scholarly journals Comparison of Genetic Merit for Weight and Meat Traits between the Polled and Horned Cattle in Multiple Beef Breeds

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 870
Author(s):  
Imtiaz A. S. Randhawa ◽  
Michael R. McGowan ◽  
Laercio R. Porto-Neto ◽  
Ben J. Hayes ◽  
Russell E. Lyons
Keyword(s):  
Birth Weight ◽  
Live Weight ◽  
Practical Solution ◽  
Genetic Merit ◽  
Production Parameters ◽  
Genetic Potential ◽  
Lower Productivity ◽  
Selection For ◽  
Estimated Breeding Values ◽  
Recent Selection

Breeding for polled animals is deemed the most practical solution to eradicate horns naturally and circumvent management costs and risks on health and welfare. However, there has been a historical reluctance by some farmers to select polled animals due to perceived lower productivity of their calves. This study has compared estimated breeding values (EBVs) between horned and polled animals (N = 2,466,785) for 12 production and carcass traits to assess historical (before 2000) and recent (2000–2018) genetic implications of poll breeding. Older generations of the polled animals in most breeds had significantly lower (Bonferroni-corrected p = 0.05) genetic merits for live (birth to maturity) and carcass weights, milk, meat quality, and fat content traits. Substantial gains of genetic potential were achieved during 2000 to 2018 in each breed, such that polled animals have significantly improved for the majority of traits studied. Generally, polled cohorts showed advantageous EBVs for live and carcass weights irrespective of the lower birth weights in some breeds. While Polled Brahman showed inferior production parameters, the poll genetics’ effect size (d) and correlation (r) were very small on recent birth weight (d = −0.30, r = −0.08), 200 days (−0.19, −0.05), 400 days (−0.06, −0.02), 600 days (−0.05, −0.01), mature cow live weight (−0.08, −0.02), and carcass weight (−0.19, −0.05). In conclusion, although there is some evidence that historical selection for polled breeding animals may have reduced productivity, there is strong evidence that more recent selection for polled genotypes in the breeds studied has not resulted in any adverse effects on genetic merit.

Options to reduce vulnerability to metabolic stress by genetic selection

1999 ◽  
Vol 24 ◽  
pp. 119-127 ◽  
Author(s):  
J. E. Pryce ◽  
P. Løvendahl
Keyword(s):  
Milk Production ◽  
Genetic Selection ◽  
Metabolic Stress ◽  
Live Weight ◽  
Genetic Merit ◽  
Condition Score ◽  
Breeding Programmes ◽  
Selection For ◽  
Breeding Goals ◽  
High Yields

AbstractGenetic selection for milk production has been very successful. However to achieve high yields, the metabolic load on dairy cows is believed to be substantial. If the size of this load is large enough then the animal may become ‘metabolically stressed’. Signs of this may include some sort of distortion of normal physiological function. There is evidence from both population studies and research herds to suggest that intense selection for milk yield has led to a deterioration in some aspects of health and fertility. Genetic correlation estimates between production and measures of fertility are unfavourable. As an example, calving intervals of high merit animals from Langhill are on average 12 days longer than those of average genetic merit, which is mostly due to a delay in days to first heat. It is suggested that some aspects of health and fertility problems in high genetic merit animals are a consequence, in part, of so-called metabolic stress. Future breeding goals should be broadened to include a broad spectrum of traits related to efficient milk production, in addition to either health and fertility traits themselves, or traits believed to be precursors of them, such as those related to metabolic stress. The complexity and subjectivity of metabolic stress and its components makes it very difficult to include in future breeding goals. However, traits related to energy balance, such as some measures of condition score, dry-matter intake and live weight may be useful in breeding programmes where one of the goals is to alleviate metabolic stress.

A note on annual variation of plasma insulin-like growth factor-I concentrations and growth rates of Jersey heifers differing in genetic merit for milk production

1989 ◽  
Vol 48 (2) ◽  
pp. 467-470 ◽  
Author(s):  
S. R. Davis ◽  
V. C. Farr ◽  
P. D. Gluckman ◽  
B. H. Breier
Keyword(s):  
Growth Factor ◽  
Milk Fat ◽  
Annual Variation ◽  
Live Weight ◽  
Insulin Like Growth Factor ◽  
Genetic Merit ◽  
Igf I ◽  
Selection For ◽  
Breed Selection ◽  
Jersey Cows

A study was made of the concentration of insulin-like growth factor-l (IGF-I) in the plasma of Jersey cows differing in genetic merit for milk and milk fat production. Plasma IGF-I concentrations exhibited an annual cycle and from this study it is concluded that, in the Jersey breed, selection for increased milk and milk fat production, with the correlated responses of increases in mature live weight and live-weight gain, will not be accompanied by increased plasma IGF-I concentration.

