Study Tracks Feeder Settings' Impact on Growth Performance

Feed intake and daily gain increased as feeder openings increased, but feed efficiency improved the most at the middle feeder adjustment setting in recent Kansas State University (KSU) grow-finish studies.

KSU researchers set out to determine the effect of different feeder settings on growth performance and whether diet type influenced the optimal feeder setting. Two experiments were conducted in a double curtain-sided, deep-pit commercial swine facility with a totally slotted floor.

Each pen was equipped with a stainless steel Staco dry self-feeder and one cup waterer. Each five-hole, single-sided feeder had a feed pan dimension of 60 in. long × 7 in. wide × 5.75 in. high.

The feeder settings were based on the factory-cut holes in the side of the feeder. Moving a dial from one hole to the next adjusted the feeder gate. Feeder setting 1 was the most open setting, while setting 5 was the most closed feeder setting.

Researchers measured feeder gap openings so the data collected could be applied to other types/brands of dry feeders. The distance between the feeder trough and the top of the feed plate was measured on both the left and right sides of the feeder in both trials. The width of the feed plate was subtracted from the height measurement to determine gap opening.

The feed gate was designed to have some “give” or “play” to allow for feed agitation. Thus, the gap opening had a low and high position, which was measured when the feed plate was in the lowest and highest positions possible.

Gap opening measurements on the left and right sides of the feeder were obtained and averaged for each respective position, low or high, for each feeder. The high gap opening measurements and percentage of pan coverage were plotted and the resulting graph was used to develop a regression equation. This regression equation makes it possible to estimate the pan coverage at any feeder gap opening.

The first experiment, a 70-day study, took place in the late spring and early summer of 2007. A total of 1,170 barrows and gilts were randomly assigned among five treatments, with nine replications per treatment. Each pen contained 23-28 pigs with an equal distribution of barrows and gilts.

Pigs were fed a corn-soybean meal-based experimental diet in meal form. The feeder settings were set at 1, 2, 3, 4 or 5 for the five experimental treatments. Feeders were left at their respective settings for the duration of the trial.

Pigs and feeders were weighed on the first day of the experiment (Day 0), and on Days 14, 28, 50 and 70 to determine average daily gain (ADG), average daily feed intake (ADFI), and feed-to-gain ratio (F/G). The two heaviest pigs from all pens were visually selected and marketed on Day 50. The remaining pigs were marketed on Day 70.

Researchers took a digital photo of each feed pan during Weeks 2, 4, 7 and 10 (See Figures 1, 2 and 3 ). Photos were analyzed separately by a trained panel of six people. Each picture was scored according to the percentage of the feed pan that was covered with feed.

From Day 0 to 28, pigs fed from feeders with increasing feeder openings had increased ADG and ADFI (Table 1, page 26).

The feeder setting did not seem to impact growth performance traits from Days 28 to 70. For the test period (Day 0 to 70), as feeder openings increased, ADFI increased. Changing feeder setting did not affect ADG or F/G. Gap opening and pan coverage data for the first experiment are shown in Tables 2 and 3.

In a second experiment, 1,250 barrows and gilts were studied for a 69-day period. Pigs were randomly assigned to one of six treatment groups, with eight replications per treatment. Each pen held 27-28 pigs with an equal distribution of barrows and gilts.

The study focused on the main effects of diet composition on the Staco stainless steel dry feeder at settings 1, 3, and 5. A basic corn-soybean meal diet with a by-product-based diet containing 15% DDGS and 5% bakery by-product was fed. The feeders remained at their respective setting for the duration of the trial.

Pigs and feeders were weighed on the first day of the experiment, then again on Days 15, 30, 42, 55 and 69 to determine ADG, ADFI and F/G.

Photos were taken of each feed pan during Weeks 2 and 6 and pictures were individually scored for pan coverage. Gap openings were measured according to the same procedures used in the first experiment.

