Genetic and non-genetic effects associated with ewe productivity in Harnali sheep

Zygote ◽  
2021 ◽  
pp. 1-5
Author(s):  
Parth Gaur ◽  
Z. S. Malik ◽  
Yogesh C. Bangar ◽  
Ankit Magotra ◽  
A. S. Yadav

Summary The objective of the current study was to estimate the genetic parameters for ewe productivity traits of Harnali sheep by examining non-genetic effects. The data records of 440 animals born to 85 sires and 259 dams were collected with respect to various traits such as litter size at birth (LSB), litter weight at birth (LWB), litter size at weaning (LSW), litter weight at weaning (LWW) and age at first lambing (AFL) for the period of 2001 to 2020. Genetic parameters were estimated by fitting a series of animal models using an average information restricted maximum likelihood (REML) algorithm in WOMBAT software. Least-squares analysis revealed significant (P < 0.05) influences of period of lambing, age and weight of ewe at lambing on the studied traits. These results indicated that heavier ewes had significantly higher (P < 0.05) values of litter weight traits than their counterparts. On the basis of likelihood ratio test, the estimates of direct heritability under best model for AFL, LSB, LWB, LSW and LWW were 0.06, 0.18, 0.09, 0.07 and 0.16, respectively. Maternal permanent environment effect made a significant contribution to the LSB trait (0.20). The genetic correlation between litter size and LWW was negative, while the remaining correlations were positive. The present results suggest that selection based on ewe productivity traits will result in low genetic progress and therefore the management role is more important for better gains.

Author(s):  
A I Adeolu ◽  
V.U Oleforuh Okoleh ◽  
W Mathew ◽  
R U Onyeneke ◽  
R N Nwose ◽  
...  

Data from 302 progeny in a heterogeneous population of rabbits were used to estimate the heritability and correlations (phenotypic and genetic) of pre-weaning litter traits (litter size at birth LSB, litter size at weaning LSW, litter weight birth LWB, litter weight at weaning LWW, kit weight birth KWB, and kit weight weaning KWW). Heritability estimates for litter size ranged from 0.16 (LSW) to 0.22 (LSB). LWB and LWW were more highly heritable (0.52 and 0.55 respectively) than KWB and KWW (0.36 and 0.25 respectively). The genetic (rG ) and phenotypic (rP) correlations between litter size and litter weight at birth and weaning were 0.69 to 0.88 (rG) and 0.28 to 0.88 (rP). Generally, litter traits gave higher estimates than individual kit traits implying that selection criteria based on litter performance rather than on individual kit performance should be applied in genetic improvement of pre-weaning traits in rabbits raised in derived savanna zone.


2002 ◽  
Vol 74 (3) ◽  
pp. 409-414 ◽  
Author(s):  
I. Boujenane ◽  
J. Kansari

AbstractGenetic parameters for body weights in Timahdite sheep were estimated using records of 10370 lambs from the ‘Société Nationale de Développement de l’Elevage’ born in 1988-89 to 1998-99. An animal model with derivativefree restricted maximum likelihood procedures was used. Random effects were direct and maternal additive genetic, maternal permanent environmental, and error. Direct and maternal heritability estimates were 0·05 and 0·05 for birth weight, 0·02 and 0·07 for weight at 30 days, 0·07 and 0·08 for weight at 70 days, 0·06 and 0·01 for weight at 90 days. Estimates of fraction of variance due to maternal permanent environmental effects were close to zero, except for weight at 90 days. Genetic correlations between direct and maternal genetic effects were –0·55, –0·51, –0·50 and –0·17 for body weights at birth, 30, 70 and 90 days, respectively. Estimates of direct genetic correlations among body weights were positive and high, ranging from 0·69 to unity. Phenotypic correlations were positive and moderate to high, being lower than their corresponding direct genetic correlations. Estimates of correlations between maternal genetic effects among weights were positive and high, varying from 0·79 to unity. Cross-correlations between direct genetic effects for one weight and maternal genetic effects for another weight were consistently negative, ranging from –0·05 to –0·63. These results indicate that selecting for improved maternal and/or direct effects in Timahdite sheep is expected to generate only slow genetic progress in terms of early growth.


