Leg Problems Research Articles

Evaluation and management of leg problems in the runner

Evaluation and management of leg problems in the runner

Beta-carotene supplementation of turkey diets varying in fat and retinol.

1. The effects of supplementary beta-carotene (BC) at 0, 1.5, 15, 150, 1500 or 15,000 mg/kg diet on performance, incidence of leg problems, tibia ash, and plasma and liver concentration of BC and retinol of poults to 4 weeks of age were studied. 2. Body weight and food intake increased with dietary BC supplementation. Incidence of leg problems was not affected but tibia ash increased with BC supplementation. Plasma and liver BC and liver retinol increased with dietary BC but plasma retinol was not affected. 3. The effects of 0, 1.5, 15 or 150 mg BC/kg in diets containing either 30 or 60 g added fat/kg and either 1.2 or 12.0 mg retinol/kg on the above properties were studied in poults to 4 weeks of age. 4. Performance was not significantly affected by dietary fat. Efficiency of utilisation of food was depressed by the higher concentration of retinol. At 3 weeks of age birds given BC had fewer leg problems and higher tibia ash values than the control birds. Liver BC and retinol and plasma BC concentration increased with dietary BC. By 4 weeks, plasma and liver BC was higher and liver retinol was lower for birds given 1.2 compared with those given 12.0 mg/kg of retinol.

Risk factors for reason-specific culling of dairy cows

A set of 7763 Holstein lactations from 34 New York herds was used to explore the influences of production and of 13 diseases on culling. Dying was predicted by high milk yield and by downer cow syndrome. The cows most likely to be sold for dairy purposes were those with shorter previous-lactation calving intervals, with lower milk per calving-interval day in the previous lactation, who calved in the summer, or who had clinical mastitis. Lower estimated transmitting ability for milk, lower milk yield per day in the previous calving interval and calving in the summer (but not clinical mastitis) were risk factors for low production. Having > 3 services, aborting and having cystic ovary were associated with culling for poor reproduction. Culling for udder problems was predicted by lower previous-lactation milk per day, higher current milk per day, clinical mastitis and teat problems. Cows with lower estimated transmitting ability, dystocia, or foot or leg problems were at higher risk of culling for feet and legs. Culling for miscellaneous reasons was associated with lower estimated transmitting ability, higher current milk per day and left displaced abomasum.

Descriptive epidemiology of culling in dairy cows from 34 herds in New York State

Data on parity, disease, farmers' stated primary reasons for culling and stage of lactation at diagnosis and at culling were used to describe patterns of culling in Holstein lactations from 34 New York herds. Of 7763 lactations, 18.7% ended in culling [death (95 cows), sales for dairy purposes (104 cows), or slaughter]. The culling rates for specific reasons were: dairy purposes 1.3%, low production 3.8%, reproduction 4.8%, udder problems 4.0%, feet and legs 1.2%, old age 0.3%, accidents 0.3% and miscellaneous reasons 2.9%. Culling increased with parity (at least through Lactation 6) and primarily was due to production, reproduction and udder problems. Culling for these 3 reasons peaked immediately after calving, again between 151 and 240 days post-partum (poor milk production) and at 240 days post-partum (poor reproductive performance). First-lactation cows sold for dairy use tended to be sold in early lactation. Death in older cows usually occurred early in lactation and was due to udder problems or to miscellaneous causes. Compared to lactations without the disease, lactations with a diagnosis of downer cow, clinical mastitis or treat problems were 3.5, 2.0 and 2.7 times more likely to end in culling, respectively. Among cows diagnosed with a disease and culled, many were culled the same day or within 30 days of the diagnosis. Such “immediate” culling upon diagnosis was especially typical of cows with milk fever, downer cow syndrome, left displaced abomasum, teat problems, and foot and leg problems (and for some cases of clinical mastitis), implying that these disorders led to “forced” culling, which was particularly costly to the farmers.

