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Calves were surgically supplied with double fistular anastomoses (duodenal and ileal) to study the dynamic of digestive processes. The experiment was carried out in three periods: sucking, transitive (milk and vegetative feed), and fully vegetative. It was found that both the duodenal and the ileal chyme of sucking calves is by its physical and chemical properties substantially different from the chyme of adult cattle. With the transition from the milk type on to the vegetative type of feeding the composition of chyme of calves changes in colour, consistency, dry matter, organic matter, and crude fibers. With the vegetative type of feeding the digestion organs of calves were found to work more actively than with the feeding with milk with added plant feed. In the transition period 10 to 20 per cent of the dry and organic matter was digested and utilized before coming to the duodenal anastomosis. In this period beside the abomasum the forestomach with its three compartments was also shown to be involved in the digestion processes. With the increase in the amount of course feed in the diet of calves the amount of dry matter, organic matter, and crude fibers digested in the forestomach reached 45-52 per cent.

The goal of this study was the investigation into the vagus nerve structure in the ruminant stomach, and a description of the participation of this nerve in the stimulation of the atrial lymph nodes of the rumen and dorsal abomasal lymph nodes. This survey was carried out on 30 sheep fetuses, whose ages are designated according to Zietzschmann and Krölling (1955). The fetuses came from the third to fifth months of pregnancy. Observations and general morphological nature may be summarized as follows: 1. to the wall of the rumen reach atrial branches coming from both vagus trunks plus a dorsal ruminal branch, and a right ruminal branch coming from the dorsal vagus trunk, 2. the reticulum receives reticular branches, coming from both vagal trunks, 3. the omasum is innervated by omasal branches of the dorsal vagus trunk plus an omasoabomasal branch coming from the ventral vagus trunk, 4. to the wall of the abomasum reach the reticulo-abomasal and pyloric branches coming from the ventral vagus trunk plus a branch to the major abomasal curvature and a visceral abomasal branch coming from the dorsal vagus trunk, 5. arterial lymph nodes of the rumen receive innervation from the reticulo-abomasal branch or the pyloric branch, both leaving from the ventral vagus trunk, 6. dorsal abdominal lymph nodes innervated by nerve branches coming from a parietal abomasal branch, coming also from the ventral vagus trunk.

Clinical features and pathological and mycological findings in a field outbreak of intoxication in dairy cattle grazing kikuyu grass are reported. The outbreak followed invasion of the grass by the army worm (Spodoptera exempta). Clinical signs included drooling of saliva, depression, apparent inco-ordination, sunken eyes, ruminal distension and atony, recumbency, moderate diarrhoea and "sham drinking". Seventy-seven cows (64%) were clinically affected over a period of 12 days. Of these, 37 died. Necropsies performed on 4 affected cattle revealed necrosis of the epithelium of the forestomach, which was consistently more severe in the omasum. Light microscopy showed extensive necrosis of the epithelium of the forestomach with associated fibrinopurulent inflammation. The stratum spinosum and s. granulosum were selectively involved, but the s. basale was generally preserved. Electron microscopical examination of ruminal and omasal epithelium from 2 of these cattle revealed cytopathological features in the s. spinosum and s. granulosum which were consistent with stages in an acute, anoxic type of injury. Mycological examination of the pastures revealed sparse growth of a mixed fungal population, which included Myrothecium verrucaria. There was no evidence of heavy fungal infestation. Previous evidence that M. verrucaria, or other fungi, may be involved in the aetiology of kikuyu grass poisoning of cattle in New Zealand is addressed. It appears improbable that any of the fungi isolated in this investigation could have played an important role in the aetiology of this outbreak.

