Carnitine, Chromium Raise Farrowing Rate, Shorten Wean-to-Estrus Interval

Feeding both chromium picolinate and L-carnitine to sows during gestation and lactation appears to increase farrowing rates and improve the wean-to-estrus interval, according to research from Kansas State University. The study was conducted on a commercial 1,500-sow, farrow-to-wean operation in central Kansas.

A total of 599 multiparious sows were assigned to one of four treatments on the first day of breeding. Each sow remained on the same treatment (control, carnitine, chromium or both) through gestation, lactation and a second gestation period.

Table 1. Effects of L-Carnitine and Chromium Picolinate on Reproductive Performancea
Treatment
Item Control Carnitineb Chromiumc Bothbc
First parity
No. of sows
Started on test 148 150 147 154
Farrowed 123 140 138 142
First service FR, %dei 82.9 91.9 95.5 92.2
No of pigs
Total borne 11.3 11.4 11.5 11.6
Born alivec 10.0 9.8 10.2 10.2
Stillborn 0.95 0.98 1.26 1.13
Mummies 0.34 0.26 0.39 0.34
WEI, ddgh 4.9 4.6 4.7 4.5
% estrus by d 7egi 84.8 88.6 86.7 92.3
% estrus by d 18cgi 88.1 91.5 91.7 94.4
Second parity
No. of sows
Weaned parity 1 123 140 138 142
Bred by d 18 108 128 127 134
Farrowed 87 104 102 122
First service FR, %degi 81.2 81.3 79.7 91.1
Percent weaned 70.7 73.9 74.3 85.9
No. of pigs
Total borncg 11.1 11.2 11.0 11.4
Born aliveeg 9.7 9.9 9.5 9.8
Stillbornc 1.02 1.02 1.09 1.31
Mummies 0.35 0.33 0.40 0.25
WEI, ddgh 4.6 4.7 4.6 4.8
% estrus by d 7efgi 80.3 76.9 81.0 75.0
% estrus by d 18efgi 80.2 80.8 82.9 75.9
Total pigs per sow for sows that completed parity two
Total borneg 19.4 19.8 19.5 21.3
Born aliveeg 17.1 17.6 16.8 18.5
Stillborne 1.7 1.7 2.1 2.3
Mummies 0.6 0.5 0.6 0.6
Total pigs per sow for sows started on test for two parities
Total borneg 15.8 18.4 18.8 19.7
Born aliveeg 13.9 16.3 16.2 17.0
Stillborne 1.4 1.6 2.0 2.1
Mummies 0.5 0.5 0.7 0.5
aInitially 599 sows bred.
b50 mg/kg L-carnitine provided as top dress daily
c200 mcg/kg chromium picolinate provided as top dress daily
dFR = First service farrowing rate; WEI = wean-to-estrus interval.
eParity was used as a covariate; 6.0, 5.6, 5.2 and 5.5 for control, carnitine, chromium, and both, respectively
fPrevious lactation length was used as a covariate; 15.2, 15.8, 15.7 and 15.4 for each treatment.
gWeek of year sow farrowed was used as a covariate; 23.6, 23.9, 23.7, and 23.9 for each treatment.
hWEI analyzed as inverse of means, previous WEI analyzed as log of means.
iP-values from chi-square statistic.


The gestation diet was milo-soybean meal containing 0.65% lysine, 1.10% calcium and 0.76% phosphorus. The lactation diet was grain sorghum-soybean meal with 1.10% lysine, 0.90% calcium and 0.80% phosphorus. A 30 g./day corn-based top dress for gestating sows included 90 mg./day and 50 mcg./day of carnitine and chromium, respectively.

The same corn-based top dress was used for lactation diets and contained 250 mg./day of carnitine and 200 mcg./day of chromium, respectively.

At farrowing, number of pigs born alive, stillborns, mummies and total born were recorded. Pigs were weaned at 15 days of age and sows rebred for the second parity.

