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Feet and legs of replacement females were objectively evaluated at selection, i.e., approximately 150 d of age (n = 319) and post first parity, i.e., any time after weaning of first litter and before second parturition (n = 277) to 1) compare feet and leg joint angle ranges between selection and post first parity; 2) identify feet and leg joint angle differences between selection and first 3 wk of second gestation; 3) identify feet and leg joint angle differences between farms and gestation days during second gestation; and 4) obtain genetic variance components for conformation angles for the two time points measured. Angles for carpal joint (knee), metacarpophalangeal joint (front pastern), metatarsophalangeal joint (rear pastern), tarsal joint (hock), and rear stance were measured using image analysis software. Between selection and post first parity, significant differences were observed for all joints measured (P < 0.05). Knee, front and rear pastern angles were less (more flexion), and hock angles were greater (less flexion) as age progressed (P < 0.05), while the rear stance pattern was less (feet further under center) at selection than post first parity (only including measures during first 3 wk of second gestation). Only using post first parity leg conformation information, farm was a significant source of variation for front and rear pasterns and rear stance angle measurements (P < 0.05). Knee angle was less (more flexion; P < 0.05) as gestation age progressed. Heritability estimates were low to moderate (0.04–0.35) for all traits measured across time points. Genetic correlations between the same joints at different time points were high (>0.8) between the front leg joints and low (

Osteochondrosis (OC) and abnormalities in conformation and locomotive characteristics (CLC) have been associated with premature culling in sows. Several CLC have been suggested to be associated with OC and might help as an in vivo indicator for and increased risk of having OC. The aim of this study was to investigate associations of OC with CLC assessed at several ages in growing gilts from 2 separate experiments over the effects of dietary restriction (Exp. 1) and floor type (Exp. 2) on OC prevalence. In Exp. 1, gilts (n = 211) were subjectively assessed for CLC at, on average, 4, 9, 11, 16, and 24 wk of age. In Exp. 2, gilts (n = 212) were subjectively assessed for CLC at, on average, 4, 9, 11, 16, and 22 wk of age. Assessment was done on 10 conformation and 2 locomotive characteristics using a 9-point grading scale by 2 observers. At, on average, 27 wk of age in Exp. 1 and 24 wk of age in Exp. 2, gilts were slaughtered and the knee, elbow, and hock joints were macroscopically assessed for OC. The CLC most frequently associated with OC were O shape or X shape of the hind legs, straight or bowed hind legs, and straight or sickled hock. X-shaped hind legs were associated with OC at slaughter in the knee joint at 4, 9, and 24 wk of age and at the animal level (all joints taken together) at 4, 9, and 16 wk of age. Straight or bowed hind legs were associated with OC at slaughter in the knee joint at 4 and 11 wk of age; in the hock joint at 11 wk of age; and at the animal level at 4, 9, 11, and 22 wk of age. Straight or sickled hock was associated with OC at slaughter in the knee joint at 4 wk of age, in the hock joint at 9 and 22 wk of age, and at the animal level at 9 and 22 wk of age. Results show that several CLC assessed at several ages were associated with OC, but consistent associations of a type of CLC in every assessment could not be found. The associations of CLC with OC are, therefore, difficult to be used as an in vivo indicator of increased risk for OC.

