Genetic and phenotypic aspects of doe productivity in four breeds of rabbits

1988 ◽  
Vol 110 (1) ◽  
pp. 191-197 ◽  
Author(s):  
M. H. Khalil ◽  
E. A. Afifi ◽  
M. E. Emara ◽  
J. B. Owen
Keyword(s):  
Litter Size ◽  
Environmental Parameters ◽  
Direct Selection ◽  
Phenotypic Correlation ◽  
Gestation Length ◽  
Environmental Correlations ◽  
Litter Traits ◽  
Genetic And Phenotypic Correlations ◽  
Mortality Percentage ◽  
Size At Birth

SummaryData on 841 purebred Bauscat, White Flander, Giza White and Baladi Red litters provided estimates of genetic, phenotypic and environmental parameters for gestation length, litter size at birth and at weaning, mortality and sex ratio at weaning. A total of 170 daughters (paternal half-sisters) of 76 sires were available for the analysis. No important differences were detected among breeds for litter traits studied except litter size at weaning (P < 0·001). Year of kindling affected (P < 0·001) gestation length, litter size at birth and mortality percentage. No clear patterns of the effect of parity and month of kindling on litter traits were observed. The sire of the doe and doe within sire affected most of the traits studied. Estimates of heritability indicated that the sire's genetic contribution to litter traits are much higher during the pre-natal period than for the suckling period. Estimates of repeatability for litter traits studied were relatively low. Genetic and phenotypic correlations between gestation length and other litter traits were relatively low. Litter size traits were positively correlated both genetically and phenotypically. Estimates of genetic and phenotypic correlation between litter size traits and preweaning mortality were generally negative. Phenotypic and environmental correlations were generally very similar in size and sign. Predicted direct selection was shown to give greater improvement in litter size at birth than indirect selection through litter size at weaning.

A genetic analysis of litter traits in Bauscat and Giza White rabbits

1987 ◽  
Vol 45 (1) ◽  
pp. 123-134 ◽  
Author(s):  
M. H. Khalil ◽  
J. B. Owen ◽  
E. A. Afifi
Keyword(s):  
Genetic Analysis ◽  
Litter Size ◽  
Litter Weight ◽  
Phenotypic Correlations ◽  
Large Litter ◽  
Litter Traits ◽  
Genetic And Phenotypic Correlations ◽  
Size At Birth

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.

scholarly journals Phenotypic relationships between gestation length and preweaning litter traits in rabbits.

2021 ◽  
Vol 31 (2) ◽  
pp. 154-160
Author(s):  
O. N. Durunna ◽  
U. E. Ogundu
Keyword(s):  
Litter Size ◽  
Average Daily Gain ◽  
Gestation Length ◽  
Litter Weight ◽  
Litter Traits ◽  
Degree Of Association ◽  
High Degree ◽  
The Relationship ◽  
Daily Gain ◽  
Size At Birth

A total of 135 kittens from 22 kindlings were used to determine the relationship between gestation length (GL) and some preweaning litter traits alongside the weight of their 12 dams. Average daily gain at 21 days (ADG21), average litter weight at birth (ALWB), kindling to weaning viability (KWV), litter size at birth{L.SB), litter size at 21 days (LS21), litter weight at 21 days(LW21), litter weight at birth (LWAB), and still birth number (SBN) when subjected to multiple regression analysis revealed non-significant t-test value with GL. However, Average litter weight at 21 days (ALW21) was highly significant (P<0.01) suggesting that such can be used to predict GL. Weight of doe (WOD) was highly significant (P<0.01) showing that such parameter is important for predicting GL. A high R2 value was obtained indicating that the variability in GL is explained by the linearity of the preweaning litter traits and WOD. However the correlation coefficient R, (0.89) revealed a high degree of association between the preweaning litter traits in the rabbits and the weight of doe in a linear form. The F-value was significant at P<0.05 indicating that WOD and the preweaning litter traits in rabbits have significant contribution to the variation in GL. The correlations among traits were positive and significant for majority of the traits, which include live birth number (LBN), ADG21, ALW21, KWV, LS21, and LW21. However SBN had negative correlation with other traits.

scholarly journals Genetic Analysis Of Rabbit Litter Traits At Birth And Weaning

2021 ◽  
Vol 19 ◽  
pp. 64-69
Author(s):  
I. K Odubote ◽  
B. Somade
Keyword(s):  
Birth Weight ◽  
Genetic Analysis ◽  
Litter Size ◽  
Weaning Weight ◽  
Litter Weight ◽  
Phenotypic Correlations ◽  
Litter Traits ◽  
Genetic And Phenotypic Correlations ◽  
Selection For ◽  
Size At Birth

Data on 260 litters were used to provide therefore to estimate the heritability and estimates of heritability, repeatability, genetic and phenotypic correlations for litter traits at birth and at weaning. Breed, sire within breed and doe within sire effects were found to be significant, (P<0.05) for litter size at birth and at weaning and for litter weight at birth and at weaning. Heritability estimates of 0.33±0.08, 0.38±0.02, 0.03±0.02 and 0.16±0.05 were obtained for litter birth weight, litter size at birth, litter size at weaning and litter weaning weight, respectively. Repeatability estimates were found to be generally moderate to high. Genetic and phenotypic correlations were positive and significant (P<0.01). Selection for litter size at birth and litter birth weight are likely to result in improved litter size at weaning and litter weaning weight respectively.

