A. B. Clark

Effects of Increasing Dietary Standardized Ileal Digestible Lysine on 15 to 24 lb Nursery Pigs

A total of 300 nursery pigs (PIC 327 × 1050, initially 14.8 lb BW) were used in a 28-d growth trial to evaluate the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on nursery pig growth performance. Pigs were weaned at approximately 21 d of age and allotted to the pens according to BW and gender. A common starter diet was fed for 6 d, then pens were allotted to 1 of 6 dietary treatments in a completely randomized design. Experimental diets were fed for 14 d followed by a common diet for 14 d. The 6 dietary treatments were formulated to contain 1.10, 1.20, 1.30, 1.40, 1.50, and 1.60% SID Lys. Increasing SID Lys resulted in improved (linear, P < 0.001) ADG and F/G during d 0 to 14 when experimental diets where fed, with no differences observed in ADFI. For ADG, broken line linear (BLL) and quadratic polynomial (QP) models demonstrated similar fits, with maximum ADG at 1.45% and above 1.60% for BLL and QP models, respectively. Similar estimates were found when modeling feed efficiency. In conclusion, this experiment determined that the SID Lys requirement for 15 to 24 lb nursery pigs was at least 1.45% SID Lys for both ADG and feed efficiency.

Modeling the effects of standardized ileal digestible valine to lysine ratio on growth performance of nursery pigs

Abstract Two experiments evaluated the effects of increasing standardized ileal digestible (SID) Ile:Lys ratio on growth performance of nursery pigs. In both experiments, dietary treatments consisted of 40, 44, 48, 52, 54, 58, or 63% SID Ile:Lys ratio. Diets were formulated using analyzed ingredient AA values and NRC (2012) SID coefficients. A combination of field peas and spray dried blood cells were used to ensure a low enough Ile diet concentration while minimizing the excess of Leu. The experiments consisted of 8 pens per dietary treatment with 5 pigs per pen for a total of 280 nursery pigs per experiment (Exp. 1: PIC 327 × 1,050, initially 6.7 ± 1.0 kg BW; Exp. 2: DNA 600 × 241, initially 6.0 ± 0.97 kg BW). Data were analyzed using mixed models with heterogeneous variance, where appropriate. The dose response was further characterized using quadratic polynomial (QP), broken-line linear (BLL), or broken-line quadratic (BLQ) functional forms. For Exp. 1, diets were initiated 6-d post-weaning and fed for 12-d followed by a common diet from d 12 to 28. From d 0 to 12, increasing dietary SID Ile:Lys ratio increased ADG (linear, P < 0.005) and ADFI (quadratic, P < 0.017) but G:F decreased (quadratic, P < 0.043). For ADG, the QP, BLL, and BLQ models resulted in maximum ADG at 64.7, 52.0, and 52.0 SID Ile:Lys ratios, respectively. For ADFI, the BLL breakpoint occurred at 50.6 and the QP predicted maximum ADFI at 56.2 SID Ile:Lys ratio. In Exp. 2, diets were initiated 6-d post-weaning for 7 pens and 3-d post-weaning for one heavier block and fed for 18-d followed by a common diet from d 18 to 32. From d 0 to 18, ADG and ADFI increased (quadratic, P < 0.016) with no evidence for difference in G:F as SID Ile:Lys ratio increased. For ADG, the QP and BLL had similar fit with breakpoints or maximums occurring at 58.3 and 51.8% SID Ile:Lys ratio, respectively. For ADFI, the BLQ breakpoint occurred at 52.0 SID Ile:Lys and the QP maximum ADFI at 57.2% SID Ile:Lys ratio. In conclusion, broken-line models reported maxima of 52.0% Ile:Lys ratio while quadratic models were as high as 64% of Lys to maximize ADG and ADFI of 6- to 11-kg nursery pigs. However, for the QP models 99% of the maximum response was achieved with a dose comparable to that from the broken line models. Therefore, these results are similar to the NRC (2012) requirement estimate of 51.1 Ile:Lys ratio.

