A multi-disciplinary approach to improve the environmental performance of niche pork production systems and marketability of Heritage swine breeds

A multi-disciplinary approach to improve the environmental performance of niche pork production systems and marketability of Heritage swine breeds

Summary

During the year 2010 three field experiments were conducted at the Center For Environmental Farming System (CEFS), located at Goldsboro as well as the swine unit at North Carolina A&amp;T State University (NC A&amp;T SU). The objective at CEFS was to evaluate the impact of sows stocking rate (4, 6 and 10 sows/a) on bermudagrass (Cynodon dactylon) ground cover; and to evaluate strategies for soil nutrients removal. Preliminary results suggest that ground cover damage was increased with increasing stocking rates. Following pigs with two hay crops showed to be effective for removing soil nutrients deposited by the pigs. The objectives at NC A&amp;T SU were to analyze the growth characteristics for heritage crossbreds to be raised in the hoop barn, and to compare meat quality of heritage crossbreds produced with different sire lines. As a result, Berkshire breeding group (Berkshire × Yorkshire) showed significantly higher weights than Yorkshire purebred (P < 0.05), however, there was not significantly different between Berkshire and Large Black breeding groups as well as between Large Black and Yorkshire groups. This information helps the small farmers who raise rare breeds to choose better breed combinations for outdoor environments. For meat quality, Backfat thickness, LMA, and drip loss were significantly different among breeding groups (P < 0.05). Large Black breeding group showed significantly higher backfat thickness followed by Berkshire, Yorkshire and Tamworth groups. However, Tamworth breeding group had significantly higher drip loss (4.50 g) than other groups; 3.77 g, 3.26 g, and 2.62 g in Yorkshire, Berkshire, and Large Black groups, respectively.

Objectives/Performance Targets

1. Determine how stocking rates affects vegetation survival, soil disturbance and soil nutrients under a pastured swine management on perennial pasture.
2. Analyze the growth characteristics for heritage crossbreds to be raised in the hoop barn.
3. Compare meat quality of heritage crossbreds produced with different sire lines.

Accomplishments/Milestones

1. Sows Stocking Rates: A rotational grazing system experiment was conducted to establish the effect of sow stocking rates (4, 6 and 10 sows/a) on the ground cover of a bermudagrass stand. Plots (0.5 a) were divided into 9 sections. Animals (480 lb BW) had permanent access to the central area and were moved weekly to a new section of the plots. Twenty Yorkshire mature sows were allocated to each of three stocking rates . Sows were fed concentrate daily in the morning (3.2 kg, 16% CP). Shades and barrels drinkers were provided at fixed locations in the central section. Used conveyor belts were used as feeders and moved weekly to the section where the animals would graze. A step point procedure was performed weekly to estimate vegetative cover changes using evenly spaced transect lines. The experimental design was a randomized complete block with two field replicates. Data were log (log[x+10]) and square root ([x+10]1/2) transformed.

2. Soil Nutrients removal: A mixture of cereal rye and ryegrass was established and then harvested to evaluate the amount of soil nutrients that could be removed from paddocks previously managed with different hogs stocking rates (15, 30, 45 and 60 pigs/a). Forage and soil were sampled. After this first crop sudangrass was established and harvested and the forage and soil sampling was repeated.

3. Comparison of pork characteristics for antibiotic free Yorkshire crossbreds to be raised in the hoop barn: The experiments have been accomplished in North Carolina Agricultural and Technical State University Farm and The Center for Environmental Farming Systems (CEFS) in Goldsboro, NC, where have been raising antibiotic free Yorkshire sows.

4. Comparison of body weights of Berkshire and Large Black crossbreds produced by the use of antibiotic free Yorkshire sows raised in a hoop facility: Pigs were reared within deep-bedded hoop houses at finishing phase. The swine unit at North Carolina A&amp;T State University has a 48 × 96 ft hoop facility that is different from standard confinement facilities.

Impacts and Contributions/Outcomes

1. To develop a rational ground cover management in outdoor swine production, it is necessary to estimate potential hog stocking rates that can be maintained in an area during a specific period of time while limiting the occurrence of soil and ground cover deterioration. Over stocking can produce deterioration of the ground cover and excessive nutrients load, whereas under stocking can result in less efficient utilization of the land area. Appropriate stocking rates and monitoring of ground cover conditions will help ensure that long term goals for natural resources are fulfilled.