1. The relations between food intake, reticulo-ruminal motility and abomasal digesta outflow were investigated in ewes receiving lucerne (Medicago sativa) v. orchard grass (Dactylis glomerata) hay. Abomasal digesta outflow was recorded continuously by means of an electromagnetic flowmeter probe inserted into a duodenal T-shape cannula and the motility using strain-gauge force transducers. Volumes and turnover rates of both rumen and abomasal liquid phases were measured by CrEDTA dilution.2. The voluntary intake of lucerne was higher (60%) than that of orchard grass hay, and paralleled by an increased abomasal outflow (65%) corresponding to an increased number of gushes of digesta through the flowmeter probe: 129/h instead of 78/h on orchard grass hay. Abomasal motor activity was enhanced (35%), and periods of regular spiking activity were seen passing along the duodenum at a higher velocity for the lucerne diet than for the orchard grass diet. The increased abomasal outflow with lucerne hay was associated with a higher reticulo-ruminal turnover rate, but not abomasal turnover rate. Abomasal, but not reticulo-ruminal volume, was increased (30%) when lucerne hay was fedad lib.3. The total number of reticulo-ruminal contractions was increased by 6.6% when the dry matter entering the duodenum was increased by 70.6%, suggesting the level of voluntary intake, rather than reticulo-ruminal motility, as a major factor governing abomasal outflow in sheep.4. More frequent passages of digesta, unrelated to duodenal contractions, were recorded in ewes receiving lucerne compared with orchard grass. Both a higher viscosity of the contents due to the addition of guar gum and the impairment of antroduodenal motility by 5-hydroxytryptophan were able to reduce the flow rate of orchard grass digesta, but did not affect the higher flow rate of lucerne digesta. The findings suggest that the high abomasal outflow in sheep fed on lucernead lib.is related to a low viscosity of the contents that are propelled, even in the case of antral contractions of low magnitude.

The effect of insulin-induced hypoglycaemia on the motility of the reticulum, rumen and abomasum of sheep was investigated using small lightly inflated balloons connected to transducers and a multichannel recorder. The principle response recorded was an inhibition of reticulo-ruminal and abomasal motility, occurring in ‘resting’ cycles only, and not during eating or rumination. The only hypermotility recorded was that shown by the abomasum just before the onset of inhibition. Ruminating cycles were recorded as frequently during hypoglycaemia as in control periods, and showed no abnormality. The inhibition was reversed by intravenous glucose or adrenaline and by feeding or ruminating.

Preliminary evidence indicates that the Langerhans cell granules (also known as Birbeck granules) may really be intercellular desmosomal discs of the more superficial layers of stratified squamous epithelium that have been taken up by the interdigitating dendritic processes of the Langerhans cells. They should therefore be considered as phagosomes whose only significance is in indicating that their hosts had traversed one or other of the various types of stratified squamous epithelium of the body. When seen in this light variable presence in Langerhans cells or occasional presence in melanocytes or keratinocytes can be satisfactorily explained. Although the Langerhans cells form the first line of immunologic defence as antigen detectors, it is unlikely that their granules play any role at all in the immune response.

Experimental acidosis of the forestomach was induced in 6 lambs and 29 ewes and rams, using starch (5-10 g/kg body mass), lactic acid (0.4-0.5 per cent of the live weight) or concentrates (50-60 g/kg body mass). Acidosis occurred spontaneously in 10 calves and 14 cows following the intake of great amounts of molasses. The changes were followed up in the total activity and properties of the alkaline phosphatase in the blood serum of the diseased animals. It was found that the total activity of the enzyme in the blood serum of the test animals dropped at the 24th hour after the beginning of the experiment, reached its lowest point at the 48th-72nd hour (50 to 70 per cent drop as compared to the initial level), and was still under the initial level with part of the test animals at the 96th hour. The decrease in the total activity of the enzyme in the blood serum was found to be linked with changes in its properties - the resistance to 1-phenylalanine rose, and the resistance to 1-arginine, 1-homoarginine, and heat treatment at 56 degrees C for 10 minutes dropped. The activity of the serum alkaline phosphatase with the spontaneously affected calves and cows was dependably lower than the activity of the enzyme un normal calves and cows. It is believed that the drop of the total activity of the blood serum alkaline phosphatase is chiefly governed by the lowered release in the blood of intestinal alkaline phosphatase as the result of its disturbed synthesis and intestinal absorption.

