Effects of diet form and feeder adjustment on growth performance of nursery and finishing pigs.

Three experiments were conducted to determine the effects of feeder adjustment and diet form on growth performance of nursery (Exp. 1 and 2) and finishing (Exp. 3) pigs. Treatments were arranged as a 2 × 3 factorial with the main effects of feeder adjustment and diet form. The 2 feeder adjustments were a narrow and wide feeder adjustment (minimum gap opening of 1.27 and 2.54 cm, respectively). The 3 diet forms were meal, poor-quality pellets (70% pellets and 30% fines for Exp. 1 and 2 and 50% pellets and 50% fines for Exp. 3), and screened pellets with minimal fines (3 to 10%). In Exp. 1, 210 pigs (initially 11.9 kg BW) were used in a 21-d trial with 7 pigs per pen and 5 pens per treatment. No feeder adjustment × diet form interactions were observed. There were no differences in ADG, ADFI, or G:F due to feeder adjustment. Pigs fed the meal diet had increased ( < 0.05) ADG and ADFI compared with pigs fed the poor-quality or screened pellets. Pigs fed meal or poor-quality pellets had decreased ( < 0.05) G:F compared with pigs fed screened pellets. In Exp. 2, 1,005 nursery pigs (initially 14.1 kg BW) were used in a 28-d trial with 26 to 28 pigs per pen and 6 pens per treatment. Pigs fed from the narrow feeder adjustment had decreased ( < 0.05) ADG and ADFI compared with pigs fed from the wide adjustment with no differences in G:F. Pigs fed the meal diet had decreased ( < 0.05) ADG compared with pigs fed poor-quality or screened pellets. Pigs fed meal or poor-quality pellets had decreased ( < 0.05) G:F compared with pigs fed screened pellets. In Exp. 3, 246 pigs (initially 56.8 kg BW) were used in a 69-d trial with 5 pens per treatment and 6 or 7 pigs per pen. Overall, ADFI decreased ( < 0.05) and G:F increased ( < 0.05) for pigs fed from the narrow adjusted feeders compared with the wide adjustment with no differences in ADG. Overall, pigs fed meal diets tended to have decreased ( < 0.10) ADG and had decreased ( < 0.05) G:F compared with pigs fed screened pellets; ADG and G:F in those fed poor-quality pellets were intermediate. Feeding meal or poor-quality pellets increased ( < 0.05) ADFI compared with pigs fed screened pellets. In conclusion, feeding nursery pigs from a wide feeder gap may increase ADG and ADFI with no negative effects on G:F. For finishing pigs, reducing feeder gap reduced feed disappearance and improved G:F. In all experiments, the greatest G:F improvements from pelleting were observed when the percentage of fines was minimized.

Effects of diet form and type on growth performance, carcass yield, and iodine value of finishing pigs.