Carcass Traits of Turkeys from Lines Selected for Increased Growth Rate or Increased Shank Width

Carcass composition of turkeys from a long-term growth-selected line (F), a subline (FL) of F selected only for increased shank width, and a randombred control population (RBC2) that served as the base population for F, were compared. Birds of both sexes were killed at 16 wk of age in the fifth and sixth generations in Line FL. A commercial sire line (C) was also included in the sixth generation.Body weight increased at comparable rates in F and FL males through the 5th generation of selection in Line FL, but the BW of FL males was significantly smaller than that observed in F males in the 6th generation. Body weights of FL females were significantly lower than BW of F females in both the 5th and 6th generations, resulting in a significant line × sex interaction. A similar interaction was also observed in both generations in the actual weight of most leg bones, leg muscles, and breast muscles. When expressed as a percentage of live BW, most of the latter line × sex interactions were not significant.Genetic increases in shank width of the FL line were associated with increases in the relative weight of all leg bones measured and drumstick muscles. This may have contributed to the improved walking ability consistently observed in FL males relative to that of F males. In general, genetic increases in BW in Line F were associated with a decreased amount of relative support (leg muscles and leg bones) in comparison with that observed in Line RBC2. These results support the hypothesis that a portion of the leg problems observed in large-bodied turkeys are attributable to an inherent weakness of body support structures resulting from the slower growth of these structures relative to that of total BW.

Effects of restricting body weight gain or limiting the photoperiod during rearing on sexual maturity, viability and semen production in large white Turkey males

Abstract 1. Severe restriction of food from 6 to 54 weeks of age resulted in lower body weights and smaller testes weights in male turkeys. 2. As a proportion, mortality was 0.5 in turkeys fed ad libitum and 0.1 in those which were restricted. There were significantly fewer leg problems in the birds undergoing food restriction. 3. Sexual maturity was delayed 4 weeks by food restriction although semen quality was similar to that in ad libitum‐fed birds. 4. Individual semen production was lower after food restriction but, because mortality and food consumption were also lower, semen production per male housed and semen production per kg of food eaten were proportionally 0.30 and 0.32 greater in restricted‐compared with ad libitum‐fed turkeys. 5. Useable quantities of good quality semen were obtained from ad libitum‐fed turkeys at 23 weeks of age. 6. A short photoperiod (7L:17D) from 10 to 18 weeks of age in ad libitum‐fed turkeys produced more rapid development of normal semen production compared with turke...

Some nutritional implications of leg problems with poultry

Summary It would appear that while numerous nutritional situations can lead to skeletal problems, treatment of such problems is far from clear. It would seem that ‘induced’ deficiencies are likely the major cause of leg problems that have a nutritional component, and as such nutritionists are urged to avoid nutrient excesses and antagonisms that may precipitate deficiencies. In many instances there is an underlying common effect of irregular vascularization of the cartilage growth plate, and this seems to be related to growth rate per se , rather than body weight. It has been suggested that genetic selection for improved growth rate has resulted in increased growth rate of the proximal growth plate, especially of the tibiotarsus. Improvements in skeletal development will accrue from more detailed studies of the metabolism of this active growth plate. High levels of diet protein aggravate skeletal development by either increasing growth rate per se , providing excess of nonessential nitrogen, or aggravating deficiencies of vitamins. A number of feed ingredients and mycotoxins seem to aggravate leg bone development in the broiler chicken. Electrolyte balance of the diet can also influence occurrence of leg problems, and in particular tibial dyschondroplasia.

Effect of Altering Dietary Mineral Balance on Growth, Leg Abnormalities, and Blood Base Excess in Broiler Chicks

Broiler cockerels were used in four trials of 3-wk duration to investigate the effects of altering dietary cation:anion ratios on chick growth, leg abnormalities, bone, and blood parameters. Dietary cation content was changed using Ca and Mg, whereas the anions P, Cl, and S were included at various levels, giving several total cation:anion ratios with several levels of ions. Narrowing the cation:anion ratios increased 3-wk body weights and the incidence of both dyschondroplasia and varus deformation. Further increases in dietary anion concentration generally caused a slight depression of body weights. Supplementation of Ca or Mg to diets containing high levels of anion relative to cation decreased the incidence of leg problems and lowered 3-wk body weights. Blood pH was not significantly affected by dietary mineral alterations, although pH tended to decrease as anion content was increased. Addition of P significantly reduced blood HCO3 and base excess (meq/L). Base excess was negatively correlated (P<.05) with the incidence of TD and 3-wk body weights. Two strain-crosses of broiler cockerels, fed diets which had previously increased the incidence of leg abnormalities, exhibited no significant differences in the incidence of varus deformation or dyschrondroplasia. The strain-cross of chicks having the lowest base excess had higher incidences of both leg disorders, although body weights were identical.