Effect of selection for leanness on overall reproductive performance in Large White sows

1995 ◽  
Vol 61 (3) ◽  
pp. 561-564 ◽  
Author(s):  
J. B. Gaughan ◽  
R. D. A. Cameron ◽  
G. McL. Dryden ◽  
M. J. Josey
Keyword(s):  
Birth Weight ◽  
Reproductive Performance ◽  
Live Weight ◽  
The Other ◽  
Large White ◽  
Weaning Weight ◽  
Weaned Piglet ◽  
Selection For ◽  
Weight Number ◽  
M 14

AbstractReproductive records from 1072 Large White sows (3589 litters) were used to examine the effect ofbackfat depth (Bd) and live weight (Lw) at selection on first litter and lifetime reproductive performance. The variables investigated included mating age, total piglets born, total born alive, piglet birth weight, number weaned, piglet weaning weight, weaning to remating period and number of litters produced. Using backfat depth, sows were categorized into three groups: L, 9 to 13 mm; M, 14 to 16 mm; and F, ≥17 mm. Bd had no significant effect (P > 0·05) on the measured traits for the sows grouped by fat at first parity. When lifetime reproductive data were analysed, the L group had fewer litters (P < 0·05), and weaned fewer pigs (P < 0·01) than either the M or F group. The birth weight for piglets from L sows were significantly higher (P < 0·05) than for piglets from the other groups. The data suggest that the reproductive performance of L sows is not as good as that of M or F sows.

Effectiveness of selection for growth rate in Zebu × British crossbred cattle. I. Pre-weaning growth

1975 ◽  
Vol 26 (2) ◽  
pp. 393 ◽  
Author(s):  
GW Seifert
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
Environmental Effects ◽  
Significant Interaction ◽  
Response To Selection ◽  
Crossbred Cattle ◽  
Weaning Weight ◽  
Genetic Potential ◽  
Low Weight ◽  
Selection For

From random-bred populations of Africander cross (AX) and Brahman cross (BX), bulls and cows were selected within breeds for high and low weight per day of age (W/A) at c. 2 years of age and mated assortatively. There was a similar and significant response to selection in both breeds in birth weight and pre-weaning W/A as well as in pre-weaning gains. Although the BX animals were heavier and gained more than the AX animals, the differences were not as great or as consistent as the effect of selection. Calf gains were inversely related to cow gains from birth to weaning, but positively correlated to cow weight. During the pre-weaning period high W/A line cows gained significantly more than the low W/A line cows, while AX animals gained more than the BX group. The higher gain of the high W/A line cows and the higher weaning weight of their calves showed that these lines were more efficient than the low lines in terms of production of weaning weight. Very early calf gains from birth in November to January, and W/A in January, appeared to be poor indicators of the genetic potential of the calf and of the permanent environmental effects affecting its growth. In contrast, the period from January to March, during which the most rapid gains were experienced, reflected both the genetic potential and permanent environmental effects. The previous lactational status of the dam only affected birth weight and day of birth significantly and affected the AX calves more than the BX calves. This resulted in a significant interaction between breed and previous lactational status for these two traits.

scholarly journals Responses to selection for lean growth in sheep

2002 ◽  
Vol 74 (1) ◽  
pp. 39-50 ◽  
Author(s):  
G. Simm ◽  
R.M. Lewis ◽  
B. Grundy ◽  
W.S. Dingwall
Keyword(s):  
Fixed Effects ◽  
Mixed Model ◽  
Live Weight ◽  
Control Line ◽  
Breeding Values ◽  
Breeding Goal ◽  
Lean Growth ◽  
Selection For ◽  
Estimated Breeding Values ◽  
And Control

AbstractThis paper reports the selection responses achieved, and related results, following 9 years of index selection for lean growth in Suffolk sheep. The breeding goal of the index used comprised carcass lean weight and carcass fat weight at a constant age, with relative economic values of + 3 and –1 per kg. The selection criteria were live weight (LWT), ultrasonic fat depth (UFD) and ultrasonic muscle depth (UMD) adjusted to a constant age of 150 days. By year 9, responses in LWT, UFD and UMD in both sexes, as judged by the divergence between selection and control line performance, amounted to 4·88 kg, -1·1 mm and 2·8 mm respectively; these responses are between 7 and 15% of the overall means of the traits concerned. Although selection was originally on index scores based on phenotypic records, the retrospective analyses reported here used the mixed model applications of residual maximum likelihood to estimate parameters and best linear unbiased prediction to predict breeding values. The statistical model comprised fixed effects plus random effects accounting for direct additive, maternal additive and temporary environmental variation. Estimated genetic trends obtained by regressing estimated breeding values on year of birth were similar to annual responses estimated by comparing selection and control line means. Estimates of direct heritabilities were 0·054, 0·177, 0·286, 0·561 and 0·410 for birth weight (BWT), weaning weight (WWT), LWT, UFD and UMD respectively. Corresponding estimates of maternal heritabilities were 0·287, 0·205, 0·160, 0·083 and 0·164. Phenotypic correlations between all pairs of traits were positive and usually moderately high. There were low negative direct additive correlations between BWT and WWT, and between BWT and LWT, but higher positive maternal additive correlations between all other pairs of weight traits.