From Day 0-30 and Day 30-69, pigs fed from feeders with increasing feeder openings had increased ADG and ADFI (Table 4, page 27). Overall, there were no interactions between feeder setting and diet type for growth performance in Experiment 2. Diet type did not affect growth performance (Table 5).

As feeder openings increased, ADG and ADFI increased. Pigs on feeder setting 1 grew fastest. When the setting was increased from 3 to 5 (the most closed setting), there was a large decrease in ADG. Optimal F/G occurred when feeders were on setting 3.

As the feeder setting increased, low gap opening and high gap opening decreased (Table 6). As feeder setting increased (decreasing gap opening), the percentage of the feeder pan covered with feed decreased for Weeks 2 and 6 (Table 7). Feed pan coverage at each gap opening was similar to coverage in the first experiment. Approximately 50% of the feed pan was covered with the high gap opening of 1.15 in. (Figures 1 and 2).

KSU researchers concluded that feeder setting 3 was optimal. The average gap opening at that setting — from the feed trough to the bottom of the feed plate — was approximately 1.15 in. when the feed plate was in the high position. The amount of feed covering the bottom surface of the feeder pan averaged 61% at setting 3. However, the range for individual feeders on setting 3 was large — ranging from 14 to 93%.

On the basis of this data, KSU researchers recommend feeders be adjusted to allow feed to cover slightly more than half of the feed pan without feed accumulating in the corners.

Researchers: Alan Duttlinger; Steve Dritz, DVM; Mike Tokach; Joel DeRouchey; Jim Nelssen; and Robert Goodband, Kansas State University. Contact Duttlinger at (785) 532-1270, or email advtt@ksu.edu.

Table 1. Influence of Feeder Adjustment on Growing-Finishing Pig Performance (Experiment 1)1

Item Feeder Setting
1 2 3 4 5
Day 0 to 28
Initial wt., lb. 129.0 129.2 128.4 128.7 129.7
Avg. daily gain, lb. 1.85 1.84 1.80 1.80 1.78
Avg. daily feed intake, lb. 4.51 4.46 4.32 4.30 4.30
Feed:Gain 2.45 2.43 2.41 2.39 2.42
Day 28 to 70
Avg. daily gain, lb. 1.72 1.78 1.81 1.73 1.74
Avg. daily feed intake, lb. 4.85 4.93 4.88 4.73 4.76
Feed:Gain 2.81 2.78 2.69 2.75 2.73
Day 0 to 70
Avg. daily gain, lb. 1.77 1.80 1.81 1.76 1.75
Avg. daily feed intake, lb. 4.71 4.74 4.65 4.55 4.56
Feed:Gain 2.65 2.63 2.57 2.59 2.60
Final weight, lb. 251.6 253.7 256.5 251.6 252.5
1A total of 1,170 pigs (PIC initially 129 lb.) were used in a 70-day experiment with 23 to 28 pigs per pen and nine pens per treatment.

Table 2. Influence of Feeder Adjustment on Feeder Gap Opening (Exp.1)1

Gap Opening, in.2 Feeder Setting
1 2 3 4 5
Low 1.14 1.04 0.90 0.79 0.68
High 1.42 1.30 1.16 1.05 0.87
1A total of 1,170 pigs (PIC initially 129 lb.) were used in a 70-day experiment with 23 to 28 pigs per pen and nine pens per treatment.
2Measured from the bottom of the feed pan to the bottom of the feed plate with the feed plate at the lowest (low) and highest (high) possible positions.

Table 3. Influence of Feeder Adjustment on Feeder Pan Coverage (Exp. 1)1

Pan Coverage, % Feeder Setting
1 2 3 4 5
Week 2 74.0 71.3 57.0 34.3 20.6
Week 4 73.1 65.9 62.9 41.9 24.9
Week 7 78.0 67.0 63.7 46.3 24.8
Week 10 78.9 73.9 64.6 45.2 26.1
1A total of 1,170 pigs (PIC initially 129 lb.) were used in a 70-day experiment with 23 to 28 pigs per pen and nine pens per treatment.