Genetic correlations for reproductive and growth traits in rabbits

2020 ◽  
Vol 100 (2) ◽  
pp. 317-322 ◽  
Author(s):  
Rym Ezzeroug ◽  
Rafik Belabbas ◽  
Maria José Argente ◽  
Ali Berbar ◽  
Samir Diss ◽  
...  
Keyword(s):  
Litter Size ◽  
Coefficient Of Variation ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
High Coefficient ◽  
Genetic And Phenotypic Correlations ◽  
The Common ◽  
Large Coefficient ◽  
Size At Birth

The objective of this study was to obtain heritability estimates for reproductive (litter size at birth, number born alive, litter size at weaning) and growth traits (individual weaning weight, individual weight at the end of the fattening period), then determine the genetic correlation between them in a synthetic rabbit line. A total of 805 females, 3242 parities, and 18 472 growth records were measured from 2006 to 2017. A pentavariate animal model was used with reproductive and growth traits. Heritability ranged from 0.025 to 0.126 for reproductive traits and from 0.033 to 0.059 for growth traits. These traits showed a large coefficient of variation (from 32% to 56% for reproductive traits and from 21% to 28% for growth traits). The repeatability of reproductive traits was low and the common litter effect for growth traits was the most important component of total variance. The genetic and phenotypic correlations between reproductive and growth traits were high and negative, especially with weight at weaning (−0.848, −0.922, and −0.854 for litter size at birth, number born alive, and litter size at weaning, respectively). In conclusion, because of the high negative correlation between reproductive and growth traits, both reproductive and growth traits should be selected in independent lines and the response to selection should be due mainly to the high coefficient of variation of the traits.

INTERRELATIONS BETWEEN SOME REPRODUCTIVE TRAITS IN SWINE

1972 ◽  
Vol 52 (1) ◽  
pp. 39-45 ◽  
Author(s):  
M. H. FAHMY ◽  
C. S. BERNARD
Keyword(s):  
Litter Size ◽  
Survival Rates ◽  
Reproductive Traits ◽  
The Other ◽  
Gestation Length ◽  
Percentage Survival ◽  
Weaning Pig ◽  
Highly Correlated ◽  
Daily Gain ◽  
Size At Birth

The associations between 15 preweaning traits in pigs were studied to determine which had the most important effects on litter weights at birth and weaning. The traits were litter size at birth and weaning, number born alive, percentage survival to birth and weaning, pig and litter weights at birth and weaning, daily gain from birth to weaning, gestation length, number of teats, weights of dam at farrowing and at weaning, and the change in dam weight during lactation. Of the 105 correlations, 66 were statistically significant, though many were markedly low. Litter weights at birth and weaning were significantly and relatively highly correlated with most of the other traits, whereas number of teats was correlated only with survival rates at birth and weaning and pig birth weight. The results showed that the importance of litter size was almost twice that of pig weight in determining litter weights at birth and weaning. The results in general indicated that most of the economically important traits related to swine reproductivity are favorably associated.

Reproductive attributes of local pig (Votho) of Nagaland, India

2016 ◽  
Author(s):  
N. Savino ◽  
Z. Chusi ◽  
A. Dhali ◽  
P. Perumal
Keyword(s):  
Mortality Rate ◽  
Litter Size ◽  
Field Survey ◽  
Gestation Length ◽  
Reproductive Parameters ◽  
Litter Weight ◽  
Significant Difference ◽  
Size At Birth ◽  
Selection Of ◽  
Age At First Farrowing

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.

Performance evaluation of Soviet Chinchilla and Californian White rabbit breeds in tropical climatic conditions of India

2017 ◽  
Author(s):  
Uday Kannegundla ◽  
S. Sai Reddy ◽  
M. Gnana Prakash ◽  
M. Mahenderand ◽  
P. Amareswari
Keyword(s):  
Least Squares ◽  
Litter Size ◽  
Climatic Conditions ◽  
Research Station ◽  
Productive Performance ◽  
Litter Weight ◽  
Body Weights ◽  
Genetic And Phenotypic Correlations ◽  
High Heritability ◽  
Size At Birth

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.