In the first parity, a carnitine by chromium interaction was observed. The chromium improved the first service farrowing rate. The researchers found no difference in total born, born alive, or mummies, but sows fed only chromium tended to have increased stillborns. The carnitine improved the wean-to-estrus interval and the number of sows in estrus by Day 7.

In the second parity, the same carnitine by chromium interaction was found. The combination also increased the number of sows that farrowed in Parity 2. Again, there was no difference in total pigs born, born alive, stillborn or mummies (Table 1).

Researchers note that the carnitine and chromium have minimal effects on the number of pigs born alive/litter, but improvements in farrowing rate and return-to-estrus interval resulted in a greater overall number of pigs born during the two-parity study.

The researchers evaluated the financial return on feeding carnitine and chromium by using the total pigs/sow started on test for two parities, so the cost-benefit ratio would be based on 15.8 vs. 19.7 pigs. The extra 3.9 pigs at $25/head equals $97.50. The cost of the carnitine and chromium was $5/sow.

Researchers: Daryl Real, Jim Nelssen, Mike Tokach, Robert Goodband, Steve Dritz, Kansas State University; Kevin Owen, Lonza, Inc., and Steve Stoller. Phone Nelssen at (785) 532-1251 or e-mail jnelssen@oznet.ksu.edu.

Liquid Diets Accelerate Growth of SEW Pigs

Research at North Carolina State University shows early weaned pigs fed liquid diets for two weeks after weaning have improved growth performance that lasts through finishing.

A total of 240 crossbred PIC pigs (11 days old, 8.65 lb.) were allotted 10/pen and assigned to one of four treatments. The treatments included hot nursery or specialized temperature nursery and/or liquid or dry pellet diets. Both diets were formulated to be nutritionally identical and exceed National Research Council requirements. Pigs on all treatments had ad lib access to feed and a nipple waterer. The research was conducted in a conventional nursery and a specialized nursery with automated milk machines, which reconstituted milk replacer to 15-16% dry matter.

In the specialized nursery, the ambient temperature was 74° to 77° F. with pig hovers heated to 90° F. In the conventional nursery, the ambient temperature was maintained from 81° to 93° F.

Pigs were weighed and feed intakes measured on Days 3, 6, 10 and 14. The pigs on the liquid diets were offered pellets from Day 12 to 14 to transition them to dry feed.

After Day 14, all pigs were moved to a conventional nursery and fed identical diets until they reached 60 days of age. Body weights and feed intakes were measured on Days 21 and 49, while barn temperatures were 70° to 75° F.

At 60 days, pigs were measured for 10th-rib backfat (BF) and longissimus muscle area (LMA) with real-time ultrasound and moved to a totally slotted, grow-finish facility. They were grouped by gender with five pigs/pen.

All finisher diets were formulated to exceed NRC requirements, with protein requirements exceeded by at least 10%. Body weight, feed intake and real-time ultrasound measurements (BF, LMA) were taken on Days 70, 91, 112, 133 and 143. That data was used to calculate the carcass fat-free lean index and lean gain rates.

At 14 days after weaning, pigs fed the liquid diet were 21% heavier and had a 44% greater average daily gain (ADG) than pigs fed the pelleted diet. The liquid diet-fed pigs gained almost four times as much weight as the dry-fed controls. But, by Days 10 to 14, all pigs in the specialized temperature nursery grew at similar rates, while the liquid-fed, conventional nursery pigs outpaced their dry-fed controls.