Table 4. Influence of Feeder Adjustment and Diet Type on Growing-Finishing Pig Performance (Experiment 2)1

Item Corn-soybean Meal By-product
Feeder Setting Feeder Setting
1 3 5 1 3 5 Diet × Feeder Setting Diet Feeder Setting
Day 0 to 30
Initial wt., lb. 77.4 77.5 77.2 77.2 77.5 77.1 1.00 0.97 0.99
Avg. daily gain, lb. 2.09 2.04 1.91 2.01 2.04 1.97 0.22 0.92 0.01
Avg. daily feed intake, lb. 4.35 4.16 4.03 4.36 4.29 4.05 0.68 0.42 0.01
Feed:Gain 2.07 2.06 2.14 2.19 2.09 2.06 0.13 0.63 0.46
Day 30 to 69
Avg. daily gain, lb. 2.11 2.06 1.94 2.09 2.07 1.94 0.90 0.97 0.01
Avg. daily feed intake, lb. 5.49 5.25 5.03 5.43 5.26 5.04 0.86 0.81 0.01
Feed:Gain 2.60 2.55 2.60 2.60 2.55 2.60 1.00 0.88 0.26
Day 0 to 69
Avg. daily gain, lb. 2.10 2.05 1.92 2.06 2.05 1.95 0.37 0.87 0.01
Avg. daily feed intake, lb. 4.99 4.77 4.59 4.95 4.84 4.61 0.74 0.75 0.01
Feed:Gain 2.37 2.34 2.40 2.42 2.34 2.35 0.31 0.87 0.19
Final weight, lb. 223.5 220.6 212.1 221.4 220.3 214.2 0.81 0.97 0.02
1A total of 1,250 pigs (PIC initially 77.3 lb.) were used in a 69-day experiment with 27 to 28 pigs per pen and eight pens per treatment for the treatments of feeder setting 1 and 3 for both diet types, and seven pens per treatment for the treatments of feeder setting 5 for both diet types.

Table 5. Main Effects of Feeder Adjustment on Growing-Finishing Pig Performance (Exp. 2)1

Item Feeder Setting
1 3 5
Day 0 to 30
Initial wt., lb. 77.3 77.5 77.1
Avg. daily gain, lb. 2.05 2.04 1.94
Avg. daily feed intake, lb. 4.35 4.22 4.04
Feed:Gain 2.13 2.07 2.10
Day 30 to 69
Avg. daily gain, lb. 2.10 2.06 1.94
Avg. daily feed intake, lb. 5.46 5.26 5.03
Feed:Gain 2.60 2.55 2.60
Day 0 to 69
Avg. daily gain, lb. 2.08 2.05 1.94
Avg. daily feed intake, lb. 4.97 4.80 4.60
Feed:Gain 2.39 2.34 2.38
Final weight, lb. 222.5 220.4 213.2
1A total of 1,250 pigs (PIC initially 77.3 lb.) were used in a 69-day experiment with 27 to 28 pigs per pen and eight pens per treatment for the treatments of feeder setting 1 and 3 for both diet types, and seven pens per treatment for the treatments of feeder setting 5 for both diet types.

Table 6. Influence of Feeder Adjustment on Gap Opening (Experiment 2)1

Gap Opening, in.2 Feeder Setting
1 3 5
Low 1.13 0.86 0.62
High 1.42 1.14 0.87
1A total of 1,250 pigs (PIC initially 77.3 lb.) were used in a 69-day experiment with 27 to 28 pigs per pen and eight pens per treatment for the treatments of feeder setting 1 and 3 for both diet types, and seven pens per treatment for the treatments of feeder setting 5 for both diet types.
2Measured from the bottom of the feed pan to the bottom of the feed plate with the feed plate at the lowest (low) and highest (high) possible positions.