Urease activity, expressed as mg N-NH3/g dry weight per 30 min at 25 degrees C, was determined in the various parts of the sheep, chicken and pig digestive apparatus. The results were as follows. Sheep: contents--rumen 1.25"/-0.09, reticulum 0.78+/-0.02, omasum 0.44+/-0.02, abomasum 0.002+/-0.001, duodenum 0.003+/-0.001, jejunum 0.18+/-0.03, ileum 0.42+/-0.03, caecum 1.34+/-0.11, colon 0.76+/-0.08, walls-rumen 0.88+/-0.16, reticulum 0.38+/-0.04, omasum 0.11+/-0.02, abomasum 0.01+/-0.002, ileum 0.092+/-0.01, caecum 0.14+/-0.03, colon 0.16+/-0.02. Chicken: contents--jejunum 0.028+/-0.009, ileum 0.043+/-0.013, caecum 0.17+/-0.03, colon and cloaca 0.04+/-0.013. Pigs: contents--jejunum 0.02+/-0.01, ileum 0.14+/-0.08, caecum 0.62+-0.12, colon 0.43+/-0.06. No urease activity was found in the walls of the digestive apparatus or the contents of the duodenum in chickens, or in the walls of the stomach and intestine and the contents of the duodenum in pigs. The results show that urease activity in the digestive apparatus of pigs and poultry is lower than in sheep. Inadequate urease activity in the digestive apparatus explains why chickens and pigs are significantly less capable than ruminants of utilizing urea nitrogen as a substitute for some of the protein in the diet.

1. Effects of feeding liquid milk-substitute to young calves either by nipple-pail or open-bucket on the rumen by-pass and on the rate of passage were studied.2.Sixteen Holstein calves, aged 1 week initially, were used in three experiments in which calves were slaughtered after they were given liquids (milk-substitute and water) containing chromic oxide and SrCl2 6H2O as a tracer either by the nipple- or bucket-feeding method, and the distribution of tracers to the rumen, abomasum and the lower alimentary tracts was examined.3.When the liquid milk-substitute containing tracers was given by the nipple- or bucket-feeding method to calves having been trained to the corresponding procedures for the preceding 1 week, most of the tracers was directed into the omasum and abomasum. There seemed no difference in the functioning of oesophageal groove closure between the two feeding procedures. Even when the liquid milk-substitute containing tracers was given by the nipple-or bucket-feeding method to calves which had been accustomed to different procedures for the preceding week, the majority of tracers were found in the abomasum immediately after administration, though a slightly greater proportion of the tracers entered the reticulo-rumen.4.Continuing bucket feeding of liquid milk-substitute effected an efficient closure of the oesophageal groove at least up to 16 weeks of age. After calves were accustomed to consume liquid milk-substitute from the bucket from 1 to 4 weeks of age, drinking warm water from the bucket also caused efficient closure at least up to 16 weeks of age.When tracers were administered with warm water, Cr2O3 and strontium, especially the latter, transferred much more rapidly to the lower gut than when they were administered with liquid milk-substitute, probably reflecting the curd formation of the milk-substitute in the abomasum. When liquid milk-substitute with tracers was fed by the bucket-feeding method, Sr transferred more rapidly to the lower gut than when the milk-substitute was fed by the nipple-feeding method, indicating that the feeding procedure of liquid milk-substitute has an apparent effect on the rate of passage.

