In November 2022 South Dakota State University held the 6th SDSU Swine Day since opening of our new swine unit. The theme for this year was "What Have We Learned?" and included research updates from faculty, a market outlook of the U.S. pork industry from Steve Meyer, Partners for Production Agriculture, and a herd health update from Levi Johnson, staff veterinarian at New Fashion Pork. It was a good day but more importantly, what did we learn?
Pigs have always added value to crops/feedstuffs and the feedstuffs used depends on nutrient profile and cost. Prior to significant ethanol production, there were many more options for swine diets including barley, wheat and/or milo. However, when the corn price and crop yield increased dramatically, most of the acres used for alternative grain production were switched to corn. Transportation and supply are the most common factors limiting use in swine diets.
As part of a sustainability plan that considers animal performance, agronomic factors and milling efficiency, an example discussed was hybrid rye:
- As a replacement for corn (0, 40, 70 and 100% direct replacement) diets were equal in SID lysine:energy. Efficiency of growth was not impacted but intake, gain and carcass yield were reduced with inclusion. Belly quality was not impacted while loin quality and iodine value were reduced. Investigation into impact of hybrid rye in swine diets on agronomic sustainability and milling efficiency is ongoing.
- While hybrid rye holds promise as an alternate feedstuff for pork producers, for it to work long term, producers must receive a premium for "more sustainable" pork, or the price of hybrid rye decreases in relationship to corn.
DDGS is probably the most available alternative and readily used feedstuff for swine diets. Considering hot and cold fermentation DDGS at high levels (0,20, 40 and 60% of the diet):
- Increasing inclusion of hot fermented DDGS did not affect overall pig performance while increasing either hot or cold DDGS decreased carcass yield and marbling.
- Increased dietary levels of DDGS resulted in:
- Increased IV levels (Lower for hot fermentation-fed pigs)
- Increased PUFA content (Higher for cold fermentation-fed pigs)
- Decreased belly flop scores
- When economical, we can feed high levels of DDGS without no-to-minimal impact on growth performance; however, management or nutritional strategies to maintain belly/carcass quality must be considered
Use of feed enzymes, particularly carbohydrases, is likely to increase as the availability of co-products from ethanol, biodiesel, and sustainable aviation fuel industries. Carbohydrases can be an effective tool to increase nutritional value of high fiber ingredients and mixed diets. Most consistently impact energy digestibility at an expected 5% energy uplift.
A challenge to the use of carbohydrases is the variety of fibers in a given feedstuff which require a similar variety of carbohydrases to degrade the different fibers. As enzyme technology continues to develop, the opportunity to create targeted enzyme complexes specific to a given diet formulation offers greater potential for improved nutritional value of feedstuffs. A targeted enzyme complex in a high fiber, reduced energy diet based on corn, soybean meal and soyhulls recovered 3 – 5% amino acid and energy digestibility and recovered any reduction in pig performance that was due to the high fiber diet.
Carbohydrase use in gestating sow diets is increasing although there is limited information on the effectiveness of carbohydrase enzymes in gestating sows, especially considering sows have greater capacity to ferment dietary carbohydrates compared to growing pigs. Enzyme complex enhanced total tract energy digestibility approximately 5% in sows and the effect was greater in low than high fiber gestation diet.
Beyond nutrient digestibility, enzymes are being considered for their potential functional roles. Protease inclusion in nursery pig diets had minimal effect on growth but reduced the incidence of scours and loose stool in the first two weeks after weaning. Considering that loose stool/scours is a practical in-barn signal for veterinary treatment, protease inclusion may enhance gut health and reduce antibiotic administration.
Gilt reproductive development
Replacement gilts are a key component to successful sow farm productivity. Besides nutrition and appropriate boar exposure, environmental management (i.e. photoperiod, rearing density, manure gases) can play a role in puberty attainment and/or age at puberty.
- Supplemental light during shortened day length can reduce days to first estrus such that at least 12h of light/d throughout the year will minimize the impact of day length on estrus attainment.
