scholarly journals Estimation of heterosis, direct and maternal additive effects from crossbreeding experiment involving two white plymouth rock lines of chickens

2014 ◽  
Vol 30 (1) ◽  
pp. 103-114 ◽  
Author(s):  
M. Lalev ◽  
N. Mincheva ◽  
M. Oblakova ◽  
P. Hristakieva ◽  
I. Ivanova
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Egg Production ◽  
Substantial Effect ◽  
Additive Effects ◽  
Positive Effects ◽  
Genetic Groups ◽  
Positive Tendency ◽  
Body Weights ◽  
Production Period

Eight hundred one-day-old female chickens from two White Plymouth Rock lines (line L and line K) and their reciprocal crosses obtained from 40 male and 480 females were used to form four genetic groups (LxL, KxK, LxK and KxL). Differences among genotypes, the direct and maternal additive effects, and the heterosis were investigated with regard to the following traits: body weight from 2 to 10 weeks of age and at 18, 26 and 30 weeks of age, age at sexual maturity, egg production per hen-day until 46 weeks of age, average egg weight (between 32 and 46 weeks of age), liveability during the production period, egg fertility, hatchability of set and fertile eggs. The results demonstrated a statistically significant effect of the genotype on body weight during the different age periods (p<0.001), age at sexual maturity (p<0.001), egg production (p<0.01) and livability (p<0.05). On the basis of analysis of direct additive effects, it could be concluded that line L was superior for obtaining combinations with more intensive growth rate. Although the lack of direct additive effect with respect to the other traits studied, there was a positive tendency favouring line K. Maternal additive effects had a substantial effect on body weight in most studied periods and livability, favouring line L. The heterosis was important for body weights at different periods of life (3.76-22.33 %), age at sexual maturity (-8.32 %) and egg production (8.25 %) with positive effects on these traits. The results pointed at a mutual complementary effect between both lines as a result of crossbreeding.

scholarly journals GENETIC AND PHENOTYPIC ASSOCIATIONS OF JUVENILE BODY WEIGHTS AND EGG PRODUCTION TRAITS IN TWO STRAINS OF RHODE ISLAND CHICKENS

2021 ◽  
Vol 18 ◽  
pp. 66-70
Author(s):  
O. O. ONI ◽  
B. Y. ABUBAKAR ◽  
S. O. OGUNDIPE
Keyword(s):  
Body Weight ◽  
Rhode Island ◽  
Sexual Maturity ◽  
Egg Production ◽  
Genetic Parameters ◽  
Laying Hens ◽  
Genetic Correlations ◽  
Selection Criterion ◽  
Production Traits ◽  
Body Weights

Data on body weight at 16 (WT16); 20 (WT20) weeks of age and at sexual maturity (WTSM) weight of first egg (WT1st), age at sexual maturity (ASM) and 120-d egg production (EN)  were used to estimate genetic parameters in 636 hens of two strains of Rhode Island chikens. There were significant (P.01) differences between  the two strains for all traits except for WTSM.The heritability estimates obtained ranged from 0.05 to 0.41 and 0.04 to 0.30 for strains 1 and 2 respectively. The genetic correlations obtained for the various traits were medium to high for the two strains. The phenotypic correlations were generally low but followed the same trend. The results indicate that selected stocks of the two strains would show improvements in egg production and age   at sexual maturity if juvenile body weight (WT20) is employed as a selection criterion at housing for laying hens.

Effect of constant photoperiods on the laying performance of broiler breeders allowed conventional or accelerated growth

2005 ◽  
Vol 143 (1) ◽  
pp. 97-108 ◽  
Author(s):  
P. D. LEWIS ◽  
D. BACKHOUSE ◽  
R. M. GOUS
Keyword(s):  
Body Weight ◽  
Sexual Development ◽  
Sexual Maturity ◽  
Egg Production ◽  
Egg Laying ◽  
Broiler Breeders ◽  
Egg Weight ◽  
Laying Performance ◽  
Body Weights ◽  
Accelerated Growth