Histology and Histomorphometry of the Tibia Growth in Two Turkey Strains

Qualitative and quantitative histological methods on decalcified and undecalcified specimens were used for comparing the linear and radial growth of the tibia in two turkey strains: a light strain, Betina, without leg problems and a heavy strain, Maxiboul, with leg problems. Groups of 10 clinically healthy male turkeys of each strain were studied at 2, 6, 8, 16, and 20 weeks of age.Three histomorphometric parameters of longitudinal growth were quantitated in the proximal growth plate and metaphysis. These were: height of the proliferative zone, density of ossification buds (metaphyseal sprouts), and volume of metaphyseal trabecular bone. Four histomorphometric parameters of radial growth were quantitated in the diaphysis. These were cortical thickness, active zone/total surface, density of maturing osteons in the active zone, and bone apposition rate at the maturing primary osteons level.The results showed some evidence for factors predisposing to leg problems in the Maxiboul strain. At 8 weeks, the Maxiboul strain had a lower ossification bud density (13.1/mm2vs. 20.7/mm2; P<.05) and a lower metaphyseal trabecular bone volume (16.4% vs. 22.0%; P<.05) when compared to the Betina strain. No difference was detected in the cortical thickness of the diaphysis in the two strains except at 2 weeks of age (799 μm vs. 387 μm; P<.001), despite the heavier weight of the Maxiboul strain.

Importance of claw quality in cattle: Review and recommendations to achieve genetic improvement. Report of the E.A.A.P. working group on “claw quality in cattle”

The objective of this report is to review results of research and to discuss recommendations to achieve genetic improvement of claw quality. High claw quality is defined as a low susceptibility for claw disorders and a low need for footcare. The economic importance of claw problems is considerable, with about 25% of dairy cows treated per year. Direct effects are costs of trimming, veterinary costs and forced culling (2–3%). Indirect costs are decreased milk production or daily gain, lower fertility, decrease of herd life, and lower salvage value. Lameness problems are mainly localized in the claws and can have a traumatic, systemic or infectious origin. The claw quality is a product of claw shape, characteristics of the horn and anatomy of the inner structure of the claw. Environmental factors like housing systems, management and nutrition give considerable herd effects. Improvement of claw quality in the short term can be achieved by managemental procedures that will reduce foot and leg problems in confinement. Genetic improvement can give a contribution in the long term. Genetic variation in claw traits and claw disorders are recorded between and within breeds. Heritabilities and additive genetic variation for claw shape measurements (e.g. claw length, claw angle) are high enough to obtain genetic change in these traits. Claw measurements are partly symptoms but also predisposition factors for claw disorders like sole ulcers. Shorter and steeper hind leg claws are favourable predispositions. Veterinary records on claw and leg disorders after treatment yield very low heritabilities. Claw judgements should be replaced by more effective measurements because of low h 2 and low correlation to claw disorders. Implementation of genetic improvement based on measurements of claw shape (angle, length) may start with a progeny test of 30–50 daughters in first lactation of the most promising A.I. bulls in milk production. Relationships of claw characteristics of young bulls with those of their parents and daughters is recommended for further analysis.

Management of Foot and Leg Problems in Dairy Cattle

Summary There is no one single cause of foot problems. Likewise, there is no one specific cure. The key is prevention, and only through diligent management practices associated with environment, nutrition, breeding and health programs can prevention be accomplished. Guidelines for foot management: 1. Observation: routinely observe cows for any apparent lameness, standing problems, or if they are lying down excessively. Also, provide an environment conducive to proper foot wear (i.e., get cows off concrete at least two hours per day, groove smooth floors, grade rough floors). 2. Monitor nutrition and breeding programs: balance diets for specific groups of cows according to National Research Council recommendations. Choose sires with high dollar product value, which also have high stayability and feet ratings. 3. Prompt treatment of disorders: treat lame cows as soon as they are noticed, not when they become a nuisance. Also, treat cows with infectious diseases (metritis, mastitis) promptly. 4. Maintain a regular hoof trimming schedule... every six months to a year depending on hoof growth and wear. 5. Provide a foot bath for cows, that is maintained on a daily basis.