Table 1. Effects of Diet Physical Form and Nursery Environment During the First 14 Days After Weaning on Live-Ultrasound Body Measurements, and Calculated Carcass Fat-Free Lean Index and Lean Gain of Pigs During Growing and Finishing Phases (Day 49 to 143)a
Conventional hot nursery Segregated-temperature nursery
Itemb Diet form: Liquid Dry Liquid Dry
Day 49
Backfat, in. 0.308 0.276 0.296 0.296
LMA, sq. in. 2.704 2.464 2.544 2.464
CFFLI, % 50.8 50.5 50.2 50.0
Day 70
Backfat, in. 0.408 0.404 0.392 0.396
LMA, sq. in. 3.120 3.408 3.360 3.344
CFFLI, % 41.9 42.9 43.0 42.8
CFFLG (Day 49 to 70), lb./day 0.638 0.662 0.673 0.649
Day 91
Backfat, in. 0.508 0.480 0.476 0.464
LMA, sq. in. 4.512 4.304 4.208 4.128
CFFLI, % 40.9 40.7 40.5 40.4
CFFLG (Day 71 to 90), lb./day 0.687 0.632 0.632 0.625
Day 112
Backfat, in. 0.656 0.664 0.620 0.636
LMA, sq. in. 5.120 5.232 5.232 5.152
CFFLI, % 38.3 38.4 38.9 38.5
CFFLG (Day 91 to 112), lb./day 0.552 0.625 0.643 0.634
Day 133
Backfat, in. 0.824 0.808 0.812 0.780
LMA, sq. in. 5.856 5.856 6.128 6.160
CFFLI, % 36.7 36.8 37.3 37.5
CFFLG (Day 112 to 133), lb./day 0.610 0.605 0.645 0.665
Day 143
Backfat, in. 0.916 0.92 0.908 0.876
LMA, sq. in. 6.576 6.608 6.88 6.72
CFFLI, % 36.5 36.5 37.0 37.0
CFFLG (Day 133 to 143), lb./day 0.649 0.654 0.665 0.662
aValues are means of 12 pens.
bLMA: longissimus muscle area, CFFLI: carcass fat-free lean index, CCFLG: carcass fat-free lean gain.


Table 2. Effects of Diet Physical Form and Nursery Environment During the First 14 Days After Weaning on Growth Performance of Pigs During Nursery (Day 0 to 49), Growing (Day 50 to 91), and Finishing (Day 92 to 143) Phasesa
Conventional hot nursery Segregated-temperature nursery
Item Diet form: Liquid Dry Liquid Dry
Day 0 to 14
ADG, lb. 0.874 0.566 0.788 0.590
ADFI, lb. 0.812 0.643 0.742 0.680
Gain/feed 0.929 1.136 0.941 1.152
Day 15 to 49
ADG, lb. 1.090 1.017 1.052 1.081
ADFI, lb. 1.876 1.731 1.788 1.856
Gain/feed 1.720 1.702 1.699 1.716
Day 50 to 91
ADG, lb. 1.969 1.933 1.947 1.874
ADFI, lb. 4.246 3.918 3.940 3.874
Gain/feed 2.156 2.026 2.023 2.067
Day 92 to 143
ADG, lb. 2.132 2.127 2.134 2.123
ADFI, lb. 5.781 5.764 5.843 5.676
Gain/feed 2.711 2.709 2.738 2.673
Day 0 to 143
ADG, lb. 1.704 1.640 1.680 1.645
ADFI, lb. 3.876 3.720 3.777 3.711
Gain/feed 2.274 2.268 2.248 2.255
Age of pigs at 24,216 lbs., days 150.6 154.7 151.2 154.4
a Values are means of 6 pens during nursery and 12 pens during growing-finishing phases.


During the grow-finish period, pigs showed only modest and temporary differences in growth. Overall, liquid-fed pigs had a greater ADG and Average Daily Feed Intake (ADFI) and reached market weight 3.5 days earlier. No difference in feed:gain was detected. See Table 1.

At Day 49, pigs fed the liquid diet and housed in the conventional nursery had more BF. That effect was reduced during finishing. The carcass fat-free lean index was not affected by the diets. See Table 2.

The researchers note that liquid diets could be applied within conventional hot nurseries to accelerate pig growth. If selectively applied to lightweight weaned pigs, it could be useful in reducing variation in days to market and market weights.

Researchers: Jack Olde, Robert Harrell, J.H. Kim, K.N. Heo, North Carolina State University; I.K. Han, Seoul National University, Korea. Phone Olde at (919) 515-4050 or e-mail jack_olde@ncsu.edu.

