Humerus Breaking Strength Research Articles

Evaluation of bone strength, keel bone status, plumage condition and egg quality of two layer lines kept in small group housing systems

1. The aim of the present study was to determine the influence of large (54 or 60) and small (36 or 40) group sizes and tiers of the small group housing system “Eurovent German” on tibia and humerus bone breaking strength, keel bone status, plumage condition and egg quality for two commercial layer lines, Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB), at the same stocking density (890 or 830 cm2/bird). 2. In 4 consecutive trials, 4752 hens were recorded for keel bone status. Evaluation of plumage condition was made for 1440 hens and bone breaking strength was recorded for 1200 hens. A total of 4962 eggs were analysed for internal and external egg quality traits. Analyses involved 30 small group compartments per trial. 3. The layer line had a much more pronounced influence on humerus breaking strength than on tibia breaking strength. 4. Plumage condition, particularly on the neck, was positively correlated with humerus breaking strength in both layer lines. 5. An average of 34% of LB and 23% of LSL hens showed keel bone deformities, with higher proportions of slight deformities. 6. Slight keel bone deformities, rather than moderate to severe, increased significantly during the laying period. 7. Stocking density had no influence on bone breaking strength, keel bone status and egg quality traits. 8. LB layers had a 1.4-fold higher humerus, but only a 1.06-fold higher tibia breaking strength compared to LSL layers. 9. Tibia breaking strength was significantly affected by the interaction of group size and layer line. LSL layers in small groups had lower tibia breaking strengths than those of the large groups.

Keeping laying hens in furnished cages and an aviary housing system enhances their bone stability

1. Tibia and humerus breaking strength of Lohmann Silver hybrids kept in conventional cages, furnished cages and an aviary with outdoor run were examined in two production cycles. Each trial lasted a full laying period; feeding, management and healthcare were identical for all hens. In both trials bone strength was investigated at the end of laying months 6, 9 and 14. 2. The objective was to determine if bone strength increases when hens are kept in alternative housing systems, especially in furnished cages, and whether hen age affects bone stability. 3. The results indicated that housing system influenced bone breaking strength, which was consistently higher for hens in the aviary compared to hens in conventional and furnished cages. Furthermore, humerus breaking strength was higher for hens in furnished cages compared to conventional cages. No significant difference regarding tibia breaking strength was found between conventional and furnished cages. 4. Our results showed that lack of exercise contributed to the problem of weak bones more than did calcium depletion from eggshell formation. 5. Tibia breaking strength increased during the last third of the production cycle, whereas humerus breaking strength remained unaffected by hen age. 6. Genetic group affected only tibial bone breaking strength, which was lower overall in genetic group A than in group B, which in turn was lower than group C. 7. The increased bone strength in the aviary and in the furnished cages probably reduced the incidence of recently broken bones in these systems compared to the conventional cages. This increase in bone strength can be regarded as an improvement in welfare. Furnished cages, like the aviary system, might be considered an alternative housing system for laying hens, because both resulted in enhanced bone strength.

Production, egg quality, bone strength, claw length, and keel bone deformities of laying hens housed in furnished cages with different group sizes

The effects of 3 different furnished cage systems (Aviplus, Eurovent 625a, Eurovent 625A) on 2 different laying hen strains [Lohmann Selected Leghorn (LSL), Lohmann Brown (LB)] were examined for the traits of production, egg quality, bone strength, claw length, and keel bone status. Two trials were carried out in which all hens received identical feeding and management. In brown hens, the traits egg production per average hen housed, cracked eggs, feed conversion, egg weight, and humerus breaking strength were significantly higher than in white hens. Furthermore, the claws of the brown hens were shorter than those of white hens. There were more dirty eggs, higher shell density, and fewer keel bone deformities in white hens than in brown hens. In the Aviplus system, egg production per average hen housed was higher than in the other systems, whereas shell thickness and density were lower. Humerus strength was also higher in the Aviplus than in the Eurovent 625a system, whereas there was no significant difference in tibia strength among the 3 systems. The shortest claws were found in the Aviplus system, and the fewest keel bone deformities occurred in the Eurovent 625a system. The study showed that the high standards of conventional cages for production and egg quality were met in furnished cages and that bone strength was significantly greater than in conventional cages. Claw shortening devices in furnished cages seemed satisfactory, because claws were generally short. However, the occurrence of keel bone deformities due to the intensive use of perches seemed to be a problem of furnished cages.

