Objective-To determine associations of health status and conformation with competition longevity and lifetime performance in young Swedish Warmblood riding horses. Design-Cohort study and genetic analysis. Animals-8,238 horses. Procedures-Horses were examined for health, conformation, and performance from 1983 to 2005, when they were 4 to 5 years old, and competition results from 1983 to 2012 were evaluated. Associations between conformation, health, and talent scores of young horses and longevity (years in competition) and lifetime performance were analyzed. Odds ratios of competing later in life among horses with joint flexion test reactions were determined. Genetic correlations between young horse health, conformation, and talent scores and longevity and lifetime performance were determined. Results-Good overall 4- to 5-year-old health, conformation, and talent scores for performance were phenotypically and genetically associated with greater longevity and lifetime performance. Good health was genetically correlated (r(g) = 0.3) to longevity and lifetime performance. Among conformation traits, body type and movements in the trot were most strongly associated with future longevity; these were genetically correlated (r(g) = 0.2 to 0.3) to longevity and lifetime performance. Intermediate-sized horses were associated with highest longevity and lifetime performance. Positive flexion test results were associated with lower ORs (OR, 0.59 for moderate to severe and 0.76 for minor reactions) of competing later in life, compared with no reaction, and were associated with lower longevity (0.4 years). Conclusions and Clinical Relevance-Horses with good health and conformation at a young age had better longevity in competitions than the mean. Positive correlations suggested that improvement of health and conformation of young horses will enhance their future athletic talent and performance.

Health in horses is thought to be influenced by conformation traits, including limb deviations. As few studies on the subject are available, the relevance of selecting for specific conformation traits to improve health is uncertain. The objective was to determine the genetic variation in conformation and relationships between conformation and health status in young riding horses. Analyses included 8187 young horses independently examined for conformation and health, during the Swedish Riding Horse Quality Test (RHQT) for 4–5 year-old horses. Both descriptive conformation traits and assessment scores of conformation were studied. Phenotypic effects were estimated using single trait General Linear Models and heritabilities and genetic correlations using multi-trait linear animal models. Four major health indicators were constructed from the detailed veterinary examinations. Conformation assessment scores were all favourably related to at least one of 4 studied health traits, both phenotypically and genetically. Genetic correlations reached 0.75 between conformation scores for head-neck-body and locomotion examinations, including flexion tests, and 0.43 for limb scores and locomotion examinations. Best health status was found for an intermediate-sized horse, with a well-positioned neck, a light front, and no major limb deviations. This finding was consistent with the role of correct movements at trot. Among limb deviations stiff pasterns, toed-out or toed-in forelimbs, and small or large hock angles showed highest negative effects on health. However, the prevalence of limb deviations was generally low, thus only toed-in forelimbs and small joints had significant genetic correlations to impaired health. Heritabilities for withers height, cannon bone circumference and overall conformation scores (except for limbs), were medium to high (0.20–0.67, s.e. 0.03–0.04). For specific limb deviations, heritabilities were in the range of 0.01–0.15 (s.e. 0.01–0.02) on the observed scale, corresponding to 0.04–0.48 on the underlying quantitative scale. Heritabilities of conformation traits and favourable correlations to health indicate good opportunities for genetic improvement of conformation, and indirectly to some extent also of health. However, only limited improvements could be expected for the prevalence of some limb deviations, where frequencies are already low.

BACKGROUND:Soundness is important for welfare and utility of the riding horse. Musculoskeletal disorders are the most common causes of interruption in training and of culling. Despite great importance, heritability of a majority of health traits in horses has previously not been estimated. The objective was to perform genetic analyses of medical and orthopaedic health traits in young riding horses, including estimates of heritability and genetic correlations between health traits, and to reveal possibilities for genetic evaluation of stallions for progeny health.RESULTS:The heritability of health traits was estimated using records from 8,238 Swedish warmblood riding horses examined as 4-5 year olds at the Riding Horse Quality Test in 1983-2005. The analyses were performed using multi-trait linear mixed animal models. The heritabilities of palpatory orthopaedic health (PALP), including effusion, swelling, heat, soreness and stiffness/atrophy, and hoof examination results (HOOF), of hoof shape and hoof wall quality, were 0.12 and 0.10, respectively. The genetic variation in these traits resulted in distinct health differences between progeny groups of stallions. The highest heritability among clinical signs of PALP was found for synovial effusions at 0.14. For systemic locations, joint related findings had the highest heritability; 0.13. The heritabilities of medical health and locomotion examination results were low, 0.02 and 0.04, respectively. A genetic improvement of health status has occurred over time but accounts only partly for the decrease in clinical findings of health during the studied period.CONCLUSIONS:The genetic variation found in PALP and HOOF implies distinct differences between progeny groups. Thus, there are possibilities for improvement of these traits in the population through selection. The weak and non-significant correlation between PALP and HOOF suggests that both traits need to be selected for in practical breeding to improve both traits. Some genetic improvements over time have already been achieved, possibly due to regular stallion health inspections and an indirect selection for lifetime performance. For further improvements stallion breeding values for health may be introduced, based on RHQT examinations, complementary to present breeding values for performance.