Table 7. Influence of Feeder Adjustment and Diet Type on Feeder Pan Coverage (Exp. 2)1

Feeder Pan Coverage, % Corn-soybean Meal By-product
Feeder Setting Feeder Setting
1 3 5 1 3 5 Diet × Feeder Setting Diet Feeder Setting
Week 2 73.3 46.9 19.4 85.5 63.2 17.8 0.37 0.10 0.01
Week 6 74.7 53.3 25.9 85.3 70.3 22.4 0.17 0.10 0.01
1A total of 1,250 pigs (PIC initially 77.3 lb.) were used in a 69-day experiment with 27 to 28 pigs per pen and eight pens per treatment for the treatments of feeder setting 1 and 3 for both diet types, and seven pens per treatment for the treatments of feeder setting 5 for both diet types.

Feeder Design Impacts Growth Performance, Carcass Traits

Wet-dry feeders improved finishing pigs' feed intake by close to 9% and growth rate by 6-7% compared to conventional dry feeders in two recent Kansas State University research trials. And, pigs fed on wet-dry feeders were 4.5% heavier at marketing, but their carcasses were fatter and they yielded less than the pigs fed with conventional feeders.

Both experiments investigated the effects of conventional dry feeders with cup waterers (see Figure 1), compared to wet-dry feeders with a nipple in the feed pan, their sole source of water. Although pens with a wet-dry feeder also contained a cup waterer, they were shut off during the experiments.

Water was delivered to all of the pens of each feeder type, independently, and daily water consumption was measured using water meters.

The first experiment included 1,186 pigs, averaging 70.8 lb., on test. Groups were divided into 26-28 pigs/pen and allocated to one of two feeder types (22 pens/feeder type).

All pigs received the same diet sequence in four phases — Day 0-10, Day 10-28, Day 28-50 and Day 50-69.

Overall, pigs using the wet-dry feeder had greater average daily gain (ADG), average daily feed intake (ADFI) and final weight compared with pigs using the conventional dry feeder (Table 1). Feed-to-gain ratio (F:G) was essentially the same with both feeder types.

Average daily water usage for pigs on the wet-dry feeder was 1.44 gal./day. Pigs on the conventional dry feeders averaged 1.38 gal./day.

The second experiment was conducted with 1,236 pigs allotted to pens with one of the two feeder types. There were 23 pens per feeder type with 25-28 pigs/pen. Pig weights averaged 63.2 lb. at the beginning of the 104-day research trial. All pigs were fed the same feed budget.

The three largest pigs per pen were marketed on Day 84. The remaining pigs were fed a fifth dietary phase containing Paylean until they were slaughtered on Day 104. Table 3 shows the effects of feeder design on the carcass characteristics and the resulting economic return.

Overall, pigs using the wet-dry feeder had greater ADG, ADFI and final weight compared with those using the conventional dry feeder. However, pigs using the wet-dry feeder consumed more feed, had poorer feed/gain and higher feed cost/pig than pigs using the conventional feeder (Table 2).

Carcass yield, fat-free-lean index, premium per pig and live value per cwt. were higher and average backfat depth was lower for pigs using the conventional dry feeder. All of these effects combined resulted in a lower net income per pig for pigs fed with the wet-dry feeder (Table 3).

The KSU researchers felt the experiments demonstrated that growth performance is improved when pigs are offered feed and water, ad libitum, via a wet-dry feeder when compared to a conventional dry feeder and drinker bowl.

Still, the research results brought up some interesting questions for further study, such as: “Can we manage within-group variation better by feeding the lightest pigs placed in a finisher, or even gilts, with a wet-dry feeder?” asks Jon Bergstrom, KSU swine laboratory research coordinator.

He predicts that with the growing emphasis on understanding behavior, maximizing welfare and related productivity, research in this area will continue. And he wonders if feeder design and feed presentation can overcome the reduced feed intake associated with feeding some by-products.