2021 ◽  
Vol 19 ◽  
pp. 114-119
Author(s):  
I. K. Odubote ◽  
J. O. Akinokun

Records of 848 West African Dwarf goat kids and 220 kiddings over a period of eight years (1982-1989) were analysed. The records were used to provide heritability and repeatability estimates for litter size at birth, kidding interval (repeatability estimate alone) and body weight at birth, weaning, 3 months, 6 months, 9 months and 1 year of age. Heritability estimates of 0.28±0.005, 0.18±0.003, 0.14±0.003, 0.29±0.005, 0.11±0.003 and 0.17±0.004 were obtained for litter size at birth, body weight at birth, and at weaning, 3 months, 6 months, and 9 months of age respectively. Corresponding repeatability estimates were slightly higher than the heritability estimates. However, repeatability estimates of 0.04±0.030 was obtained for kidding interval.


1993 ◽  
Vol 56 (3) ◽  
pp. 399-405 ◽  
Author(s):  
C. Cervera ◽  
J. Fernandez-Carmona ◽  
P. Viudes ◽  
E. Blas

AbstractIn an experiment of factorial design, female rabbits were given four diets, containing 13·0, 11·4, 10·4 and 9·7 kJ digestible energy (DE) per g and subjected to two remating intervals (R) of 1 to 2 days (intensive) or 9 days (semi-intensive) from parturition. The experiment lasted for 2 years during which 352 does produced a total of 1254 litters. The only major differences due to diet were that the diet with the highest energy concentration, and which contained 35 g/kg added fat, promoted a significantly higher energy intake in lactation (111 v. an average of 94 MJ DE) than the other diets, and thereby increased litter weight at weaning at 28 days (3·48 v. 2·99 kg). Diet and R showed no major interactive effects. The intensive treatment significantly reduced parturition interval (46 v. 52 days) and increased the output of weaned rabbits per doe per year (35 v. 29). As actual R was more variable than the theoretical R imposed by the treatments, further analyses were made by dividing the does into four groups according to the actual R. In these analyses, the effects of R on current and subsequent lactation performance were assessed separately. The main difference between the groups was that litter size increased significantly with R (e.g. litter size at birth in subsequent parities was 8·0, 9·2, 9·7 and 9·0 for mean intervals of 2, 10, 16 and 37 days). However, the same pattern of differences occurred in the current parity, indicating that it was litter size that affected R, rather than the reverse (i.e. does with small litters conceived earlier than those with larger litters).


1977 ◽  
Vol 57 (4) ◽  
pp. 627-634 ◽  
Author(s):  
HITOSHI MIKAMI ◽  
H. T. FREDEEN ◽  
A. P. SATHER

The regression of reproductive performance of dams and post-natal performance of progeny on inbreeding was examined for a population of replicated lines subjected to mass selection over a period of nine generations. Inbreeding advanced by 2.0–2.3% per generation. Regression coefficients per 1% increase in inbreeding, based on 817 degrees of freedom for first parity sows, were −.56 ±.23 kg for dam weight at first parturition (12 mo), −.48 ±.19 kg for dam weight change from parturition to weaning, −.013 ±.034 for litter size at birth, −.103 ±.033 for litter size at weaning and −1.36 ±.36 kg for litter weight at weaning. Regressions for post-natal traits, estimated for progeny produced by second parity dams during the final three generations (638 df) were 10.3 ± 4.0 g for birth weight, 16.8 ± 32.7 g for weaned weight, −4.53 ± 1.22 g for post-weaning daily gain, −.34 ±.16 mm for backfat,.10 ±.04 cm2 for cross-sectional area of the longissimus dorsi, and.09 ±.04% for estimated yield of trimmed retail product from the carcass.


2006 ◽  
Vol 38 (5) ◽  
pp. 445 ◽  
Author(s):  
Juan Gutiérrez ◽  
Blanca Nieto ◽  
Pepa Piqueras ◽  
Noelia Ibáñez ◽  
Concepción Salgado

