scholarly journals Direct and maternal annual genetic changes for selected traits at weaning and yearling in beef cattle

2018 ◽  
Vol 41 (1) ◽  
pp. 42572 ◽  
Author(s):  
Arione Augusti Boligon ◽  
Isadora Dos Santos Vicente ◽  
Vanerlei Mozaquatro Roso ◽  
Fabio Pablos de Souza
Keyword(s):  
Weight Gain ◽  
Beef Cattle ◽  
Genetic Changes ◽  
Genetic Merit ◽  
Genetic Gains ◽  
Scrotal Circumference ◽  
Nellore Cattle ◽  
Selected Traits ◽  
Maternal Heritability ◽  
Genetic Trends

Heritability and direct and maternal genetic changes were estimated in Nellore cattle for the following traits: birth to weaning weight gain (BWG), weaning to yearling weight gain (YWG), weaning conformation (WC), weaning precocity (WP), weaning muscling (WM), yearling conformation (YC), yearling precocity (YP), yearling muscling (YM) and yearling scrotal circumference (SC). Direct and maternal heritability for weaning traits were 0.21±0.03 and 0.13±0.01 (BWG); 0.19±0.03 and 0.07±0.01 (WC); 0.22±0.03 and 0.07±0.01 (WP); 0.20±0.03 and 0.07±0.01 (WM), respectively. For yearling traits, direct heritability were 0.19±0.04 (YWG); 0.32±0.05 (YC); 0.37±0.05 (YP); 0.38±0.05 (YM) and 0.41±0.04 (SC). Positive and significant direct genetic changes (p < 0.05) were found for all traits, except for WC (p = 0.09), equal to 0.138 kg year-1 (BWG), 0.003 units year-1 (WC), 0.011 units year-1 (WP), 0.009 units year-1 (WM), 0.132 kg year-1 (YWG), 0.003 units year-1 (YC), 0.011 units year-1 (YP), 0.011 units year-1 (YM) and 0.020 cm year-1 (SC), indicating favorable genetic gains in the period. For weaning traits, we obtained negative and non-significant (p > 0.05) maternal genetic trends, with values of -0.084 kg year-1 (BWG), -0.004 units year-1 (WC), -0.004 units year-1 (WP) and -0.004 units year-1 (WM). Thus, greater emphasis should be given for maternal genetic merit of weaning traits in this population, if improvements in maternal ability were desirable.

Genetic relations and indirect response to selection based on indices for scrotal circumference, visual scores and weight gain in beef cattle

2018 ◽  
Vol 58 (7) ◽  
pp. 1210 ◽  
Author(s):  
A. A. Boligon ◽  
P. P. Farias ◽  
V. M. Roso ◽  
M. L. Santana ◽  
A. B. Bignardi ◽  
...  
Keyword(s):  
Weight Gain ◽  
Beef Cattle ◽  
Selection Process ◽  
Selection Index ◽  
Genetic Correlations ◽  
Correlated Response ◽  
Indirect Response ◽  
Genetic Gains ◽  
Scrotal Circumference ◽  
Selection For

Genetic improvement in beef cattle involves evaluation for fertility, growth, carcass and visual scores traits. In general, genetic and economic parameters of these traits are considered for selection index construction. The present study was conducted to establish the magnitude of genetic and phenotypic correlations between visual scores of conformation, precocity and muscling at weaning and at yearling, birth to weaning weight gain, weaning to yearling weight gain and yearling scrotal circumference, and between these traits with selection indices applied in this population. In addition, the expected gains were obtained in such traits by taking under consideration the adopted selection criteria based on indices. Positive and high genetic correlations were estimated between weaning traits (visual scores and weight gain), ranging from 0.70 ± 0.02 to 0.97 ± 0.01. In genetic terms, the same visual scores, but evaluated in two ages (weaning and yearling) showed positive and high associations, with values of 0.90 ± 0.01 (conformation), 0.88 ± 0.01 (precocity) and 0.84 ± 0.02 (muscling). Genetic associations between yearling visual scores with scrotal circumference and weaning to yearling weight gain ranging from 0.36 ± 0.02 to 0.53 ± 0.01. Using the weaning index, are expected genetic gains ranging from 0.26% to 0.70%/year of the phenotypic mean of each weaning trait. Using the yearling index, annual genetic gains estimated for weaning traits (ranging from 0.25% to 0.63% of the phenotypic mean of the trait) were lower than that obtained at yearling (ranging from 0.27% to 0.98% of the phenotypic mean of the trait). Selection for one of traits obtained at weaning should result, by correlated response, in gain for the others. Also, the choice of animals with higher breeding values for weaning visual scores, beyond anticipate the selection process, should lead to favourable changes in these traits at yearling. Selection for better body composition at yearling (higher scores) should provide increase in scrotal circumference and weight gain. The use of higher values of the indices should result in positively correlated response, but in different magnitudes for each trait used in these indices. However, in both weaning and yearling, higher genetic gains to visual scores are expected in the same period, when the selection is based on the values of these indices.