Two experiments were conducted to determine the effects of pelleting, diet type (fat and fiber level), and withdrawal of dietary fiber and fat before marketing on growth performance, carcass yield, and carcass fat iodine value (IV) of finishing pigs. Each experiment used 288 pigs (initially 49.6 and 48.5 kg BW, respectively) with 6 dietary treatments arranged as 2 × 3 factorials. In Exp. 1, main effects were diet form (meal vs. pellet) and diet regimen. Diet regimens were 1) a low-fiber, low-fat (corn-soybean meal) diet from d 0 to 81, 2) a high-fiber, high-fat (30% dried distillers grains with solubles [DDGS] and 19% wheat middlings [midds]) diet from d 0 to 64 followed by the low-fiber, low-fat diet from d 64 to 81 (fiber and fat withdrawal), and 3) the high-fiber, high-fat diet fed from d 0 to 81. Pigs fed pelleted diets had increased ( < 0.05) ADG and G:F compared with those fed meal diets. Pigs fed pelleted diets had increased belly fat IV (2.9 mg/g) compared with those fed meal diets, with a greater increase when fed high-fiber, high-fat diets throughout the entire study (interaction, < 0.05). Pigs fed the low-fiber, low-fat diet throughout had increased ( < 0.001) G:F compared with pigs fed the other 2 treatments. Pigs fed low-fiber, low-fat diets throughout the study or pigs withdrawn from high-fiber, high-fat diets had increased ( < 0.001) carcass yield compared with pigs fed high-fiber, high-fat diets throughout. In Exp. 2, treatment main effects were diet form (meal vs. pellet) and diet type (corn-soybean meal-based control, the control with 30% DDGS and 19% midds, or the control diet with 3% corn oil). The diet containing corn oil was calculated to produce carcass fat IV similar to diets containing DDGS and midds. Overall, pigs fed pelleted diets had increased ( < 0.05) ADG, G:F, and belly fat IV (1.3 mg/g) compared with those fed meal diets. Pigs fed the diets containing DDGS and midds had decreased ( < 0.05) ADG, carcass yield, and HCW compared with pigs fed the control or corn oil diets and decreased ( < 0.001) G:F compared with pigs fed added corn oil. Belly IV was greatest ( < 0.001) for pigs fed diets with DDGS and midds and lowest for pigs fed the control diet, with pigs fed the corn oil diets intermediate. In conclusion, pelleting diets improves pig ADG (approximately 3%) and G:F (approximately 6%); however, a novel finding of this study is that pelleting diets fed to finishing pigs also increases belly fat IV.

Evaluation of standardized ileal digestible valine:lysine, total lysine:crude protein, and replacing fish meal, meat and bone meal, and poultry byproduct meal with crystalline amino acids on growth performance of nursery pigs from seven to twelve kilograms.

Five experiments were conducted to evaluate replacing fish meal, meat and bone meal, and poultry byproduct meal with crystalline AA for 7- to 12-kg pigs. In all experiments, pigs (PIC TR4 × 1050) were fed a common diet for 3 d postweaning, treatment diets for 14 d (d 0 to 14), and, again, a common diet for 14 d (d 14 to 28). Treatment diets were corn-soybean meal based and formulated to contain 1.30% standardized ileal digestible (SID) Lys. Experiment 1 evaluated replacing dietary fish meal with crystalline AA. For the 6 treatments, crystalline Lys, Met, Thr, Trp, Ile, Val, Gln, and Gly all increased to maintain minimum AA ratios as fish meal decreased (4.50, 3.60, 2.70, 1.80, and 0.90 to 0.00%). There was no difference in ADG, ADFI, or G:F among treatments, validating a low-CP, AA-fortified diet for subsequent experiments. Experiment 2 evaluated deleting crystalline AA from a low-CP, AA-fortified diet with 6 treatments: 1) a positive control similar to the diet validated in Exp. 1, 2) positive control with l-Ile deleted, 3) positive control with l-Trp deleted, 4) positive control with l-Val deleted, 5) positive control with l-Gln and l-Gly deleted, and 6) positive control with l-Ile, l-Trp, l-Val, l-Gln, and l-Gly deleted (NC). Pigs fed the positive control or Ile deleted diet had improved (P < 0.05) ADG and ADFI during d 0 to 14 compared with pigs fed diets with l-Trp or l-Val deleted or NC. Experiment 3 evaluated 6 treatments with total Lys:CP of 6.79, 6.92, 7.06, 7.20, 7.35, and 7.51%. Fish meal was adjusted as a source of dispensable N to achieve the target Lys:CP. There were no differences in growth performance among pigs fed different Lys:CP diets. Experiment 4 evaluated increasing SID Val:Lys with Val at 57.4, 59.9, 62.3, 64.7, 67.2, and 69.6% of Lys. Average daily gain and ADFI increased (quadratic, P < 0.01) and G:F improved (linear, P = 0.02) during d 0 to 14 as Val:Lys increased from 57.4 to 64.7%. Experiment 5 was a 2 × 3 factorial arrangement of treatments with main effects of low or high level of crystalline AA and 3 animal protein sources (fish meal, meat and bone meal, or poultry byproduct meal). Low- and high-crystalline AA diets contained 4.5 or 1% fish meal, 6 or 1.2% meat and bone meal, and 6 or 1% poultry byproduct meal, respectively. No AA × protein source interactions were observed. From d 0 to 14, no differences in growth performance among protein sources was found, whereas increasing crystalline AA improved (P = 0.04) ADG. In conclusion, crystalline AA can replace fish meal, meat and bone meal, and poultry byproduct meal when balanced for SID AA ratios of Met and Cys:Lys (58%), Thr:Lys (62%), Trp:Lys (16.5%), Val:Lys (65%), and Ile:Lys (52%).