Effects of different phosphorus sources in the diet on bone composition and stability (breaking strength) in broilers

In two fattening trials (in each 100 broilers kept in four groups with 25 animals) as well as in a balance trial (four groups with four broilers in a group) the effects of inorganic phosphorus sources [monocalcium phosphate (MCP), dicalcium phosphate (dihydrate; DCP) and defluorinated phosphate (DFP)] in broiler diets were examined. The four diets contained up to 9 g calcium and 6 g phosphorus per kg and comparable energy and nutrient contents. Controls were fed a commercial diet with Ca-Na-phosphate as inorganic phosphorus source supplemented by phytase. In both fattening trials body weight gain, feed consumption and feed conversion were proved as well as the calcium and phosphorus levels in serum, the breaking strength of tibia or humerus and the femur mineralization (ash content in the fat free dry matter). Furthermore, in the balance trial the retention of calcium and phosphorus was determined by calculation (intake minus excretion) as well as by analysis of body composition. On a high performance level (that was only slightly influenced by the different treatments), the addition of DFP resulted in significantly reduced phosphorus availability (estimated by analysis of the whole carcass: control/MCP/DCP/DFP: 48.6/46.0/45.7/35.5%). The significantly reduced phosphorus level in serum (1.77 +/- 0.20/1.77 +/- 0.24/1.73 +/- 0.28 1.34 +/- 0.33 mmol/l) indicates the lower phosphorus retention in broilers given DFP. Furthermore, the crude ash content (582 +/- 17.6/580 +/- 18.6/563 +/- 15.2/547 +/- 29.7 g/kg fat free DM) and the breaking strength of bones (in right tibia in trial 2: 232 +/- 82.4/227 +/- 51.5/232 +/- 41.7/196 +/- 655 N) were lowest when given DFP. For diagnostic purposes it is of special interest that the phosphorus levels in the serum reflected markedly the different concentrations of available phosphorus in the diet.

Accuracy and precision of dual-energy x-ray absorptiometry for ex vivo determination of mineral content in turkey poult bones.

The right humerus was removed from 30 20-week-old male turkey poults for humerus strength analysis using dual-energy x-ray absorptiometry and humerus-breaking strength. Specimens were cleaned and dried before scanning. To determine the most precise and accurate protocol of bone densitometry analysis for avian long bones, we scanned each specimen using five different techniques, all aimed to simulate soft-tissue thickness. Correlation coefficients and linear regression equations between 1) bone mineral content and humerus ash, and 2) bone mineral density and humerus-breaking strength were estimated with each technique and compared. The coefficient of variation values for precision ranged from 0.40% to 1.69% for bone mineral content and from 0% to 4.19% for bone mineral density. The accuracy was determined by comparing the bone mineral content of each humerus with the corresponding ash weight; the correlation coefficients between the two parameters were highly significant (range 0.949-0.963; P < or = 0.01). Significant correlations were also observed between humerus-breaking strength and bone density measurements (range 0.762-0.785; P < or = 0.01). Linear regression coefficients relating both parameters considered were also highly significant. We concluded that dual-energy x-ray absorptiometry is an accurate and precise method with which to determine ex vivo bone mineral content and strength in turkey bones. Further investigations are requested for field applications of this method to study factors affecting bone physiology and strength.

Quantitative assessment of forearm muscle size, forelimb grip strength, forearm bone mineral density, and forearm bone size in determining humerus breaking strength in 10 inbred strains of mice.