The stability of beta-carotene in the rumen contents of cows, calves and sheep was investigated in vitro and in vivo. Incubation tests with rumen liquor consistently showed that carotene was relatively stable, less than 10% losses being found under a wide variety of incubation conditions and with different sources of carotene. There was no relation between the small carotene losses and the extent of fatty acid hydrogenation. Rumen liquor samples taken from a fistulated cow over a 24 h period after the feeding of alfalfa meal had a nearly constant ratio of carotene to unsaponifiable matter. Carotene was injected into the rumen of a ram after surgical ligation of the pylorus. The recovery of carotene from the combined contents of the reticulo-rumen, omassum and abomasum 24 h later amounted to 89% whereas vitamin A palmitate, under the same conditions, yielded a recovery of 70%. It is concluded that little carotene is lost normally during its passage through the pre-intestinal part of the alimentary canal of ruminants.

Summary Simultaneous oral challenge of calves with S. dublin, S. typhimurium and S. choleraesuis produced a severe disease essentially similar to that produced by giving one of the serotypes alone. In general, organisms of the three serotypes were similarly distributed throughout the contents of the alimentary tract and the tissues. This applied even when the challenge dose of each of the three serotypes was reduced to 104. The distribution of organisms was different in rabbits, mice and fowls simultaneously challenged with these three serotypes.

1. Observations were made on the daily intake and excretion of potassium and sodium in sheep housed in metabolism cages and fed once daily. 2. The diet of chaffed hay and crushed oats provided 400-600 m-moles K and 50-60 m-moles Na daily. About 90% of the K was excreted in the urine, and over 90% of the Na was found in the faeces. 3. In two groups of three experiments on each of three sheep, the urinary responses to intra-ruminal dosing just before feeding of (i) 1 l. distilled water, (ii) 1 l. 0·25 N-KCl, and (iii) 1 l. 0·125 N-NaCl, were studied. In the first group, urine was collected via the urine/faeces separator of the metabolism cage, whereas for part of the experiments in the second group it was collected by an indwelling bladder catheter. 4. In a third group of experiments with the same sheep, the effects on urinary excretion of K and Na of intra-ruminal dosing with (i) 1 l. distilled water, (ii) 1 l. 0·25 N-K acetate, and (iii) 1 l. 0·25 N-Na acetate were investigated. During part of these experiments urine was again collected via an indwelling bladder catheter. With chloride, 82% of the additional potassium was excreted in urine in the 24 hr after dosing, but with acetate only 65%. For sodium, the corresponding figures were 12-40% with chloride and 43% with acetate. 5. In most experiments, the administration of K salts produced a marked kaliuresis and, in spite of the low sodium intake, a natriuresis as well, which did not usually coincide with maximum K excretion. No adequately tested explanation appears to exist for the natriuresis observed in response to treatment with K salts.

1. Two experiments involving 106 lambs were conducted to study the functioning of the oesophageal groove reflex in lambs sucking from either individual feeders or from a bulk dispenser. The effects on the performance of lambs given either a high-protein or a low-protein creep feed in conjunction with either a ewe's milk substitute, Ewelac, or a homogenate of calcium caseinate, Casilan, were studied. Two milk substitutes, one with a long and one with a short clotting time were compared in terms of their effects on the incidence of diarrhoea.2. The location of the liquid feeds in the stomach was studied radiologically.3. In both experiments the sucking behaviour of the lambs was closely related to thefunctioning of the oesophageal groove reflex and performance of the lambs. In the first experi-ment the milk substitute consistently entered the abomasum in seven of the ten individually fed lambs and in twelve of the twenty-two group-fed lambs. The corresponding figures for the second experiment were twenty-two of the twenty-four individually fed and thirty-four of the fifty group-fed lambs.4. When the milk substitute entered the abomasum it always did so throughout the fattening period even in those instances where the milk had been withheld for 1 month.5. Poor sucking, low milk consumption and the entry of the milk into the rumen resulted in very poor performance by the lambs. Such lambs demonstrated a non-specific unthriftiness similar to the ‘tail enders’ sometimes observed with lambs reared with ewes.6. Continued feeding with either the milk substitute or casein homogenate with a low-protein creep feed did not improve performance.7. The clotting time of the milk substitute did not appear to influence the incidence of diarrhoea among the lambs.

