scholarly journals Keel bone fractures are more prevalent in White Leghorn hens than in Red Jungle fowl hens—A pilot study

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255234
Author(s):  
Käthe Elise Kittelsen ◽  
Pall Gretarsson ◽  
Per Jensen ◽  
Jens Peter Christensen ◽  
Ingrid Toftaker ◽  
...  
Keyword(s):  
Pilot Study ◽  
Egg Production ◽  
Laying Hens ◽  
Bone Fractures ◽  
Laying Hen ◽  
White Leghorn ◽  
Red Jungle Fowl ◽  
White Leghorns ◽  
Selection For

Fractures and deviations to the keel bone are common in commercial laying hens, with reported variations in occurrence across strains and breeds. The aetiology is not fully understood, however, modern genetics and selection for efficient egg production has been claimed to be important factors for the keel bone fractures. To explore this further, we investigated keel bones from two different breeds, representing different degrees of selection for egg production: Red jungle fowl (n = 82), and White Leghorn (n = 32), where the latter is a selected laying breed which is the origin for many modern laying hen hybrids. Keel bones from a total of 116 birds, 53 hens and 63 roosters, were examined by necropsy at 80 weeks of age. All birds were raised in modified aviaries in the same holding facility. Overall, 24.5% of the hens had one or more fractures to the keel, with a difference in the prevalence between hens from the two breeds (p<0.01): 10% (95% CI: 3.7–24%) in the Red Jungle fowl hens and 69% (95% CI: 37–90%) in the White Leghorn hens. No roosters, regardless of breed, had keel bone fractures. Mild to moderate keel bone deviations were present in 54% (95% CI: 25–80%) of the hens and 4.7% (95% CI: 0.5–30%) of the roosters, all White Leghorns.

scholarly journals Prevalence of Keel Bone Damage in Red Jungle Fowls (Gallus gallus)—A Pilot Study

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1655 ◽  
Author(s):  
Käthe Elise Kittelsen ◽  
Per Jensen ◽  
Jens Peter Christensen ◽  
Ingrid Toftaker ◽  
Randi Oppermann Moe ◽  
...  
Keyword(s):  
Pilot Study ◽  
Egg Production ◽  
Bone Fractures ◽  
Single Fracture ◽  
Red Jungle Fowl ◽  
Bone Damage ◽  
Causative Factors ◽  
Selection For ◽  
Shed Light

Keel bone damage (KBD) is a highly prevalent problem in commercial egg production. KBD consists of two different conditions affecting the keel: Keel bone deviation and keel bone fractures (KBF). Deviations are linked to pressure on the keel, e.g., from perching. The causative factors for KBF are not clear; however, selection for efficient egg production has been suggested as a major contributing factor. An important step to shed light on the role of selective breeding as an underlying cause of KBF in modern laying hens is to evaluate the keel bones of the ancestor, the red jungle fowl. To the authors’ knowledge, this has never previously been published. The aim of this study was therefore to describe the prevalence of KBD in a study group of red jungle hens and roosters housed in an aviary system. The present study examined 29 red jungle fowls 112 weeks of age post-mortem; 12 hens and 17 roosters. Keel bones were evaluated by external palpation for deviations and fractures. Palpation was followed by autopsy. No fractures were detected in the 17 roosters; one had a very slight deviation. Of the 12 red jungle hens in this pilot study, one had a single fracture and 10 hens had a very slight deviation.

scholarly journals Bayesian inference of genetic parameters for reproductive and performance traits in White Leghorn hens

2018 ◽  
Vol 63 (No. 6) ◽  
pp. 230-236 ◽  
Author(s):  
J.O. Rosa ◽  
G.C. Venturini ◽  
T.C.S. Chud ◽  
B.C. Pires ◽  
M.E. Buzanskas ◽  
...  
Keyword(s):  
Bayesian Inference ◽  
Fixed Effects ◽  
Egg Production ◽  
Genetic Parameters ◽  
Laying Hens ◽  
Reproductive Traits ◽  
A Posteriori ◽  
White Leghorn ◽  
Performance Traits ◽  
And Performance