The influence of genetic increases in shank width on body weight, walking ability, and reproduction of turkeys.

Body weight and breast width have been greatly increased in the modern turkey. However, the relative amounts of leg muscles and leg bones have declined. A similar decline also occurs with age. It was theorized that this is an inherent weakness that magnifies other causes of leg problems. In an attempt to increase the relative amount of leg bone, a subline (FL) was developed by mass selection for increased shank width at 16 weeks of age from a long-term growth-selected line of turkeys (F). Shank width of FL was increased greatly by selection. The realized heritability of shank width, based on the regression of accumulated selection response on accumulated selection differential, was .33 +/- .05 over five generations of selection. Body weight of males from FL increased at a rate comparable to that of F at 16 weeks of age. However, there was no comparable improvement in body weight of FL females, resulting in a significant line X sex interaction. A similar interaction was observed for body weight at 8 and 20 weeks of age in these lines. The genetic increases in shank width in FL resulted in significantly improved walking ability of males at 16 weeks of age in comparison to F, even though body weight of males from the two lines was similar. The walking ability of FL did not change relative to the control line from which F originated. Thus, large genetic increases in body weight of males can be achieved without loss in walking ability by genetic increases in shank width.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of High Dietary Calcium and Wide Calcium-Phosphorus Ratios in Broiler Diets

The effect of varying dietary calcium (Ca) and phosphorus (P) levels and ratios on broiler performance and the incidence of leg abnormalities was studied using 180 Cobb broilers. A 3 × 2 factorial arrangement of treatments involving three Ca (1.0, 2.0, 3.0%) and two P (.6, 1.2%) levels was used. Manganese (Mn) was kept at 70 mg/kg for all diets. Only P main effects were significant for performance parameters, and Ca × P interractions effects were significant for leg abnormality scores and Mn status. High dietary P (1.2%) depressed (P<.01) gains (18.6 vs. 13.3 g/day), increased (P<.01) feed conversion ratio (2.4 vs. 2.8 kg/kg), and caused higher (P<.01) mortality (8.9 vs. 18.8%). At normal P (.6%), high dietary Ca (2.0% and 3%) disrupted Mn metabolism, causing a high incidence and severity of leg problems and associated bone disorders. Increasing dietary P to 1.2% attenuated these disruptive effects of high dietary Ca. This strategy, however, is not a satisfactory management alternative, because high dietary P adversely affected broiler performance and survival. The possibility of managing the condition by increasing dietary Mn was investigated in a second study in which 150 Cobb broilers grouped into five lots of 30 each were fed five diets containing graded levels of Mn (77.5, 140, 200, 255, and 300 mg/kg) for 6 weeks. All diets contained similar Ca (3%) and P (.6%) and adequate levels of other essential nutrients. Control birds (77.5 mg/kg) had the highest (P<.05) leg abnormality score (1.75), which decreased (P<.05) as dietary Mn increased up to and including 200 mg/kg, above which no additional reduction (P>.05) was observed. A similar trend was observed for tibia ash and volume, as well as the Mn status of the birds, but dietary Mn had no effect (P>.05) on performance parameters. Thus, the tendency to induce leg abnormalities of broiler diets containing Ca as high as 3% and, or Ca:P ratios as wide as 5:1, could be alleviated by increasing dietary Mn to 200 mg/kg.

