Two 21-d experiments were conducted to determine the optimum standardized ileal digestible (SID) Trp:Lys ratio for growing pigs; 1 experiment fed diets supplemented with or without an antibiotic. The primary response variables in both experiments were ADG, ADFI, G:F, and plasma urea N (PUN) concentrations with the optimum SID Trp:Lys ratio detected using broken-line analysis. Experiment 1 evaluated the optimum SID Trp:Lys ratio in growing pigs fed diets supplemented with an antibiotic. This experiment used 120 crossbred pigs that were blocked by sex and initial BW (24.13 ± 2.72 kg) and allotted to 6 SID Trp:Lys ratios in 4 replicates. Dietary treatments were formulated by the addition of crystalline Trp to create 6 SID Trp:Lys ratios (13.08%, 14.06%, 15.04%, 17.00%, 18.95%, and 20.91%) with a constant SID Lys level of 0.655%. As SID Trp:Lys ratios increased, ADG, ADFI, and G:F increased, and PUN concentrations decreased linearly ( < 0.05) and quadratically ( < 0.05). Linear broken-line analysis yielded optimum SID Trp:Lys ratios of 17.93% ( < 0.001) and 16.17% ( = 0.009) for ADG and PUN, respectively, resulting in a mean optimum SID Trp:Lys ratio of 17.05%. Experiment 2 evaluated the optimum SID Trp:Lys ratio in growing pigs fed diets supplemented with or without an antibiotic. It used a total of 324 crossbred pigs (initial BW: 30.81 ± 3.56 kg) that were allotted to 6 SID Trp:Lys ratios in 6 replicates. Dietary treatments were formulated by the addition of crystalline Trp to create 6 SID Trp:Lys ratios (12.52%, 14.86%, 17.20%, 19.54%, 21.88%, and 24.22%) with a constant SID Lys level of 0.67%. As SID Trp:Lys ratios increased, ADG, ADFI, and G:F increased, and PUN concentrations decreased linearly ( < 0.001) and quadratically ( < 0.001) regardless of antibiotic inclusion. There were no differences by the antibiotic treatment in ADG, ADFI, G:F, or PUN concentrations ( > 0.49) and no interactions between antibiotics and Trp:Lys ratios ( > 0.29). When the data for all pigs were pooled for the various Trp:Lys ratios, the optimum SID Trp:Lys ratios for ADG and PUN based on linear broken-line analysis were 14.58% ( < 0.001) and 14.54% ( < 0.001), respectively, resulting in an optimum SID Trp:Lys ratio of 14.56% as the mean of the determined optima for ADG and PUN responses. These results demonstrate that the optimum SID Trp:Lys ratio for 30- to 50-kg growing pigs is not impacted by the dietary inclusion of an antibiotic as long as the diets are formulated on an SID AA basis.

Three 21-d experiments were conducted to determine the optimum standardized ileal digestible (SID) Ile:Lys ratio in 10- to 22-kg and 24- to 39-kg pigs. In Exp. 1, 144 Yorkshire pigs (initial BW = 10.2 kg) were assigned to 6 diets with 6 pens per treatment. Diets 1 to 5 were formulated to contain 5 graded SID Ile:Lys (44, 51, 57, 63, and 70%), 1.18% SID Leu, and 0.90% SID Lys (second limiting). Diet 6 (diet 5 with added Lys) was formulated (1.06% SID Lys) as a positive control. Pigs fed diet 6 had higher (P < 0.05) ADG and G:F and lower (P < 0.05) plasma urea N (PUN) than pigs fed diet 5 (P < 0.02), indicating that Lys was limiting in diets 1 to 5. Final BW, ADG, and ADFI increased (linear and quadratic, P < 0.05) while G:F and PUN at d 21 were not affected (P > 0.10) by dietary Ile:Lys. Overall, ADG and ADFI were highest for pigs fed diet 2 (51% SID Ile:Lys). In Exp. 2, 216 Yorkshire pigs (initial BW = 9.6 kg) were assigned to 9 diets with 6 pens per treatment. Diets 1 to 4 contained 0.40, 0.47, 0.54, and 0.61% SID Ile, respectively, and 1.21% SID Lys; diets 5 to 8 contained 0.72, 0.84, 0.96, and 1.08% SID Lys, respectively, and 0.68% SID Ile. Diet 9 was high in both Ile and Lys (0.68% SID Ile and 1.21% SID Lys). All diets contained 1.21% SID Leu. The ADG and G:F increased (linear and quadratic, P < 0.05) as SID Ile:Lys increased (diets 1 to 4 and 9). The ADG and G:F increased (linear, P < 0.05) as SID Lys increased (diets 5 to 9). The PUN at d 21 decreased (linear, P < 0.05) by increasing dietary Ile:Lys. The SID Ile:Lys to optimize ADG was 46% by curvilinear plateau or exponential regression. For G:F, the optimal SID Ile:Lys was 47 and 51% by curvilinear plateau and exponential regressions, respectively. In Exp. 3, 80 pigs (PIC 327 × C23; initial BW = 24.0 kg) were allotted to 5 treatments with 4 pigs per pen. Diets 1 to 5 were formulated to contain 5 graded SID Ile:Lys (39, 46, 53, 61, and 68%), 1.17% SID Leu, and 0.91% SID Lys (second limiting). Final BW and ADG increased (linear and quadratic, P < 0.05) and ADFI increased (linear, P = 0.047) as SID Ile:Lys increased. Using ADG and G:F, the optimum SID Ile:Lys was 54 and 53%, respectively, by curvilinear plateau and exponential regression. The PUN was minimized at 53 and 59% SID Ile:Lys by curvilinear plateau and broken line regression. Overall, the average optimum SID Ile:Lys was approximately 51% for 10- to 22-kg pigs and 54% for 24- to 39-kg pigs fed diets containing nonexcess levels of Leu.