Bermudagrass, with its rhizomes and stolons, has a great potential to provide sustainable cover within hog pastures. Vegetative ground cover in the Bermudagrass stand decreased as a result of animal activity, and paddocks with the higher stocking rates showed a faster decrease. Sow stocking rate of less than 10 sows/acre must be implemented to maintain over 60 percent ground cover during 56-day periods in bermudagrass paddocks

Environmental concerns associated with pastured swine can be mitigated with rotational hay production. Nevertheless, rotational hay production may not be sufficient to prevent leaching of nutrients. Studies have shown that in addition to stocking rate, one must consider maintenance of ground cover, limiting occupation time, use of high quality feed, and movement of shade structures to reduce total soil nutrient loads and provide more heterogeneous distribution of nutrients while pigs are on pasture.

2. Twenty 4 sows were impregnated in each research farm with the semen of Berkshire, Large Black, Tamworth and Yorkshire as a control group. Litters were weaned, and reared within deep-bedded hoop houses. The deep bedding, generally straw, corn stalks, or hay, was spread approximately 14–18 inches thick and provided a comfortable environment for the animals, which allows rooting and other natural behaviors. One hundred four pigs were used to compare pork characteristics which include pH, color score, L*, a*, b*, marbling score, drip loss, hot carcass weight, backfat thickness (BF), loin muscle area (LMA), and shear force. The data was analyzed with GLM in SAS 9.01 including research farm, season, breeding group and sex as fixed effects.

Backfat thickness, LMA, and drip loss were significantly different among breeding groups (P < 0.05). Large Black breeding group showed significantly higher backfat thickness followed by Berkshire, Yorkshire and Tamworth groups. However, Tamworth breeding group had significantly higher drip loss (4.50 g) than other groups; 3.77 g, 3.26 g, and 2.62 g in Yorkshire, Berkshire, and Large Black groups, respectively. This information helps the small farmers who raise rare breeds to choose better breed combinations for outdoor environments.

3. The deep bedding, generally straw, corn stalks, or hay, is spread approximately 35–45 cm thick and provides a comfortable environment for the animals which allows rooting and other natural behaviors. It is relatively difficult to measure feed intake and growth rates for pigs raised in outdoor systems compared with confinement systems. Eight Feed Intake Recording Equipment (FIRE, Osborne Industries Inc. Osborne, Kansas) stations were used to collect body weight, feed intake, feeding time, feeding rate, number of feedings per day, and feed conversion.

There were 3 breeding groups that were 23 finishing pigs (5 Berkshire × Yorkshire; 10 Large Black × Yorkshire; 8 Yorkshire × Yorkshire) in total. Before analysis, each individual?s feed intake records were evaluated for outliers by plotting feed intake by day and testing each feed intake observation with the Cook?s D test statistic and studentized residuals. After removal of outliers, 5 time points at 64, 125, 162, 176, 197, and 229 d of age, were selected to analyze the data with the repeated measurement method, which included 138 observations (30 records in Berkshire × Yorkshire; 60 records in Large Black × Yorkshire; 48 records in Yorkshire × Yorkshire).

As a result, Berkshire breeding group (Berkshire × Yorkshire) showed significantly higher weights than Yorkshire purebred (P < 0.05), however, there was not significantly different between Berkshire and Large Black breeding groups as well as between Large Black and Yorkshire groups. This information helps the small farmers who raise rare breeds to choose better breed combinations for outdoor environments.

With the preliminary information generated abstracts and posters were prepared and presented at:

* Abstract presented the 2010 American Society of Animal Science Meeting. July 2010.
Animal weight gain in a pastured hog production system.
Weight gain of Duroc pigs managed in a Sudangrass (Sorghum bicolor) pasture.
Behavior of Duroc pigs on sudangrass (Sorghum bicolor) pastures.

* Abstract presented to the 2011 American Society of Animal Science meeting, Southern Meeting. Corpus Christi, Texas. February, 2011.
Effects of sow stocking rates on soil nutrients in a bermudagrass (Cynodon dactylon) pasture.

* Abstract presented the 2011 American Society of Animal Science Meeting. New Orleans, Louisiana. July 2011.
Effects of sow stocking rate and season on bermudagrass ground cover.
The effect of stocking rate on pasture nutrient budgets and forage production in pasture swine systems.
Comparison of pork characteristics of antibiotic free Yorkshire crossbreds raised in the hoop barn.
Comparison of body weights in Berkshire and Large Black crossbreds produced by the use of antibiotic-free Yorkshire sows.

Workshop:
Conservation practices in outdoor hog production. Goldsboro, May 2010.

Collaborators: