Genetic and phenotypic parameters of body weight and wool production in Iranian Moghani sheep

2005 ◽  
Vol 2005 ◽  
pp. 134-134
Author(s):  
M. Nosrati ◽  
J. Shoja

In spite of the fact that there are many sheep breeds in Iran, few studies have been established with respect to their economical traits. Moghani sheep is one of the best Iranian meat type breeds with a 5.5 million population. Some specifications of this breed include Resistance to weather conditions, big body size and ability to producing heavy lambs. The aim of this research was to survey the environmental effects and estimates of genetic parameters for birth weight (BW), average daily gain from birth to three mounts of age (ADG1), three months age weight (TRW), average daily gain from three to six months age (ADG2), six months age weight (SIW), nine months age weight (NIW), yearly weight (twelve months age weight or TWW), lamb fleece weight (LFW) and yearly greasy fleece weight in mature sheep (YFW). The effect of birth year, ewe’s gestation period (or age for yearling greasy fleece weight), birth type and sex as fixed effect and sires (nested in years) as random effect on aforesaid traits were studied.

1980 ◽  
Vol 30 (2) ◽  
pp. 271-276 ◽  
Author(s):  
A. P. Mavrogenis ◽  
A. Louca ◽  
O. W. Robison

ABSTRACTData on 792 Chios lambs born during the 1972/73 and 1973/74 lambing seasons were used to estimate genetic and phenotypic parameters for birth weight, weaning weight, age at weaning, pre-weaning daily gain, body weight at 5, 10, 15 and 20 weeks of age, and postweaning daily gain. Body weight at 15 weeks of age had the highest heritability estimate (0·73 ± 0·17) and that of post-weaning daily gain was also high (0·56 ± 0·15). Selection for either weight at 15 weeks or post-weaning daily gain would be expected to yield a greater response than selection for pre-weaning daily gain or weaning weight. Genetic correlations among weights and/or gains were positive (approximately 0·20). Phenotypic correlations among weights and gains were generally higher than genetic correlations. However, the correlation between pre— and post-weaning daily gain was small (0·08). Likewise, post-weaning daily gain had low correlations with all weights before 10 weeks. Age at weaning had moderate negative associations with all weights but a very low positive correlation with post-weaning daily gain.


2012 ◽  
Vol 52 (11) ◽  
pp. 1046 ◽  
Author(s):  
Hasan Baneh ◽  
Mojtaba Najafi ◽  
Ghodrat Rahimi

The present study was carried out to estimate variance components for growth traits in Naeini goats. Bodyweight records were collected for two flocks under supervision of the Agriculture Organisation of the Esfahan province between 2000 and 2007. Investigated traits were birthweight (BW; n = 2483), weaning weight (WW; n = 1211) and average daily gain from birth to weaning (ADG; n = 1211). Environmental effects were investigated using fixed-effect models, while (co)variance components and genetic parameters were estimated with single- and three-trait analyses using REML methods and WOMBAT software. Six different animal models were fitted to the traits, with the best model for each trait determined by log-likelihood ratio tests (LRT). All traits were significantly influenced by herd, birth year, sex of the kid, birth type and dam age (P < 0.01). On the basis of LRT, maternal permanent environmental effects (c2) were significant for WW and ADG, while BW was affected only by direct genetic effects. Direct heritability estimates for BW, WW and ADG were 0.25 ± 0.05, 0.07 ± 0.06 and 0.21 ± 0.11, respectively. The estimate of c2 was 0.16 ± 0.06 for both WW and ADG. Estimates of genetic correlation for BW–ADG, BW–WW and ADG–WW were 0.49, 0.61 and 0.94, respectively. The estimated phenotypic correlations were positive and were between 0.03 (BW–ADG) and 0.95 (ADG–WW). These results indicate that selection can be used to improve growth traits in this goat breed.


