J.D. Schneider

Determining the effect of lysine:calorie ratio on growth performance of ten- to twenty-kilogram of body weight nursery pigs of two different genotypes

Four experiments were conducted to determine the effects of standardized ileal digestible (SID) Lys:calorie (Lys:Mcal) ratio on growth performance of 10- to 20-kg pigs of 2 different genotypes. Experiment 1 (360 pigs, average BW = 10.2 kg; source 1) and Exp. 2 (351 pigs; average BW = 9.3 kg; source 2), were both organized as a combination of 2 simultaneous experiments with the first set of diets consisting of 5 treatments with increasing SID Lys and the second set of diets consisting of 5 treatments with increasing energy density (Exp. 1: 9.9, 10.7, 11.5, 12.2, and 13.0 g/kg of Lys and 2.95, 3.09, 3.24, 3.38, and 3.52 Mcal/kg of ME, respectively; Exp. 2: 11.1, 11.9, 12.6, 13.4, and 14.2 g/kg and 2.95, 3.10, 3.25, 3.40, and 3.55 Mcal of ME/kg, respectively). In Exp. 1, increasing dietary SID Lys increased (linear, P < 0.01) ADG and G:F, and increasing dietary ME increased (quadratic, P < 0.05) G:F. In Exp. 1 the optimal Lys:Mcal ratio was estimated to be at least 4.1 g of Lys/Mcal of ME based on G:F. In Exp. 2, increasing dietary SID Lys increased (linear, P < 0.01) ADG and G:F. Increasing dietary ME increased (linear, P < 0.01) G:F. Because of the linear responses in this experiment, optimal Lys:Mcal ratio was at least 4.0 g of Lys/Mcal of ME. In Exp. 3 (350 pigs; average BW = 9.4 kg; source 1) and Exp. 4 (350 pigs; average BW = 7.5 kg; source 2), Lys:Mcal ratios in Exp. 1 and 2 were compared by titrating Lys at 2 energy levels. Pigs were fed diets with 2.95 or 3.29 Mcal/kg of ME with SID Lys:Mcal ratios of 3.1 to 4.1 g/Mcal of ME (Exp. 3) and 3.5 to 4.5 g/Mcal of ME (Exp. 4). In Exp. 3, there was an ME x Lys:Mcal ratio interaction (P < 0.03) for ADG. The greatest ADG was a Lys:Mcal ratio of 3.60 for pigs fed low ME and a ratio of 3.35 for pigs fed high ME. Gain:feed ratio increased with increased (P < 0.01) ME concentration and as Lys:Mcal ratio increased (quadratic, P < 0.01); the best G:F was observed at 3.67 g of Lys/Mcal of ME. In Exp. 4, there was a tendency for ME x Lys:Mcal ratio interaction (P < 0.08) for G:F. The greatest G:F was achieved with a Lys: Mcal ratio of at least 4.50 for pigs fed low ME and a ratio of 4.29 for pigs fed high ME. Results (i.e., lack of ADG response to high energy density) suggest pigs reared in this environment were not in energy dependent growth phases. These pigs needed approximately 11 g/d of SID Lys (19 g of Lys/kg of gain) to optimize ADG and G:F. Based on these results, optimal Lys:Mcal ratio may differ depending on daily caloric intake of the pig.

Effects of restricted feed intake on finishing pigs weighing between 68 and 114 kilograms fed twice or 6 times daily.

In a previous study with limit-fed gestating gilts, we observed that gilts fed 6 times/d had greater ADG than those fed the same amount over 2 feedings. To confirm these earlier responses, we used finishing pigs as a model in two 42-d trials and two 28-d trials to evaluate the effects of restricted feed intake and feeding frequency (2 vs. 6 times/d, floor fed) on pig performance between 68 and 114 kg. In all experiments, pigs (10/pen) were housed in 1.8 × 3.1 m pens with a half-solid, half-slatted concrete floor. Pigs were fed a corn- and soybean meal-based diet formulated to 1.15% standardized ileal digestible Lys and 3,294 kcal of ME/kg. In Exp. 1 to 3, energy and Lys were supplied to pigs according to NRC (1998) calculations to target an ADG of 0.80 kg. In Exp. 4, the diet was supplied to pigs to target an ADG of 0.80 kg (low feed intake) or 0.95 kg (high feed intake) to determine if the amount of energy above the maintenance requirement and feeding frequency affected pig performance. Pigs were fed by dropping similar amounts of feed onto the solid concrete floor either 2 (0700 or 1400 h) or 6 times (3 meals within 2 h at the morning and afternoon feedings) per day with an Accu-Drop Feed Dispenser (AP Systems, Assumption, IL). In Exp. 1 and 2, pigs fed 6 times daily had increased (P < 0.02) ADG and G:F compared with pigs fed 2 times per day. Greater feeding frequency increased (P < 0.05) the duration of time spent feeding and standing and reduced the lying time. In Exp. 3, a third treatment was included to determine whether the improvements in performance were due to decreased feed wastage. This treatment was designed to minimize feed wastage by dropping feed closer to the floor for pigs fed 2 times per day. Pigs fed 6 times daily had improved (P < 0.05) ADG and G:F compared with pigs in either treatment fed 2 times per day. No difference (P > 0.05) in performance was observed between pigs fed 2 times per day when feed was dropped from the feed drop or by the modified method. In Exp. 4, increasing the feeding frequency from 2 to 6 times per day improved (P < 0.01) ADG and G:F for pigs fed the low feed intake and tended to increase (P < 0.06) ADG and improved (P < 0.05) G:F for pigs fed the high feed intake. In limit-feeding situations, increasing the frequency of feeding from 2 to 6 times per day improved pig performance, which confirmed our earlier findings in gestating gilts.

Determining the accuracy of gestation feed drops

Materials and methods: Econo, Accu, and Ultra feed drops (Automated Production Systems, Assumption, Illinois) were attached to feed lines at three angles (90 , 75 , and 60 ). Feed was collected and weighed at settings of 2, 4, 6, 8, and 10 lb (0.9, 1.8, 2.7, 3.6, and 4.65 kg) for the Econo and Accu feed drops and 2, 4, 6, and 8 lb for the Ultra feed drops. Results: There was a drop type × angle × feed level interaction (P < .01) for the feed settings versus the actual amount dropped. At 90 , the relationship between the feeder setting (x) and actual quantity of feed dropped was best described by the regression equation (1.156x + 0.244) for the Econo, (1.010x + 0.072) for the Accu, and (1.009x + 0.231) for the Ultra feed drops. At 75 , the regression equations were (1.014x – 0.139) for the Econo, (0.997x + 0.057) for the Accu, and (1.005x + 0.156) for the Ultra feed drops. At 60 , the regression equations were (0.689x – 0.076) for the Econo, (0.989x – 0.249) for the Accu, and (0.951x + 0.026) for the Ultra feed drops.

Determining the threonine requirement of the lactating sow.

A total of 182 lactating sows were used in a study to determine the threonine requirement, and the relative difference in resulting performance of lactation diets with high concentrations of crystalline amino acids, compared with a conventional corn-soybean meal diet. All experimental diets were based on corn-soybean meal and formulated to contain 0.88% true ileal digestible (TID) lysine (1.00 and 0.97% total lysine for the control treatment and crystalline amino acid treatments, respectively). The control treatment was a conventional corn-soybean meal diet with no added crystalline amino acids. The other five experimental diets contained 0.37% L-lysine HCl, with other amino acids added to ensure that threonine was first limiting. The TID threonine contents in these diets were formulated to 0.44, 0.50, 0.57, 0.64, and 0.70%. Sows were farrowed in seven farrowing groups and were randomly allotted to the dietary treatments on the basis of parity. Over the entire lactation period, sows fed the diets containing crystalline amino acids consumed more (P<0.04) feed than did the sows fed the control corn-soybean meal diet. The sows fed the control diet also lost numerically (P>0.10) more weight over the lactation period. Sows fed the control diet had higher (P<0.01) PUN values at day 18 of lactation than did sows fed diets with added crystalline amino acids. There was no effect (P>0.10) on litter weaning weight with increasing dietary threonine. The numeric changes in PUN, litter weight gain, and feed intake suggest that the TID threonine requirement was 0.50%, which calculated to a threonine-to-lysine ratio of 57%. But the greatest implication of this study was that the use of crystalline amino acids as a replacement for soybean meal in lactation diets resulted in increased feed intake and decreased sow weight loss.; Swine Day, 2005, Kansas State University, Manhattan, KS, 2005

EFFECT OF RESTRICTED FEED INTAKE ON FINISHING PIGS WEIGHING BETWEEN 150 AND 250 lb FED TWICE OR SIX TIMES DAILY

Two 42-d trials and two 28-d trials were conducted to evaluate the effects of restricted feed intake and feeding frequency (2 or 6 times daily) on the performance of pigs weighing between 150 to 250 lb (initially 148 lb in Exp. 1; 155 lb in Exp. 2; 156 lb in Exp. 3; and 156 lb in Exp. 4). In all experiments, pigs were housed in 6 × 10 ft pens with halfsolid concrete and half-slatted flooring and with one nipple waterer. Pigs were fed a cornsoybean meal-based diet formulated to 1.15% TID lysine and 1,491 kcal of ME/lb.