Effects of Monosodium Glutamate on 14- to 56-lb Nursery Pigs

A total of 700 nursery pigs (PIC C-29 × 1050 × 1040, initially 13.6 lb BW) were used in a 42-d growth study to determine the effects of monosodium glutamate (MSG; Ajinomoto Heartland, LLC, Chicago, IL) on growth performance. Pigs were fed 1 of 5 dietary treatments: 0, 0.5, 1.0, 1.5, or 2.0% MSG. Experimental diets were fed in three phases from d 0 to 14, 14 to 28, and 28 to 42. Phase 1 was pelleted and phases 2 and 3 were fed in meal form. Diets were formulated to balance Na and Cl content with increasing MSG using salt, sodium bicarbonate, and potassium chloride. Pigs were weaned at approximately 21-d of age and allotted to pens, which were then allotted to treatment according to BW in a randomized complete block design. There were 14 replications per treatment and initial BW was used as a covariate. There were no significant differences between dietary treatments for ADG or ADFI within any phase or for the overall nursery period. Increasing MSG did not affect F/G during phase 1; however, it tended (quadratic, P < 0.079) to improve F/G in phase 2, but resulted in poorer F/G (linear, P < 0.002) for phase 3. For the overall nursery period, F/G tended (quadratic, P < 0.092) to be poorer with increasing MSG. There were no significant differences among dietary treatments for intermediate or final BW. Results from this study indicate that MSG did not influence overall nursery pig growth performance. Additional research may be necessary to determine the appropriate dietary inclusion of MSG and its role during the post-weaning period.

Effects of Antimicrobial or Probiotic Treatments on Growth Performance of 13- to 56-lb Nursery Pigs

A total of 612 nursery pigs (21-d of age; Line 241 × 600; DNA, Columbus, NE) were used in two 44-d experiments to determine effects of antibiotic or different probiotic products on nursery pig performance and fecal consistency. In Experiment 1, 297 pigs (initially 12.8 lb) were used with 6 replications per treatment and 5 or 6 pigs per pen. In Experiment 2, 315 pigs (initially 13.3 lb) were used with 7 replications per treatment and 5 pigs per pen. In both experiments, pens were randomly allotted to 1 of 9 dietary treatments in a randomized complete block design. The nine treatment diets included a control diet, or the control diet with either carbadox (Mecadox-2.5 Phibro Animal Health, Teaneck, NJ) at 50 g/ton, BioPlus 2B (Chr. Hansen USA, Inc., Milwaukee, WI) with an inclusion rate of 0.05%, or 1 of 6 DSM Probiotic products (DSM Nutritional Products, Inc., Parsippany, NJ) with an inclusion rate of 0.20%. For Experiment 1, pigs fed the diet containing carbadox had increased (P < 0.05) ADG compared to pigs fed the control diet or diets containing DSM Probiotic 1, 2, 3, or 6, with the other probiotic treatments intermediate. Pigs fed the diet with carbadox had greater (P < 0.05) ADFI compared to those fed the control or diets containing DSM Probiotic 1, 2, or 3, with the other probiotic treatments intermediate. Feed efficiency was not affected by treatment. For fecal consistency, there was no evidence to indicate a treatment effect (P > 0.05) or treatment × day interaction (P = 0.951). For Experiment 2, pigs fed carbadox had greater (P < 0.05) ADG than all other treatments. Pigs fed BioPlus 2B had greater (P < 0.05) ADG compared to those fed the diet containing DSM Probiotic 3, with the control and all other probiotic treatments intermediate. Pigs fed carbadox had increased (P < 0.05) ADFI compared to the control and DSM Probiotics, with BioPlus 2B intermediate. There was no evidence of difference to indicate that dietary treatment influenced F/G nor to indicate a treatment effect for fecal consistency. In summary, pigs fed diets containing carbadox consistently had increased ADG and ADFI compared to pigs fed any of the other dietary treatments. There was no evidence the probiotics improved performance based on these results; however, the DSM probiotic 4 had the highest numerical ADG of all the DSM products relative to the nonmedicated control diet in both experiments.

Effects of Increasing Salt Concentration on Growth Performance of 25- to 67-lb Nursery Pigs