Bone strength is an important clinical endpoint of osteoporosis research. The evaluation of the relative importance of bone and muscle components to bone strength has widespread implications for the understanding and preventing of osteoporosis. The objectives of this study were to understand the interrelationship between the different components of the muscular skeletal system and to determine the effect of forearm muscle size, forelimb grip strength, forearm bone mineral density (BMD), and forearm bone size on the humerus breaking strength among 10 inbred strains of mice. The forearm muscle size was measured using a peripheral quantitative computed tomography (pQCT). The forearm BMD and forearm bone size were measured using a PIXIMUS Densitometer. The forelimb grip strength and humerus breaking strength were measured using an Instron Mechanical Tester. Significant correlations were found among the five regional phenotypes. All variables have a moderately high genetic component with heritability estimates of 0.83 for forelimb grip strength, 0.76 for forearm muscle size, 0.6 for forearm BMD, 0.63 for forearm bone size, and 0.68 for humerus breaking strength. Forward stepwise multiregression analysis showed that the forearm BMD, forelimb grip strength, and forearm bone size were three major determinants of bone strength and explained 61% of the variation in bone breaking strength. These data suggest that evaluation of these three parameters together, rather than BMD alone, is a more effective, noninvasive approach for predicting fracture risk.

Osteoporosis in Cage Layers

Osteoporosis in laying hens is a condition that involves the progressive loss of structural bone during the laying period. This bone loss results in increased bone fragility and susceptibility to fracture, with fracture incidences of up to 30% over the laying period and depopulation not uncommon under commercial conditions. A major cause of osteoporosis is the switch in bone formation from structural to medullary bone at the onset of sexual maturity, but structural bone loss is accelerated by the relative inactivity of-caged birds. Allowing birds more exercise, as in aviary systems, results in better bone quality but may not decrease the overall fracture incidence. Good nutrition can help to minimize osteoporosis but is unable to prevent it. Best nutritional practice involves transferring birds to a higher calcium diet at lighting up rather than at first egg, providing a source of calcium in particulate form, and not withdrawing feed some days before depopulation. Breeding may be an effective way of combating ostoporosis. Some bone strength traits have been shown to be heritable, and divergent selection for resistance or susceptibility to osteoporosis has resulted in lines with markedly different bone characteristics. After three generations of selection, the lines differ by 19% for keel bone mineral density, 13% for humerus breaking strength, and 25% for tibia breaking strength and show a sixfold difference in fracture incidence under commercial breeding conditions. The difference in bone quality among the lines is maintained under different housing systems.

Effect of cage area, cage height and perches on feather condition, bone breakage and mortality of laying hens

1. The health of 2 flocks of 896 ISA Brown laying hens were studied successively over the years 1995 and 1996 under different caging conditions. Hens were kept in groups of 4 in a total of 224 cages. The treatments (7 different types of cages) differed in area per hen (450, 600 or 800 cm2) and height (40 or 60 cm). In the large (800 cm2/hen) and high (60 cm cage) treatment, half of the cages were equipped with perches (20 cm/hen). Each study lasted 48 weeks. 2. Feather condition was found to be independent of cage type. 3. No differences were apparent between the 7 treatments in tibia breaking strength (using the 3-point breakage technique). A significant increase in humerus breaking strength was observed in the high cages. The frequency of broken wings recorded after slaughter was lower in high cages (23%) than in low ones (36%). 4. Mortality was different between treatments. This was explained by a higher proportion of birds killed by 'body cannibalism' in the 60 cm high cages, and by a higher proportion of birds killed by 'vent cannibalism' in the cages with perches.

