SEARCH
Industry Partners
Prairie Swine Centre is an affiliate of the University of Saskatchewan
Prairie Swine Centre is grateful for the assistance of the George Morris Centre in developing the economics portion of Pork Insight.
Financial support for the Enterprise Model Project and Pork Insight has been provided by:
Estimating Genetic Merit
Posted in: Production by admin on | No Comments
In estimating the genetic merit of an animal, breeders are trying to determine the animal’s value as a parent, its breeding value. The phenotype of an animal (the traits we see and measure) is a combination of genetic and environmental effects. Genetic effects are the result of the genes inherited from parents. Environmental effects are the result of conditions the animal experienced, such as level of nutrition, stocking density, temperature, or health status.
The challenge to the breeder is to determine how much of an animal’s superiority (or inferiority) for a trait is due to additive genetic effects, since this is what will be passed on to its progeny through its own genes. Defining what constitutes genetic merit is an important first step in this process. This will be discussed further in NSIF-FS9, “Multiple Trait Selection for Pork Improvement,” but genetic merit can be defined as how an animal ranks, relative to other selection candidates, for its ability to produce superior offspring.
Favorable performance for a characteristic is an obvious way to rank animals; however, it should be done relative to other animals that are of similar age and housed and raised under similar conditions. It is best to compare an animal’s performance record to the average of the group of animals that they were raised with. This can be done by calculating performance deviations from the group average or the ratio of animal’s performance with the group average. For example, a gilt has an average daily gain of 1.9 lb/day for the grow-finish period while the other gilts of similar age and raised in the same building averaged 1.8 lb/day for average daily gain. The gilt in question would have a performance deviation of 0.1 lb/day, which is favorable and a ratio of 105.6 (1.9/1.8). This is the first step in evaluating an animal’s genetic merit for performance characteristics. For further examples see Table 1.
Two terms are often used in discussing genetic merit. The first term, Estimated Breeding Value (EBV) is the estimated genetic merit of animal, expressed as a deviation. The second term, Expected Progeny Difference (EPD) is one-half an animal’s Estimated Breeding Value and can be used to determine the expected performance change of progeny if the animal in question is used as a parent. Methods to estimate genetic merit in swine have evolved considerably this century. As breeders have been able to incorporate increasing amounts of information to assess an animal’s breeding value, methods have grown from simple visual appraisal to complex statistical techniques. The purpose of this fact sheet is to discuss these alternative methods.
Structure of the Global Markets for Meat
Posted in: Production by admin on | No Comments
Ammonia, Volatile Fatty Acids, Phenolics, and Odor Offensiveness in Manure from Growing Pigs Fed Diets Reduced in Protein Concentration
Posted in: Environment by admin on | No Comments
The objective of this study was to investigate whether reducing dietary crude protein (CP) concnetration decreases fecal volatile fatty acis (VFA), manure ammonia, emission and odor and fecal urinary phenolic metobilities. Six barrows were alotted on of 6 dietary treatments in a Latin square deisgn. Treatments consisted of four corn-soybean meal based diets containing 15, 12, 9, and 6% crude protein, a caesin based diet containing 15% CP and a protein free diet. The caesin based and prtoein free diet were used to determine basal endogenous contribution of VFA, phenolics, ammonia and manure odor. Pigs were housed individually in metabolsim crates to allow total collection of faeces and urine. Feaces and urine were analyzed for VFA and phenolic metabolite concentrations, respectively. Faeces and urine were then mixed, stored and fermented at room temperature for 30 days. For ammonia determination, headspace air was sampled from manur slurries at 24, 48, and 72 hours after fermentation. Slurry samples were placed into vials, capped and randomized before odor panel evaluation. Odor effensiveness was classified on severity 1 – non-offensive and 5 – extremely offensive. Reucing CP increased VFA concentrations but did not effect phenolic concentrations in the urine. Manur ammonia emission was reduced as dietary CP concentration decreased from 15-0%. The 15% diet had the least offensive manure with odor qualitative ranking of 2.58. Compared with the 15% CP diet, manure from the 9 and 6% CP diet was found to be more offesnive with odor qualitative rankings of 2.92 and 3.10 respectively. Odor qualitative rank for th 12% CP, potein free,and casein based diets did not differ from the 15% CP iet. These results indicate that recution in dietary CP concentrations decreases ammonia emissions but doesn’t reduce odor offesniveness.
Ammonia Accumulation in Settling Basins
Posted in: Environment by admin on | No Comments
Ammonia concentration is believed to increase with time in undrained settling basins, but little data exists on how quickly the ammonia accumulates. This study examined how quickly ammonia accumulates and factors that influence the ammonia accumulation.
At cold temperatures, ammonia concentrations remained at approximately the initial concentration, therefore the warmer the temperature the faster the conversion occurs. In all the tests pH remained essentially constant at approximately 6.8. Swine manure is similar to beef but converts to ammonia at a faster rate making it more important to dewater before conversion occurs. There is also more clean water to dilute the liquid from a solids settling structure immediately after an event when the concentration is the lowest. The results then show that it is important to dewater settling basins as quickly aster a rainfall as possible, before the conversion to ammonia occurs.
Test Manure After Feed Ingredient Change
Posted in: Environment by admin on | No Comments
In recent research at Iowa State University, including lysine, alone, in swine diets resulted in a reduction of dietary crude protein from 17.4% to 17%. Adding lysine, methionine, threonin and tryptophan to the diet reduced crude protein content even further, to 14.5%. Incorporation of lysine and methionine, though not tested in this study, would have resulted in a dietary crude protein content of approximately 16.2%. The reduced diet content does translate into less manure excretion. Urine nitrogen, where most of the nitrogen is excreted, decreased by 15% by adding the four amino acids. In addition, ammonia emissions were reduced by half. Others have demonstrated similar results. Similar results would be expected following feeding to poultry. However, data that addresses the combined use of lysine and methionine for poultry or swine is somewhat limited.
Nutrient excretion reductions will be site-specific based on how the amino acids are formulated in the diet and which amino acids are used. Producers who want to see how such practices affect their manure values should plan to test their manure before and after implementing such a change. If the change in diet formulation has already taken place, producers should still test their manure to see how composition in their manure storage facility compares to values used by a producer in his/her manure management plan. The change in nitrogen content may have a positive effect on manure management planning.
Short-term effects of manure application on soil leachates in a mountain catchment
Posted in: Environment by admin on | No Comments
Fluctuations in Manure Nutrient Concentration during Storage Pump-out
Posted in: Environment by admin on | No Comments
This study was initiated to better understand the changing composition of manure samples within a storage and between different liquid swine manure storages used in Manitoba. In a recent study done by Fitzgerald and Racz, 2001, various storages across Manitoba were sampled and analyzed. This study found large variations between hog type (finisher, nursery, sow) and at different levels in the storage. (top, middle, or bottom) It is well known that stratification, settling of solids, occurs in all types of storages and when agitated the solids are mixed back into the liquids. This project will look at a single-cell, two-cell, and a circular storage system during a typical application and characterize the nutrient composition.
Harvesting Winter Forages to Extract Manure Soil Nutrients
Posted in: Environment by admin on | No Comments