Outdoor Swine Production Management: Relationships Among Stock Selection and Carcass/Meat Quality

<p>NON-TECHNICAL SUMMARY:<br/> In order to address global food security to increase production of safe, local foods, grown in a manner that supports human and animal health and well-being, alternative production systems have grown in popularity. Such production systems in the swine industry, including group housing in deep-bedded hoop barns and pasture based production, have the potential to address animal welfare, environmental and food safety concerns and could be a way in which producers can take advantage of the niche/specialty markets these systems target if a quality product is developed. In addition, support of these alternative systems, which are national and international in scope, also helps address NC A&T State University's Cooperative Extension Program focus areas of local foods and profitable and sustainable agriculture for North Carolina. The Berkshire
breed has been touted as a breed that does well in alternative systems and is a breed known to have excellent carcass traits. Generally, excellent growth and carcass traits are related to lower reproductive performance. Selection of reproductive performance while considering carcass traits in an outdoor or hoop type system would be an important step forward for limited resource producers interested in using this popular breed in alternative systems. In addition to genetic selection, crossbreeding can influence carcass traits and is typically recommended in pork production systems, both indoor and outdoor. Recently, swine farmers and extension field staff mentioned growth and carcass quality of heritage/outdoor type breeds or crossbreeds as a topic for additional research in N.C. Therefore a crossbreeding study will also be conducted at A&T Farm with Berkshires (a popular outdoor
breed) and other outdoor/heritage breeds to look at growth and carcass quality. Currently, several outdoor pork farmers that Cooperative Extension works with are having problems with carcass/meat quality which is negatively impacting the amount and quality of pork available for purchase. The officers and vendors of a marketing cooperative these producers work with feel that part of the issue may be related in large part to breeds, crossbreeds or stock selection at the farm level. So, the information on crossbreeds as well as genetics for the selected stock from the purebred Berkshire herd will be used in on-farm testing to help farmers increase their carcass quality. Because outdoor pork production is growing nationally and internationally, this information can help producers develop a quality product for addressing global food security and hunger. The project will collect data from the
farms to determine how much of these problems may be due to breed (or crossbreeding) and breeding stock selection issues. Producers will be surveyed on management practices and educated using information produced from the studies and genetics developed at A&T. They will also learn how to select proper breeding stock on their farm. The survey will be used to determine other factors that may be impacting carcass quality on producer farms which can help in current educational programming and future research planning.
<p>APPROACH:<br/> Objective 1 - One of the main purposes of this research is to select purebred Berkshire animals based on economically important traits related to growth/carcass as well as reproductive performance such as average daily gain, backfat thickness, litter size, litter weight, weaning weight, carcass traits, and so on. Purebred Berkshire pigs previously selected will be raised in a 15m x 30m hoop facility deep bedded with straw or hay spread approximately 34 to 45 cm thick. Because the animals need to be selected in the environment that is similar to or the same as that in which they will be raised by producers, pigs will be farrowed outdoors in farrowing huts, weaned at 4 weeks of age, and reared within deep-bedded hoop houses after that. Weights for average daily gain and backfat thickness will be collected as possible every 4 weeks from birth to 20 weeks of
age to at least 45.5 kg; LEA will be measured at around 45.5 kg. The animal model will be analyzed with MTDFREML to estimate genetic parameters and breeding values. Animals for future breeding will be selected based on data collection/analyses as well as body condition score and leg conformation. Objective 2 - Thirty Berkshire sows not used in the genetic selection studies will be estrus synchronized, and will be impregnated with the semen of heritage breeds such as Hereford, Large Black, and Tamworth as available during three parities. Berkshire semen will be used as a control group. Weaned pigs will be reared within deep-bedded hoop houses until harvest with ad libitum NRC based diets balanced for stage of production and free choice fresh water. Fifty progeny of each cross will be selected randomly to investigate growth, carcass traits and meat quality. Weight, back fat thickness and
muscle depth will be measured every month from pigs grown in hoop structures. A subset of pigs will be individually identified for slaughter at a commercial facility where hot carcass weight and carcass composition data will be collected. Pork quality will be evaluated based on Minolta color, pH, and water holding capacity, percent lipid, and shear force. Loins will be scored on the Japanese color scale, and for firmness and marbling. Consumer taste panel evaluations of pork loin will be conducted at the farmer's market in Greensboro after each slaughter. Objective 3 - While genetic selection studies are being conducted, surveys of pasture-based pork production systems will be conducted by NC Cooperative Extension, including producers that are a part of the NC Natural Hog Producers Association. The survey will include breed types used and feeding regimes. The producers will be
worked with to get detailed production data and carcass quality will be measured in a subset of hogs on the farm via ultrasound. This will be preliminary data. Then, when ready, boars from the Berkshire herd will be made available for use on the selected producer farms and changes in pork quality will be measured. Data can be compared to preliminary data on the farm as well as between farms for pilot information that would allow for determination of specific breed/breed types and possible feeding regimes/issues that need further research.