Determining the effect of restricted feed intake on developing pigs weighing between 150 and 250 lb, fed two or six times daily

Two 42-d studies were conducted to evaluate the effect of restricted feed intake and feeding frequency on the performance of pigs weighing from 150 to 250 lb (initially 148 lb in Exp. 1 and 155 lb in Exp. 2). Our objective was to use the limit-fed finishing pig as a model for gestating sows who are also limit fed. In both experiments, pigs were housed in a 6 ×10 ft pen with half solid cement and half slatted flooring, and with one nipple waterer. The diet consisted of a diet based on cornsoybean meal, formulated to 1.15% TID lysine (1.29% total lysine) and 1,494 kcal of ME/lb. Energy and lysine were supplied to pigs to target an average growth rate of 1.75 lb/d, based on NRC (1998) values. Pigs were fed by dropping similar amounts of feed, either 2 or 6 times per day, by an Accu-Drop Feed Dispenser (AP Systems, Assumption, IL) on the solid cement flooring with ad libitum access to water. In Exp. 1, there was an increase (P<0.01) in ADG and a decrease (P<0.02) in F/G for pigs fed similar amounts of feed 6 times per day, compared with pigs fed 2 times per day. In Exp. 2, increasing the feeding frequency of pigs fed a restricted diet from 2 to 6 times per day improved ADG (P<0.02) and F/G (P<0.03). These studies indicate that increasing the frequency of feeding may improve the metabolic efficiency of the growing pig fed a restricted diet. More research is needed to determine whether the greater gain is due to improved efficiency or whether there is another reason, such as a decrease in feed wastage.

Effects of water-soluble and in-feed organic acids on the growth performance of weanling pigs.

A total of 360 weanling pigs (initially 11.5 lb and 18 ± 3 d of age, PIC) were used in a 42d growth assay to determine the effects of water-soluble antimicrobials and organic acids in feed and/or water on nursery pig growth performance. Pigs were allotted to one of 9 experimental treatments: 1) control (no feed or water antimicrobials or acids); 2) water containing 38 mg/L neomycin sulfate; 3) water containing 0.06% Activate WD; 4) water containing 0.12% Activate WD; 5) feed containing Neo-Terramycin (140 g/ton neomycin sulfate, 140 g/ton oxytetracycline HCl; neo/oxy); 6) feed containing 0.50% Activate DA; 7) feed containing 0.45% Starter L; 8) feed containing 0.45% Multimax L; and 9) feed containing 0.50% Activate DA and 0.10% Mintrex P. Overall (d 0 to 42 after weaning), pigs provided neo/oxy in the feed had greater (P<0.05) ADG, compared with pigs in all other treatments, except the pigs provided the combination of Activate DA and Mintrex P in the feed. Pigs provided neo/oxy in the feed had greater ADFI (P<0.02) than did pigs provided the control treatment. There were no differences in feed efficiency between any of the treatments. These data demonstrate that pigs provided in-feed antimicrobials had improved growth, whereas those provided organic acids in feed and water did not.

Investigation into the effects of feeding schedule on body condition, aggressiveness, and reproductive failure in group housed sows.

A total of 208 sows and 288 gilts (PIC line C29) were used to determine the influence of feeding frequency (2 vs. 6 times/d, floor fed) on performance and welfare measurements on a commercial sow farm. Treatments consisted of feeding similar amounts of feed to each sow (2.5 kg) or gilt (2.05 kg) over 2 (0700 and 1530) or 6 times daily (0700, 0730, 0800, 1530, 1600, and 1630). There were 8 sows or 12 gilts in each pen. Gilts and sows were moved to pens 1 to 4 d after breeding. In sows, there were no differences (P > 0.10) in ADG, backfat change, or variation in BW. There was a trend (P < 0.08) for sows fed twice daily to farrow more total pigs born, but number born alive or other reproductive performance traits were not different (P > 0.10) among treatments. Sows fed 6 times per day had increased vocalization during the morning (P < 0.07) and afternoon (P < 0.01) feeding periods compared with sows fed twice daily. Sows fed twice daily had more skin (P < 0.01) and vulva (P < 0.04) lesions as well as a small increase in feet and leg (P < 0.01) and hoof (P < 0.02) problems. In this commercial facility, the standard management protocol required moving gilts to a different gestation facility on d 42. On d 42, two pens of gilts with similar breeding dates and treatment were combined and moved to another facility with larger pens until farrowing. Gilts fed 6 times daily had a tendency for greater ADG (P < 0.07) from d 0 to 42 and a tendency for greater (P < 0.09) backfat on d 42. After movement to the larger groups from d 42 to farrowing, ADG was similar (P > 0.10) for gilts fed 2 or 6 times daily. Gilts fed twice daily had lower BW variation at d 42 (P < 0.04) and tended to at farrowing (P < 0.10). In gilts, there were no differences (P > 0.10) for reproductive performance, skin and vulva lesions, and feet and leg scores. In conclusion, there were few growth, farrowing, or aggression differences among gilts fed 2 or 6 times daily. This suggests that either feeding method is suitable for group-housed gilts. Among sows, feeding frequency resulted in few growth or farrowing performance differences. Feeding 6 times daily resulted in a small but significant reduction in skin and vulva lesions and structural problem scores while increasing vocalization. Increasing the feeding frequency from 2 to 6 times daily does not appear to have a negative or positive impact on performance or welfare of group-housed gilts and sows.