An experiment was conducted at the University of KwaZulu–Natal to assess the effect of constant photoperiods on sexual maturity and egg-laying performance in broiler breeders given two levels of control-feeding during the rearing phase. Cobb broiler breeder females were grown to reach 2·1 kg body weight at 17 or 21 weeks, and maintained on 10, 11, 12, 13, 14 or 16-h photoperiods from 2 days to 68 weeks of age. There were no significant interactions between photoperiod and growth rate for any production parameter. The time required reaching 2·1 kg increased proportionally with photoperiod but, because of delayed sexual development, birds on longer photoperiods consumed more feed to, and were heavier at, sexual maturity than shorter daylengths. The longer-photoperiod birds also had inferior rates of lay in the first half of the cycle, but superior in the second, which, together with the photoperiodic effects on maturity, resulted in birds on 11, 13 or 14 h producing most eggs to 68 weeks, and those on 16 h fewest. It is possible that the pattern of egg production was due to some of the birds on [ges ]13-h photoperiods becoming photorefractory, having a mid-cycle pause, and then spontaneously resuming egg production in the latter half of the cycle. However, a hinge-analysis of current and other data to the more usual depletion age of 60 weeks showed that the combined effects of photoperiod on sexual maturity and egg production resulted in constant 10-h birds producing the highest number of eggs, with numbers decreasing by 3·6 eggs/h of photoperiod above the hinge and 7·8 eggs/h of photoperiod below it. Mean egg weight increased by 0·4 g/h of photoperiod, but the proportion of abnormally large and floor eggs and the incidence of mortality were unaffected by daylength. For each photoperiod, accelerated growth resulted in body weights being heavier than controls at sexual maturity, despite the mean age at maturity being 10 days earlier for the faster-growing birds. Body weights for the two growth groups were not significantly different at 68 weeks. Faster-growth birds consumed 1 kg less feed to 2·1 kg body weight, but 1·3 kg more feed to sexual maturity and 2·7 kg more to 68 weeks, and produced 6 more eggs than, but had similar patterns of egg production to, the conventionally managed controls. Mean egg weight, the proportion of floor eggs and the incidence of mortality were similar for both groups. Notwithstanding that the overall production of abnormally large eggs was low (1·1 eggs per bird); the faster-growing birds produced significantly more than the controls. Egg weight was positively influenced by age at sexual maturity, body weight at sexual maturity and photoperiod, but was unaffected by rate of growth to 2·1 kg per se.These findings show that there are differences between broiler breeders and egg-type pullets in their response to constant photoperiods. It is likely that the factors responsible for these differences, particularly in terms of sexual development, are the exhibition of photorefractoriness by, and the retardational effects of controlled feeding on, broiler breeders.

scholarly journals Backyard poultry farming for meat and egg production: rural enterprise

2020 ◽  
Vol 1 (1) ◽  
pp. 52-55
Author(s):  
Dinesh Mahto ◽  
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Egg Production ◽  
The Body ◽  
Egg Weight ◽  
Backyard Poultry ◽  
Poultry Birds ◽  
Body Weights ◽  
Poultry Farming

Twenty farmers selected from each village for 6 villages of the district and skill based training on various aspects of backyard poultry farming. Participants enriched with sound knowledge were distributed with 25 Vanaraja & Grampriya chicks per person. The records of mean body weight of Grampriya and Vanaraja at different week interval. The body weight of crosses differ significantly (p < 0.05) after 4th week of age from their parents. The body weights of crosses were significantly (p < 0.05) higher than Hazra (Desi) birds and nearly similar to Vanaraja birds at different period of age attaining the sexual maturity in different groups of poultry birds. Vanaraja matures at the age of 141.62 days, Hazra (Desi) bird at 186.47 days and Grampriya at 158.32 days. The pullet egg weight of Vanaraja, Hazra (Desi) and Grampriya were 38.75, 30.82 and 34.94 g, egg weight at 40 weeks of age were 55.87, 42.89 and 51.26 g and increase in egg weight were 17.12, 12.07 and 15.42 g respectively. The hatchability percentages were 87.56%, 89.36% and 85.72% on fertile egg set and 68.23%, 68.92% and 64.74% on total egg set basis respectively in Vanaraja, Grampriya and local desi birds.

Evaluation of Pilgrim, Hungarian, Chinese, Synthetic and Embden strains of geese and their crosses for body weight

2004 ◽  
Vol 84 (2) ◽  
pp. 187-195 ◽  
Author(s):  
J. N. B. Shrestha ◽  
A. A. Grunder ◽  
J. W. Dickie
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Animal Research ◽  
Research Centre ◽  
Additive Effects ◽  
Body Weights ◽  
Specific Strain ◽  
Total Fat ◽  
Terminal Sire ◽  
Animal Research Institute