No Difference Between Roundup Ready, Conventional Corn

University of Nebraska researchers find no difference in growth performance and carcass quality when grow-finish pigs are fed rations made from Roundup Ready corn.

Table 1. Performance, Carcass and Tissue Composition, and Eating Quality of Pork from Pigs Fed Corn-Soybean Meal Diets Containing Conventional or Roundup Ready Soybean Mealab
Item Conventional Roundup Ready
Performance data
Daily gain, lb. 1.84 1.88
Feed/gain 3.04 3.09
Carcass data (scanned)
Backfat, 10th rib, in. 0.74 0.75
Loineye area, sq. in. 5.41 5.24
Estimated carcass lean% 52.9 52.5
Lean gain, lb./day 0.75 0.74
Loin tissue
Water, % 72.8 72.5
Protein, % 23.4 23.3
Fat, T 3.0 3.4
Ash, % 1.1 1.1
Eating quality of pork loin chopsc
Juiciness score 5.52 5.58
Tenderness score 5.91 6.10
Overall acceptance score 5.80 6.05
Biotech protein in pork tissue n/a none
aEach treatment mean based on 10 pens of five pigs/pen from 52 to 244 lb. bodyweight. Experiment conducted at the University of Kentucky's Research and Education Center, Princeton, KY, in the summer of 2000
bNo significant treatment differences (P < 0.05).
cBased on a scoring system of 1 to 10 with the highest score being the most desirable.


A total of 72 barrows and 72 gilts (PIC × Duroc × Hampshire), weighing 50 lb., were assigned to one of four diet treatments. The diets were made from either Roundup Ready corn (CRR 0633), the parental control corn (RX 670) or two commercial sources of non-genetically modified corn (RX 760 or DK 647).

The diets were formulated with corn and soybean meal and met or exceeded National Research Council (NRC) requirements. Four phases, two grower and two finisher, were each fed for 28 days, except the final finisher diet was fed for 19 days. When pig weight averaged 255 lb., all pigs were sent to slaughter.

Pigs were housed in a modified-open-front building with 24 pens, six barrows or gilts per pen. Pigs had ad lib access to feed and water throughout the period.

Pigs were weighed and feed intakes measured biweekly to measure average daily gain (ADG), average daily feed intake (ADFI) and feed-to-gain ratio (F:G). Real-time ultrasound measurements, including backfat depth and longissimus muscle area (LMA), were recorded at the end of the feeding period.

Pigs were shipped to Sioux Preme Packing, Sioux Center, IA, for slaughter and carcass measurements, including backfat at the first, 10th, last rib and last lumbar. LMA was traced at the 10th rib. Carcass quality tests, including pH, firmness and marbling scores and Minolta L*, a* and b* values, were run on the loin at the 10th rib at 24 hours postmortem. Samples were taken from five barrows and five gilts from each diet treatment for loin muscle chemical composition.

ADG, ADFI and F:G were not affected by corn variety. Researchers found the traditional sex differences in growth performance between gilts and barrows. The dietary treatment did not affect ultrasound and carcass measurements.

The researchers have concluded that the feeding value of Roundup Ready corn is equivalent to that of conventional corn and that Roundup Ready corn can be used in swine diets with no detrimental effects on growth performance or carcass characteristics.

Researchers: Robert Fischer, Austin Lewis and Phillip Miller, University of Nebraska. Phone Miller at (402) 472-6421 or e-mail pmiller1@unl.edu.

GMO Soybean Meal Has No Impact on Performance, Carcass

Research by University of Kentucky scientists shows that Roundup Ready soybean meal (SBM) is essentially equivalent in composition and nutritional value to conventional SBM. Testing failed to detect the modified DNA or the specific protein that makes Roundup Ready soybeans tolerant to glyphosate herbicides.

The soybeans used in the test were a Roundup Ready variety containing the CP4 EPSPS protein and a near-isogenic conventional soybean. The beans were grown in the summer of 2000 and processed into meal at the same plant.