A total of 300 pigs (Line 241 × 600; DNA, Columbus, NE; initially 25.0 lb BW) was used in a 34-d growth trial to determine the effects of added dietary salt on the growth performance of nursery pigs weighing 25 to 67 lb. Upon entry to the nursery, pigs were allotted by BW and fed a phase 1 common starter diet (0.50% Na and 0.67% Cl) for 11 d and then a common phase 2 diet (0.35% Na and 0.59% Cl) from day 11 to 25 after weaning. At d 25 after weaning, considered d 0 in the trial, pigs were allotted by pen weight and assigned to 1 of 5 dietary treatments containing either 0.20, 0.35, 0.50, 0.65, or 0.80% salt. This corresponds to calculated dietary Na levels of 0.10, 0.16, 0.22, 0.28, and 0.34%, respectively. Calculated Cl levels were 0.23, 0.32, 0.41, 0.50, and 0.59%, respectively. A common diet containing 0.35% lb/ton salt (0.16% Na and 0.29% Cl), was then fed from d 27 to 34. From d 0 to 14, ADG, ADFI, and F/G improved (quadratic, P < 0.001, 0.089, and 0.012, respectively) as added salt increased from 0.20 to 0.65%, with no further benefits observed thereafter. From d 14 to 27, there was no significant effect on ADG; however, pigs fed 0.50% added salt had numerically the greatest ADG. Average daily feed intake increased (linear, P < 0.001) and F/G marginally worsened (linear, P < 0.095) with increasing added salt. From d 0 to 27, ADG and F/G improved (quadratic, P < 0.05 and 0.054, respectively) using up to 0.5% added salt while ADFI increased (linear, P < 0.001). From d 27 to 34, when pigs were fed a common diet, there was no evidence of difference to indicate that previous dietary treatments influenced ADG; however, ADFI, and d 34 BW increased (linear, P < 0.001) while F/G worsened (linear, P < 0.001) with increasing salt previously fed from d 0 to 27. In conclusion, results of this study indicate that the pig’s Na and Cl requirement estimate changes and that diets for pigs weighing 25 to 45 lb, should be formulated with enough added salt to provide 0.28% Na and 0.48% Cl, which in this study was 0.65%. However, from 45 to 67 lb, 0.20% Na and .39% Cl (0.50% added salt) was sufficient to maximize growth performance.

Effects of Standardized Ileal Digestible Lysine on 15- to 25-lb Nursery Pigs

A total of 300 pigs (DNA 241 × 600; initial pen average BW of 15.4 lb) were used in a 22-d growth trial to determine the standardized ileal digestible (SID) lysine (Lys) requirement of nursery pigs from 15to 25-lb. Pigs were weaned at approximately 21 d of age and allotted to pens based on BW and gender. There were 10 replicate pens per treatment and 6 pigs per pen. Pigs were fed a common pelleted diet for 10 d postweaning. Subsequently, pens of pigs were randomly assigned to 1 of 6 experimental diets in a randomized complete block design, with BW as a blocking factor. Dietary treatments consisted of 1.10, 1.20, 1.30, 1.40, 1.50, and 1.60% SID Lys and were achieved by the inclusion of crystalline amino acids at the expense of corn. Experimental diets were fed for 11 d followed by a common diet fed for 11 d. Experimental data were analyzed using generalized linear and non-linear mixed models, fitting the data with heterogeneous residual variances as needed. Competing models included linear (LM), quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). For the overall treatment period, increasing SID Lys improved (linear, P < 0.001) ADG and F/G, with no differences observed in ADFI. Similarly, as dietary SID Lys increased, BW increased linearly on d 11 and 22. Feed cost per pig, feed cost per pound of gain, and total revenue per pig increased (linear, P < 0.001) as SID Lys increased, with no observed differences in income over feed cost (IOFC). For ADG, the best-fitting models were the LM and QP models. The maximum mean ADG was estimated at greater than 1.60%, and at 1.54% (95% CI: [1.34, >1.60]%), with 99% of the maximum ADG achieved at 1.43% SID Lys, in the LM and QP models, respectively. Similarly, the best-fitting models for feed efficiency were LM and QP, both estimating the requirement at greater than 1.60% SID Lys. In conclusion, this experiment determined that the mean SID Lys required for nursery pigs from 15to 25-lb ranged from 1.54% to at least 1.60%. These data provide evidence that different response variables and statistical models can result in different estimates of the requirements. However, formulating nursery diets for 15to 25-lb pigs to 1.40% would allow for the highest income and approximately 99% of maximum growth to be captured.

