September, 1997 ^. Volume 20, Number 8

At the recent annual meeting of the American Society of Animal Science in Nashville, TN many swine related research papers were presented. The following are summaries of papers that have some potential for rapid application in the swine industry.

• Researchers at PIC studied the genetic relationships between litter size, growth and carcass traits, and maternal ability in a commercial dam line. The data consisted of 29,868 litter and performance records and 2,187 litter weaning weight records from two nucleus farms. Their results indicate that slower growing gilts have the genetic potential to produce larger litters. Also, faster growth and lower leg conformation scores were genetically associated with increased milking ability (measured as litter weight).

• Iowa State University researchers evaluated the effect of weaning age on behavior of commercial crossbred pigs. Early weaning technologies prevent pigs from satisfying their drive to suckle, therefore aberrant behavior and its effect of performance as a measure of welfare was evaluated. Early weaned pigs were taken from their dams at 8 to 13 days and late weaned pigs were taken at 27 to 34 days of age. Behaviors evaluated by direct observation included time spent lying, standing, sitting and play-fighting, as well as frequency of belly-nosing, metal biting and manipulation of another pig (nosing, biting, or pushing the head, ear, flank etc.). Early weaned pigs gained 7 more pounds from birth to 42 days of age. No differences were observed in feeding and drinking after weaning. However, time spent play-fighting was greater in early weaned pigs immediately following weaning. At 42 days of age early weaned pigs did manipulate pen mates more frequently than late weaned pigs (7.2 vs. 2.5).

• Ohio State University Research projects measured sow behavior and evaluated its relationship with reproductive traits. 270 multiple parity Duroc and Landrace sows were evaluated in trial 1. A desirable overall mothering score was associated with more offspring at birth and 21 d, with heavier birth and 21 d weights and an ability to accept her pigs, have an easier farrowing and no milking problems. Trial two evaluated 36 Yorkshire and Landrace sows and found the ability of sows to adapt to a crate was desirably related to heavier 21 d weights, to no milking problems and with superior overall mothering score. This researcher suggests that behavior in sows can be measured subjectively and is significantly associated with reproduction traits.

• Three studies evaluating pork quality were reported by Purdue and Iowa State. The Purdue project evaluated two genotypes with different rates of lean growth and fat deposition and found differences in quality of pork from high lean and average lean genotypes to be a result of changes in intramuscular fat deposition. The Iowa State projects reported on a model to predict intramuscular fat in live swine using real-time ultrasound. This research indicates that real-time ultrasound can be an effective estimator of intramuscular fat in the loin eye of live swine.

• A 27 day Kansas State growth trial conducted with 320 SEW barrows evaluated the interactive effects between diet complexity, zinc oxide, and feed grade antibiotic. No interaction between complexity, zinc oxide, and antibiotic was found. Overall pigs fed complex diets grew faster than pigs fed simple diets. Response to antibiotic occurred in the latter half of the growth trial, while the responses to zinc oxide occurred primarily during the first 10 days. Their data indicate that both zinc oxide and antibiotic are beneficial in the diets of SEW pigs.

• Eric van Heugten presented the results of two separate studies to determine the effect of pelleting and fat supplementation on performance of grower pigs (n=346) and finisher pigs (n=327). Pelleting and fat addition had similar effects on feed intake and therefore nutrient levels in pelleted diets may need to be adjusted to maintain total daily nutrient intake and pig growth performance.

• The impact of water quality on weaning pig performance was evaluated at the Prairie Swine Center in Saskatoon, Canada. Inorganic contaminants, very high levels of sulfates and associated mineral cations, were studied by comparing performance of pigs that received water directly from the well or that was treated by a reverse osmosis unit. The well water contained 3,086 mg total dissolved solids/L, 1,634 mg sulfate/L and 7.2 mg iron/L and the treated water contained 15 mg sulphate/L, 193 mg total dissolved solids/L and .4 mg iron/L. While nursing, the sow and all piglets had access to the treated water. Pigs were allocated to one of the two treatments and performance was monitored for 35 days following weaning. Although diarrhea was more prevalent in the pigs on the well water there were no significant differences in average daily gain, average daily feed intake or feed efficiency. The authors suggest that care be taken to not assume that osmotically induced diarrhea is automatically associated with pork animal performance.

Todd See

Progress in plant genetics has lead to the development of a new corn variety with a higher oil content than regular corn. A high oil corn (HOC) can provide an efficient means to increase the energy density of swine diets without the use of additional fat. Furthermore, handling characteristics of HOC may be improved due to less dust.

The nutrient value of HOC

In a recent experiment (Adeola and Bajjalieh, J. Anim. Sci. 1997, p. 430) the nutritional value of HOC was evaluated. In this experiment several varieties of HOC were used.

As can be seen from the table above, all HOC varieties contained more fat and more protein and lysine. The level of metabolizable energy (ME; or the amount of energy the pig can use for body functions and growth) was 4 to 10% higher for the HOC varieties.

In another experiment (Risley and Bajjalieh, J. Anim. Sci. 1996, Abstract, p. 176) it was shown that pigs performed equally well when fed diets with HOC or diets with regular corn plus added fat.

