Principal component analysis of breeding values for birth weight milk and reproductive traits of the Egyptian buffalo

Phenotypic data from female Canchim beef cattle were used to obtain estimates of genetic parameters for reproduction and growth traits using a linear animal mixed model. In addition, relationships among animal estimated breeding values (EBVs) for these traits were explored using principal component analysis. The traits studied in female Canchim cattle were age at first calving (AFC), age at second calving (ASC), calving interval (CI), and bodyweight at 420 days of age (BW420). The heritability estimates for AFC, ASC, CI and BW420 were 0.03 ± 0.01, 0.07 ± 0.01, 0.06 ± 0.02, and 0.24 ± 0.02, respectively. The genetic correlations for AFC with ASC, AFC with CI, AFC with BW420, ASC with CI, ASC with BW420, and CI with BW420 were 0.87 ± 0.07, 0.23 ± 0.02, –0.15 ± 0.01, 0.67 ± 0.13, –0.07 ± 0.13, and 0.02 ± 0.14, respectively. Standardised EBVs for AFC, ASC and CI exhibited a high association with the first principal component, whereas the standardised EBV for BW420 was closely associated with the second principal component. The heritability estimates for AFC, ASC and CI suggest that these traits would respond slowly to selection. However, selection response could be enhanced by constructing selection indices based on the principal components.

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Principal Component Analysis (PCA) of the reproductive traits in the Large White sows

UKRAINIAN BLACK SEA REGION AGRARIAN SCIENCE ◽

10.31521/2313-092x/2019-2(102)-11 ◽

2019 ◽

Vol 102 (2) ◽

pp. 75-81 ◽

Cited By ~ 1

Author(s):

S. Kramarenko ◽

◽

A. Kramarenko ◽

S. Lugovoy ◽

A. Lykhach ◽

...

Keyword(s):

Principal Component Analysis ◽

Principal Component ◽

Reproductive Traits ◽

Component Analysis ◽

Large White

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SEPARATION OF THE EFFECTS OF AGE, BODY WEIGHT AND GAIN ON PREGNANCY RATES OF BEEF HEIFERS BY PRINCIPAL COMPONENT ANALYSIS

Canadian Journal of Animal Science ◽

10.4141/cjas85-070 ◽

1985 ◽

Vol 65 (3) ◽

pp. 595-602 ◽

Cited By ~ 1

Author(s):

M. MAKARECHIAN ◽

A. FARID ◽

R. T. BERG

Keyword(s):

Principal Component Analysis ◽

Body Weight ◽

Birth Weight ◽

Pregnancy Rate ◽

Principal Component ◽

Component Analysis ◽

Birth Date ◽

Factor Scores ◽

Dependency Structure ◽

Daily Gain

Pregnancy records of 174, 2-yr-old heifers from four beef breed groups — Hereford (HE), Beef Synthetic (SY), Crossbred Hereford (HX) and Dairy Synthetic (SD) — were used in a principal component analysis. Four principal components (PC) were required to explain at least 90% of the total variation which existed in the dependency structure of birth date, birth weight, preweaning daily gain, weaning weight, weaning to yearling daily gain, yearling weight, yearling to breeding daily gain and weight at the start of breeding season in each of the breed groups. The interpretation of each of the four PCs was fairly consistent in the four breed groups. Principal component analysis separated variation in the dependency structure of the above eight variables into preweaning daily gain and body weight (PC1), age (PC2), weaning to yearling daily gain (PC3) and yearling to breeding daily gain (PC4) indices. Birth weight was less emphasized by PC1 in the HE compared with the other breed groups. Birth date (age) was highly emphasized by PC2 in all the breed groups except the HE, in which there was moderate emphasis on both birth date and birth weight. Regression equations of pregnancy rate on the factor scores were different among the four breed groups. For the HE and SY heifers, preweaning and body weight index was the only component that was significantly related to pregnancy rate and it explained 30 and 23.7% of the variation, respectively. None of the components affected variation in pregnancy rate in the HX heifers. Pregnancy rate had a curvilinear relationship with the weaning to yearling gain index in the SD. The results of regressing pregnancy rate on factor scores derived from the principal component analysis indicated that generally when variation in age is small (as a result of short breeding season), weight gains and body weights of heifers have much greater influence on pregnancy rate than their age. Key words: Beef cattle, heifer reproduction, principal component analysis, age, body weight, gain

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