Effects of Monosodium Glutamate and Aminogut on Nursery Pig Performance

A total of 1,134 nursery pigs (PIC 359 × 1050, 10.9 ± 0.46 lb BW) were used in a 42-d growth study to determine the effects of monosodium glutamate (MSG), AminoGut, and glutamine (Ajinomoto Heartland, LLC, Chicago, IL) on growth performance. Pigs were fed 1 of 6 dietary treatments. Treatments were fed in 2 phases from d 0 to 7 and 7 to 21. The dietary treatments contained 0, 0.5, 1.0, or 1.5% MSG fed in both phases, 0.8 and 0.6% AminoGut fed in phase 1 and 2, respectively, or a combination of 1.0% MSG and 0.4% glutamine fed in both phases. A common post-treatment diet was fed from d 21 to 42. Phase 1 was in pellet form and the subsequent phases were in meal form. Pigs were randomly allotted to pens at weaning and pens were then allotted to treatment according to BW in a randomized complete block design with 7 replications per treatment. During phase 1 (d 0 to 7), there was no evidence for difference (P > 0.553) for ADG, ADFI, or F/G with the addition of MSG, AminoGut, or MSG+Gln. In phase 2 (d 7 to 21), the addition of MSG did not impact ADG or ADFI (P > 0.163), but resulted in a marginal improvement (linear, P = 0.097) in F/G. Pigs fed AminoGut demonstrated improved ADG (P < 0.05) compared to all other treatments and increased (P < 0.05) ADFI compared to pigs fed 0.5, 1.0, or 1.5% MSG. There was no evidence for difference (P > 0.105) during the common post-treatment period, overall period, or in final BW. Results from this study indicate that feeding MSG alone or with Gln does not result in improved postweaning growth performance. AminoGut provided a growth and intake response from d 7 to 21 postweaning. While the increase in BW for pigs fed AminoGut was maintained through the common phase, the response was no longer significant. Further investigation is required to determine the appropriate timing and feeding duration of AminoGut in the nursery.

Effects of Monosodium Glutamate on 11- to 50-lb Nursery Pigs

A total of 1,134 nursery pigs (PIC 280 × 1050, 11.2 lb BW) were used in a 48-d growth study to determine the effects of monosodium glutamate (MSG; Ajinomoto Heartland, LLC, Chicago, IL) on growth performance. Pigs were fed 1 of 6 dietary treatments: 0, 0.5, 1.0, 1.5, or 2.0% MSG, or a high salt treatment formulated to match the sodium content of the 1.0% MSG treatment. Experimental diets were fed in 3 phases from d 0 to 12, d 12 to 26, and d 26 to 48. Phase 1 was in pellet form and phases 2 and 3 were in meal form. Pigs were randomly allotted to pens at weaning and pens were then allotted to treatment according to BW in a randomized complete block design with 7 replications per treatment. During phase 1 (d 0 to 12), no significant differences were detected among MSG treatments, but pigs fed the high salt diet tended (P < 0.053) to have poorer F/G than pigs fed the 1% MSG treatment. In phase 2 (d 12 to 26), increasing MSG decreased (linear, P = 0.045) ADG, ADFI, and worsened F/G while pigs fed the high salt diet had decreased (P < 0.001) ADG and poorer (P < 0.001) F/G than pigs fed the 1% MSG diet. In phase 3 (d 26 to 48), no significant differences were detected among the MSG treatments however pigs fed the high salt diet had decreased (P < 0.028) ADG and ADFI compared with those fed the 1% MSG diet. Pig BW was reduced (linear, P < 0.016) on d 26 and 48 for pigs fed the MSG diets and pigs fed the high salt treatment had decreased (P < 0.001) BW compared to pigs fed 1% MSG. For the overall nursery period (d 0 to 48), increasing MSG decreased (linear, P = 0.033) ADG and tended (linear, P = 0.095) to decrease ADFI. Furthermore, pigs fed the high salt treatment had decreased (P < 0.009) ADG and ADFI and poorer (P < 0.001) F/G compared to their 1% MSG counterparts. Results from this study indicate that feeding MSG may have had a negative impact on ADFI and therefore, subsequent BW and ADG. In addition, the high salt treatment formulated to match the sodium content of the 1% MSG diet had consistently poorer performance than the 1% MSG treatment, suggesting that high salt content may negatively affect pig growth. Further research is warranted to determine the effects of feeding monosodium glutamate to nursery pigs in diets balanced for sodium content.