scholarly journals Genetic trends for mature body weight, visual scores, and growth traits in Nellore cattle

2017 ◽  
Vol 47 (3) ◽  
Author(s):  
Celso Koetz Júnior ◽  
◽  
Vanerlei Mozaquatro Roso ◽  
Luís Afonso Marques Claus ◽  
Rui Paulo Lopes de Oliveira ◽  
...  
Keyword(s):  
Birth Weight ◽  
Variance Components ◽  
Production Systems ◽  
Growth Traits ◽  
Selection Index ◽  
Economic Traits ◽  
Genetic Progress ◽  
Scrotal Circumference ◽  
Nellore Cattle ◽  
Genetic Trends

ABSTRACT: Mature weight (MW) of cows is related to the costs of their production. Usually, cows with moderate MW are more efficient in challenging environments, such as those available in the production systems in Brazil. In the present study, the selection index comprises the following traits: conformation, finishing precocity, musculature at weaning (WC, WP, WM) yearling (YC, YP and YM), scrotal circumference at yearling (SC), days to gain 160kg from birth to weaning (D160) and 240kg after weaning (D240). This are related to birth weight gain at weaning (WG) and from weaning to yearling (YG). The mature (MW) and birth weight (BW) traits were not considered in the selection index. The aim of this study was to estimate the values for the genetic trends (GT) of some important selection (MW) and economic traits (BW). A bi-character analysis of MW and other characteristics was performed to estimate the (co)variance components and genetic parameters. The GT results obtained for MW were null (0.0065% or 0.02718kg per year) in the period 1990-2007. The GT values were determined for BW (-0.0650% or -0.02017kg), WG (0.0758% or 0.0865kg), YG (0.1051% or 0.11377kg), and MW (0.0393% or 0.11276kg) per year. The visual score values (in score units) were also determined for GTat weaning [WC (0.2310%; 0.00707), WP (0.3624%; 0.3623%),aWM (0.01149; 0.01087)] yearling [YC (0.3256%; 0.00990), YP (0.4795%; 0.01496),YM (0.5041%; 0.01457)] per year. Index-based selection was effective to promote genetic progress in WG, WC, WP, WM, YG, YC, YP, and YM characteristics keeping BW and MW constant.

scholarly journals Expected increases in genetic merit from using optimized contributions in two livestock populations of beef cattle and sheep1

2003 ◽  
Vol 81 (12) ◽  
pp. 2964-2975 ◽  
Author(s):  
S. Avendaño ◽  
B. Villanueva ◽  
J. A. Woolliams
Keyword(s):  
Beef Cattle ◽  
Genetic Merit

scholarly journals A Comparison of Pearl Millet and Sorghum–Sudangrass Pastures during the Frost-Prone Autumn for Growing Beef Cattle in Semiarid Region

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 541
Author(s):  
Leonard M. Lauriault ◽  
Leah H. Schmitz ◽  
Shad H. Cox ◽  
Eric J. Scholljegerdes
Keyword(s):  
Weight Gain ◽  
Beef Cattle ◽  
Pearl Millet ◽  
Nutritive Value ◽  
Agricultural Science ◽  
Forage Yield ◽  
Hydrocyanic Acid ◽  
Science Center ◽  
Forage Crops ◽  
Sorghum Sudangrass