Because carcasses of pigs fed with a wet-dry feeder yielded less and were fatter, the use of wet-dry feeders may not be justified with some carcass incentive programs, note researchers.

Researchers: Jon Bergstrom; Mike Tokach; Steve Dritz; Jim Nelssen, DVM; Joel DeRouchey and Robert Goodband, Kansas State University. Contact Bergstrom at 785-532-1277 or e-mail jberstr@ksu.edu.

Table 1. The Effects of Feeder Design on Growth Performance of Finishing Pigs (Experiment 1)1

Item Feeder Type
Conventional Dry Wet-Dry
Day 0 to 69
Avg. daily gain, lb. 2.10 2.26
Avg. daily feed intake, lb. 5.13 5.58
Feed:Gain 2.44 2.47
Day 69 average wt, lb. 216.35 227.30
Water use, gal./day per pig 1.38 1.44
Water use, gal./lb. gain 0.66 0.64
1A total of 1,186 pigs (PIC, 337 × 1050) with 26 to 28 pigs per pen and 22 pens per treatment were used in a 69-day experiment to compare the growth performance of pigs fed from either a conventional dry feeder with a cup waterer or a wet-dry feeder.

Table 2. The Effects of Feeder Design on Growth Performance of Finishing Pigs (Experiment 2)1

Item Feeder Type
Conventional Dry Wet-Dry
Day 0 to 104
Avg. daily gain, lb. 1.90 2.01
Avg. daily feed intake, lb. 4.96 5.40
Feed:Gain 2.62 2.68
Day 104 average wt, lb. 261.35 272.80
Water use, gal./day per pig 1.68 1.48
Water use, gal./lb. gain 0.89 0.73
1A total of 1,236 pigs (PIC, 337 × 1050) with 25 to 28 pigs per pen and 23 pens per treatment were used in a 104-day experiment to compare the growth performance of pigs fed from either a conventional dry feeder with a cup waterer or a wet-dry feeder.

Table 3. The Effects of Feeder Design on the Carcass Characteristics of Finishing Pigs and Economic Return (Example 2)1

Item Feeder Type
Conventional Dry Wet-Dry
Plant live wt, lb. 253.7 265.9
Hot carcass weight, lb. 194.9 200.0
Yield, % 76.86 75.21
Avg. backfat depth, in. 0.64 0.70
Loin muscle depth, in. 2.41 2.45
Lean, % 57.10 55.89
Fat-free lean index 50.48 49.94
Premium/pig, $ 8.67 5.26
Value/hundred weight (live), $ 56.28 54.83
Total revenue/pig, $2 142.78 145.80
Feed cost/pig, $ 56.23 61.12
Feed, $/cwt. gain 28.43 29.17
Net income/pig, $ 26.15 24.28
1Carcass data from 494 pigs (11 pens/feeder-type) were obtained for the comparison of carcass data and economic evaluation.
2Base carcass price of $71.43/cwt. as used to calculate total revenue. Facility cost of $10.40/pig and initial pig cost of $50.00/pig were used to calculate net income per pig.

Corn and DDGS Diet Switching Do Not Affect Pig Performance

Pork producers looking to optimize feed ingredients are including distiller's dried grains with solubles (DDGS) for grow-finish pigs when costs are in line.

To better understand the implications of suddenly including economically priced DDGS in pig diets, researchers at the University of Minnesota conducted a trial to determine the effects of switching between corn-soybean meal and corn-soybean meal-DDGS diets on pig performance and carcass quality of finishing pigs.

The 216 pigs housed in 24 pens were placed on one of four dietary treatments — the corn-soybean control diet (D0), a corn-soybean meal diet containing 20% DDGS fed throughout the study (D20), D20 and D0 diets alternated bi-weekly (D20SW), and a 40% DDGS diet alternated bi-weekly with the D0 diet (D40SW). Pigs were fed corn-soybean meal diets until they went on test at 110 lb.