Osteochondrosis (OC) is a degenerative joint condition developing in a short time frame in young growing gilts that may cause lameness at an older age, affecting welfare and leading to premature culling of breeding sows. Causes of OC are multifactorial including both genetic and environmental factors. Floor type has been suggested to affect OC prevalence and effects might be age dependent during the rearing period. The aim of this study was to investigate possible age-dependent effects of floor type, conventional concrete partially slatted versus wood shavings as deep bedding, on OC prevalence in gilts (Dutch Large White × Dutch Landrace) at slaughter (24 wk of age; 106.5 [14.7 SD] kg of BW). At weaning (4 wk of age; 6.9 [1.3 SD] kg of BW), 212 gilts were subjected to 1 of 4 flooring regimens. Gilts were either subjected to a conventional floor from weaning until slaughter (CC), wood shavings as bedding from weaning until slaughter (WW), a conventional floor from weaning until 10 wk of age after which gilts were switched to wood shavings as bedding (CW), or wood shavings as bedding from weaning until 10 wk of age after which gilts were switched to a conventional floor (WC). After slaughter the elbow, hock, and knee joints were macroscopically examined for OC and scored on a 5 point scale where 0 indicates no OC and 4 indicates the severest form of OC. There was no significant difference (P > 0.4) between treatments on the overall OC prevalence for any joint assessed or at the animal level (all joints combined). At the animal level, however, gilts had greater odds to have OC scores 3 and 4 in the CW treatment (odds ratios [OR] = 2.3; P = 0.05), WC treatment (OR = 2.6; P = 0.02), and WW treatment (OR = 3.7; P < 0.001) compared with gilts in the CC treatment. The results indicate that there are no age-dependent effects of floor types on overall OC prevalence. However, wood shavings as bedding seems to increase the odds for severe OC and might affect animal welfare in the long term.

Osteochondrosis (OC) is one of the main causes of leg weakness causing premature culling in breeding sows and develops in a short time frame in young growing gilts. Dietary restriction may have different effects on OC prevalence depending on the age of the gilts. The aim of this study is to investigate age-dependent effects of dietary restriction, ad libitum vs. restricted (80% of ad libitum), on the occurrence of OC in gilts at slaughter (26 wk of age). At weaning (4 wk of age), 211 gilts were subjected to one of 4 treatments of a feeding regime. Gilts were administered either ad libitum feeding from weaning until slaughter (AA); restricted feeding from weaning until slaughter (RR); ad libitum feeding from weaning until 10 wk of age, after which gilts were switched to restricted feeding (AR); or restricted feeding from weaning until 10 wk of age, after which gilts were switched to ad libitum feeding (RA). At slaughter, the elbow, hock, and knee joints were harvested. Joints were scored macroscopically for articular surface deformations indicative of OC. Gilts in the RA treatment had significantly higher odds of being affected by OC than gilts in the RR and AR treatments in the hock joint (OR=3.3, P=0.04 and OR=8.5, P=0.002, respectively) and at animal level (OR=2.5, P=0.001 and OR=1.9, P=0.01, respectively). Gilts in the AA treatment had higher odds of being affected by OC than gilts in the AR treatment in the hock joint (OR=5.3, P=0.01). The results indicate a possible pathway to reduce the prevalence of OC in breeding gilts that will have to last several parities. Switching from restricted feeding to ad libitum feeding after 10 wk of age increases OC prevalence as opposed to restricted feeding after 10 wk of age.

Results of mare performance tests in the field (MPT-F) of 10,949 mares, mare performance tests at station (MPT-S) of 1,712 mares, and inspections of horses intended for sale at riding horse auctions (AU) of 4,772 horses were used to investigate genetic correlations between corresponding performance traits. Mare performance tests were held in 1995 to 2004 and auction inspections in 1999 to 2004. Scores on a scale from 0 to 10 were given for gaits under rider (walk, trot, canter), rideability (evaluated by judging commission and test rider), free-jumping (ability, style, total), and character. Radiography results of 5,102 Hanoverian Warmblood horses were used to investigate genetic correlations between performance traits and particular radiographic findings. The radiographic findings included osseous fragments in fetlock and hock joints, deforming arthropathy in hock joints, and distinct radiographic findings in the navicular bones, which were analyzed as binary traits, and radiographic appearance of the navicular bones, which was analyzed as a quasi-linear trait. Genetic parameters were estimated multivariately in linear animal models with REML using information on the horses radiographed and their contemporaries (n = 18,609). Heritability of performance traits ranged between 0.14 and 0.61, and heritability of radiographic findings between 0.14 and 0.33. Additive genetic correlations between corresponding performance traits were close to unity for MPT-F and MPT-S, ranged from 0.81 to 0.90 for MPT-F and AU, and were 0.75 to 0.92 for MPT-S and AU. Genetic correlations between performance and radiography results were mostly close to zero. Indications of negative additive genetic correlations were observed for deforming arthropathy in hock joints and canter, rideability evaluated by test rider, jumping traits and character, and osseous fragments in hock joints and character. Selection of horses for radiological health of their limbs will assist further genetic improvement of the performance of young Warm-blood riding horses.

