Nutrition

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.

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 [email protected].

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.

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 [email protected].

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.

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 [email protected].

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 [email protected].

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.

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 [email protected].

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