BACKGROUND:Soundness of an individual horse is important for animal welfare and owner economy. However, knowledge of health status in normal horse populations is limited due to lack of systematic health recordings. The aim of the investigation was to study the prevalence of veterinary clinical findings in 4-5-year-old Swedish warmblood riding horses, and their influence on overall health scores, where associations to future longevity has been indicated.RESULTS:The prevalence of clinical findings in 8,281 horses examined during 1983-2005 was studied according to a standardised protocol and related to overall health scores in linear statistical models. Effects of sex, age, examination event and changes over time were included. In total, 49% of the horses had clinical findings of medical health (MED), 42% in hooves (HOOF) and 74% of palpatory orthopaedic health (PALP). However, only 6%, 3% and 24% had moderate or severe findings, of MED, HOOF and PALP, respectively. Flexion test reactions were reported in 21% of the horses (5% moderate/severe), heavily influencing the overall score (H2). One fifth of these horses also had findings of unprovoked lameness while 83% had PALP findings (44% with moderate/severe findings). Acute clinical signs, i.e. heat or soreness, had a large influence on the H2 score but were rare, whereas more common clinical findings had smaller effects on overall health. Large variations in recorded health results were observed among events. A decrease in findings has occurred since 1983, in particular for PALP findings.CONCLUSIONS:Results of occurrence and relevance of evaluated clinical findings could be used for advice on preventive actions to keep horses sound, and possibly for benchmarking, and genetic evaluation of health traits. The distinct effect of event on recorded clinical findings emphasises that further harmonisation of veterinary examinations are desirable.

Reyna Creole cattle in Nicaragua comprise about 650 purebred animals, and the breed has been shown to have a high level of inbreeding. To characterize the breed, as basis for a conservation program, information from two herds on birth weight (BW, n = 1097), age at first calving (AFC, n = 449) and calving interval (CI, n = 1,347) was analysed. Overall averages were 27.8 kg for BW, 37.4 months for AFC and 424 days for CI. Large differences between the herds were observed for all traits. Thus, there would be opportunities for management interventions to improve reproduction results. The heritability for BW was 0.34. For CI, the heritability of 0.20 and the additive genetic standard deviation of 36 days were comparatively high values. No genetic variation was found in AFC. Estimated inbreeding effects were associated with large standard errors due to the small size of the data and incompleteness of pedigrees. Nevertheless, significant effects were shown of dam inbreeding level on all traits. For each percentage of increased inbreeding, BW decreased by 0.06 kg, AFC increased by 3.5 days and CI increased by 1.4 days. The effects of the inbreeding level of the individual itself were not significant. The relatively good reproduction traits of Reyna Creole cattle shown in this study, despite high inbreeding levels, will be supplemented with a characterization of milk production traits.

Reyna Creole cattle originated from Bos taurus cattle brought to Latin America during the Spanish colonization in the fifteenth century and are the only remaining local breed in Nicaragua. However, the current genetic status of this breed is unknown. Therefore, the population structure of three recorded Reyna Creole herds in Nicaragua was studied to estimate their level of inbreeding, effective population size, and generation intervals. Data from 2,609 animals born between 1958 and 2007 were analyzed. A pedigree completeness index higher than 0.8 was required to obtain reliable estimates of the level of inbreeding, and this criterion was met for 367 animals (14%) in two herds. The average level of inbreeding was 13.0%, with values ranging from 0% to 43.8% for individual animals. One of the herds had an average inbreeding level of 21.6%, primarily due to long periods in which the same bulls were used for mating, leading to excessive frequencies of matings between closely related animals. The effective population size differed between years and ranged from 28 to 46 animals, showing that the Reyna Creole cattle breed is endangered, close to critical status. The average generation interval was 6.9 years with values as high as 19.1 years for some sires that were used for artificial insemination over a long period of time. Due to the high level of inbreeding and small population size, urgent actions are required for the development of a breeding program to protect the breed and support its sustainable utilization.

The main objective of this study was to investigate possibilities, to increase accuracy in the selection and test of Swedish warmblood stallions by combining information from stallion performance tests (SPT) with information from competitions and riding horse quality tests (REQT). Data on 801 stallions judged at the SPT 1979-2005 were used for the analyses, which also included about 14 900 horses from the RHQT, 26 800 horses with results in show jumping and 14 200 horses with results in dressage competitions. Heritability coefficients were on average 0.41 for individual gaits under rider and 0.36-0.65 for jumping traits in SPT. Heritabilities for competition traits were 0.17 for dressage and 0.27 for show jumping. The heritability for overall conformation in SPT was 0.25. Genetic correlations between stallion performance test traits and competition results were 0.44-0.77 for gaits and dressage, and 0.78-0.96 for jumping traits in SPT and show jumping. The genetic correlation between conformation and results in dressage competitions was 0.22.For stallions participating in SPT in 2004 and 2005 accuracy increased when evaluating stallions by adding information from relatives that have taken part in RHQT and competitions. For show jumping accuracy changed from 0.60 to 0.68 for stallions born in Sweden, an increase with 13%, when information from RHQT and competitions in show jumping were used. For stallions born in a foreign country, the corresponding figure was, 5%, lower. For dressage the information from RHQT and competition results in dressage changed the accuracy from 0.41 to 0.55, an increase with 34%, for stallions born in Sweden. The improvement in accuracy for imported stallions was 11%. (C) 2008 Elsevier B.V All rights reserved.