There were five, two-week feeding periods. Pigs assigned to the D20SW and D40SW treatments started and ended the trial on DDGS-containing diets.

Dietary treatments had no effect on average daily gain (Table 1). Except for feed efficiency, growth performance was similar for pigs fed the control diet continuously, the 20% DDGS diet continuously or the 20% DDGS and control diets in an alternating pattern.

Researchers point out that for some reason, pigs fed the 20% DDGS diet were continuously less efficient than pigs fed the DDGS diet alternated with the control diet.

They also noted that the pigs switched on and off a 40% DDGS diet were lighter at the end of the 70-day study (Table 1), and these pigs yielded lighter carcasses than pigs in other treatment groups because they ate less feed.

Dressing percentage and carcass fat-free lean percentage were not affected by dietary treatments.

The results of this study showed no adverse effects of frequently alternating between inclusion and removal of 20% DDGS from diets for finishing pigs in terms of performance or carcass characteristics.

The researchers plan to conduct a related trial to determine if lighter pigs will respond in the same manner.

Researchers: Lee Johnston and Adrienne Hilbrands, University of Minnesota, West Central Research and Outreach Center; and Jerry Shurson, University of Minnesota-St. Paul. Contact Johnston by phone (320) 589-1711, fax (320) 589-4870 or e-mail johnstlj@morris.umn.edu.

Table 1. Effects of Frequent DDGS Inclusion and Removal on Pig Performance and Carcass Traits

Trait D01 D202 D20SW3 D40SW4
Initial weight, lb. 113.0 113.0 113.0 113.3
Final weight, lb. 247.4xy 247.4xy 249.1x 243.8y
Average daily gain, lb. 1.92 1.92 1.94 1.87
Average daily feed intake, lb. 5.95xy 6.06x 5.97xy 5.80y
Feed:Gain 3.09ab 3.15a 3.08b 3.10ab
Hot carcass weight, lb. 184.7a 184.3a 185.8a 178.8b
Dressing, % 74.8 74.6 74.6 73.8
Carcass lean, % 54.4 54.0 53.8 54.2
abWithin a row means without a common superscript differ (P < 0.05).
xyWithin a row means without a common superscript differ (P < 0.10).
1Corn-soybean meal control
2Corn-soybean meal diet containing 20% DDGS fed throughout the study
3D20 and D0 diets alternated bi-weekly
440% DDGS diet alternated bi-weekly with the DO diet

Enhanced DDGS Offer Improved Swine Diets

Enhanced distiller's dried grains with solubles (E-DDGS) provides greater energy concentration in swine diets, improving the nutritional value of DDGS for pigs, according to a study at the University of Illinois.

The end result is not only improved feed efficiency, but in many cases, increased growth rates, leading to increased profits.

DDGS has a high fiber content. A process known to separate fiber from DDGS — called the elusieve process — removes about 10% of the material, mostly fiber, yielding E-DDGS with 2.3% less total dietary fiber than conventional DDGS (28.7% vs. 26.4% fiber).

The E-DDGS has higher crude protein (CP) and higher fat concentration (Table 1).

The goal of this experiment was to determine digestible energy (DE) and metabolizable energy (ME) in two sources of DDGS, and in E-DDGS produced from each of the DDGS sources.

The trial consisted of 30, 51-lb. growing pigs and 30, 161-lb. finishing pigs placed in metabolism cages and assigned a randomized diet.

The two groups of pigs received five different diets: standard corn and soybean meal and four additional diets formulated by replacing 40% of the base diet with 40% of each source of DDGS and E-DDGS.

Pigs were fed experimental diets for 14 days. Urine and feces were collected during the final five days.

Diets containing E-DDGS produced 6-7% greater DE and ME than those containing DDGS (Table 2). Researchers said the result was expected due to the fiber removal from DDGS, resulting in an ingredient higher in fat and protein content.

