I.Six 45 kg pigs with re-entrant ileal cannulas were used in two 3 x 3 Latin-square design experiments to study the site of absorption of protein and amino acids. Semi-purified diets containing soya-bean meal (SBM), rapeseed meal (RSM) or no protein source (protein-free) were offered at the rate of I kg dry matter/d.2. Flow-rates of ileal contents for 24 h collection periods, corrected for recovery of marker, were 3135, 3127 and 1243 ml (SE 390) for SBM, RSM and protein-free diets respectively.3. Amounts of dry matter digested in the small intestine were 730,669 and 809 g/d for SBM, RSM and protein-free diets respectively, all values being significantly different ( P < 0.001).4. Nitrogen intakes were 32'6,29'9 and 5.9g/d, and amounts digested in the small intestine were 25'7, 20.2 and 1.6 g/d for SBM, RSM and protein-free diets respectively, all values being significantly different (P < 0.001). Amounts digested in the large intestine were 2.6, 3.7 and 0.7 g/d. . Total amino acid intakes and amounts collected at the ileum and in the faeces were (g/d):SBM, 177,24 and 18; RSM, 149,~s and z z ; protein-free 3,9 and IZ. Digestibility in the small intestine was higher for SBM than RSM for seventeen of the eighteen amino acids estimated. Greater quantities of arginine, methionine, cystine and tyrosine were voided in the faeces than passed through the ileal cannulas for pigs receiving the SBM and RSM diets. For those receiving the protein-free diet this was true for each amino acid except proline.6. Significant differences were found between all diets in the concentration of some amino acids in ileal and faecal amino-N, and endogenous protein secretions did not mask the differences between diets.7. Differences in digestibility between SBM and RSM were greater at the ileum than in the faeces. Amino acid fermentation in the large intestine obscured or reduced differences between SBM and RSM.

High-speed cinematography with computer aided analysis was used to study equine hindlimb kinematics. Eight horses were filmed at the trot or the pace. Filming was done from the side (lateral) and the back (caudal). Parameters measured from the lateral filming included the heights of the tuber coxae and tailhead, protraction and retraction of the hoof and angular changes of the tarsus and stifle. Abduction and adduction of the limb and tarsal height changes were measured from the caudal filming. The maximum and minimum values plus the standard deviations and coefficients of variations are presented in tabular form. Three gait diagrams were constructed to represent stifle angle versus tarsal angle, metatarsophalangeal height versus protraction-retraction (fetlock height diagram) and tuber coxae and tailhead height versus stride (pelvic height diagram). Application of the technique to the group of horses revealed good repeatability of the gait diagrams within a limb and the diagrams appeared to be sensitive indicators of left/right asymmetries.

I. Two surgical techniques were developed in the calf to study the role of pancreatic secretion in digestion. The secretion was collected through a cannula placed in a small sac of duodenum into which the pancreatic duct drained. The continuity of the duodenum was re-established in the first technique by duodenal reentrant cannulas, and in the second technique by end-to-end anastomosis of the duodenum with a cannula placed cranial to the anastomosis to return the pancreatic secretion. The accessory pancrcatic duct was ligated.z. The flows of digesta through the duodenum of milk-fed calves were 5505, 6369 and 7709 ml/rz h at 7, 24 and 63 d of age respectively, similar to values reported previously in the literature. In a 12 h collection period 297, 441 and 602 ml pancrcatic fluid werc sccreted by calves of 7,24 and 63 d of age respectively. The secretion from the mucosa of the duodenal sac was 40 ml/12 h in t w o other calves.3. The rate of secretion from the pancreas varied markedly in milk-fed calves, being lowest 2-3 h and highest 6-10 h after feeding. Changes in the concentration of chloride and bicarbonate with pancreatic secretion rate were indicative of a secretin stimulus to secretion.4. The rates of inactivation of pancreatic enzymes collected from the duodenal sac were measured at 4O, zon and 39O.

Abdominal, inguinal and scrotal testes of horses were examined grossly and by light microscopy. An average of 1.5, 2.3 and 4.6 layers of spermatogenic cells, and mean seminiferous tubule diameters of approximately 66.2, 83.6 and 146.6 µm in the abdominal, inguinal and scrotal testes, respectively, were recorded.The interstitial spaces and the number of interstitial cells (of Leydig) seemed to be increased while spermatogenesis appeared to be arrested in the retained testes. Early spermatocytes were the most mature stages of the spermatogenic cells in the retained testes. An extensive vacuolation of spermatogenic cells was evident in these testes.The changes may result due to a high temperature of the abdominal environment in concert with the altered production of androgens.

1. Pigs were fitted with re-entrant duodenal cannulas anterior to the pancreatic duct, and total collections of digesta were made for 12 h periods.2. Maize–soya-bean diets were made from maize which had been harvested with a dry-matter content of 770 g/kg and either dried, preserved with acetic or propionic acid or ensiled naturally. The pigs received two meals of these diets/d at 12 h intervals, and the amount of digesta flowing through their cannulas was measured.3. Between 4.5 and 5.25 l of digesta flowed through the cannulas in the 12 h collection period, 0.9 of the total 12 h flow passed through the cannulas in the first 9 h with the dry-maize diet and 0.8 with the acid-treated-maize diets.4. The mean total dry matter intake was 358 g/meal, and 304 g dry matter passed through the duodenal cannulas in the 12 h collection period. The corresponding intake and flow of nitrogen (g/12 h) was 11.1 and 9.6, and for chromic oxide 1.13 and 0.94.5. The pigs consumed 205 g starch (total α-linked glucose polymers)/meal, and 1.5 g free glucose/meal. Only 110 g starch and 4.1 g free glucose reached the duodenal cannulas, suggesting that digestion and absorption of up to 92 g glucose had taken place anterior to the pancreatic ducts.