OF DISSERTATION EVALUATING THE EFFECTS OF MATERNAL AND PROGENY DIETARY SUPPLEMENTATION OF SELENIUM YEAST AND VITAMIN E ON THE PERFORMANCE OF BROILER-BREEDER HENS AND PERFORMANCE AND MEAT QUALITY OF PROGENY The objectives of these experiments were to evaluate the effects of selenium (Se) and vitamin E (Vit.E) supplementation in maternal and progeny diets on the performance of breeder hens and the performance and meat quality characteristics of progeny. Inclusion of Se, as Se yeast, in the diets of developing broiler breeder pullets resulted in greater Se accumulation of Se (P<0.01) in liver, pancreas, and breast tissues than when Se yeast was not provided. Improving the overall Se status of breeder pullets in the early stages may help maintain adequate tissue Se concentrations during egg production. Maternal supplementation of Se yeast and Vit.E increased the liver and breast Se concentration (P<0.05) of newly hatched chicks compared to the chicks originating from hens not receiving dietary Se. At 7d of age, Se yeast supplementation in either the chick or maternal diet increased breast and liver Se concentrations (P<0.01). At 14d of age, breast and liver Se concentrations remained the highest for chicks supplemented with Se yeast (P<0.01), however there was no effect of maternal Se supplementation. Vitamin E supplementation in either the chick or maternal diets did not affect the liver Vit.E concentrations of chicks at 7 or 14d of age. Supplementing broiler diets with Se yeast and Vit.E improved the meat quality characteristics of raw and marinated breast fillets. The Se content of breast meat from broilers fed Se yeast was higher (P<0.01) than those from broilers that were not fed Se yeast. Antioxidant supplementation improved the drip loss (P<0.05) and oxidative stability (P<0.10) of raw breast fillets after 7d of refrigerated storage. Marination appeared to increase the susceptibility for lipid oxidation of the marinated breast fillets. Dietary supplementation of Se yeast and Vit.E reduced lipid oxidation (P<0.01) of marinated breast fillets after prolonged refrigerated storage, thus improving oxidative stability. Overall, dietary supplementation of Se yeast can increase the accumulation of Se in the tissues of broiler breeder hens and their subsequent progeny. Improvements in the avian antioxidant system may have beneficial effects on the performance of broiler breeder hens, broilers, and the meat quality characteristics of broiler breast fillets.

Two 21-d experiments were conducted to determine the optimum standardized ileal digestible (SID) Trp:Lys in growing pigs fed corn-based diets compared with non-corn-based diets. The primary response variables in both experiments were ADG and plasma urea N (PUN) concentrations with the optimum SID Trp: Lys determined using broken-line analysis. Experiment 1 evaluated the optimum SID Trp: Lys in growing pigs fed corn-based diets consisting primarily of corn with minor inclusion of Canadian field peas and corn gluten meal to keep the SID Trp: Lys low. This experiment used 120 crossbred pigs (initial BW: 25.73 +/- 2.46 kg) that were blocked by sex and initial BW and allotted to 5 SID Trp: Lys with 5 pens each for the first 4 treatments and 4 pens for the last treatment and 5 pigs/pen. Diets were formulated by the addition of supplemental Trp to create various SID Trp: Lys (12.77, 14.07, 15.50, 16.91, and 17.94%) with a constant SID Lys of 0.66%, which was determined to be 83% of the Lys requirement for pigs at this location. As the SID Trp: Lys increased from 12.77 to 17.94%, ADG increased (0.562, 0.648, 0.788, 0.787, and 0.815 kg/d) linearly (P < 0.001) and quadratically (P = 0.009), resulting in an optimum SID Trp: Lys of 15.73% (P < 0.001). Plasma urea N decreased (10.43, 9.30, 8.21, 8.55, and 9.25 mg/dL) linearly (P = 0.069) and quadratically (P = 0.015), resulting in an optimum SID Trp: Lys of 15.83% (P = 0.007). Experiment 2 evaluated the optimum SID Trp: Lys in growing pigs fed non-corn-based diets consisting primarily of barley and Canadian field peas, with smaller proportions of corn and wheat. Experiment 2 used 120 crossbred pigs (initial BW: 28.49 +/- 2.92 kg) that were allotted to 5 increasing SID Trp: Lys (13.05, 14.32, 15.59, 16.85, and 18.11%; 0.66% SID Lys) in the same manner as Exp. 1. As SID Trp: Lys increased in Exp. 2, ADG increased linearly (P = 0.007) with the optimum SID Trp: Lys of 15.99% (P = 0.048). Plasma urea N concentrations decreased linearly (P = 0.056) and quadratically (P = 0.067) as SID Trp: Lys increased, resulting in an optimum SID Trp: Lys of 15.29% (P = 0.009). Averaging the break point values for ADG and PUN obtained from broken-line analysis for Exp. 1 and 2 produced optimum SID Trp: Lys of 15.78 and 15.64%, respectively. Based on the results from these 2 experiments, it seems that the optimum SID Trp: Lys is virtually unaffected by the dietary feedstuffs used as long as the diets are formulated on an SID AA basis.

