UNDERSTANDING AND IMPROVING FEED INTAKE

Feed intake can account for 60 to 85 percent of the variation observed in pig growth rate during finishing (Young, 2005). The facilities and production systems in which most pigs are raised will limit feed intake in some respect. In a study at North Carolina State University comparing maximum performance potential to commercial performance, researchers found that pigs potentially could consume 27 percent more feed on a daily basis (4.87 versus 3.84 lb/day). Many factors that stress the pig can negatively affect feed intake. These stressors can include temperature, space, health, equipment, and feed and water availability.

To understand pig growth and appetite, it is important to know what performance can be expected at the difference sizes and ages of pigs. Table 1 describes “typical” finisher performance. As pigs grow, their daily feed intake (ADFI) will increase, but they will become less efficient (F:G) in converting the feed consumed into weight gain (ADG). Depending on genetic line, ADG may increase throughout finishing or plateau as pigs reach final weights. The lean growth potential of a genetic line of pigs will set the maximum performance potential that can be expected.

The growing pig is most comfortable and will achieve the best performance at temperatures below 75^oF. The lower critical temperature declines from 65^oF at placement in finishing to 50^oF when the pig reaches a weight of 150 pounds. Forty-five pound pigs may experience as much as a 1 percent decline in feed intake for each degree above their comfort zone. Larger pigs (greater than 220 lb) may experience as much as a 2.5 percent decrease in feed intake for each additional degree in temperature above their comfort zone. Cold temperatures increase the pigs’ maintenance requirements and will also decrease pig performance even though feed intake may be higher. Average daily feed intake is also significantly reduced when the relative humidity in the barn is high. A pig’s ability to dissipate body heat through evaporation is minimized when the humidity is high.

Good health is essential. Pigs that are compromised by disease infection will suffer a 5 to 24 percent reduction in feed intake and growth rate. Diseased animals also have a higher demand for nutrients for various bodily functions, reducing nutrients available for lean growth. Maintaining biosecurity, through cleaning between groups of pigs and careful, daily animal observation, combined with early treatment can help.

Feeders need to be clean at all times, and pigs should have unlimited access to feed and clean, fresh water. Feeders should allow the pig to eat easily. Pigs should be observed to determine how long they spend eating and if they can easily get access to feed. The design of the feeder can impact feed consumption by 15 to 20 percent (Whittington et al.). Interruptions in feed supply result in decreased performance and contribute to ulcer formation and mortality. A pig requires twice as much water as feed each day (measured by weight).

Any management practice of moving pigs that upsets their established social hierarchy may decrease feed consumption for as long as 4 to 5 days.

Feed intake is one of the most important economic factors as feed costs contribute nearly 60 percent of the total production costs. Feed intake is influenced by a number of interrelated factors that should be monitored to improve growth rate and feed efficiency.

References

• Whittington, D. L., Nyachoti, C. M., Patience, J. F., Gonyou, H. W., Zijlstra, R. T., and Lemay, S. P. 2000. Feed Intake – A checklist of nutritional, environmental and management strategies to achieve success. Presented at Manitoba Pork Council/PSCI Meetings on Focus on the Industry, February 2000. online: www.thepigsite.com.
• Young, M. 2005. Managing growing-finishing pig diets for maximum profitability. Presented at 2005 Banff Pork Seminar. online: www.albertapork.com.

-Todd See

2007 STATE FAIR SWINE SHOW WINNERS

Sydney Cox of Jones County drove the Grand Champion Junior Market barrow and took home $10,000 from the Sale of Champions at the 2007 North Carolina State Fair. Harris Teeter bought his 280-pound pig, shown in Class 12.

A.J. Carpenter of Macon County sold his 262-pound Reserve Grand Champion from Class 7 to Martin Livestock and Neese Sausage for $8,500.

The Junior Market Barrow Show, held october 12 and judged by Steve Nichols of Delphi, Indiana, drew 185 pigs weighing between 230 and 280 pounds. The show was divided into 13 classes and three divisions.

The three different hog shows attracted 317 market pigs. In addition to the 185 pigs in the Junior Show, there were 48 pigs in the Performance Show and 84 pigs in the open Barrow Show.