2007 ◽  
Vol 50 (5) ◽  
pp. 476-486 ◽  
Author(s):  
D. Škorjanc ◽  
M. Brus ◽  
M. Čandek Potokar

Abstract. A study was conducted to find out the effect of birth weight and sex on growth rate of piglets in pre-weaning period. A total of 466 piglets from 48 litters of multiparous sows (Landrace) were involved in the experiment. Using a clustering approach piglets were assigned into three birth weight groups (Heavy (H), Intermediate (I), Light (L)). For the analysis of growth performance, pigs were weighed every 7 days until weaning at 28 days of age and average daily gain (ADG) was calculated. During lactation, body weight of L piglets was 5.5-fold increased, whereas the increase in I and H piglets were only 4.7-fold and 3.4-fold, respectively. Piglets of L group were significantly lighter at all studied ages compared to piglets of I and H group. The highest ADG was noted in the second week for all three groups; thereafter it decreased in H and L piglets (24% and 17%, respectively). The average birth weight of piglets was positively and significantly correlated with body weight at days 7, 14, 21 and 28. Sex did not affect significantly the ADG of the investigated animals during the four weeks of lactation. The present results indicate that neither milk production after the second week of lactation nor consumption of creep feed are sufficient enough to cover nutrition needs of fast growing piglets. There’s still a lack of optimization of nutrition in pre-weaning period especially for heavier piglets with their higher growth potential.


1978 ◽  
Vol 26 (2) ◽  
pp. 185-192 ◽  
Author(s):  
A. Farid ◽  
M. Makarechian

ABSTRACTThe pre-weaning records (birth weight, weaning weight and gain from birth to weaning) of 291 male and female lambs and the post-weaning records (body weight, feedlot gain and food conversion) of 136 male lambs were used to study relationships between different traits. The lambs were derived from three fat-tailed Iranian sheep breeds (Karakul, Mehraban and Naeini) and their crosses with Corriedale and Targhee rams. All lambs were weaned at 75 + 5 days of age and the males were fed in a feedlot for 100 days after weaning. Feedlot measurements were taken at 20-day intervals.Weaning weight and pre-weaning average daily gain showed positive and significant associations with birth weight. Birth weight, weaning weight and gain from birth to weaning were positively associated with body weight at subsequent ages in feedlot as well as with final weight (P<0·01). Birth weight, weaning weight and pre-weaning average daily gain were positively and significantly associated with total feedlot gain.Of the different traits, total gain during the first 20 days in feedlot (adjust period) had the lowest and total gain during the second 20 days had the highest association with total feedlot daily gain. There was no evidence that the heavier lambs at weaning and those showing high growth rate before weaning, were more efficient in the feedlot. Gain during the second 20-day period in the feedlot had a significant negative association with the total food conversion (unit food/unit gain) and therefore was a good predictor for food conversion.When the feedlot period was divided into two 40-day periods, it was found that gain during both had a significant negative association with the corresponding food conversion. A similar association was observed between total feedlot gain and food conversion, indicating that the rate and efficiency of gain improved simultaneously.


2012 ◽  
Vol 40 (1-2) ◽  
pp. 1-7
Author(s):  
S Aktar ◽  
AKFH Bhuiyan ◽  
NG Saha ◽  
MA Hoque

Records on four bulls and 96 of their progeny born from 2005 to 2011 with pedigree information were used to estimate the impact of bull performance on progeny early growth and the genetic relationships between traits of bull and their progeny. Traits included in this study were metabolic body weight, feed intake and residual feed intake (RFI) for bull performance and birth weight and average daily gain for progeny performance. The variance and covariance components were estimated by the REML method with the VCE computer program. The metabolic body weight of breeding bulls ranged from 92.88±1.22 to 106.05±2.28 kg. The average daily feed intake of breeding bulls differed significantly (p<0.05). The RFI of breeding bulls were ranged from -0.57±0.07 to 0.54±0.06 kg/day. It has been found that the RFI values of two bulls were negative and the other two bulls were positive. The mean values for birth weight of calves produced from different breeding bulls ranged from 16.15±2.01 to 17.71±1.89 kg. Effects of breeding bulls on birth weight and average daily gain of male calves were highly significant (p<0.01). Mean values for birth weight and average daily gain of female calves were affected also significantly (p<0.05) among breeding bulls. Estimated heritability for birth weight was moderate (0.30) and for average daily gain was low (0.26). The genetic correlation between metabolic body weight of bulls and birth weight of their progeny was strong (rg=0.52), whereas feed intake of bulls with birth weight and average daily gain of their progeny were moderate (0.43±0.21 and 0.40±0.23, respectively). Low but favorable negative genetic correlation (rg=-0.10) was observed between RFI of bulls with average daily gain of their progeny. Estimated moderate heritability indicated that variation exist on average daily gain of calves. The negative genetic correlation between RFI of bulls and average daily gain of their progeny indicated that it was possible to improve simultaneously RFI of breeding bulls and daily gain of their progeny. DOI: http://dx.doi.org/10.3329/bjas.v40i1-2.10620 Bang. J. Anim. Sci. 2011. 40 (1-2): 1-7