Author(s):  
N. Savino ◽  
Z. Chusi ◽  
A. Dhali ◽  
P. Perumal

The present study was conducted to measure the reproductive attributes of Naga local pigs (Votho) in Kohima, Peren and Phek district of Nagaland. The reproductive parameters were measured through field survey and reproductive records of owner. The reproductive parameters such as age at first fertile service (AFFS), age at first farrowing (AFF), gestation length, farrowing interval, litter size at birth, litter size at weaning, litter weight at birth, litter weight at weaning, mortality rate and stillbirth rate were measured. The result revealed that there was a significant difference among the different districts of Nagaland in AFFS, AFF and litter weight at birth. Parameters such as AFFS, AFF and litter weight at birth were significantly higher and gestation length, farrowing interval, litter size at weaning, litter weight at birth, litter weight at weaning were non-significantly higher in Kohima than in Peren and Phek District. Similarly, parameters such as litter size at birth, mortality rate were non-significantly higher in Peren district and stillbirth was non- significantly higher in Phek district than other districts of Nagaland. These reproductive attributes analyses may be useful in selection of breeding stock for future parents and select the place for breeding programme for indigenous local Naga pigs.


Author(s):  
Uday Kannegundla ◽  
S. Sai Reddy ◽  
M. Gnana Prakash ◽  
M. Mahenderand ◽  
P. Amareswari

Study was conducted to evaluate the performance of Soviet Chinchilla and Californian White rabbit breeds maintained in tropical environment at rabbit research station, Hyderabad, Telangana. Data generated on total of 1364 bunnies, 701 belongings to the Soviet Chinchilla born in 122 litters and 663 bunnies of Californian White born in 124 litters during the period from 2012 to 2015 were utilized to examine the various productive performance traits. The overall least-squares mean litter size and litter weight was 5.52 ± 0.16 and 264.75 ± 7.86 at birth and 3.56 ± 0.17 and 1439.67 ± 72.55 g at weaning, respectively. The overall least-squares mean pre weaning body weights were 48.39 ± 0.48, 113.65 ± 1.38, 161.50 ± 2.03, 226.15 ± 3.47, 417.89 ± 7.53g at birth, 1, 2, 3 and 4 weeks of age and the post weaning weights at 6, 8, 10, 12, 14 and 16 weeks of age were 628.75 ± 13.02, 844.11 ± 14.81, 1040.79 ± 16.42, 1225.96 ± 17.81, 1437.57 ± 20.54 and 1636.99 ± 28.87 g, respectively. Season of birth and litter size at birth showed significant (£0.01) effect on body weights while genetic group, parity of the doe and sex of the bunny had slight effects only. The low to high heritability estimates, genetic and phenotypic correlations of body weights are the indication for improvement of body weights by appropriate breeding plans.


1987 ◽  
Vol 45 (1) ◽  
pp. 123-134 ◽  
Author(s):  
M. H. Khalil ◽  
J. B. Owen ◽  
E. A. Afifi

AbstractAn analysis of doe productivity traits was carried out on 884 litter records including 52 sires and 210 daughters (paternal half sisters) of Bauscat (B) and Giza White (G) rabbits. Traits examined included litter size and weight at birth and at weaning, pre-weaning mortality and mean weight of young at weaning. Year-of-kindling affected most litter traits but no pattern of parity effects on litter size and pre-weaning mortality was observed. Litter weight and mean weight of young at weaning generally increased linearly as parity advanced. Litter size and weight and mean weight of young tended to increase as month of kindling advanced from October to March, and to decrease again during April and May. Pre-weaning mortality decreased as month of kindling advanced up to March and increased thereafter during April and May. The sire of the doe affected all litter traits studied, with the exception of litter size at birth and pre-weaning mortality in the B breed. Estimates of heritability for most of the litter traits were moderate or high. Genetic and phenotypic correlations among litter size traits and between litter size and litter weight traits were positive and relatively moderate or large. Litter weight traits were positively correlated both genetically and phenotypically. The genetic and phenotypic correlations between litter size traits and mean weight of young at weaning were negative and relatively moderate or large.


1981 ◽  
Vol 33 (2) ◽  
pp. 219-222
Author(s):  
W. R. Congleton

ABSTRACTThe relationship between litter size at birth and litter weight at weaning is curvilinear, with an intermediate litter size resulting in the heaviest litter weight at weaning. Relative to feral mice, the mean and variation for litter size at birth was larger for domesticated mice which had been selected for fertility and crossbred. Consequently, some of the litters from the crossbred domesticated mice were larger than the litter size at birth which optimized litter weight at weaning, primarily due to increased pre-weaning mortality. If litter weight at weaning is to be optimized by indirect selection for litter size at birth, the variation around an intermediate optimum litter size at birth could be most effectively reduced by negative assortative mating.


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