Pig producers are aware that there are differences in piglet size, weaning weight, body size, and Backfat thickness measured by imported backfat meters among pigs. If these animals can quickly acquire these excellent ideal traits. Unfortunately, this is not the case. These important economic traits are greatly influenced by the environment (feeding, growth, health, management, etc.), therefore, some animals can only inherit significant improvements to their offspring.

As expected, environmental improvements cannot be inherited. This means that if the improvement of most important economic traits is the result of environmental improvement, then the imported backfat analyzer considers this trait as a low heritability trait, and it is difficult to improve genetic progress through selection. However, if it is a highly heritable trait, significant genetic progress can be achieved through selection. Therefore, the coat color of pigs is a highly heritable trait because the environment has little effect on it. However, traits such as weaning weight have lower heritability due to significant environmental influences (such as the feeding ability of sows).

Backfat analyzer

Therefore, it is necessary to understand the genetic and environmental changes of each important economic trait (Table 5.1). These heritages are estimated as averages based on a large amount of data, so deviations may occur in individual pig pOPUlations. Even though the heritability of many traits listed in the table is low, understanding their cumulative and permanent effects is still meaningful.

ratio

Imported backfat meters usually use ratios to compare animals in different environments and determine whether genetic or environmental factors determine the superior traits of animals. The ratio is simply expressed as the ratio of individual animal performance to the average value of the entire population or the measured population. The calculation formula is as follows:

Animal performance x 100/population average performance

For example, if the daily weight gain of one male pig is 2.201b and the average daily weight gain of its population is 2.00lb, then the daily weight gain ratio of this male pig is 2.201b × 100/2.001b=110. A ratio of 110 means that the male pig is 10% higher than the average value of the test group in this trait. Similarly, a 90% ratio indicates that the performance of boars is 10% lower than the average performance of pigs in the same population. A ratio of 100% indicates that the animal's performance is at an average level.

The imported backfat analyzer ratio eliminates differences in average performance levels between groups (usually between traits). Therefore, they enable unbiased comparisons between individuals in different measurement groups. This situation only applies to cases where the inter group mean difference is not caused by genetics. Most of the differences between groups are caused by factors such as feeding, climate, pigsty, and management. A ratio is a comparison between an individual and a group within the same group. This is a good method for comparing individuals from different generations, such as comparing individuals in different measurement groups or groups, or comparing individuals of different gender traits. The National Pig Improvement Federation (NSIF) suggests that the production performance levels of different traits should be expressed in the form of ratios in the production testing plan.

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