About 94% of the DE and ME in the original DDGS was captured in the E-DDGS. The DE and ME values were not different between growing and finishing pigs.

In conclusion, the co-product E-DDGS is nutritionally more appropriate for pigs than DDGS because of the lower fiber concentration and higher energy density.

Researchers: J.A. Soares, H.H. Stein, R. Srinivasan, V. Singh and J.E. Pettigrew, University of Illinois. Contact Pettigrew by phone (217) 244-6927, fax (217) 333-7861 or e-mail jepettig@uiuc.edu.

Table 1. Nutrient Composition As Fed, (%)

Item DDGS-11 DDGS-2 E-DDGS-12 E-DDGS-2
Dry Matter, % 90.16 88.77 91.62 90.16
Crude Protein, % 28.14 26.74 30.01 28.20
Ether Extract, % 9.94 10.85 10.36 11.27
Total Dietary Fiber, % 29.61 27.79 25.10 25.34
1DDGS refers to distiller's dried grains with solubles.
2E-DDGS refers to enhanced distiller's dried grains with solubles.

Table 2. Energy Values of DDGS1 and E-DDGS2

Item Ingredient
DDGS-1 DDGS-2 E-DDGS-1 E-DDGS-2
Growing pigs
Digestible energy, kcal/kg, dry matter 3,390 3,483 3,703 3,670
Metabolizable energy, kcal/kg, dry matter 3,047 3,159 3,226 3,339
Finishing pigs
Digestible energy, kcal/kg, dry matter 3,303 3,436 3,518 3,691
Metabolizable energy, kcal/kg, dry matter 3,128 3,239 3,293 3,453
1DDGS refers to distiller's dried grains with solubles.
2E-DDGS refers to enhanced distiller's dried grains with solubles.

Feed Additives Don't Resolve Mycotoxin Contamination

Two related feed additives failed to resolve the impact of mycotoxin contamination in a nursery pig trial.

Feeding diets containing about 2 ppm Deoxynivalenol (DON), a mycotoxin, depressed feed intake by almost 10% when consumed by nursery pigs for three weeks.

Moreover, feed additives, regardless of their mode of action, did not reverse the detrimental effects of the mycotoxin.

DON is a mycotoxin produced by fusarium molds found in corn and wheat. Pigs consuming DON-contaminated feed will initially reduce the amount of feed consumed as well as growth rate. Signs such as vomiting are evident if the contamination is severe. This can have serious consequences resulting in an economic loss of 8-10 ($CAN)/hog (under average market conditions).

Several feed additives are reported to reduce the effect of the mycotoxin by either binding the mycotoxin in the gut and preventing absorption, chemically transforming the toxin to decrease its toxicity or enhancing immune system function.

To test the additives, five nurseries with 24 pens/nursery and four pigs/pen weighing 20 lb. were fed 0.6 lb. of Provision 1, then Provision 2 (FeedRite, Winnipeg, Canada) until Day 14, and treatment diets containing DON from Day 15-35, postweaning.

Pigs were weighed seven and 14 days postweaning, and at the start and end of treatment diets at 35 days of age when they exited the nursery.

Treatment diets were formulated to meet or exceed nutrient requirements for pigs of this age. Samples of corn shown to contain DON were used for 35% of the corn in nursery diets to provide an average of 2 ppm DON in the nursery diets.

Diet samples showed control diets were negative for DON, compared to up to 2.61 ppm DON in late nursery diets.

Overall, average daily gain and average daily feed intake of control pigs were superior to pigs consuming a diet containing DON, regardless of the feed additive used.

Researchers: A.D. Beaulieu, J.F. Patience and D. Gillis, all of the Prairie Swine Center at Saskatchewan, Canada. Contact PSC's Ken Engele by phone (306) 373-9922, fax (306) 955-2510 or e-mail Ken.Engele@usask.ca.