The Pilgrim, Hungarian, Chinese, Selected C hinese, Synthetic (developed from Pilgrim, Chinese and Hungarian), Selected Synthetic, Large Embden and Small Embden strains of geese raised from 1980 to 1988 at the Greenbelt farm of the Centre for Food and Animal Research (formerly Animal Research Centre, and Animal Research Institute) in Ottawa, Canada varied significantly in body weight at 9 and 16 wk of age. The Large Embden strain weighed more than the Small Embden strain in 1986, and both were heavier than the Pilgrim strain (P < 0.05). Significantly different body weights for the Large Embden, Small Embden and Pilgrim strains averaged over sexes were 5.03, 4.45 and 3.59 kg, respectively, at 9 wk, and 6.15, 5.49 and 4.33 kg, respectively, at 16 wk. The Pilgrim strain was similar to the Chinese and Synthetic strains in body weight, whereas the Hungarian weighed consistently less (P < 0.05). Body weights for the Pilgrim, Chinese, Synthetic and Hungarian strains averaged over sexes and years 1980, 1983 and 1986 were 3.70, 3.56, 3.70 and 3.37 kg, respectively, at 9 wk, and 4.65, 4.43, 4.53 and 4.17 kg, respectively, at 16 wk. From 1982 onwards, the Chinese and Synthetic strains were selected for four generations in order to increase egg production over a 24-wk laying period and body weight at 16 wk of age, and to simultaneously decrease total fat (abdominal and intestinal). These Selected Chinese and Synthetic strains not only weighed significantly more than their corresponding Chinese and Synthetic strains maintained as randombred populations, but were also heavier than the Pilgrim strain. Corresponding body weights for Selected Chinese, Selected Synthetic, Chinese and Synthetic strains averaged over sexes and years 1983–1988 were 3.72, 3.69, 3.47 and 3.59 kg, respectively, at 9 wk, and 4.69, 4.77, 4.26 an d 4.31 kg, respectively, at 16 wk. The range in heterosis estimates for specific strain cross combinations were as follows: -6 to 8% for the Large Embden × Selected Chinese, 2 to 6% for the Selected Chinese × Selected Synthetic, -2 to 3% for the Selected Synthetic × Selected Chinese, -8 to -9% for the Large Embden × Small Embden, -1 to 1% for the Small Embden × Selected Chinese, and 4 to 8% for the Small Embden × Selected Synthetic. The variability among heterosis estimates for body weight was specific to strain crosses and subject to sampling associated with low number of sires used to produce crossbred offspring as well as the absence of reciprocal crosses. Larger studies evaluating all possible cross combinations of strains for additive and non-additive effects are warranted. Although, the Selected Chinese and Synthetic strains achieved genetic superiority for body weight, the inherent potential in the Embden strain demonstrated considerable merit for use as a terminal sire in a crossbreeding program for commercial geese production. Key words: Embden, Pilgrim; Chinese, Synthetic, Hungarian geese, crosses

scholarly journals DOMINANCE AND EPISTASIS IN HETEROSIS OF WHITE LEGHORN STRAIN CROSSES

1987 ◽  
Vol 67 (3) ◽  
pp. 663-680 ◽  
Author(s):  
R. W. FAIRFULL ◽  
R. S. GOWE ◽  
J. NAGAI
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Egg Production ◽  
Significant Contribution ◽  
Production Traits ◽  
White Leghorn ◽  
Cross Combination ◽  
Commercial Strain ◽  
Better Than

Four unrelated pure strains of White Leghorns including a grandparent strain from industry and 12 two-strain, 24 three-strain, 24 four-strain and 12 F2 strain crosses produced contemporaneously were used to examine the role of dominance and epistasis in heterosis. A control strain and a commercial strain were also included. For egg weight, the heterosis observed closely approximated that expected due to dominance alone. For sexual maturity and body weight, dominance was the major component of heterosis, but epistasis made a significant contribution — additive by additive (A × A) genetic effects for sexual maturity and 140-d body weight, and parental epistasis for mature body weight. Both dominance and epistasis played a significant role in heterosis for egg production traits. A × A, dominance by dominance (D × D) and additive by dominance (A × D) epistasis were all important for hen-housed egg production and hen-housed egg yield. For hen-day rate of egg production, A × A epistasis was significant only early in the laying year (to 273 d), A × D and D × D were significant to 385 d and in the full year (to 497 d); however, none (A × A, A × D and D × D) was significant near the end of lay (386–497 d). Overall heterosis estimates for full year egg production measured as hen-housed egg production to 497 d or hen-day rate from housing to 497 d clearly showed that on average two-strain crosses were superior to three-strain crosses which were superior to four-strain crosses which in turn exceeded the F2 crosses. Nevertheless, several three-strain crosses had performance for egg production that was equal to or better than the two-strain cross with the highest egg production. Thus, in commerce, where the level of egg production is of great economic importance, the testing and use of a specific three-way cross combination will usually result in a better commercial product. Key words: Heterosis, egg production genetics, epistasis, stocking rate, strain cross, White Leghorn

scholarly journals Effect of Sex-linked Feathering Genes on Body Weight, Age At Sexual Maturity, Feed Intake and Subsequent Laying Performance of Baladi Chickens