1980 ◽  
Vol 60 (3) ◽  
pp. 599-607
Author(s):  
G. W. RAHNEFELD ◽  
R. J. PARKER ◽  
S. YODSERANEE ◽  
E. W. STRINGAM

This study was designed to estimate and evaluate environmental factors affecting birth weight, weaning weight and preweaning average daily gain (ADG) of purebred Shorthorn calves from the control line of a selection experiment. Nine years of data consisted of 635 birth weight and 607 weaning weight records. Least squares analysis of variance revealed that sex of the calf was the most important source of variation: males averages 2.31 kg heavier at birth, were 14.3 kg heavier at weaning and gained 0.08 kg more per day from birth to weaning than females. Heavier cows in June, October, and December prior to parturition and at parturition produced heavier calves at birth. Heavier cows in October prior to parturition, at parturition, and in June or October following parturition produced calves which grew more rapidly from birth to weaning and were heavier at weaning. There was no apparent effect of cow weight changes before or after parturition on preweaning traits. Correlations of birth weight with weaning weight, preweaning ADG and cow weight at parturition were 0.56 ± 0.03, 0.43 ± 0.04 and 0.24 ± 0.04 respectively. Correlations of weaning weight and preweaning average daily gain with cow weights at parturition were 0.42 ± 0.04 and 0.40 ± 0.04. Correlations among cow weights in June, October, and December prior to parturition, at parturition, and in June and October following parturition were estimated.


2001 ◽  
Vol 137 (3) ◽  
pp. 365-371 ◽  
Author(s):  
S. A. AL-SHOREPY

Genetic parameters were estimated for purebred and crossbred lambs of a local breed using a single trait animal model. The traits recorded were: birth weight (BWT), weight at 30 days (WT30), weaning weight (WWT), average daily gain from 1 to 30 days (ADG1) and average daily gain from 30 to 90 days (ADG2). Five different animal models were fitted for each trait; all including additive direct genetic variance and various combinations of additive maternal and environmental maternal effects. The most appropriate model was chosen based on likelihood ratio tests. Additive maternal and permanent environmental effects were important (P < 0·05) for birth weight in purebred and crossbred lambs, when compared with a model containing only additive direct effects. Inclusion of maternal permanent environmental effects provided a better fit (P < 0·05) for weaning weight in purebred lambs than a model containing only additive direct effects. Estimates of heritability from the model containing additive direct, maternal effects and maternal permanent environmental effects, but not additive direct-maternal correlation, for combined purebred and crossbred lambs were 0·32 for BWT, 0·19 for WT30, 0·24 for WWT, 0·26 for ADG1 and 0·12 for ADG2. Estimates of additive maternal and maternal permanent environmental variances, respectively, as a proportion of phenotypic variance were 0·06 and 0·07 for BWT, 0·05 and 0·02 for WT30, 0·02 and 0·03 for WWT, 0·03 and 0·05 for ADG1 and 0·00 and 0·03 for ADG2. Estimates of direct-maternal correlation in subsequent analyses were significant and ranged from −0·16 to −0·95 for live weights and from −0·73 to −1·0 for daily gains. However, the very large negative correlations probably resulted from undefined non-genetic covariances as well as possible antagonistic genetic effects. These results indicate that it would be possible to improve growth traits in a local sheep breed through genetic selection.