Sudden Death Syndrome in Broilers: Dietary Fat Supplementation and Its Effect on Tissue Composition

The effects of dietary fat sources on the general performance of broiler chickens and the incidence of sudden death syndrome (SDS) were investigated in two experiments. In Experiment 1, a wheat-soy diet supplemented with sunflower oil was found to improve significantly (P<.05) performance characteristics and reduce the mortality attributed to SDS as compared with the same diet supplemented with tallow. The blood lipid parameters — total lipids, triglycerides, and cholesterol at 4 and 7 weeks of age — were not affected (P>.05) by the type of fat used in the diet. In Experiment 2, wheat-soy diets were supplemented with either tallow or sunflower oil at the same dietary levels and two stocking densities (.09 m2/bird or .08 m2/bird). The sunflower oil diet significantly (P<.05) improved the general performance of the birds and reduced mortality from SDS. Bird density had no significant effect. Fatty acid composition of the heart and liver tissues from SDS birds showed differences when compared with culled birds (leg problems) from the same experimental period. In the heart tissue, increased palmitic (16:0) and oleic (18:1) acids were observed, while linoleic (18:2) and arachidonic (20:4) acids were lower. Liver tissue showed increased 18:1 and lower 18:2 and 20:4. Analysis for copper and zinc in heart tissue did not indicate significant (P>.05) treatment effects, but calcium concentration was significantly (P<.05) higher in SDS than culled birds. Analysis performed on the liver tissue showed significant (P<.05) differences in copper and zinc between these two groups of birds.

Concurrent Infections with Reoviruses and Coccidia in Broilers

These experiments investigated the interaction among two species of coccidia (Eimeria acervulina and E. mitis) and three strains of reovirus (virus 2035, a weak to moderate pathogen; and viruses 2408 and 1733, severe pathogens). When reoviruses were not present, high inoculation dosages (10(6) sporulated oocysts/bird) of both E. acervulina and E. mitis depressed weight gain, plasma pigment, and plasma protein. Low doses of coccidia (10(4) oocysts) in the absence of virus had no such effect on weight gain. When high doses of coccidia were present at the same time as virus 2035 or 2408, they resulted in a significantly greater depression of weight gain than when either virus or coccidia were present alone. With virus 2035, this greater depression was seen even when low doses of coccidia were used. Lesion scores due to coccidiosis and the number of oocysts produced were not affected by previous exposure to reovirus. Both coccidiosis and reovirus infections increased the frequency of some leg problems and other abnormal conditions. The most obvious interaction between coccidia and reovirus was the marked increase in swollen hocks seen when coccidia and virus 2035 were present together (20-27%) compared with either the virus or coccidia alone (0-10%). Virus 2408 interfered slightly with the development of immunity to coccidia. There was some indication that early coccidiosis could increase the ability of some virus isolates to infect various tissues of the host.

Disease, production and culling in Holstein-Friesian cows V. Survivorship

Effects of disease on the risk of removal in Holstein-Friesian cows were investigated in a two and a half year study. Records were available from 141 sold cows, 415 culled cows and 1452 comparison cows in 32 commercial dairy herds within a 50 mile radius of Guelph, Ontario. Removals were subdivided into culls (cows sent to slaughter) and sales for dairy purposes. Discriminant analysis was used to identify disease conditions associated with an increased risk of removal before the 150th day or after the 150th day of the lactation. Age and herd effects were controlled in all analyses and the effect of level of production was controlled in analyses of removals after Day 150. Subclinical mastitis was associated with increased risks of culling and of being sold for dairy purposes after Day 150. Mastitis, milk fever, feet and leg problems, teat injuries and respiratory disease were associated with an increased risk of culling early in the lactation. No disease conditions were significantly associated with the risk of being sold for dairy purposes early in the lactation. The survival experience of these cows was determined by the use of life table analyses, the median survival time being 5.6 years. Risk of removal was highest in cows aged 3.0–4.9 years and in cows over 7 years old. Survival was positively associated with level of milk production.

Estimation of genetic parameters for skeletal defects in broiler chickens

Analysis of variance and proband methods for estimating heritabilities and genetic correlations in low incidence, binomially distributed traits are compared using a computer simulation. It is concluded that reliable but conservative results are obtained by the proband method for heritabilities while analysis of variance techniques are more appropriate for estimating genetic correlations. These results apply providing that the incidences involved are not much less than 0·01, and that the true genetic correlation is not very small. These methods are then applied to pedigree broiler data, including information on live-weight and various skeletal defects. It appears that all the defects considered are heritable, that leg problems have positive genetic correlations with weight, and that it is reasonable to group abnormalities together for the purposes of selection.