This study estimated the genetic parameters for reproductive and performance traits and determined which ones can be used as selection criteria for egg production in laying hens using the Bayesian inference. The data of 1894 animals from three generations of White Leghorn laying hens were analyzed for fertility (FERT), hatchability (HATC), and birth rate measurements at 60 weeks of age (BIRTH), body weight at 16 and 60 weeks of age (BW16 and BW60), age at sexual maturity (ASM), egg height/width ratio, weight, and density at 28, 36, and 40 weeks of age (RHW28, RHW36, RHW40, WEGG28, WEGG36, WEGG40, DENS28, DENS36, and DENS40, respectively) traits. The genetic parameters were estimated by the Bayesian inference method of multi-trait animal model. The model included the additive and residual genetic random effects and the fixed effects of generation. The a posteriori mean distributions of the heritability estimates for reproductive traits ranged from 0.14 ± 0.003 (HATC) to 0.22 ± 0.005 (FERT) and performance from 0.07 ± 0.001 (RHW28) to 0.42 ± 0.001 (WEGG40). The a posteriori mean distributions of the genetic correlation between reproductive traits ranged from 0.18 ± 0.026 (FERT and HACT) to 0.79 ± 0.007 (FERT and BIRTH) and those related to performance ranged from –0.49 ± 0.001 (WEGG36 and DENS36) to 0.75 ± 0.003 (DENS28 and DENS36). Reproductive and performance traits showed enough additive genetic variability to respond to selection, except for RHW28. This trait alone would have little impact on the genetic gain because environmental factors would have a higher impact compared to those from the additive genetic factors. Based on the results of this study, the selection applied on the BIRTH trait can be indicated to improve FERT and HATC of eggs. Furthermore, the use of the WEGG40 could improve egg quality in this population.

THE EFFECT OF GRADED LEVELS OF NICARBAZIN ON REPRODUCTIVE PERFORMANCE OF LAYING HENS

1989 ◽  
Vol 69 (3) ◽  
pp. 757-764 ◽  
Author(s):  
S. LEESON ◽  
L. J. CASTON ◽  
J. D. SUMMERS
Keyword(s):  
Reproductive Performance ◽  
Feed Intake ◽  
Egg Production ◽  
Visual Loss ◽  
Laying Hens ◽  
Marked Effect ◽  
Significant Loss ◽  
White Leghorn ◽  
Egg Weight ◽  
Egg Shell

Three experiments were undertaken to investigate the coccidiostat, nicarbazin, on reproductive performance of layers. In trial 1, levels of 0, 5, 10, 20, 40, 80, 125, and 200 ppm nicarbazin were fed to White leghorn laying hens for 5 wk. By the 2nd week of nicarbazin treatment, egg production was significantly reduced in birds fed 125 and 200 ppm (P < 0.05). Similarly, increasing levels of nicarbazin resulted in decreasing egg weights (P < 0.01) and feed intake was significantly decreased. However, by the 2nd week post-nicarbazin treatment, egg production, egg weight, and feed intake had returned to normal. Nicarbazin had no effect on egg shell deformation or body weight. Nicarbazin had a marked effect on hatchability; levels of 125 and 200 ppm reduced hatchability significantly (P < 0.01) as well as producing an increased incidence of malpositions and malformations. When nicarbazin was withdrawn from the diet, hatchability returned to pretreatment values although malpositions and malformations were still in evidence. Experiments 2 and 3 were designed to study the effect of nicarbazin on production of brown-shelled eggs. In the 2nd experiment 0, 5, 10, 20, and 40 ppm of dietary nicarbazin resulted in significant loss of shell color at 20 and 40 ppm, whereas in exp. 3 with levels of 0, 80, 125, and 200 ppm, brown eggs lost virtually all their color. It is concluded that the adult White Leghorn bird can tolerate up to 125 ppm nicarbazin without significant (P < 0.01) loss of reproductive performance although lower levels show a trend for reduced production. Hatchability is depressed with nicarbazin levels in excess of 80 ppm, while trace levels will produce a visual loss of color in brown-shelled eggs. Key words: Layer, coccidiostat, reproductive performance