2020 ◽  
pp. 52-55
Author(s):  
N. M. Alekseeva ◽  
P. P. Borisova ◽  
V. V. Romanova

Relevance and methods. The article presents experimental data on the selection and genetic parameters of the productive qualities of young specialized meat breeds (Hereford and Kalmyk) in Yakutia.Results. Musculature in animals of Hereford breed remained well developed, the animals remained well-fed. The skeleton is strong, in general, have strong and correctly set legs. The indices of elongation in bulls of Hereford breed were 114.5, the indices of incidence were 129.6, the index of chest was 56.6, and the index of pelvic was 87.1. In heifers of Hereford breed, the indices of elongation were 116.9, overgrowth 110.3, and bones 19.6. The dynamics of the live weight of young specialized meat breeds in the conditions of the farms of Central Yakutia shows that heifers and calves of the Kalmyk breed live birth weight was 19.2–20.8 kg, at 3 months of age 53.3–55.5 kg, at 5 months of age, 109.7–117 kg, respectively. In the period from birth to 3 months, the absolute increase was 34.1–34.7 kg with an average daily gain of 378–385 g.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Morteza Bitaraf Sani ◽  
Javad Zare Harofte ◽  
Mohammad Hossein Banabazi ◽  
Saeid Esmaeilkhanian ◽  
Ali Shafei Naderi ◽  
...  

AbstractFor thousands of years, camels have produced meat, milk, and fiber in harsh desert conditions. For a sustainable development to provide protein resources from desert areas, it is necessary to pay attention to genetic improvement in camel breeding. By using genotyping-by-sequencing (GBS) method we produced over 14,500 genome wide markers to conduct a genome- wide association study (GWAS) for investigating the birth weight, daily gain, and body weight of 96 dromedaries in the Iranian central desert. A total of 99 SNPs were associated with birth weight, daily gain, and body weight (p-value < 0.002). Genomic breeding values (GEBVs) were estimated with the BGLR package using (i) all 14,522 SNPs and (ii) the 99 SNPs by GWAS. Twenty-eight SNPs were associated with birth weight, daily gain, and body weight (p-value < 0.001). Annotation of the genomic region (s) within ± 100 kb of the associated SNPs facilitated prediction of 36 candidate genes. The accuracy of GEBVs was more than 0.65 based on all 14,522 SNPs, but the regression coefficients for birth weight, daily gain, and body weight were 0.39, 0.20, and 0.23, respectively. Because of low sample size, the GEBVs were predicted using the associated SNPs from GWAS. The accuracy of GEBVs based on the 99 associated SNPs was 0.62, 0.82, and 0.57 for birth weight, daily gain, and body weight. This report is the first GWAS using GBS on dromedary camels and identifies markers associated with growth traits that could help to plan breeding program to genetic improvement. Further researches using larger sample size and collaboration of the camel farmers and more profound understanding will permit verification of the associated SNPs identified in this project. The preliminary results of study show that genomic selection could be the appropriate way to genetic improvement of body weight in dromedary camels, which is challenging due to a long generation interval, seasonal reproduction, and lack of records and pedigrees.


2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 238-238
Author(s):  
Olivia Harrison ◽  
Samantha Tauer ◽  
Brent Frederick

Abstract Number of pigs born alive has been a key factor of the increasing efficiency of the U.S. swine industry. However, with increased pigs in the uterus, birth weight has been negatively impacted, with more small or at-risk pigs being born per litter. In order to overcome these changes, a study testing three commercial oral drenches against a control to determine which would increase average daily gain and decrease preweaning mortality. In a completely randomized design, 877 one-day-old suckling pigs from a high-health farm were selected for the experiment if they appeared to be in the bottom 20% of bodyweight compared to their contemporaries. Selected pigs were given one of four drenching treatments: 1) none (control), 2) bioactive proteins (BP), 3) high energy sugars (HES), and 4) immunoglobulins (IgY). Pigs were weighed on d 1 and d 19 of age (weaning), with mortality tracked during the suckling period. Data were analyzed using SAS v 9.4 (Cary, NC), with pig as the experimental unit and an accepted alpha of 0.05. Treatment had no detected effect on birth weight, weaning weight, ADG, or mortality (P = 0.79, 0.96, 0.86, 0.38 respectively). Likewise, statistical contrasts were used to determine there was no detected impact (P &gt; 0.10) of drench, regardless of type, compared to the control in any measured response criteria. Interesting, pigs drenched with BP or IgY had numerically lower preweaning mortality (11.2 and 11.5% respectively), than those administered the control or HES (15.4 and 15.2%, respectively). In conclusion, this experiment showed no significant difference in the performance between piglets given no product vs. those drenched with bioactive proteins, high energy sugars, or immunoglobulins. However, additional research is warranted with greater replication or disease stressors to better understand if oral drenches may improve preweaning performance or mortality in different situations.


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