Simultaneous estimation of daily weight and feed intake curves for growing pigs by random regression

Abstract

In this study, random regression models were used to estimate covariance functions between feed intake and BW in boars from the two breeds: the Norwegian Landrace and the Norwegian Duroc. In total, 1476 animals of the Norwegian Landrace breed and 1300 animals of the Norwegian Duroc breed had registrations on daily feed intake and growth from 54 to 180 days of age. Random regressions on the Legendre polynomials of age were used to describe genetic and permanent environmental curves in BW (up to the second order) and feed intake (up to the first order) for both the breeds. Heritabilities on BW increased over time for the Landrace (0.18 to 0.24), but were approximately constant for the Duroc (0.33 to 0.35). Average heritabilities for feed intake were approximately the same in both the breeds (0.09 to 0.11), and the estimates decreased over time, most pronounced in Duroc. On the basis of the current data, daily feed intake was seemingly controlled by the same genetic factors throughout the test period for Duroc; however, for Landrace, genetic correlations between test days decreased with increasing distance in time. For BW, the genetic correlations between test days were in general high, and did not go below 0.8 for any of the two breeds in this study. For both feed intake and BW, permanent environmental correlations between start and end of the test were reduced with increasing difference in days, most pronounced in Duroc. This study indicates that weight of the animal at the end of the test was more closely genetically correlated to feed intake of earlier periods compared with later periods of growth for both the breeds. This may be explained by the fact that BW is the cumulative growth of an individual, which is likely to be heavily affected by the feed intake during the most intense growth period.

Interaction of direct and social genetic effects with feeding regime in growing rabbits

“…In the previously published studies, was computed as the difference between body weight at the beginning and end of the fattening period divided by the number of days elapsed (ranging from 28 to 42 days), whereas we analysed weekly measures of . It is well known that heritability increases with the length of the period measured because the residual variance is reduced by averaging the observations over a longer time period [35]. Therefore, estimates from those studies are not directly comparable with ours.…”

Osteochondrosis in pigs diagnosed with computed tomography: heritabilities and genetic correlations to weight gain in specific age intervals

“…To help ease the estimation of genetic parameters, records of weight gain of Landrace boars tested in the same time period were included in the dataset. In our study, animals with erroneous growth and feed intake records were removed from the dataset as described by Wetten et al (2012), which included filtering and restrictions on plausible records, for example, if the weight is plausible compared with the age of the animal. In addition, weights from both 5 days ahead and 5 days past are used to check if the weight is reasonable (within a range estimated with a general linear model).…”

Utilizing random regression models for genomic prediction of a longitudinal trait derived from high‐throughput phenotyping

“…Thus, these models utilize a few parameters to describe the full covariance and are much more computationally efficient. In animal breeding, RR models have been used extensively to estimate heritabilities and perform pedigree‐based prediction of important longitudinal traits such as growth, feed intake, fat, and milk production (Bermejo et al., ; Bohmanova et al., ; Costa et al., ; Howard et al., ; Nobre et al., ; Wetten et al., ).…”