DEVELOPMENT OF DLS BREED OF SHEEP: GENETIC AND PHENOTYPIC PARAMETERS OF DATE OF LAMBING AND LITTER SIZE

1990 ◽  
Vol 70 (3) ◽  
pp. 771-778 ◽  
Author(s):  
MOHAMED H. FAHMY
Keyword(s):  
Key Words ◽  
Genetic Correlation ◽  
Breeding Season ◽  
Litter Size ◽  
Least Square ◽  
Phenotypic Correlation ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations

Least square means, heritabilities, repeatabilities, genetic and phenotypic correlations of date of lambing and litter size in a population of DLS sheep selected for extended breeding season were estimated by different methods. Mean date of lambing for first, second and third parities was 20 Jan., 6 Jan., 31 Dec. and mean litter size was 1.20, 1.25 and 1.41 lambs, respectively. Heritabilities for date of lambing were 0.37 (sire component, 0.25 (sire and dam component), 0.52 (correlation between full sisters) and 0.17 (regression of daughter on dam). For litter size these methods gave the following estimates: 0.17, 0.14, 0.22 and 0.04, respectively. Repeatability estimates averaged 0.21 for date of lambing and 0.24 for litter size. Genetic correlation between the two traits was calculated at −0.38 (sire component), −0.25 (full sisters) and −0.07 (regression of daughter on dam) while the phenotypic correlation was estimated at −0.19 (P < 0.01). Key words: DLS sheep, heritability, repeatability, genetic correlation, phenotypic correlation, date of lambing, litter size

scholarly journals Descriptive characterization of a nigerian heterogeneous rabbit population - factors affecting litter traits.

2010 ◽  
Vol 18 (2) ◽  
pp. 111
Author(s):  
S.O. Oseni ◽  
B.A. Ajayi
Keyword(s):  
Litter Size ◽  
Reproductive Traits ◽  
Daily Weight Gain ◽  
Average Weight ◽  
Font Size ◽  
Factors Affecting ◽  
Litter Traits ◽  
Nigerian Population ◽  
Size At Birth

<span style="font-size: small;"><span style="font-size: 13px; line-height: 14px;">Thi study evaluated the effect of female body weight at conception (FWC), season of mating (SM), type of mating (TM) and litter size at birth (LSB) on the litter performance in a heterogeneous Nigerian population of rabbits. Data on 116 litters from 10 bucks and 48 does across three parities were analysed. Reproductive traits evaluated included LSB, number born alive (NBA), litter sizes and weights at 7, 14 and 21 d post-kindling, pre-weaning survival rate (SR) and daily weight gain of kits from kindling to weaning (DWG). A fi xed linear model that included FWC (light and heavy does), TM (homospermic and heterospermic matings), LSB classes (low, medium and large) and SM (rainy or dry) was used. Results showed that heavier does at concenption showed higher performance for LSB and NBA (P&lt;0.05) than lighter does. Average weight of kits at kindling and at 28 d, as well as kit SR and DWG, were signifi cantly higher in low-sized litters, when compared with intermediate- and large-sized litters (P&lt;0.05). LSB, NBA and litter size at weaning were higher in litters produced by heterospermically mated does compared with homospermically mated does. Season of mating affected LSB and NBA (P&lt;0.05), being signifi cantly larger the litters in the rainy season.</span></span>

Performance of Hereford and crossbred Hereford cattle in the subtropics of New South Wales: genetic analyses of pre-weaning performance of first-cross calves

1980 ◽  
Vol 31 (2) ◽  
pp. 417 ◽  
Author(s):  
R Barlow ◽  
GH O'Neill
Keyword(s):  
Birth Weight ◽  
Genetic Correlations ◽  
Environmental Variation ◽  
Direct Selection ◽  
Gestation Length ◽  
Strongly Correlated ◽  
Weaning Weight ◽  
Selection For ◽  
Sire Breed ◽  
Size At Birth

First-cross calves of Simmental (S), Friesian (F), and Brahman (B) sires were compared with straight-bred calves of Hereford (H) sires over 5 years at Grafton, N.S.W. There was a total of 775 calves sired by 205 bulls with complete records of performance from conception to weaning. Analyses were conducted to determine sire breed and sire breed x environment effects, and to provide paternal half-sib estimates of heritabilities and genetic and phenotypic correlations. Various models were used to ascertain the sensitivity of genetic parameters to the removal of different sources of variation. Among females, S x H were heaviest at birth, while among males, B x H were heaviest. The regression coefficient of birth weight on gestation length was significantly greater for B x H calves than for other crosses. All crosses grew significantly faster to weaning and were significantly heavier at weaning than H x H calves. However, there were a number of significant interactions between sire breed and environmental variables for measures of pre-weaning growth. S x H and F x H calves appeared most sensitive to environmental variation, while B x H appeared least sensitive. The significance of this is discussed. Estimates of heritability for most traits were high. Values derived by using simple models were: gestation length, 0.68; birth weight, 0.56; average daily gain (ADG) to weaning, 0.47; weaning weight, 0.54; eyelid pigmentation, 0.50. Heritabilities of birth weight and ADG during the early pre-weaning period appeared most sensitive to the amount of environmental variation removed in the model. Gestation length was positively correlated with size at birth but negatively correlated with growth to weaning. There were large positive genetic correlations among various measures of size at birth, and among various measures of growth to weaning. When compared with ADG to weaning, weaning weight was more strongly correlated with birth weight, but less strongly correlated with gestation length. The results also indicated that selection for gain over a fixed time period, immediately prior to weaning, would be as efficient as direct selection for total ADG to weaning.

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