1. Fluids were given by mouth in various ways to young sheep. The extent to which closure of the oesophageal groove operated to direct the fluid to the abomasum was assessed by radiography.2. Salt solutions and milk given as a drench did not produce complete closure of the groove. However, when the animals were accustomed to sucking from a teat before weaning, any liquid suspension and also water, sucked from a bottle, passed entirely to the abomasum even in 12-month-old sheep.3. This technique may be useful when it is desirable to cause protein or other nutrients to by-pass fermentation in the rumen.

Ruminant animals differ from monogastric species in being able to digest cellulose material by means of microbiological fermentation processes. A device has been constructed which can dispense chopped hay to ruminants in operant conditioning experiments.

Three modifications of the digestive system of kids were made by removing rumen, reticulum, and omasal laminae. Operated animals with a control were subjected to long feeding trials. After weaning, several highly digestible feeds were prepared and fed. One of five animals having all forestomach compartments removed survived more than a year during which the animal encountered pyloric obstruction twice. Two of three animals having the ruminoreticulum removed survived more than 9 mo. These long survivors finally were slaughtered. Though appetite of these animals became a problem, digestive abilities for highly digestible solid feeds were almost the same as those of animals with the intact rumen. No regeneration of the stomach compartment was observed, but cecum became significantly larger. In the reticulum of the animal with omasal laminae removed, dietary bone particles accumulated, suggesting an omasal function of passing heavier particles. Chemical components of blood, saliva, and body fat were measured.

In the early weeks of life of the young calf, digestion and metabolism are in a transition state, during which processes typical of the monogastric change to those of the ruminant. Characterizing the transition is a rapid increase in the size and capacity of the forestomach (rumen, retieulum, and omasum) relative to the other organs o£ the digestive tract. Certain dietary factors have been shown to control digestive capacity and function, as well as enzyme and metabolic activities. This paper will emphasize comparative data between the nonruminating calf and the functional ruminant.

The llama and guanaco stomach consisted of three compartments. A transverse pillar divided the large, first compartment into cranial and caudal sacs. Both sacs contained recessed glandular saccules. The saccules in the caudal sac were everted during the gastric contraction cycle. The non-recessed surfaces of this compartment were covered by stratified squamous epithelium. The first compartment communicated on the right with a smaller, reniform second compartment. Except on the lesser curvature, this compartment contained deep cells which were lined by a papillated glandular mucosa. The ventricular groove, defined by a single muscular lip, coursed along the cranial sac of the first compartment, over the lesser curvature of the second compartment, and terminated at the tubular passage to the third compartment. The initial four-fifths of the elongate third compartment contained mucigenous glands like those found in the saccules and cells of the first and second compartment Proper gastric glands and pyloric glands were confined to the terminal one-fifth of the third compartment. Attempts to homologize the compartments of the camelid stomach with those of the Pecora or so-called advanced ruminants were unsuccessful. The results of this study and concurrent physiologic investigations indicated that the processes of ruminant digestion can operate within wide anatomic boundaries, and that the camelid stomach with its extensive glandular mucosa is adapted for greater digestive efficiency than the advanced ruminant stomach.

The metabolism of a single dose of 3H-DL-α-tocopherol was studied in 16 sheep fed a dystrophy-producing hay alone or supplemented with cod liver oil. During the experimental period, which lasted for 5 days after the radioisotope dosing, radioactivity was higher in the rumen liquor of cod liver oil fed sheep than in those which received only hay. Significantly lower levels of radioactivity were found in the non-saponifiable material of various tissues of cod liver oil fed sheep than in the corresponding tissues of the unsupplemented animals. By means of column chromatography, thin layer chromatography, and radioautography the bulk of liver radioactivity was identified as unchanged α-tocopherol. Possible reasons for the difference in tissue radioactivity levels between cod liver oil fed and unsupplemented sheep are discussed.