Sorghum–sudangrass (Sorghum bicolor × S. sudanense (Piper) Stapf.) and pearl millet (Pennisetum glaucum (L.) R. Br.) provide adequate nutritive value for growing beef cattle; however, unlike pearl millet, sorghum–sudangrass produces hydrocyanic acid (which is toxic to livestock) when frosted. Forage yield, nutritive value, and weight gain of growing cattle grazing sorghum–sudangrass and pearl millet were compared during the frost-prone autumns of 2013 and 2014, at New Mexico State University’s Rex E. Kirksey Agricultural Science Center in Tucumcari, NM USA, in randomized complete block designs each year with two replicates. No differences existed between pearl millet and sorghum–sudangrass forage yield, although there was a year–forage interaction for fiber-based nutritive value components because of maturity differences across years between the forages when freeze-killed. Pearl millet allowed for extending grazing of available forage for an additional 14 and 24 d in 2013 and 2014, respectively, compared to sorghum–sudangrass during the frost-prone autumn periods. During that period, when sorghum forages produce potentially toxic levels of hydrocyanic acid, animals grazing pearl millet accumulated an additional average of 94.9 kg live-weight gain ha−1 (p < 0.001). These factors afford producers an opportunity to increase returns on the similar investments of establishing and managing warm-season annual forage crops each year, and allow more time to stockpile cool-season perennial and annual forages for winter and early spring grazing, or to reduce hay feeding.

scholarly journals PSXII-22 Genomic prediction accuracy for feed efficiency related traits using different pseudo-phenotypes, prediction and validation methods in Nellore cattle

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 245-246
Author(s):  
Cláudio U Magnabosco ◽  
Fernando Lopes ◽  
Valentina Magnabosco ◽  
Raysildo Lobo ◽  
Leticia Pereira ◽  
...  
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Genomic Prediction ◽  
Feed Efficiency ◽  
Prediction Accuracy ◽  
Body Weight Gain ◽  
Prediction Methods ◽  
Genomic Breeding ◽  
Validation Population ◽  
Nellore Cattle

Abstract The aim of the study was to evaluate prediction methods, validation approaches and pseudo-phenotypes for the prediction of the genomic breeding values of feed efficiency related traits in Nellore cattle. It used the phenotypic and genotypic information of 4,329 and 3,594 animals, respectively, which were tested for residual feed intake (RFI), dry matter intake (DMI), feed efficiency (FE), feed conversion ratio (FCR), residual body weight gain (RG), and residual intake and body weight gain (RIG). Six prediction methods were used: ssGBLUP, BayesA, BayesB, BayesCπ, BLASSO, and BayesR. Three validation approaches were used: 1) random: where the data was randomly divided into ten subsets and the validation was done in each subset at a time; 2) age: the division into the training (2010 to 2016) and validation population (2017) were based on the year of birth; 3) genetic breeding value (EBV) accuracy: the data was split in the training population being animals with accuracy above 0.45; and validation population those below 0.45. We checked the accuracy and bias of genomic value (GEBV). The results showed that the GEBV accuracy was the highest when the prediction is obtained with ssGBLUP (0.05 to 0.31) (Figure 1). The low heritability obtained, mainly for FE (0.07 ± 0.03) and FCR (0.09 ± 0.03), limited the GEBVs accuracy, which ranged from low to moderate. The regression coefficient estimates were close to 1, and similar between the prediction methods, validation approaches, and pseudo-phenotypes. The cross-validation presented the most accurate predictions ranging from 0.07 to 0.037. The prediction accuracy was higher for phenotype adjusted for fixed effects than for EBV and EBV deregressed (30.0 and 34.3%, respectively). Genomic prediction can provide a reliable estimate of genomic breeding values for RFI, DMI, RG and RGI, as to even say that those traits may have higher genetic gain than FE and FCR.