Evaluation of standardized ileal digestible lysine requirement of nursery pigs from seven to fourteen kilograms.

Four experiments were conducted to determine the standardized ileal digestible (SID) Lys requirement of pigs (Sus scrofa) from 7 to 14 kg. In Exp. 1, 294 pigs (6.8 kg BW) were used in a 28-d growth trial with 7 pigs per pen and 7 pens per treatment. Treatment diets were fed from d 0 to 14, and a common diet was fed from d 14 to 28. The 6 SID Lys levels tested were 1.15, 1.23, 1.30, 1.38, 1.45, and 1.53%. The diets were corn- and soybean-meal [Zea mays L. and Glycine max (L.) Merr.] based, with 10% spray-dried whey, 4.5% fish meal, and contained 3.37 Mcal of ME/kg. From d 0 to 14, ADG increased (quadratic, P < 0.001) as SID Lys increased from 1.15 to 1.30% with no further increase at greater levels. Gain:feed increased (linear, P < 0.001) with increasing SID Lys. Experiments 2 to 4 were 14-d growth trials with diets containing 1.22, 1.32, 1.42, 1.52, or 1.62% SID Lys. Diets were corn- and soybean-meal based with 3.45 Mcal of ME/kg. Soybean meal and lactose were constant in all diets at 30 and 7% of the diet, respectively. In Exp. 2, 840 pigs (7.6 kg BW) were used, with 24 pigs per pen and 7 pens per treatment. Increasing SID Lys from 1.22 to 1.42% increased (quadratic, P < 0.01) ADG and G:F with no further improvement observed in pigs fed the 1.52 or 1.62% SID Lys diets during d 0 to 14. In Exp. 3, 1,260 pigs (8.5 kg BW) were used with 42 pigs per feeder (2 pens per feeder) and 6 feeders per treatment. Increasing dietary Lys increased (quadratic, P < 0.02) ADG and G:F with the greatest response observed as SID Lys increased from 1.22 to 1.32% and, then, slight improvements with 1.42 and 1.52% during d 0 to 14. In Exp. 4, 770 pigs (7.4 kg BW) were used with 22 pigs per pen and 7 pens per treatment. Increasing SID Lys increased (quadratic, P = 0.05) ADG with pigs fed 1.32 and 1.42% SID Lys diets having the greatest BW gains during d 0 to 14. Increased SID Lys decreased (linear, P < 0.001) ADFI and increased (linear, P < 0.001; quadratic, P = 0.02) G:F. In conclusion, results of these experiments indicate that the 1998 NRC Lys recommendations (e.g., 1.19% SID Lys for 5 to 10 kg pigs) are less than required for optimal growth for 7 to 14 kg pigs. One-slope straight broken-line analysis indicated that the SID Lys requirement for optimal growth was at least 1.30% for ADG and 1.37% for G:F, or at least 3.86 and 4.18 g SID Lys/Mcal ME, respectively. Quadratic broken-line analysis indicated that the SID Lys requirement for optimal growth was at least 1.37% for ADG and 1.54% for G:F, or at least 4.19 and 4.92 g SID Lys/Mcal ME, respectively.