SUBSTITUTION OF SORGHUM FOR WHEAT IN DIETS FOR LAYING HENS

1982 ◽  
Vol 62 (1) ◽  
pp. 305-306 ◽  
Author(s):  
E. E. GARDINER ◽  
D. J. MAJOR ◽  
S. DUBETZ
Keyword(s):  
Body Weight ◽  
Key Words ◽  
Egg Production ◽  
Laying Hens ◽  
Feed Consumption ◽  
White Leghorn ◽  
Egg Weight ◽  
Single Comb

The effects of substituting various levels of sorghum for wheat in diets for laying hens were studied. Egg production, egg weight, feed consumption, body weight and hatchability of eggs from Single Comb White Leghorn hens were not affected by the proportion of sorghum in the diet. Key words: Sorghum, wheat, nutrition, egg production

scholarly journals Differences in oviposition and egg quality of various genotypes of laying hens

2017 ◽  
Vol 62 (No. 9) ◽  
pp. 377-383 ◽  
Author(s):  
E. Tůmová ◽  
J. Vlčková ◽  
D. Chodová
Keyword(s):  
Egg Production ◽  
Laying Hens ◽  
Egg Quality ◽  
Laying Hen ◽  
Sequence Length ◽  
Production Traits ◽  
Egg Weight ◽  
Egg Shell ◽  
Egg Components

The differences in egg production traits in six laying hen genotypes (brown-egg hens Bovans Brown, Bovans Sperwer, ISA Sussex; white-egg hen Dekalb White; laying hens with tinted shells Moravia Barred and Moravia BSL) and the interactions of genotype and oviposition on egg quality were evaluated. The genotype affected the laying rate (P ≤ 0.003), mean sequence length (P ≤ 0.001), and time of oviposition (P ≤ 0.001). The brown-egg genotypes laid eggs approximately 1 h earlier than the white-egg genotypes and approximately 2 h earlier than the tinted-egg genotypes. Egg shell strength was the lowest in tinted-egg genotypes (P ≤ 0.001) and declined with the time of oviposition (P ≤ 0.002). Egg shell percentage (P ≤ 0.011) and thickness (P ≤ 0.011) were affected by the interaction of genotype and oviposition. None of the effects affected egg weight; however, the proportion of egg components was significantly influenced by the interaction of genotype and oviposition. The study confirmed that the differences in the egg production and egg quality of various genotypes are associated with the laying pattern.

Continuous selection for egg production using short-term records

1963 ◽  
Vol 14 (6) ◽  
pp. 909 ◽  
Author(s):  
JA Morris
Keyword(s):  
Genetic Correlation ◽  
Egg Production ◽  
Continuous Selection ◽  
Total Production ◽  
White Leghorn ◽  
Short Term ◽  
Selection For ◽  
Residual Performance ◽  
Actual Response ◽  
Selection Differentials

A closed flock of White Leghorn has been selected for high egg production, since 1947. Selection has always been based on performance achieved from date of first egg until May 31 (part-period test). Selection has been effective in providing gains of approximately three eggs per generation for the part-period and, at the end of the experiment, there is no evidence that the rate of gain has lessened. Total 72-weeks egg production increased during the earlier years of selection but seems to have plateaued subsequently. This leveling off of total production is due to a decline in performance for the period June 1 to 72 weeks of age. The magnitude of this decline is sufficient to offset the gain in the part-period. Annual selection differentials were calculated for the later years, and generally the realized selection differentials were the same size as that intended, which indicated that natural selection was not opposed to the direction of artificial selection. The estimates of heritability of part-period production index show no decline as a result of selection; the actual response observed during the last years of selection supports the contention of absence of such a decline. Although it cannot be statistically confirmed, there are indications that the genetic correlation between part-period and residual performance has decreased in value with the progression of selection. The size of the correlated decline in the residual production suggests not only a reduction in value of the genetic correlation but also a change of sign. The results obtained imply that continuous selection, based on egg production for the part-period, may be an unrewarding procedure; and that selection based on other characters, favourably correlated genetically with total production, might be more effective in providing genetic gain in total production.