Adding Amino Acids Cuts Protein Costs, Boosts Net Energy

Supplementing a low-protein diet with synthetic amino acids can provide a cost-effective way to avoid adding excess crude protein (CP).

Two experiments with grow-finish pigs confirmed that performance could be maintained when either high- or low-crude protein diets are fed as long as amino acids are balanced and the diets are formulated to provide similar net energy.

The introduction of crystalline amino acids has allowed a reduction in the crude protein (CP) in swine diets. Low-CP diets supplemented with essential amino acids can decrease nitrogen excretion in the manure and may reduce diet costs.

This study compared the performance of grow-finish pigs fed either high- or low-CP diets supplemented with crystalline amino acids.

High-CP diets were formulated to meet the lysine and other amino acid requirements of the pig (Table 1). Low-CP diets were formulated to provide the same amount of lysine, but the CP was reduced from 20% to 16% in the grower and from 16% to 12% in the finisher diet.

Diets were formulated to provide equal net energy. Sodium bicarbonate was added to the low-CP diets to maintain the electrolyte balance of the diet.

Average daily feed intake was lower when the pigs consumed the high-CP diet, while average daily gain was similar between treatments, resulting in an improved feed:gain ratio with the high-CP diet (Table 2).

The low- and high-CP diets resulted in similar pig performance during the finishing phase (Table 2).

In summary, CP levels can be decreased by 4% in grower and finisher diets without impacting pig performance, provided that diets are formulated to be equivalent in available amino acid, net energy and dietary electrolyte balance.

Researchers: J.F. Patience, A.D. Beaulieu and I.U. Haq, all of the Prairie Swine Centre (PSC). Contact PSC's Ken Engele by phone (306) 373-9922, fax (306) 955-2501 or e-mail Ken.Engele@usask.ca.

Table 1. Ingredient Composition and Calculated Nutrient Contents of Experimental Diets

Ingredients (% as fed) Grower (55 to 121 lb.) Finisher (165 to 264 lb.)
High crude protein Low crude protein High crude protein Low crude protein
Corn 60.50 73.51 77.25 87.80
Soybean meal 34.50 20.80 18.70 7.40
Tallow 1.13 0.00 0.87 0.00
Lysine 0.00 0.43 0.03 0.38
Methionine 0.00 0.11 0.00 0.02
Tryptophan 0.00 0.05 0.00 0.06
Threonine 0.00 0.05 0.00 0.06
Valine 0.00 0.05 0.00 0.03
Isoleucine 0.00 0.00 0.00 0.03
Othera 3.87 5.69 3.18 4.80
Nutrients
DE, Mcal/kg 3.51 3.41 3.50 3.42
NE, Mcal/kgb 2.30 2.30 2.40 2.40
Crude protein, % 20.44 16.94 16.13 12.31
Calcium, % 0.70 0.70 0.50 0.52
Phosphorous, % (total) 0.60 0.60 0.45 0.47
TID Lys, %c 1.02 1.02 0.66 0.66
TID Met, % 0.29 0.30 0.22 0.26
dEB, meq/kgd 221 222 145 146
aConsisting of dicalcium phosphate, limestone, salt, sodium bicarbonate, potassium carbonate, vitamins,minerals and celite.
bEstimated according to CVB (1998). NE stands for net energy.
cTID refers to true ileal digestible.
dDietary electrolyte balance, milliequivalents/kg.

Table 2. Performance of Grower and Finisher Pigs Fed High- or Low-Crude Protein (CP) Diets

Grower Finisher
High CP Low CP High CP Low CP
Initial body weight, lb. 55.70 55.60 170.00 170.30
Final body weight, lb. 116.14 118.00 255.2 250.40
Avg. daily gain (lb./day) 2.21 2.22 2.44 2.30
Avg. daily feed intake (lb./day) 4.00 4.40 7.60 4.30
Feed:Gain (lb./lb.) 1.21 1.12 1.00 1.00