The utilization of calcium soaps from animal fat by laying hens

Use of Polyunsaturated Fatty Acids with α-Tocopherol in Poultry Feeds

The ability of α-tocopherol to prevent the degradation of the polyunsaturated fatty acids, docosahexaenoic acid (DHA) and linolenic acid (ALA) at elevated temperature was investigated in a series of laboratory experiments. DHA is known to promote nervous system function and health, however, DHA and other highly unsaturated fatty compounds are readily oxidized with loss of bioactivity. Mixtures of DHA or ALA and α-tocopherol were incubated at 70 °C. Samples of these mixtures were analyzed by gas chromatography. After 72 hours at 70 °C mixtures with 0.25 mg α-tocopherol/mg retained 79.6% of the initial amount of DHA and 94.2% of the ALA. When α-tocopherol was present at 2.5 mg/mg the amount of DHA decreased to 62.5% and ALA decreased to 87.4%. Control samples that did not contain α-tocopherol retained 43% DHA and 52.6% ALA. These results indicate that α-tocopherol can limit the degradation of these polyunsaturated fatty acids at elevated temperature. However, the greatest protective effect was not obtained with the highest level of α-tocopherol. This relationship needs to be considered when formulating feeds where elevated process temperatures are likely to occur.

Effects of added dietary fat and phosphorus on the performance and egg quality of laying hens subjected to a constant high environmental temperature

Two experiments were conducted to study the combined effect of nonphytate P (NPP), fat, and temperature on the performance and egg quality of hens pre- and postpeak. In Experiment 1, 192 Single Comb White Leghorn layers, aged 22 wk, were individually housed in cages under ambient (AT) and constant high temperature (CHT) of 33 +/- 1 C. In Experiment 2, 28-wk-old birds were used with a CHT of 35 +/- 1 C. Diets contained 0 and 4% added vegetable fat with four dietary NPP levels, ranging from 0.20 to 0.50% in Experiment 1 and from 0.15 to 0.45% in Experiment 2, at increments of 0.1%. These diets were fed to hens for 84 d. Performance and egg quality criteria were measured in both experiments, whereas serum and tibia Ca and P were determined in Experiment 2. Results showed that there was no significant interaction among NPP, fat, and temperature, for any criteria measured. The CHT significantly reduced BW, feed intake, egg production, egg weight, egg mass, and shell thickness. Moreover, it decreased (P < 0.05) serum Ca, P, tibia ash, and tibia P. The lowest NPP levels resulted in the greatest shell thickness (P < 0.05), which decreased with increasing NPP levels in both trials. In the postpeak experiment, the feed intake was significantly reduced by 0.15 and 0.25% NPP. Moreover, 0.15% NPP significantly reduced egg production as compared to 0.35 and 0.45% NPP diets. Levels between 0.25 and 0.45% significantly improved the serum phosphorus content as compared to 0.15%. Added fat improved only serum P level (P < 0.05). The beneficial effect of supplemental fat on hen performance was evident in Experiment 1 but not in Experiment 2, indicating that nutrients were oriented more toward supporting egg production rather than maintaining the BW at the postpeak stage.

Production variables and nutrient retention in single comb White Leghorn laying pullets fed diets supplemented with direct-fed microbials

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.

Performance of single comb White Leghorn layers fed corn-soybean meal and barley-corn-soybean meal diets supplemented with a direct-fed microbial

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).