstrates that the CWVC could be incorporated into piglet diets up to 3% level, and that the CWVC might activate intestinal functions both at villus and cellular levels.

This study was conducted to establish the relationship between histological alterations of the intestinal villus and intestinal function, and to histologically assess the enteral nutrient absorption of raw pigeon pea seed meal (PM). Piglets were allotted into five groups: feed withdrawal for 3 days or 5 days, refeeding soybean meal (SM) or PM for 2 days after the 3-day fast, and access ad libitum to conventional feed for the last 2 days without fasting. After the end of each experiment, the intestinal segment and duodenum of each piglet were processed and examined by light and scanning electron microscopy, respectively. After fasting, villus height, cell area and cell mitosis number were decreased in most parts of each intestinal segment, and duodenal villus tips had a smooth surface. After refeeding SM or PM, the decrease in body weight improved, but there was not a significant difference between them. The atrophic morphology of the intestine was reversed by refeeding SM, suggesting that the intestinal villi might be activated by absorption of SM. On the other hand, in the piglets refed PM, the recovery of light microscopic parameters and duodenal villus tip morphology was less clear than with SM. The present histological results suggest that although the absorption of PM is less than that of SM, the PM nutrients might be effectively absorbed, even in the raw form, and establish that in pigs intestinal histological alterations correspond well with intestinal absorptive function.

To investigate the effects of dietary pigeon pea (Cajanus cajan L.) seed meal (PM) on growth performance in early life stage of pigs and whether the raw PM could be used as a plant protein resource, 32 piglets were randomly allotted into 0, 10, 20 and 30% dietary PM groups of 8 pigs (2 pigs attained to the final 30kg body weight. Then, the composition of basal diet was changed from piglet diet to growing pig (30-60kg) diet. In both experimental feeding periods, feed intake, body weight gain, feeding period (day) until respective final body weights and feed conversion ratio were measured. Up to 20% PM group in growing pigs, there was no definite difference in the feed intake between each group, but the body weight gain tended to insignificantly decrease with the increasing dietary PM level, resulting in the insignificant increase of the feeding period and feed conversion ratio. However, all parameters significantly changed (P<0.05) at 30% PM level in growing pigs except in the feed conversion ratio which showed a significant difference (P<0.05) between 10 and 30% PM levels.This suggests that as a plant protein source the PM could be incorporated beyond the 30% level for piglet diet (53.4% substitution rate of PM for soybean meal) and up to the 20% level for growing pig diet (76% substitution rate of PM for soybean meal) and that the effective utilization of PM enables to reduce the feed cost in pig production.

Raw legume seeds are important source of protein and other nutrients for monogastric animals. However, these legume seeds include many kinds of anti‐nutritive factors (ANF) such as trypsin and chymotrypsin inhibitors, lectins and tannins. Although these ANF vary by species, cultivation areas and harvesting methods, they play a role in decreasing the utilization of nutrients. The pig is a monogastric animal which is slightly tolerant to the ANF in raw legume seed. Nevertheless, the optimal use of legume seed as a pig feed necessitates a lowering of the toxicity in the raw seed until it is appropriate for incorporation in the feed. There are many methods to improve the utilization of nutrients in legume seed, such as breeding improvement, physical treatments (decortications, dehulling, milling and others), heat treatments (toasting, boiling, extrusion, streaming or autoclave), chelating substances for binding toxics, radiation and soaking. The choice of the treatment depends on the availability of facilities and economic considerations. This article reviews and discusses the nutrients in legume seeds and might offer an important information on legume seeds for pig feed to nutritionists.

Mekbungwan, A., Yamauchi, K. and Thongwittaya, N. 2003. Histological alterations of intestinal villi in growing pigs fed soybean and pigeon pea seed meals. Can. J. Anim Sci. 83: 755-760. To clarify whether specific damage to intestinal tissue is induced by feeding pigs pigeon pea seed meal (PM), growing pigs were fed soybean meal (SM) or PM, and intestinal villi and epithelial cells on the tip of villi were compared using light and electron microscopy. Fifteen 85-d-old pigs were allotted to three groups of five animals each. Within each group, a pig was randomly assigned to: (1) a conventional (control) diet, (2) SM or (3) raw PM for 10 d. At the end of the experiment three pigs per group were randomly slaughtered. Intestinal villus height, cell area and cell mitosis tended to be highest in the SM group and lowest in the PM group. Dome-like cells were seen on the surface of villi in SM group, but flat cells were observed in the PM group. These histological data suggest that intestinal villi are much more activated in pigs fed SM than PM. However, the fact that physical damage was not observed on the tips of villi in pigs fed PM suggests that raw PM could be used as a plant protein source by adding it as a supplement to conventional diets. (1) ration ordinaire (témoin), (2) TS ou 3) PC brut pendant dix jours. Au terme de l'expérience, trois animaux ont été prélevés au hasard dans chaque groupe et abattus. La hauteur des villosités, la surface cellulaire et la mitose ont tendance à être plus importantes chez les animaux du groupe TS que chez ceux du groupe PC. On observe des cellules en dôme à la surface des villosités des animaux du groupe TS alors que chez ceux du groupe PC, ces cellules sont plates. Ces données histologiques donnent à penser que les villosités intestinales sont beaucoup plus mises à contribution chez les porcs nourris de TS que chez ceux recevant du PC. Néanmoins, l'absence de dommages à l'extrémité des villosités chez ces derniers laisse croire que le PC brut pourrait être utilisé comme source de protéines végétales sous forme de supplément dans les rations habituelles.