Disease, production and culling in Holstein-Friesian cows II. Age, season and sire effects

Effects of age, season and sire on the occurrence of common diseases of Holstein-Friesian cows were evaluated in a two and a half year study. The data were from 2875 lactation records from 2008 cows in 32 commercial dairy herds within a 50 mile radius of Guelph, Ontario. Age patterns for all disease conditions were determined using χ 2 or quadratic regression analyses. Linear increases with age were observed for milk fever, mastitis requiring local therapy only, cystic ovaries and foot and leg problems. Quadratic relationships with age were observed for ketosis (clinical and subclinical), mastitis requiring systemic therapy, subclinical mastitis, dystocia, respiratory diseases and traumatic reticulo-peritonitis. No consistent age patterns were found for retained placentas, reproductive tract infections, abomasal displacements, teat injuries, digestive disorders and abortions. Seasonal patterns were evaluated using a formal statistical test for the seasonality of events. Significant peaks were found in the risk of ketosis and cystic ovaries during the winter, and in the risk of teat injuries in the late winter or early spring. Seasonal patterns, more complex than a simple unimodal pattern, were observed for mastitis requiring local therapy only, traumatic reticulo-peritonitis and abortions. Heritabilities were determined for 9 disease conditions. All heritabilities were low or 0 with the exception of clinical ketosis ( h 2 = 0.31).

Influence of Vitamin Deficiency and Level of Dietary Protein on the Incidence of Leg Problems in Broiler Chicks

Diets containing either 22 or 30% protein were supplemented with a vitamin mix where one of 11 added vitamins were singly eliminated from the mix. Male, day-old broilers were fed these diets to 3 weeks of age, and weight gains, feed utilization, and leg problems were recorded.In general, the higher protein diet did not result in a greater incidence of leg problems; however, it did alter performance of several of the vitamin-deficient diets as compared to the lower protein diet. Of the 11 vitamins studied only nonsupplementation of riboflavin markedly reduced weight gain and feed utilization during the 3-week feeding period. However, deletions of vitamin D3 and niacin also resulted in reduced performance.Riboflavin deficiency resulted in paralysis in a high percentage of the birds, while the niacin-deficient diet gave a high percentage of birds with deformed legs and problems of mobility. The results demonstrate that a high incidence of leg problems may be present in a flock with little or no signs of reduced gain or feed utilization.The data suggest that under practical conditions the elimination of a particular vitamin from a diet for a short period of time would probably have a negligible effect on performance.

Effects of a Nonspecific Nitrogen Deficiency on Growth Rate and Leg Problems in Chicks

Five experiments were conducted using crystalline amino acid and semipurified diets containing adequate levels of all indispensable amino acids, vitamins, and minerals to study the effects of dispensable amino acids on growth and the incidence of leg abnormalities of male chicks. Purified diets containing 5% L-glutamic acid as the sole source of nonspecific nitrogen resulted in poor growth and feed efficiency, high mortality, and a high incidence of leg abnormalities with many severe cases of this condition. Increasing the dietary level of L-glutamic acid to 10% of the purified diet or supplementing the 5% L-glutamic acid diet with 2.40% glycine or 1.68% L-serine improved weight gain but did not eliminate the leg conditions . Higher L-serine (3.36%) resulted in a growth depression, indicating that this level was toxic to the birds. It was necessary to increase the dietary L-glutamic acid to 12.5% to reduce the incidence of leg problems to a minimum. Plasma dispensable amino acid levels (aspartic acid, glutamic acid, and alanine) paralleled the levels of L-glutamic acid in the diets fed to the chicks. Plasma serine and glycine levels were increased by adding either serine or glycine, but the magnitude of the increase of either amino acid was greatest with the addition of that amino acid to the diet. Plasma proline concentrations increased when chick diets were supplemented with high levels of glycine (2.4%), serine (3.36%), or glutamic acid (9.7%) in relation to those supplemented with only 5% L-glutamic acid. Feeding an intact protein (isolated soybean protein) diet did not alleviate leg disorders, although it did improve weight gain.