Effects of Dietary Standardized Ileal Digestible Isoleucine:Lysine Ratio on Nursery Pig Performance

A total of 560 nursery pigs were used in 2 experiments to evaluate the effects of increasing dietary standardized ileal digestible (SID) Isoleucine:Lysine (Ile:Lys) ratio on growth performance. In Exp. 1, 280 pigs (PIC 327 × 1050, initially 14.9 lb BW) were fed experimental diets for 12 d with 8 replications and 5 pigs per pen. In Exp. 2, 280 pigs (DNA Genetics Line 600 × Line 241, initially 13.3 lb BW) were fed experimental diets for 18 d with 8 replications and 5 pigs per pen. In both experiments, pens were allotted to 1 of 7 dietary treatments in a randomized complete block design. The 7 dietary treatments were 40, 44, 48, 52, 54, 58, and 63% SID Ile:Lys ratio. After the experimental diet feeding period, a common diet was fed for 14 d. Diets in both phases were fed in meal form. For Exp. 1, from d 0 to 12 when experimental diets were fed, ADG and ADFI improved (ADG, linear, P < 0.001; and ADFI, quadratic, P < 0.017) and F/G became poorer (quadratic, P < 0.041) as SID Ile:Lys ratio increased. For ADG, the quadratic (QP), broken-line linear (BLL), and broken-line quadratic (BLQ) models reported maximum ADG at 64.7, 52.0, and 52.0% SID Ile:Lys ratio, respectively. For ADFI, the BLL breakpoint occurred at 50.6% and the QP predicted maximum ADFI at 56.2% SID Ile:Lys ratio. In Exp. 2, from d 0 to 18 when experimental diets were fed, ADG and ADFI improved (quadratic, P < 0.009) with no significant differences for F/G as SID Ile:Lys ratio increased. For ADG, the BLL and QP had similar fit with breakpoints/maximums occurring at 51.8% SID Ile:Lys ratio and 58.3% SID Ile:Lys ratio, respectively. For ADFI, the QP reported maximum ADFI at 57.2% SID Ile:Lys ratio and the BLQ breakpoint occurred at 52.0% SID Ile:Lys. In summary, these experiments demonstrate that the SID Ile requirement for 15 to 25 lb nursery pigs is approximately 52% of Lys for ADG and ADFI using broken line models and can be as high as 64% of Lys using quadratic models. A slight quadratic effect was observed in feed efficiency for Exp. 1, however in Exp. 2, there were no appreciable differences detected in F/G. The Ile requirement for 15 to 25 lb pigs was found to be similar to NRC (2012) requirement estimates.

Evaluation of Added Sodium and Chloride for 15 to 24 lb Nursery Pigs

A total of 360 pigs (Line 241 × 600; DNA, Columbus, NE) were used in a 14-d growth trial to determine if the response to added dietary salt in nursery pigs (15 to 24 lb) was due to either the Na or Cl concentration in the diet. Upon entry to the nursery, pigs were allotted by BW and fed a common starter diet (0.33% Na and 0.76% Cl) for 7 d after weaning. On d 7 after weaning, considered d 0 in the trial, pens were assigned to 1 of 4 dietary treatments that were fed from d 0 to 14. The 4 experimental treatments included a 10% dried whey diet with 12 lb/ton added salt (0.37% Na and 0.75% Cl); or 3 diets with dried whey replaced by 7.2% lactose containing either: 7 lb/ton added salt (0.18% Na and 0.47% Cl); 15.5 lb/ton added salt (0.35% Na and 0.72% Cl); or 23 lb/ ton sodium bicarbonate and 8 lb/ton potassium chloride (0.35% Na and 0.45% Cl), respectively. From d 0 to 14, pigs fed the 10% dried whey diet with 12 lb/ton added salt or the diet with lactose and 15.5 lb/ton added salt had improved (P < 0.05) ADG compared to pigs fed the lactose diet with 7 lb/ton added salt, with pigs fed the lactose diet with 23 lb/ton sodium bicarbonate and 8 lb/ton potassium chloride intermediate. Pigs fed the 10% dried whey diet with 12 lb/ton added salt had greater (P < 0.05) ADFI than those fed the lactose diet with 7 lb/ton added salt, with pigs fed the lactose diet with 15.5 lb/ton added salt and the lactose diet with 23 lb/ton sodium bicarbonate and 8 lb/ton potassium chloride intermediate. However, F/G tended to be poorest for pigs fed 10% dried whey compared with pigs fed 7.2% lactose and 15.5 lb/ton added salt, with others intermediate. In conclusion, diets should be formulated with enough added salt in order to meet NRC (2012) recommendation of dietary Na concentration of 0.35%, which is higher in Na than many nursery diets for 15 to 25 lb pigs.