Two experiments were carried out for six and seven 28-d periods, respectively, with DeKalb XL Single Comb White Leghorn laying pullets to ascertain the effect of feeding 1,100 mg Lactobacillus (Lacto)/kg diet (ppm) and 2,200 ppm Lacto diets, and the supplementation of these diets with 1 and 3% fat, on layer performance and nitrogen, calcium, and phosphorus retention. The dietary treatments were corn-soybean meal (C-S) control, C-S plus condensed cane molasses solubles (CCMS)-1,100 ppm Lacto (4.4 x 10(7) cfu/mg Lacto), and C-S plus CCMS-2,200 ppm Lacto (8.8 x 10(7) cfu/mg Lacto) without fat (Experiment 1) and without and with 1 and 3% supplemental fat to each Lacto level (Experiment 2). In both experiments, layers fed the 1,100 ppm Lacto diets had better (P < .05) hen-day production, daily feed consumption, egg mass, egg weight, egg size, and feed conversion than layers fed diets without Lacto. Egg mass, interior egg quality, and feed conversion (Experiment 1), mean body weight gains, and nitrogen, calcium, and phosphorus retention (Experiment 2) were further improved (P < .05) with feeding 2,200 ppm Lacto diets. Feeding Lacto diets with 1% fat provided (P < .05) larger eggs and better (P < .05) nitrogen and phosphorus retention, whereas 3% fat decreased (P < .05) feed consumption and nutrient retention and improved (P < .05) feed conversion and body weight gain. Positive correlations between Lacto diets and nitrogen and calcium retentions, daily feed consumption, and egg size were observed. Feeding 1,100 ppm Lacto diets to layers stimulated appetite and improved egg production, egg mass, egg weight, egg size, and feed conversion. Addition of fat to Lacto diets reduced daily feed consumption and provided better feed conversion, egg masses, egg sizes, body weight gains, and nutrient retentions.

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Three hundred sixty Peterson x Arbor Acres chicks were fed two feed regimens to compare their effects on adipose cellularity, adipocyte lipolysis, hepatic glucose oxidation, adipocyte lipogenesis, bird performance, and abdominal fat level. Broilers in the first regimen had ad libitum access to feed throughout the 7-wk experiment, whereas broilers in the second regimen consumed feed at will throughout the experiment except that they were subjected to feed restriction (1.49 kcal/g BW2/3 daily) from 7 to 12 d of age (DOA). No differences in mean body weights were observed between the full-fed and restricted males and combined sex broilers at 49 DOA. Feed conversion and abdominal fat levels of female and combined sex were lower (P < .05) for the restricted than full-fed broilers. No differences in adipocyte numbers based either on whole abdominal fat pads at 28 and 42 DOA or per gram fat at 42 DOA were observed between broilers fed the two feed regimens. However, the adipocyte numbers per gram fat at 28 DOA were greater (P < .05) for the restricted broiler than for the broilers that ate freely. Lipolysis based per million adipocytes was not different between the treatments at 28 and 42 DOA; however, lipolysis based on per gram adipose tissue was increased (P < .05) with the addition of isoproterenol and theophylline for the restricted broilers compared to the full-fed broilers at 28 DOA. No difference was observed between the feed regimens at 42 DOA with hormone addition. Lipogenesis of the restricted broilers was lower (P < .05) than that of the full-fed broilers at 14 and 56 DOA. No difference in glucose oxidation was found between chickens fed the two regimens. Reduced abdominal fat in the restricted broilers is attributed to the reduction of adipocyte volume, which may be due to decreased lipogenesis.

An experiment was conducted with Single Comb White Leghorn (SCWL) layers to determine the effect of feeding either corn-soybean meal (C-S) or barley-corn soybean meal (B-C-S) diets with or without condensed cane molasses solubles (CCMS) or with or without CCMS-1,100 mg Lactobacillus (Lacto)/kg (ppm) diet on performance, nutrient retentions, digesta passage rate, and histological changes of the gastrointestinal (GI) tracts. Six dietary treatments were fed for eight 28-d periods and consisted of C-S (control), C-S + CCMS, C-S + CCMS-1,100 ppm Lacto (4.4 x 107 cfu/mg Lacto), B-C-S (control), B-C-S + CCMS, and B-C-S + CCMS-1,100 ppm Lacto. The CCMS served as the carrier for the Lacto, and the CCMS-Lacto premix (55 g Lacto/kg) was incorporated at 2% of the diet. Lactobacillus supplementation in C-S diets improved (P < .05) egg weight, egg mass, egg size, and body weight gains, and in B-C-S diets improved body weight gains. There were no differences in feed consumption, feed conversion, internal egg quality, and egg specific gravity among the dietary treatments. Passage rates of digesta were increased (P < .05) when either C-S or B-C-S layer diets were supplemented with Lacto. Lactobacillus supplementations of the C-S and B-C-S diets increased (P < .05) fat and calcium, and fat, phosphorus, copper, and manganese retentions, respectively. Increased cellularity of Peyer's patches in the ileum indicated a stimulation of the mucosal immune system that responds to antigenic stimuli by secreting immunoglobulin (IgA).

Two experiments were conducted with Hubbard broiler chicks on the metabolism of high levels of dietary zinc. In the first experiment, chicks were fed a basal diet or the basal diet plus 500, 1,000, 2,000 or 4,000 ppm zinc, and in the second experiment chicks were fed the basal diet or the basal diet plus 1,000, 2,000, 4,000, 8,000 or 16,000 ppm zinc, using zinc acetate. Zinc was found to be associated with 4 peaks when the cytosols from tissues (liver, kidney, pancreas and intestinal mucosa) were eluted through columns of G-75 Sephadex. Although the zinc content of all four peaks increased with increased zinc content of the diet, the greatest elevation occurred in metallothionein (MT). This protein was purified from all four tissues (liver, kidney, pancreas and intestinal mucosa) and the amino acid analysis revealed the presence of about 30% cysteine. Zinc accumulated to the greatest extent (microgram in MT/g tissue) in MT of the pancreas. The zinc in MT disappeared very rapidly when chicks which had been fed a diet containing high levels of zinc were fed a low zinc diet, indicating the extreme lability of this metal in this protein. The results suggest the involvement of MT in zinc homeostasis.