scholarly journals Perch Positioning Affects both Laying Hen Locomotion and Forces Experienced at the Keel

Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1223
Author(s):  
Christina Rufener ◽  
Ana K. Rentsch ◽  
Ariane Stratmann ◽  
Michael J. Toscano
Keyword(s):  
Factorial Design ◽  
Food Reward ◽  
Laying Hens ◽  
Bone Fractures ◽  
Laying Hen ◽  
Treatment Combination

The aim of this study was to assess the effect of perch positioning on laying hens’ locomotion and the resulting energy experienced at the keel. Twenty Nick Chick and 20 Brown Nick hens were trained to transition from a platform to a perch in several configurations. Three variables of perch positioning were tested in a 2 × 2 × 2 factorial design: direction (upward vs. downward), angle (flat vs. steep), and distance (50 cm vs. 100 cm). All hens were tested for five jumps of each treatment combination at 27–28 weeks of age. As predicted, we found steep angles and long distances to result in higher peak forces and impulse during take-off, flight, and landing; longer latency to jump; a higher likelihood to perform balancing movements; and a longer latency to peck at the provided food reward. The effect of perch positioning on locomotion and force at the keel during downwards jumps and flight was more pronounced in Brown Nick hens than in Nick Chick hens. Although we cannot state how the observed forces at the keel relate to the risk for keel bone fractures, our results indicated that optimizing perch positioning can reduce accumulated forced at the keel and consequent risk for fracture due to unsuccessful transitions.

scholarly journals Selection for Increased Egg Production Based on Annual Record in Three Strains of White Leghorns.

1987 ◽  
Vol 66 (7) ◽  
pp. 1077-1084 ◽  
Author(s):  
B. BOUKILA ◽  
M. DESMARAIS ◽  
J.P. PARE ◽  
D. BOLAMBA
Keyword(s):  
Egg Production ◽  
White Leghorns ◽  
Selection For

scholarly journals RESPONSE OF WHITE LEGHORNS TO DIETS CONTAINING GROUND OR WHOLE TRITICALE

1987 ◽  
Vol 67 (2) ◽  
pp. 583-585 ◽  
Author(s):  
S. LEESON ◽  
J. D. SUMMERS
Keyword(s):  
Body Weight ◽  
Key Words ◽  
Feed Intake ◽  
Egg Production ◽  
Laying Hens ◽  
Energy Value ◽  
White Leghorns

Growing leghorn pullets and laying hens were fed diets containing triticale as the sole cereal source. Body weight of pullets was not affected (P > 0.05) by up to 70% dietary inclusion of triticale. When layer diets contained 70% whole or ground triticale in place of corn, egg production was depressed (P < 0.05) while birds consumed more feed (P < 0.05). The feed intake effect is discussed in relation to the energy value of triticale. Key words: Triticale, pullets

scholarly journals FEED UTILIZATION AND THE COMPOSITION OF ORGANS OF THREE STRAINS OF LAYING HENS FED CONSTANT ZINC AND VARYING LEVELS OF CALCIUM

2021 ◽  
Vol 4 (2) ◽  
pp. 18-23
Author(s):  
B. K. Ogunmodede ◽  
E. G. Ijagbuji
Keyword(s):  
Egg Production ◽  
Laying Hens ◽  
Dietary Calcium ◽  
Feed Utilization ◽  
Laying Hen ◽  
Tissue Accumulation ◽  
Bone Calcium ◽  
Egg Shell ◽  
The Tropics

At about 16 mg, zinc per 100 gm of diet feed consumed by laying hens increased until a level of 2.0% dietary calcium. Increasing the dietary calcium to 2.0% also stimulated more egg production. When less than 2.0% dietary calcium was fed more feed was required to produce a dozen egg and the eggs were of small sizes. The egg shell strength and the bone calcium were improved when at least 2.0% dietary calcium was given to the laying hen. These results were correlated with tissue accumulation of zinc thus establishing that for profitable egg production in the tropics 2.0% dietary calcium is required when 16 mg zinc per 100 grains of feed is given 

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