scholarly journals Direct and correlated responses to selection for autumn lambing in sheep

2020 ◽  
Vol 52 (1) ◽  
Author(s):  
Masood Asadi-Fozi ◽  
Heather L. Bradford ◽  
David R. Notter
Keyword(s):  
Birth Weight ◽  
Selection Line ◽  
Sheep Population ◽  
Estrous Cycles ◽  
Breeding Values ◽  
Scrotal Circumference ◽  
Ram Effect ◽  
Selection For ◽  
Estimated Breeding Values ◽  
Sheep Production

Abstract Background Seasonal reproduction limits productivity, flexibility, and profitability in commercial sheep production. Hormonal and (or) photoperiodic manipulation can be used to control estrous cycles in sheep and reduce limitations that are imposed by the seasonal anestrous but are often impractical or incompatible with the extensive management systems preferred for ruminant livestock. Thus, the current study investigated the use of selection to improve realized fertility (i.e., the proportion of ewes that lambed) following an out-of-season spring joining period (May and June) in a crossbred sheep population. Results Over 17 years, estimated breeding values (EBV) for fertility in selected (S) ewes increased by 0.175 (0.01 per year). The mean EBV for fertility of S ewes was greater than that of control ewes by year 10 (P = 0.02), and the fertility of adult (≥ 3 years old) ewes reached 0.88 ± 0.05 by year 17. Lambing began approximately 140 days after the introduction of rams, and 64% of the S ewes that lambed did so in the first 17 days of the potential lambing season, which indicated that most of the S ewes were cycling at the time of ram introduction and were not induced to cycle by the introduction of breeding males (i.e., the so-called “ram effect”). Animals in the S line had modest increases in body weight and scrotal circumference. A modest negative trend in the additive maternal effect on birth weight was observed but was reversed by additional selection on EBV for maternal birth weight. The heritability of litter size in autumn lambing was low (0.04) and could potentially limit the response to selection for this trait. Conclusions Selection improved realized ewe fertility in out-of-season mating, with absolute increases of approximately 1% per year in the percentage of joined ewes that lambed in the autumn. Genetic antagonisms with other performance traits were generally small. A modest antagonism with maternal breeding values for birth weight was observed but it could be accommodated by selection on EBV for maternal birth weight. Our results support results of previous studies that indicate that these selected ewes had one of the shortest seasonal anestrous periods reported for temperate sheep breeds and that spring-lambing lactating ewes from the selection line were capable of relatively rapid rebreeding in the spring.

scholarly journals Estimating internal pelvic sizes using external body measurements in the double-muscled Belgian Blue beef breed

2003 ◽  
Vol 76 (2) ◽  
pp. 229-235 ◽  
Author(s):  
F. Coopman ◽  
S. de Smet ◽  
N. Gengler ◽  
A. Haegeman ◽  
K. Jacobs ◽  
...  
Keyword(s):  
Birth Weight ◽  
Caesarean Section ◽  
Live Weight ◽  
High Rate ◽  
Management Tool ◽  
High Birth Weight ◽  
Beef Breed ◽  
Pelvic Area ◽  
Selection For ◽  
Few Data

AbstractIn the double-muscled (DM) Belgian Blue beef (BBB) breed, caesarean section (CS) is being applied systematically as a management tool to prevent dystocia. As a matter of fact, CS is the only possible way of calving in the breed. High birth weight and a relatively small pelvic area are the main causes of dystocia and, in the DM-BBB breed, the reasons for the systematically applied CS. Selection for lower birth weight and larger pelvic sizes might reduce dystocia and routine CS. Few data on inner pelvic sizes of pedigree animals are available. Using external measurements to estimate the inner pelvic sizes might be an option to resolve this problem. In this study, animals of the DM-BBB breed were measured and weighed on farms and in abattoirs. External and internal pelvic sizes increased with live weight and age of the animals. Gender had a significant influence on inner pelvic traits. Increased muscular conformation was associated with decreased inner pelvic dimensions. Models with weight, gender, age, withers height and outer pelvic width (TcTc) can be used to estimate inner pelvic sizes (R2 between 0•35 and 0•77). The estimated inner pelvic sizes can then be used to genetically evaluate pelvic traits in the DM-BBB breed. Improving weight, withers height and TcTc width in combination with lowering muscular conformation may help to decrease the high rate of caesarean section in the DM-BBB.