Quantitative study of genetic gain for growth, carcass, and morphological traits of Nelore cattle

2019 ◽  
Vol 99 (2) ◽  
pp. 296-306
Author(s):  
Daniel Duarte da Silveira ◽  
Lucas De Vargas ◽  
Rodrigo Junqueira Pereira ◽  
Gabriel Soares Campos ◽  
Ricardo Zambarda Vaz ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Correlated Response ◽  
Genetic Associations ◽  
Muscle Area ◽  
Genetic Gains ◽  
Fat Thickness ◽  
Nelore Cattle ◽  
Genetic Trends

The aim of this study was to evaluate the genetic variability, genetic and phenotypic associations, and genetic gains of birth (BW), weaning (WW), and yearling (YW) weights, loin muscle area (LMA), backfat thickness (BF), rump fat thickness (RF), scores of body structure (BS), finishing precocity (FS), and muscling (MS) in Nelore cattle. Genetic parameters were obtained through Bayesian inference using BLUPF90 programs. All studied traits showed genetic variability, with heritability ranging from 0.29 to 0.47. In all studied ages, weights presented positive genetic correlations with LMA (ranging from 0.13 to 0.53), being generally stronger in comparison with the other carcass traits analyzed (BF and RF). Similarly, weights were higher genetic associated with BS (0.47–0.92) than with FS (0.18–0.62) and MS (0.22–0.65), respectively. The BF and RF showed positive and moderate genetic associations with FS and MS (0.31–0.36). Genetic trends were significant (P < 0.05) and favorable for WW, YW, and visual scores. Selection for increasing BW, WW, YW, and LMA will result in modest or no change in BF and RF (correlated response ranging from −0.04 to 0.07 mm per generation). In this population, carcass traits must be included in the selection indexes to obtain genetic gains in carcass quality, if desired.

The effects of plane of nutrition and diet type on metabolic hormone concentrations, growth and milk production in high genetic merit dairy herd replacements

2000 ◽  
Vol 70 (2) ◽  
pp. 349-362 ◽  
Author(s):  
A.F. Carson ◽  
A.R.G. Wylie ◽  
J.D.G. McEvoy ◽  
M. McCoy ◽  
L.E.R. Dawson
Keyword(s):  
Weight Gain ◽  
Milk Production ◽  
Live Weight ◽  
Live Weight Gain ◽  
Genetic Merit ◽  
Grass Silage ◽  
Nutrition And Diet ◽  
Condition Score ◽  
Metabolic Hormone ◽  
Diet Type

AbstractSeventy high genetic merit Holstein heifers were used in two experiments to investigate (1) the effects of plane of nutrition and diet type during the pre-pubertal period and (2) the effects of plane of nutrition during the post-pubertal period on metabolic hormone concentrations, growth and milk production. In experiment 1, treatment 1 and 2 heifers were given food to achieve a live-weight gain of 0·70 and 0·95 kg/day from 3 to 10 months of age on a grass silage based diet, while treatment 3 heifers were given food to achieve 0·95 kg/day on a barley straw/concentrate diet. During the pre-pubertal period, heifers reared on treatment 1 had significantly higher growth hormone(GH) concentrations (ng/ml per 1 h) than heifers reared on treatment 2 (P < 0·01) and had significantly lower insulin concentrations than heifers reared on treatment 3 (P < 0·01). Heifers reared on treatment 1 had significantly lower insulin-like growth factor 1 (IGF-1) concentrations than those reared on treatment 3 (P < 0·01). At 10 months of age heifers reared on treatment 1 were of lower condition score (P < 0·01) than those on treatment 2 and had a smaller heart girth diameter (P < 0·01) than those on treatments 2 and 3. During the first lactation, milk yield and composition produced by the heifers was not significantly affected by treatment. In experiment 2, treatment A heifers were given, from 14 to 24 months of age, a low plane of nutrition to allow a live-weight gain of 0·65 kg/day on a grass silage and grass based diet during the winter and summer periods respectively. Treatment B heifers were kept on a high plane of nutrition to allow a live-weight gain of 0·90 kg/day on the same forage along with concentrate supplementation. During the rearing period, GH and IGF-1 concentrations were not significantly affected by treatment. Treatment A heifers weighed less before calving (P < 0·05), had a lower condition score (P < 0·01), and had a smaller heart girth diameter (P < 0·01) than those on treatment B. During the first 10 weeks of lactation, heifers on treatment A had a higher silage dry matter intake and lost less weight (P < 0·05) than those on treatment B, however, by 20 weeks of lactation these effects had disappeared. Milk yield and composition during the first lactation were not significantly affected by treatment. Overall, the findings of experiments 1 and 2 did not show any beneficial effects of higher weights at first calving in high genetic merit Holsteins and therefore indicate that accelerated growth in the pre- or post-pubertal period may not be required.

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