In the experiment, 100 crossbred pigs (initial weight, 53 lb.) were fed diets with the two types of soybean meal. Diets contained 0.95% lysine and were reduced to 0.80% and 0.65% at 120 and 190 lb., respectively. Pigs were housed in 10 pens with five barrows or gilts per pen. All pigs were scanned with ultrasound at 235 lb., and all barrows were slaughtered at the end of the test (245 lb.) for carcass measurements and tissue collection.

Rate and efficiency of gain, scanned backfat, loineye area and percent lean were not different for pigs fed the two diets. Gilts gained slower, but were leaner.

Loin muscle samples from the barrows fed the conventional SBM tended to be leaner than the barrows fed the Roundup Ready SBM, but the difference was not significant. Water, protein and ash were similar. Sensory scores of cooked chops were not different. See Table 1 for results.

Researchers: Gary Cromwell, Merlin Lindemann, Benjy Mikel, Gary Parker and Richard Coffey, University of Kentucky. Phone Cromwell at (859) 257-7534 or e-mail gcromwel@ca.uky.edu.

Three-Sieve Test Accurately Predicts Particle Size

Researchers at Kansas State University (KSU) have developed a three-sieve method for predicting particle size of feed in on-farm testing. Testing shows the method is 91% accurate, when compared to a standard 13-sieve test.

Table 1. Accuracy of Particle Size Prediction (Percentage of Samples Within Each Deviation Category)
Deviation from Ro-tap
Analysis, microns One-sieve method Three-sieve method
<25 5% 32%
25 to 50 9% 25%
50 to 75 11% 34%
75 to 100 16% 5%
100 to 150 18% 2%
150 to 200 14% 2%
>200 27% 0%


Researchers note the standard method for determining particle size is time consuming and expensive. Therefore, producers have turned to a one-sieve method, but the results can be variable, when compared to the standard method.

Previous KSU research shows feed efficiency is optimized when particle size is between 600 and 800 microns. Producers can save $0.50/pig marketed for every 100 microns they reduce feed particle size. For example, dropping the particle size from 1,000 to 700 microns saves $1.50/pig in feed efficiency.

To test the three-sieve method, two experiments were conducted. The first determined the appropriate shaking time for the three-sieve method. Ground corn (50 g.) was placed on a stack of three sieves: U.S. #12 (1,700 microns), #30 (600 microns), and #50 (300 microns). One ball and one carnucle (small brush) were included on the #30 sieve and one ball and two carnucles were on the #50 sieve. A lid was placed on top and a pan on the bottom of the stack. The sieves were shaken vigorously by hand for five, 30-second intervals. The sample left on each screen was weighed after each interval.

This process was repeated for 10 corn samples. As most of the grain passed through the screens in the first three intervals, 90 seconds of shaking was used in experiment two.

For experiment two, 44 samples of ground corn were tested for particle size with a standard test, a Ro-Tap tester with a 13-sieve stack in the KSU swine lab. The samples ranged from 422 to 1,143 microns.

The particle size was also determined by using a one-sieve tester. In this experiment, 0.6 lb. (280 g.) of ground corn was placed on a #14 sieve (1,400 microns) and shaken until all the small particles had fallen through the screen.

Finally, the particle size was determined with the three-sieve method and the measurements were compared to the 13-sieve and one-sieve results.

Of the 44 samples, the one-sieve method was able to predict 11 of the samples within 75 microns of their actual size. The prediction was incorrect by more than 150 microns on 18 samples and off by more than 200 microns on 12 of those 18 samples. See Table 1.

The three-sieve method predicted 40 of the 44 samples within 75 microns and one sample was off by more than 150 microns.

The researchers remind that, even though the three-sieve method is more accurate than one sieve, it is still not as accurate as the standard 13-sieve test. They recommend doing multiple tests and sending samples monthly to a laboratory that performs particle size analysis.

Researchers: Allen Baldridge and Jason Woodworth, Kansas State University. Phone Robert Goodband at (785) 532-1228 or e-mail goodband@ksu.edu.

For more information on testing equipment, phone Brad James, KSU swine laboratory manager at (785) 532-1277.