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Tree leaf meals (TLM) are increasingly used in the tropics to feed pigs. The nutritive value of the TLM of cocoyam (Xanthosoma saggitifolium), mulberry (Morus alba) and Trichanthera gigantea, their effect on the digestive tract and their fermentation rate in the large intestine, were determined in adult sows given diets containing 150 or 300 g TLM per kg. The TLM contained from 8·5 to 12·0 MJ digestible energy per kg dry matter (DM) and from 60 to 125 g digestible protein per kg DM. The digestibility was not affected ( P>0·05) by their rate of incorporation in the diet. The apparent ileal protein digestibility of the diets containing 300 g TLM per kg was also determined by the slaughtering method. It reached 80% for the basal diet and 54, 70 and 74% for the Trichanthera-, mulberry- and cocoyam-based diets, respectively. No diet effect ( P>0·05) was observed on the weight and length of the gastro-intestinal tract, with the exception of a heavier caecum in sows given the Trichanthera-based diet ( PTrichanthera

A comparison was made between the rate of passage of digesta through the digestive tract of pigs with an ileo-rectal anastomosis (IRA) or an Heal T-cannula according to the single marker dose method by using polyethylene glycol (PEG) as liquid marker, Cr2O3 as solid phase marker and Yb2O3-mordantedcell walls as fibre marker. The rate of passage was slightly faster with IRA than with cannulated pigs.

The effect of fibre level in protein-free diets on the recovery and amino acid composition of endogenous protein collected from the ileum in pigs was studied. Although the Heal nitrogen excretion increased slightly with dietary fibre level, no significant difference was observed on the amino acid recovery between diets containing 30, 60,90 or 120 g wood cellulose per kg.

A comparison was made between the Heal digestibility of the amino acids in pigs obtained by the use of a basal diet, the apparent Heal digestibility obtained with a semi-synthetic diet where peas were the sole protein source and the true Heal digestibility obtained with synthetic and nitrogen-free diets.