scholarly journals The impact of maternal genetic merit and country of origin on ewe reproductive performance, lambing performance and ewe survival

2021 ◽  
Author(s):  
N Fetherstone ◽  
N McHugh ◽  
T M Boland ◽  
F M McGovern
Keyword(s):  
New Zealand ◽  
Birth Weight ◽  
Litter Size ◽  
Country Of Origin ◽  
Reproductive Traits ◽  
Gestation Length ◽  
Genetic Merit ◽  
Genetic Groups ◽  
One Year ◽  
The Impact

Abstract The objective of this study was to investigate the impact of the ewe’s maternal genetic merit and country of origin (New Zealand or Ireland) on ewe reproductive, lambing and productivity traits. The study was performed over a four year period (2016 to 2019) and consisted of three genetic groups: high maternal genetic merit New Zealand (NZ), high maternal genetic merit Irish (High Irish) and low maternal genetic merit Irish (Low Irish) ewes. Each group contained 30 Suffolk and 30 Texel ewes, selected based on the respective national maternal genetic indexes; i.e. either the New Zealand Maternal Worth (New Zealand group) or the €uro-star Replacement index (Irish groups). The impact of maternal genetic merit on reproductive traits such as litter size; lambing traits such as gestation length, birth weight, lambing difficulty, mothering ability, and productivity traits such as the number of lambs born and weaned were analyzed using linear mixed models. For binary traits, the impact of maternal genetic merit on reproductive traits such as conception to first AI service; lambing traits such as dystocia, perinatal lamb mortality and productivity traits such as ewe survival were analyzed using logistic regression. New Zealand ewes outperformed Low Irish ewes for conception to first AI (P&lt;0.05) and litter size (P=0.05). Irish ewes were more likely to suffer from dystocia (6.84 (High Irish) and 8.25 (Low Irish) times) compared to NZ ewes (P&lt;0.001); birth weight and perinatal mortality did not differ between groups (P&gt;0.05). Lambs born from NZ ewes were 4.67 (95% CI: 1.89 to 11.55; P&lt;0.001) and 6.54 (95% CI: 2.56 to 16.71; P&lt;0.001) times more likely to stand up and suckle unassisted relative to lambs born from High or Low Irish ewes, respectively. New Zealand and High Irish ewes had a greater number of lambs born and weaned throughout the duration of the study compared to their Low Irish counterparts (P&lt;0.001). New Zealand ewes tended to be more likely to survive from one year to the next compared to Low Irish ewes (P=0.07). Irish ewes of high maternal genetic merit outperformed their Low counterparts in total number of lambs born and weaned per ewe, but performance did not differ across other traits investigated. This highlights the importance of continuous development of the Irish maternal sheep index to ensure favourable improvements in reproductive, lambing and productivity traits at farm level. Overall, results demonstrate the suitability of NZ genetics in an Irish production system.

A comparison of the Charolais, British Friesian and Hereford breeds as sires of crossbred singlesuckled calves for beef production

1973 ◽  
Vol 17 (3) ◽  
pp. 267-273 ◽  
Author(s):  
R. E. Haycock ◽  
D. A. Stewart
Keyword(s):  
Weight Gain ◽  
Birth Weight ◽  
Live Weight ◽  
The Other ◽  
Cattle Production ◽  
Significant Relationships ◽  
Grazing Period ◽  
Beef Cattle Production ◽  
Breed Crosses ◽  
Selection Of

SUMMARYIn three successive years cows from an Aberdeen Angus cross Shorthorn herd were mated to pedigree Charolais, British Friesian and Hereford bulls. A comparison of the progeny of the three breeds of sire under controlled conditions was therefore possible using a random selection of dams for mating, and identical rearing of the calves. Results for live-weight gain of the suckled progeny were analysed and showed superiority of the Charolais breed over the other two when used in this form of beef cattle production.For birth weights and daily live-weight gains, particularly during the grazing period, the Charolais cross progeny showed superiority over the other two. There was a consistent although not always statistically significant tendency for these differences between the breed crosses to occur in the male calves only, the females showing little difference between breeds. The data also showed highly significant relationships between gestation period and birth weight, both within and between breed crosses.

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