- Both crowding and isolation can negatively impact puberty attainment. Space allowance of 9 – 10 ft2/gilt will minimize impact of rearing density on puberty.
- A greater proportion of gilts exposed to 5 ppm NH4 attained puberty between 24 – 29 weeks of age compared to gilts exposed to 20 ppm NH4. It is speculated this may be related to olfactory damage and lower ability to detect boar odor.
It is well known that reproductive hormones and their relative concentration are important for gilt development. However, appetite-controlling hormones may also play a role in reproductive development through interaction with kisspeptin, a key hormone involved in GnRH release which is required for release of FSH and LH signaling the onset of puberty. This suggests that manipulation of metabolic hormones may provide a means to alter pubertal attainment. Efforts are being extended to establish predictive markers of pubertal attainment in the prepubertal female that can be easily applied on-farm.
Feeding nursery pigs
Rapid gains in sow prolificacy produce challenges for managing sows and pigs. Overall mortality continues to rise at an estimated $2.6 billion cost to the swine industry annually. Continuing to be vigilant in assessing existing, and developing new, strategies to improve pig health and resilience allows opportunity to capture gains in sow prolificacy.
Ingredient prices can be expected to continue to increase; similarly, viral disease-related challenges in the post-weaned period, beyond PRRS, are likely to increase.
Older weaning age and heavier weight remain consistently effective strategies to reducing post-weaning growth lag.
Strategies to enhance immunological status that specifically target high risk pigs (e.g. gilt litters) can also improve post-weaning growth performance.
In the diet, soybean meal has more value than the known supply of nutrients; similarly, strategic use of crystalline amino acids (e.g. arginine) can improve gut health during periods of greater gut insult. "Simply" getting pigs to eat is another consistently effective strategy to reducing post-weaning growth lag. Ingredient quality and diet palatability play a key role in accomplishing this goal.
Herd health update
Feed and water availability and early treatment of illness remain the largest contributors to wean-to-finish mortality. Having a biosecurity plan that outlines the 'who, what, when, where' that is well communicated to all who set foot on site is critical.
Cleaning more than the pig space (i.e. office, boot room, boots, storage areas) in between fills is important to reducing pathogen load and disease risk.
Disease challenges plaguing grow-finish production include gastritis and APP serotype 15:
- Gastritis: peak mortality 10 – 15 days after being placed; lower lysine and high fiber diets seem to help.
- APP-15: This is no joking matter. Unexplained mortalities in finishing should be posted, even if in the middle of marketing. Call the vet and report mortalities daily. Mass treat with antibiotics. The efforts required for mass injecting pigs is far less than the efforts required to haul hundreds of mortalities.
Market weights are not likely to decline anytime soon; breakeven costs in the $80 – 90 range are likely to stay and increases in soybean crushing capacity may provide some relief for meal prices. Recent drought in areas of heavy beef production and declining cow herd size may provide more opportunities to build pork sales.
There are limited signs of growth in the overall swine herd due to labor, building costs (In 2022, 50% higher costs compared to 2020), material/equipment delays, builder availability, production/feed costs, gilt availability and processing space.
Three items lead the list of concerns for the next three to five years:
- Keeping foreign animal disease out of the United States
- Labor supply for producers and packers
- Packing capacity
Steve Meyer's expectations for the next few years included:
- Modest sow herd growth (1 – 2% per year)
- Back to 1.2 – 1.8% annual growth in litter sizes
- Continued challenges for aggregate litters and breeding animals primarily due to Proposition 12
- Exports to China will continue to be variable with big opportunities in other markets like Central and South America and the Caribbean
- Need to, at minimum, maintain strong domestic demand, even better increase domestic sales, amidst potential economic slowdown, inflation and higher interest rates.
This brief summary of things that we have learned here at South Dakota State University is provided as a recap of SDSU Swine Day 2022, an annual event hosted by SDSU Extension in Brookings, South Dakota. We are looking forward to what is to come for 2023. The swine industry is a great industry with so much to offer. Here's to a good 2023.