Foot and Skeletal Disorders in Laying Hens: Effects of Perch Design, Hybrid, Housing System and Stocking Density

Abstract In four experiments a total of 3660 SCWL laying hens kept in conventional cages at low and high stocking densities with and without a perch, Get-away (GA) cages and aviaries with litter (AL), were used for studies on the presence of bumble foot (BF), distal toe pad hyperkeratosis (TPH), keel bone lesions (KBL) and of the breaking strength of tibia and humerus. Commercial hybrids were used: LSL (Expts. 1, 2 and 4); LSL and Shaver (Expt. 3). Only clearly observed in systems with perches, the incidence of BF and KBL was mostly affected by perch design, while BF was also strongly affected by strain and housing system. LSL showed significantly higher incidence of BF, especially in GA and AL. TPH, only found in conventional cages, was affected both by strain and stocking density, LSL hens and lower stocking density showing significantly lower incidence. Apart from welded wire net platforms, a European beech hardwood circular prototype perch with a flattened upper and lower surface seemed to combine in ...

Effect of bone strength on the frequency of broken bones in hens

Bird weight, breaking strength of humerus and tibiotarsus and the number of bones broken during culling were recorded for four breeds of end-of-lay hens housed in battery cages. The probability of a bone being broken increased with bird weight and decreased with increasing bone strength. Bone strength increased with bird weight within each breed but the increase in strength was not great enough to prevent the extra damage suffered by heavier birds. There were differences in tibiotarsal strength between the four breeds of bird but overall no breed was more likely to suffer from broken bones than another. The rate of increase of bone strength with weight was similar between breeds and between humerus and tibiotarsus. The results show that differences in bone strength due to the type of housing system in which birds are kept are great enough to affect the ease with which bones are broken during bird handling during removal from cages at the end of lay.

Bone Strength of Height-Restricted Broilers as Affected by Levels of Calcium, Phosphorus, and Manganese

Three experiments were conducted to determine the effects of certain dietary minerals on humerus breaking strength of broilers grown for 7 weeks in colony cage floor pens 30 cm high or grown in regular floor pens. Data were also collected on tibia strength in the first two experiments. The following dietary factors were involved: Experiment 1 consisted of three diets with increasing amounts of calcium (Ca) and phosphorus (P) but constant Ca:P ratio of 1.3:1.0; Experiment 2 comprised four diets with different P levels but with Ca constant at .9%, causing the Ca:P ratio to vary from 1.8:1.0 to .8:1.0; Experiment 3 was made up of six diets with three increasing levels of Ca and P but a constant Ca:P ratio of 1.3:1.0 and two manganese levels in a factorial arrangement.Data from all three experiments showed humerus breaking strength for broilers grown in regular floor pens to be significantly greater than for those grown in colony cage floor pens. No significant difference was found in tibia strength due to pen type. In Experiment 1, tibia and humerus breaking strengths increased as dietary Ca and P increased. In Experiment 2, humerus breaking strength maximized with dietary P at .7 and .9%. In the final experiment, varying manganese (Mn) caused no statistically significant differences in humerus breaking strength. There was some evidence that high Mn levels may interfere with Ca and P absorption or utilization when these minerals are at low levels.These data show slight improvements can be made in humerus strength of height-restricted birds by increasing dietary Ca and P provided a Ca:P ratio of approximately 1.3:1.0 is maintained.

Relationship of Pen Height to Bone Strength of Broilers

Broilers reared in cages have a high incidence of wing breakage during processing. Three trials were conducted to determine the effects of cage dimensions and floor types on bone breaking strength and wing breakage during processing.Broilers were fed commercial-type diets and processed through the pickers at a commercial processing plant or a research facility. Broken bones were detected by palpation, and humeri and tibia were removed. Breaking strength was determined for the humeri and tibia with a testing instrument. Incidence of breast blisters, crooked keels, follicle infection, fleshing downgrades, and slabsidedness were determined in one trial.Cage height was the major factor affecting wing breakage and humerus strength. Incidence of wing breakage for broilers on wire floors with cages .64 m high was not significantly different from that of control broilers reared on litter with ceiling 2.54 m high. Humerus breaking strength was significantly reduced in two of three trials by the .64-m-high ceiling. Cage rearing increased the incidence of crooked keels and feather follicle infections.