The economic value of HOC

The economic value of HOC comes from the increased level in ME (or the extra fat) and from the slightly higher level of amino acids (protein). By putting a dollar value on energy (based on the price of fat) and protein (based on the price of soybean meal), the extra value of HOC, compared to regular corn, can be calculated.

Based on these calculations, the price of HOC can be 5.8% higher than the price of regular corn. However, this calculation only applies if the diets for pigs are adjusted appropriately to account for the nutrient value of HOC.

Eric van Heugten

On July 2-3 1997, Mr. Glenn Slack, Executive Director of Livestock Conservation Institute (LCI) facilitated the North Carolina PRV Summit meeting in Kenansville, NC. The mission of the meeting was to provide a forum for industry leaders and decision makers to meet with key government officials. The purpose of the meeting was to:

• Identify any and all obstacles to achieving complete eradication of pseudorabies virus (PRV) from North Carolina
• Identify solutions and resources needed to overcome those obstacles
• Build consensus in carrying out the solutions

At that meeting, Commissioner Graham announced that Dr. J.K. Atwell will be the director of the program and he will be assisted by an Industry Advisory Task Force. The first two weekly reports follow.

LCI hosted a PRV Summit in Kenansville, North Carolina July 1 & 2. The major stakeholders were represented from industry, USDA and NCDA. Each segment rededicated their commitment to PRV eradication by 2000.

A new seven (7) member PRV Advisory Committee was appointed by Commissioner Graham. The new members are:

• Dr. Terry Coffey
• Dr. Gary Dial
• Mr. Robert W. Ivey
• Mr. Zack McCullen
• Dr. Bill Plummer
• Dr. Harry Snelson
• Mr. Joe Young

Dr. Terry Coffey was appointed chairman. Commissioner Graham has expressed his appreciation to previous members of the task force for their efforts in PRV eradication.

Dr. John Atwell was appointed director of the PRV eradication effort in North Carolina.

The first meeting of the new PRV Advisory Committee was held July 18, 1997. The following was agreed to at the meeting:

Committee will meet monthly at Mount Olive Community College on Thursday at 1:00 pm (next meeting to be determined). Special meetings may be called as needed. All meetings will be open to the public. Dr. Atwell and staff will propose an agenda, report progress, planned actions, and seek input from the committee.

Dr. Atwell reported on actions since the PRV Summit and presented an organizational chart and action plan.

A short weekly report will be prepared to keep everyone informed.

Goal is PRV free by 2000. Immediate goal must be to reduce infection and quarantine herd in Stage III counties before October 1.

A small technical committee will be named to address technical problems that arise

An organizational meeting of the PRV Eradication team was held July 18, 1997.

The new approach and organization to emphasize the urgency for PRV eradication became operational July 21, 1997

The PRV Management team has been meeting a few minutes each day to develop plans and establish specific tasks and goals.

The epidemiologists have developed suggested goals and time tables that if met would maintain Stage III and keep N.C. swine moving interstate.

Each producer with quarantined swine in Stage III counties will be visited by a team (VMO, Epidemiologist & PRV Manager) to discuss actions that must be taken if we are to meet the October deadline for status.

The first meeting is planned with Brown's of Carolina (BOC) on Friday, August 1. They have by far the largest problem and actions BOC takes are critical if status is to be maintained.

Meetings with other producers will quickly follow.

Specific goals and time tables for all quarantined herds are being developed by the epidemiologist and VMOs.

The PRV Advisory Committee has established a 5-person Technical Committee to advise on technical matters. Dr. Harry Snelson will chair the technical committee.

To maintain Stage III status, there can not be more than 62 herds under quarantine in all Stage III counties.

Morgan Morrow

Electromagnetic scanning (EMS) technology could offer producers a fast, accurate and less expensive tool for predicting carcass composition, according to research at the University of Nebraska. Electromagnetic scanners create a weak electromagnetic field, causing objects moving through the scanner to disrupt the field. The pattern and amount of disruption reveal the object's composition via computer.

Researchers compared the prediction power of electromagnetic scanning with conventional calculations based on carcass measurements, such as backfat thickness and loin eye area, and found that EMS predicted fat and moisture composition more accurately than conventional carcass measurements. EMS also was good or better than carcass measurements at predicting protein.

"Not only do you get a more accurate prediction with EMS, it appears to be more applicable to different types of animals that the current carcass data," says Chris Calkins, a meat specialist involved with the study. "One reason for the improved accuracy is that EMS scans the entire carcass and indicates total body composition instead of sampling a single point as is done with carcass measurements," adds Calkins.

Hog Health
Vol. 7, No. 1

Lean pork is just as effective as chicken in keeping cholesterol levels in check, according to a new study from Duke University Medical Center. Participants in the research project ate 2 large servings of either skinless chicken breast or lean pork each day as part of a weight-maintaining diet with 25% of calories derived from fat.

"We found that both meats were equally effective in helping people lower their cholesterol levels by as much as 7-8% during the study," says Connie Bales, a scientist involved with the project.

Retail cuts of pork today are 31% lower in fat, 10% lower in cholesterol and have 14% fewer calories than 10 years ago, according to the USDA. In fact, when comparing the leanest cut of pork to skinless chicken breast, the cuts are comparable in fat, calories and cholesterol.

HogHealth
Vol. 6, No. 2

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Last modified August 5, 2000.

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