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An experiment was conducted to study the effect of adding crystalline niacin to low-protein diets on pig performance from weaning to market weight. Niacin was added at 0, 3, 9, 27, or 81 ppm to a low-protein test (LPT) diet fortified with crystalline amino acids and at 0 or 81 ppm to a positive control (PC) diet. Pens (four pigs/pen) were the experimental units with 12 and 8 pens per treatment during the 35-d nursery and 98-d growing-finishing phases, respectively. Niacin supplementation did not affect (P > .10) ADFI, ADG, gain:feed ratio, hair and skin condition, or the incidence of toe cracks and lameness during the nursery or the growing-finishing phases. There were no linear, quadratic, or cubic responses (P > .20) with increasing concentrations of added niacin in the LPT diets for the production criteria measured. Also, there were no interactions (P > .20) between niacin (0 or 81 ppm) and protein level (LPT or PC diets) for any of the criteria studied. Pigs fed the PC diets had greater (P < .05) ADFI, ADG, and gain:feed ratios over the entire experiment than pigs fed the LPT diets that contained 0 or 81 ppm of added niacin. In conclusion, the addition of niacin to low-protein or positive control corn-soybean meal diets did not improve pig performance criteria from weaning to market weight.

Five groups of vervet monkeys (Cercopithecus aethiops) were fed regular monkey chow, low protein (LP), low B-vitamin complex (LBV), LP-LBV, or low protein- low calorie (LP-LC) diets, respectively. After eight weeks the animals were infected with cholera vibrios. IgG, IgA and IgM increased in the sera of all animals after the challenge but the avidity of the immunoglobulins was lower in vervets on LP diets. Diarrhea and excretion of vibrios lasted longer in animals consuming less protein.

Vitamin E--selenium deficiency in dogs resulted in complete suppression of lymphocyte responsiveness to stimulation with mitogens. Depressing effects on neutralizing antibody synthesis were also noted. A serum factor associated with the inability of lymphocytes to respond has been isolated and partially purified. The suppressor factor can be removed or transformed by both in vivo and in vitro vitamin E supplementation.

Summers et al., 1978, described an experiment in which performance and leg conditions of birds fed diets devoid of synthetic biotin, choline, folic acid, manganese, and miacin were observed and recoreded. This is a report on birds from the same experiment. Dyschondroplasia of the tibia was documented and the distal end of each tibia examined histologically. Metatarsal length and condyle depth of the distal tibia were also determined. Metatarsal length was influenced by vitamin deficiencies as well as the type of floor on which binds were raised. The depth of the intercondyle space was affected more by a manganese deficiency than by vitamin deficiencies and, in this case, was greater on plastic and litter as opposed to wire floors. There did not appear to be a correlation between the space depth and slipping of the tendons; however, a large number of birds should be examined to provide more data. Dyschondroplasia was more prevalent in choline deficient birds, particularly those birds raised on litter or plastic floors. Histology changes in relation to nutrient deficiencies were comparable to those reported previously.

Five groups of eight vervet monkeys (Cercopithecus aethiops) were fed regular monkey chow, low protein (LP), low B-vitamin complex (LBV), low protein - low B-vitamin complex (LB-LBV), or protein - low calorie (LP-LC) diet, respectively, for eight weeks. Hematocrit values, hemoglobin, BUN, total protein, albumin, riboflavin and body weight decreased, the ratio of dispensable/indispensable amino acids increased in all animals receiving a deficient diet. Total globulin, IgG and IgM remained unchanged in vervets on LBV diet; panthotenic acid and cyanocobalamin in animals receiving LBV, LP or LP-LC chow; and pyridoxal on the LP or LP-LC diet.

Two experiments were conducted to investigate the effects of varying levels of pantothenic acid on the efficiency of energy utilization and changes in body composition of the growing chick. The results indicate that a pantothenic acid deficiency does not interfere with the chick's ability to obtain metabolizable energy from the diet. The data do show that the efficiency of energy utilization and body composition were markedly affected when chicks were fed diets deficient in pantothenic acid. In both experiments, protein, fat and energy stores were significantly reduced when pantothenic acid-deficient diets were fed. Increased estimates of heat increment per gram of diet were observed when levels of pantothenic acid below the N.R.C. (1971) recommended level of 10 mg. per kg of diet were fed.