1997 ◽  
Vol 2 ◽  
pp. 37
Author(s):  
A. AI-Sobayel ◽  
A.A. AI-Mulhem
Keyword(s):  
Body Weight ◽  
Feed Intake ◽  
Sexual Maturity ◽  
Egg Production ◽  
Management Practices ◽  
Feed Conversion ◽  
Standard Management ◽  
Laying Performance ◽  
Adult Body ◽  
Adult Body Weight

A total of 320 twenty week-old slow and rapid feathering Saudi Arabian Baladi pullers were used to assess the effect of sex-linked feathering genes on body weight, age at sexual maturity, feed intake and subsequent laying performance. Similar numbers of rapid feathering Leghorns pullets were included in the study for the purpose of comparison. The experimental birds of each genotypic group were randomly divided into four replicates and subjected to standard management practices. Slow feathering Baladi pullers had higher (P<0.05) adult body weight, rate of mortality, and feed intake and a similar age at sexual maturity but showed lower (P< 0.05) hen-day, and hen-housed egg production and feed conversion compared with rapid feathering Baladi pullets. Rapid feathering Leghorns had higher (P<0.05) adult body weight. age at sexual maturity, hen-day egg production, rate of mortality and feed intake and lower feed intake/kg eggs than rapid and slow feathering Baladi. However, rapid feathering Baladi and Leghorns had similar hen-housed egg production and feed intake per dozen eggs and had better (l’<0.05') performance than slow feathering Baladi.

scholarly journals Body weight and morphometric traits of fulani ecotype chickens in South Western Nigeria are closely related

2020 ◽  
Vol 44 (5) ◽  
pp. 19-23
Author(s):  
O. J. Ogunshola ◽  
S. A. Daramola ◽  
O. B. Omotoso ◽  
O. I. Baki ◽  
C. A. Chineke
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Goodness Of Fit ◽  
Live Weight ◽  
The Body ◽  
Quadratic Model ◽  
Body Parts ◽  
Morphometric Traits ◽  
Body Weights ◽  
Accuracy Of Prediction

The native chickens constitute about 80 percent of the 120 million poultry birds found in Nigeriabut have not been adequately characterized. Thus, the study was undertaken to establish the relationship among body weight and morphometric traits of thirty six Fulani Ecotype chickens raised for 25 weeks. Body weights were collected per bird and the morphometric traits (body length, drumstick length, drumstick circumference, breast girth, nose to shoulder, shoulder to tail and height at withers) were measured with tape rule on weekly basis. The measured parameters were subjected to correlation and regression analyses. Analysis showed that positive and high significant correlation existed between body weight and morphometric traits (p< 0.01). The result showed that accuracy of prediction was attained with linear and quadratic models but quadratic model had theoretical advantage over the linearmodelwith respect to its goodness of fit to the data. This means that an increase in growth rate of the body parts would correspondingly cause an increase in live weight gain of the bird. In conclusion, body weight and morphometric traits could be used to separate males and females Fulani Ecotype chicken at 17 weeks old. At this age, males appeared bigger than the females and their combs were well pronounced, this would help both sexes to grow uniformly, prevent indiscriminate mating before attaining the age of sexual maturity and help in selection of Fulani Ecotype chicken for improvement in meat and egg production.

Four statistical tests for detecting major genes in an Iranian pedigree chicken flock

2007 ◽  
Vol 2007 ◽  
pp. 249-249
Author(s):  
Sadegh Alijani ◽  
Hassan Mehrabani Yeganeh ◽  
Ardashir Nejati Javaremi ◽  
Ghodratollah Rahimi ◽  
L.L.G. Janss
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Statistical Tests ◽  
Chicken Flock ◽  
Egg Weight ◽  
Major Genes ◽  
Production Period

The objective of this research was to look for the evidence of segregating major genes in an Iranian pedigree chicken flock (Mazandaran station), using four statistical tests: Normality, Bartlett, Fain and Mixture tests for four economically important traits. These traits are age at first egg (AFE), body weight at the end of week eight (BW8), average egg weight (EW) and number of eggs laid during egg production period (EN).

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