This study was conducted to determine normal rates of growth of different skeletal segments in the thoroughbred horse. Growth of body weight and eight skeletal segments (wither height, hip height, body length, knee to pastern length, hock to pastern length, shoulder to pastern length, width of chest, depth of girth) were monitored in 106 horses (60 colts, 46 fillies) during the period from 14 to 588 d of age. Body weight gains were slightly higher (30 to 40 kg) than previously reported values. Growth in wither height and hip height were similar to previous reports. During the period measured in this study hip height was consistently 2 or 3 cm larger than wither height. Growth patterns for wither height, body length, and shoulder to pastern lengths were similar to one another. Growth of the knee to pastern and hock to pastern segments reached a plateau at approximately 140 d of age, which coincided with the cessation of longitudinal bone growth. These data define skeletal growth patterns in the thoroughbred horse and are useful in determining the relationship between growth and the occurrence of orthopedic diseases in horses.

Crossbred gilts (n = 288) were weaned at 4 to 5 wk of age and retained through three parities. They were used to determine the effects of feeding restricted energy (ad libitum vs 75% ad libitum) and elevated calcium-phosphorus levels (100 vs 150% of the dietary percentage suggested by NRC, 1979) from weaning to 100 kg of body weight on subsequent sow gait characteristics obtained from 16-mm motion pictures. After 100 kg, all females were fed and managed similarly throughout breeding, gestation and lactation. At 50 and 100 kg body weight and 21 d after weaning, females were filmed from the side and rear as they walked on a treadmill (traveling at the rate of .90 cm/s with zero slope) using two 16-mm Arriflex cameras. Objective measurements were taken from the film by projecting it on a reverse screen. Visual appraisal of structural soundness were scored subjectively for each female at each time period. The front foot pastern angle was correlated positively with structural soundness scores, suggesting that sows with smaller angles (more sloping) were given more desirable soundness scores. Early dietary energy and Ca-P levels did not influence number of sows completing three parities or culled for various reasons, front and hind pastern angles, the angles at the hock and carpal joint or rear view measurements, but sows fed ad libitum to 100 kg had a larger frame size even after three parities. Sows that survived three parities tended to have larger body capacity (girth diameter and width across hams) and smaller front and bind pastern angles and angles of the carpal joint and hock at maximum flex than did culled sows. Structural soundness scores did not differ between culled and surviving sows.

Sixty Duroc pigs, representing offspring of three lines from the fifth generation of divergent selection for leg weakness, were examined to determine correlated responses in joint angularity. The lines were low, control, and high, with the latter having superior front leg structure. At approximately 100 kg, 10 pigs of each sex and line were scored for front and rear leg structure and movement. The shoulder, elbow, carpal and hock joints were measured for resting angles and range of motion. The model to analyze the data included the effects of line, sire, sex and side and covariable for weight. High-line pigs had significantly smaller (P less than .05) resting angles of the elbow joint than did control- or low-line pigs. The low-line pigs, however, had significantly smaller resting angles at the carpal joint (P less than .01) and greater resting angles at the hock joint (P less than .05) than did control- or high-line pigs. The low-line pigs had fewer degrees extension at the elbow joint and fewer degrees flexion at the carpal joint than did control- or high-line pigs. High-line pigs had fewer degrees of flexion of the elbow joint than did control-or low-line pigs. Resting angles and range of motion for the elbow and carpal joints were less on the left side than on the right side. Males had greater degrees of extension and total degrees of movement at the elbow joint than did females. Selection for different degrees of leg weakness resulted in accompanying alterations in angularity of joints.