Determining the total sulfur amino acid to lysine requirement of the lactating sow

A total of 163 sows were used in a study to determine the requirement for total sulfur amino acids (TSAA), relative to lysine, during lactation. All experimental diets were cornsoybean meal-based and formulated to contain 0.88% true ileal digestible (TID) lysine (0.97% total lysine). The experimental diets contained 0.37% L-lysine HCl, with other crystalline amino acids added to ensure that TSAA was first limiting. The dietary TID TSAA rates were formulated to 0.44, 0.48, 0.53, 0.57, and 0.62%, corresponding to 50, 55, 60, 65, and 70% of lysine, respectively. Sows farrowed in six farrowing groups, and were randomly allotted to the dietary treatments on the basis of parity. Over the entire lactation period, there were no differences (P>0.14) in ADFI, weight loss, backfat loss, or plasma urea nitrogen among sows fed increasing TSAA:Lys ratios. Increasing TSAA, relative to lysine, had no effect (P>0.25) on litter weaning weight or preweaning mortality. In summary, there were no differences in litter performance with increasing TID TSAA:Lys ratio. These results suggest that the requirement for TID TSAA is no more than 50% of lysine. Additional research is needed to confirm this relatively low TSAA requirement, and that the relatively high feed (and amino acid) intake of sows, coupled with possible tissue breakdown as a source of TSAA, did not decrease the dietary requirement.

Determining the optimal lysine:calorie ratio for growth performance of pic nursery pigs

Two studies were conducted to evaluate the effects of increasing dietary lysine and energy density on nursery pig performance. Experiment 1 was organized as a combination of two simultaneous experiments,with one set of diets consisting of five treatments with increasing true ileal digestible (TID) lysine (1.11, 1.19, 1.26, 1.34, and 1.42%) and the second set of diets consisting of five treatments with increasing energy density (1,341, 1,408, 1,475, 1,542, and 1,609 kcal/lb). The highest level of both lysine and energy density (1.42% and 1,609 kcal/lb, respectively) were combined as one diet and used in both the lysine and energy-density titrations, to give a total of 9 diets for the 10 treatments. Pigs (PIC, avg BW = 22.5 lbs) were randomly allotted to eight replications with five pigs per pen, on the basis of BW. Overall (d 0 to 21) in Experiment 1, increasing TID lysine linearly increased (P<0.01) ADG and improved (linear, P<0.01) feed efficiency. Increasing energy density had no effect on ADG, but it decreased (linear, P<0.01) ADFI, which resulted in a linear (P<0.01) improvement in F/G. Regression analysis of the response surface was used to predict the optimal lysine:calorie ratios for ADG and F/G of 4.06 and 3.92 g lysine/Mcal ME for the PIC pigs used in this experiment. In Experiment 2, pigs (PIC, avg BW = 16.6 lbs) were fed diets with two different energy densities (1.34 or 1.49 Mcal ME/lb) with TID lysine:calorie ratios ranging from approximately 3.5 to 4.5 g/Mcal ME. There was an energy density × TID lysine:calorie ratio interaction observed for F/G. Pigs fed the low-energy diets had the greatest ADG, at a lysine:calorie ratio of 4.55. For pigs fed the high-energy diets, ADG improved as the lysine:calorie ratio improved to 4.26 g of TID lysine/Mcal ME. There was a quadratic (P<0.03) improvement in feed efficiency as the lysine:calorie ratios were increased for the pigs fed the low-energy diet, with the best F/G value observed at 4.55, but the pigs fed the high-energy diets experienced a linear (P<0.01) improvement in F/G as the lysine:calorie ratios were increased. These results suggest that the optimal lysine-tocalorie ratio is 4.26 to 4.55 g of TID lysine/Mcal ME for 20to 50-lb PIC pigs in these facilities.