Evaluations of the nutritional impact of antibiotics have largely centered on effects related to the digestibility and utilization of protein and energy. Recent research has demonstrated that virginiamycin increases P digestibility. Because of the importance of P in diet cost and in waste management plans, the present study evaluated the potential impact of 2 additional antibiotics, bacitracin methylene disalicylate (bacitracin) and tylosin, on P digestibility in swine. A total of 48 barrows (mean initial BW, 63.0 to 82.9 kg) were used in 2 nutrient balance experiments. A basal corn-soybean meal diet that was not supplemented with any inorganic source of P was used in each experiment. In Exp. 1, two diets were tested: basal vs. basal plus 33.1 mg of bacitracin/kg of diet. In Exp. 2, two diets were also tested: basal vs. basal plus 44.1 mg of tylosin/kg of diet. In both experiments, the pigs were fed their diets for a minimum of 12 d before fecal and urine collection, and pigs were fed the diet at 2.7% of BW during the adaptation and collection period. In Exp. 1, the apparent DM, Ca, and P digestibility values for the basal and bacitracin diets were 91.69, 65.96, and 43.03 vs. 91.47, 65.46, and 41.79%, respectively, and did not differ by diet. In Exp. 2, the DM, Ca, and P digestibility values for the basal and tylosin diets were 91.03, 62.17, and 38.80 vs. 91.11, 63.20, and 40.10%, respectively, and did not differ by diet. The effect of the antibiotics on gut microflora was also appraised but the evaluations failed to demonstrate an effect on the microflora measured, with the exception that tylosin decreased the number of phytate-utilizing bacteria (P = 0.05). Therefore, because these 2 antibiotics did not demonstrate an improvement in P digestibility, improvements in P digestibility seem to be an antibiotic-specific response rather than a generalized antibiotic response.

These experiments were conduct to study the use of sticky coffee hull (SCH) silage (SCHS) on starting pigs feeding. SCH (caffeine = 0.59%; tannin = 0.82%, as-fed-basis) is a by-product obtained from coffee processing (conversion the raw fruit of the coffee plant (cherry) into the commodity green coffee) and may represent an environmental threat. In Brazil there is a great supply of this cheap by-product. SCH was ground (4 mm screen-opening diameters) before ensilaging. There were at least 30 days of ensilage period before using it. Chemical composition (as-fed-basis) of SCHS is: DM= 66.48%; CP= 6.79%; GE= 2,753 kcal/kg; CF= 10.48%; ADF= 15.97%; NDF= 19.23%; hemicelulose= 3.26%; lignin= 3.77 %; ash= 4.587%; Ca= 0.20 %; P= 0.07%. Experiment I consisted of a digestibility trial using 15 piglets (Initial BW= 20.78±2.86 kg). In the Experiment II, 60 piglets (BW = 15.52±2.19 to 32.52±3.51 kg) were used in a performance study. Piglets were allotted to treatments with six replicates of two pigs per replicate in a randomized complete block design. Treatments consisted of a corn-soybean meal basal diet (0%) and four diets with sticky coffee hull (4, 8, 12, and 16%). Experimental diets were formulated to meet the same nutrients levels (NRC, 1998). From Experiment I it was obtained: Digestibility coefcient of energy of SCHS= 57.49%, which means 1,583 kcal of DE/kg (as-fed-basis). Performance data (Experiment II) were, respectively for 0, 4, 8, 12 and 16 % of SCHS inclusion: DFI = 1.345, 1.359, 1.304, 1.222 and 1.264 kg; DWG = 0.665, 0.671, 0.643, 0.592 and 0.640 kg; F: G ratio: 2.027, 2.031, 2.028, 2.056 and 1.976. The regression analysis indicates no effects (P≥0.05) of sticky coffee hull silage inclusion on piglet performance (DFI, DWG and F: G ratio). The results indicated 1,583 kcal of DE/kg of SCHS and suggest that it is feasible to use up to 16% of sticky coffee hull silage on starting piglet diet.