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1. On a “synthetic milk” ration containing approximately 0.8% methionine (30% casein) the baby pig requires 0.1% choline in its diet.

Individual full feeding and group self-feeding were used to determine the effect of three different arsenical compounds on weight gains and wool production of growing-fattening lambs. Practical type Corn Belt growing-fattening rations made up of alfalfa, corn, and soybean oil meal were used in the trials.Potassium arsenite, arsanilic acid, and arsonic acid were used to supply equal amounts of arsenic at levels of 0,002, 0.004, 0.006, 0.012, and 0.024 percent of the total ration based on the arsonic acid. None of these arsenicals fed at these levels consistently increased weight gains significantly when fed with an excellent quality or a poor quality ration. Experiment 2 indicated an increase in weight gains, which Experiment 3 did not, due to the arsenic on the poor quality ration. The gains of the lambs on the excellent ration exceeded those of the lambs on the poor ration, the difference being significant at the 1 percent level in both trials in which these were compared.In Experiment 3 arsonic acid at the 0.024 percent level did not reduce the numbers of coccidia as Experiment 2 had indicated it might.Rumen microflora, prothrombin time, and wool growth were not observed to be affected by any of the treatments.No histological difference was observed in the livers, kidneys, and adrenal glands from the lambs in the first experiment.No toxicity effect was observed at any time during the first three experiments. All rations were eaten satisfactorily and all lambs made very good gains.These results do not indicate any benefit from including these arsenicals in a practical farm ration for growing-fattening lambs. It appears that these arsenicals are not as toxic for sheep as they are for swine and poultry.

Favorable growth responses were obtained when sufficiently high levels of a vitamin B12concentrate were added to the basal alpha-protein diet, which is low in vitamin B12.When 50 micrograms of vitamin B12per Kg. of dry matter of the diet were fed, optimum growth rates were obtained. The addition of more vitamin B12concentrate did not result in a further growth response.Even the highest levels of vitamin B12concentrate fed did not induce completely normal hematopoiesis in 77 days of observation, as indicated by an abnormally high total erythroid percentage in the bone marrow.Gross symptoms which might be attributed to the deficiency existing in the basal diet were hyper-irritability, posterior incoordination, voice failure, and pain in the rear quarters.

In 1945 work was started at Illinois on the development of a “synthetic” diet for young calves in order to study the water-soluble vitamin requirements of ruminants. Since the “synthetic milk” diet developed was used successfully in the rearing of calves, it appeared worthwhile to attempt to rear baby pigs on the same diet.It was hoped that by starting with the very young animal it might be possible to produce deficiencies that do not appear in weanling or older pigs. Such animals would not have an opportunity to build up large body stores of the vitamins from the sow's milk and their rapid rate of growth should mean high requirements. Thus, the baby pig seemed an ideal experimental animal with which to study certain nutritive requirements of swine. It was also hoped that studies on baby pigs would lead to useful information applicable to infant nutrition.

Newborn lambs were fed a purified “synthetic milk” diet deficient in vitamin E and containing tocopherol-low molecular-distilled lard as a source of fat. Those animals maintained on this basal diet for about 7 weeks exhibited either paralysis of the legs or anorexia and weight loss. Addition of tri-o-cresyl phosphate to the basal diet (0.4 to 1.0 gm per liter of “milk” containing 19.5% dry matter) caused either severe leg weakness or sudden death after approximately 4 weeks. The effects of this compound could be delayed or prevented, but not cured, by oral administration of synthetic dl-alpha-tocopherol acetate at a rate of 100 mg per week. Lambs showing paresis induced by tri-o-cresyl phosphate ingestion died within three days despite the administration of large amounts of tocopherol either orally or intravenously as an emulsion. The outward manifestations of vitamin E deficiency obtained by feeding this diet, in addition to the muscular dystrophy, creatinuria and low plasma tocopherol levels also observed, indicate that the syndrome is identical with “stiff-lamb disease” which occurs among the suckling offspring of ewes fed a vitamin E-low practical ration. Abnormalities in the electrocardiograms of paralytic lambs were also detected. In a corollary experiment, it was found that when the basal diet was fed to rats, the addition of tri-o-cresyl phosphate (2 mg per gram) induced earlier development of a vitamin E deficiency, as identified by growth depression and the hemolysis test of Rose and György (’50), than was obtained on the basal regimen alone. Supplementation with synthetic dl-alpha-tocopherol acetate (24 mg per 100 gm diet) prevented the occurrence of deficiency symptoms in rats receiving the above level of tri-o-cresyl phosphate in the diet over a 10-week period.

One and 4-day-old pigs have been raised on a “synthetic” diet made up to simulate milk.

The effect of a Bi2 deficiency on transmethylation from methionine to choline has been studied. The deficiency did not influence the level of choline in the liver nor the excretion of urinary choline. Histological examination of livers and kidneys did not reveal the fatty infiltration or renal damage characteristic of a choline deficiency. From this study it appears that vit. Bi2 is not involved in this direct transmethylation.