In the Junior Market Barrow Show, Samantha Wiggins of Jones County had the Lightweight Champion out of Class 4, and Chad Byrum had the Reserve Champion out of Class 1. other class winners were Abigail Wood in Class 2, MacKenzie Metts in Class 3, and Jordan Cox in Class 5.

A. J. Carpenter of Macon County showed the Middleweight Champion from Class 7, and Landis Looper of Caldwell County showed the Reserve pig out of Class 9. other middleweight class winners were Faith Kennedy of Lenoir County in Class 6, and Lawton Looper of Caldwell County in Class 8.

Sydney Cox of Jones County won the Heavyweight Division with the first place pig from Class 12, and Marian Morgan of Macon County showed the Reserve Champion with her Class 10 winner. other class winners were Kaelyn Mohrfeld of Lenoir County in Class 11 and Landis Looper of Caldwell County in Class 13.

Each junior exhibitor was allowed to sell one pig in the sale. These pigs were purchased by Martin Livestock for $36.50 per hundredweight, which established a floor for the sale that followed. Further, the N.C. Farm Bureau put a $65.00 premium on each animal, and some individual pigs were granted additional premiums. The sale was conducted by Ronnie Powell of Johnston County.

The Performance Hog Show, held october 12, attracted 48 pigs shown in four classes. These pigs were from a large group of pigs placed on test in July, and each pig carried its average daily gain (ADG) paint-branded on its rump. The Grand Champion Performance Pig belonged to Nahunta Farm from Wayne County from Class 4. The Reserve Champion also belonged to Nahunta Farm from Class 3. other class winners were Anthony Locklear, Class 1, and Daniel Sharp, Class 2.

The open Barrow Show, held october 13, included six classes, with each containing 14 barrows. Floyd Sauls won Grand Champion with his Class 6 winner, and Nahunta Farm won Reserve with the second place winner in Class 6. other class winners were Joe Wiggins, Class 1; Julie Feezer, Class 2; Nahunta Farm, Class 3; Floyd Dauls, Class 4; and Joe Wiggins, Class 5.

A new contest this year was Junior Market Barrow Showmanship. Classes were determined by age of contestant, with five classes in the Junior Division, 11 years and under; three classes in Intermediate, with ages 12-14; and three classes in Senior Division, with ages 15 and up. Kaelyn Mohrfeld was the Junior Champion, and Emma See was the Reserve Junior Champion. Jordan Cox was Intermediate Champion, and Garrett See was Reserve Champion of that division. Daniel Winstead was Senior Champion, and Taryn Looper won Reserve Champion in the Senior division.

The Champion carcass in the Performance Market Hog class was won by Nahunta Farm, which was first in Class 4 and the Grand Champion Performance Barrow on-foot. The 267-pound pig on-foot had a 9.01-inch loin eye, 0.49-inch backfat, and 1.068-pound lean gain per day on test. The Reserve Champion carcass went to Anthony Locklear on the sixth place in Class 4 on-foot. This pig had an 8.89-inch loin eye, 0.46-inch backfat, and 1.046-pound lean gain per day on test. The Reserve Champion on-foot was twelfth placing on-foot.

The champion carcass in the open Barrow Show was won by Wesley Looper. This 256-pound barrow (fifth place in Class 4 on-foot) had 0.55-inch adjusted backfat, 10.24-inch adjusted loin, and 64.44 percent lean. The Reserve Champion carcass in the open show was won by Amy Hassell. This 230-pound pig (ninth in Class 1) had 0.42-inch adjusted backfat, 9.10-inch adjusted loin, and 63.37 percent lean. The Grand Champion on-foot in the open Market Barrow Show was number 62 in the carcass contest with 54.82 percent lean, while the Reserve Grand Champion on-foot was number 20 in the carcass contest.

The sow and 10 pigs, along with the Champion and Reserve Champion Junior Market pigs, were on exhibit in the Ark Building, next to the sheep tents.

Some of the people assisting with the swine shows, under the direction of Superintendent Ron Hughes, were Dr. Todd See, Dr. Bob Jones, Frank Hollowell, David Lee, Justin Fix, Steve Lathrop, Kyle Lovercamp, Charles Young, Martin Rowe, and Amanda Hughes. The overall Livestock Director was Bruce Shankle.

— Bob Jones