The aim of the present investigation was to study the genetic relationships between pelt quality traits (shade of fleece, size of curl, score for fleece colour, score for curl, score for quality of hair, score for thickness of fleece, sum of pelt scores, and overall score) on one hand and maternal ability, live weight, and carcass traits on the other hand for the Gotland sheep breed. Data were received from the Swedish Sheep Recording Scheme and included observations on 4-month weight (4MW) and pelt quality for 51,402 lambs and on weight (CW), fatness (FAT), and fleshiness (FLESH) of the carcass for 12,440 lambs. The lambs were born during the period 1991–2003. When maternal genetic and permanent environmental effects were included in the model direct heritabilities for the pelt quality traits varied between 0.16 and 0.25. Maternal heritabilities (0.01 to 0.05) and common environmental variances as a fraction of the total phenotypic variances (0.07 to 0.10) were low. Maternal heritabilities were higher for 4MW (0.11) and CW (0.12) than for the pelt quality traits. Direct-maternal genetic correlations were both for the pelt quality traits and for 4MW and CW generally negative and low to medium high. Direct genetic correlations between pelt quality traits on one hand and 4MW, CW, FAT or FLESH on the other hand were low (− 0.16 to 0.12). Maternal genetic correlations between pelt quality traits and 4MW or CW were positive and high (0.38 to 0.96). It was concluded that breeding for increased growth and improved carcass quality would not influence pelt quality negatively or vice versa. If maternal genetic effects are considered for 4MW and CW in the breeding program for the Gotland sheep breed, selection for maternal effects on 4MW and CW will have positive effects both on lamb weight and pelt quality.

In Swedish Red (SRB) dairy cattle, genetic effects on stillbirth and calving difficulty were studied in 804,268 first- and 673,150 second-calvers. Uni- and bivariate linear sire-maternal grandsire models were used to analyse calving data gathered between 1985 and 2000. Mean incidences of stillbirth were low and differed little between first and second parity, 3.6% vs. 2.5%. At first calving, the heritability of stillbirth on the visible scale was 0.7 - 1.3% for the direct effect and 0.5 - 0.9% for the maternal effect. For calving difficulty, the heritabilities were around 2.5% and 1.8 - 2.1% for direct and maternal effects, respectively. At second calving the corresponding heritabilities for the two traits were of the same order as at first parity, albeit somewhat lower for stillbirth. The genetic correlations between first and second calving results were around 0.8 for direct and maternal effects in stillbirth and around 0.7 for calving difficulty. Univariate models for first and second calvings, analysed separately and together in a repeatability model, were compared with a bivariate model which was assumed to be the most correct. The correlations between bulls' transmitting abilities for stillbirth were 0.94 - 0.96 between results for first calving analysed with a bivariate model and results from the repeatability model. It was concluded that calving traits at first and second parities could be treated approximately as the same trait. Bivariate analyses, or a repeatability model, including calving results for both heifers and cows should be preferred in genetic evaluations of SRB bulls as sires and maternal grandsires.

Contents: Eighty‐five animals were used to develop an embryo transfer programme including a study on how oestrus synchronization influenced the ovulation rate. The animals, both ewes and ewe lambs, were divided into three groups: donors, recipients and controls. Oestrus was synchronized in donors and recipients by the use of progesterone‐impregnated vaginal pessaries. The donors also received one injection of 600 IU PMSG. Samples for microbiological investigation of the vaginal flora were taken in connection with synchronization. The ovulation rate was determined by laparoscopy in the control animals and by laparotomy in the donors and recipients. The embryos were surgically recovered from the donors by flushing of the uterine horns seven days after pessary removal. The embryos were classified according to developmental stage and quality. At transfer each recipient received 2–4 embryos (moruhs or blastocysts) by a surgical method. A ± 1 day asynchrony in oestrus between donors and recipients was tolerated. All synchronized animals came into oestrus within 2.5 days after pessary removal. The interval was shorter if the animals had been injected with PMSG. The largest number of ovulations occuwed in the synchronized and PMSG‐treated animals (mean 4.5 ± 2.1). Synchronized animals that did not receive PMSG had almost the same ovulation rate as the control animals (2.6 ± 0.9 versus 2.5 ± 0.7). The pessary treatment influenced the bacterial flora of the vagina. The number of ewes with bacterial growth in the vagina increased. The number of isolated organisms also increased. The embryo recovery rate was 80.8% and 3.7 ± 2.7 ovas was recovered on average. Eighty‐eight percent of all donors yielded transferable embryos. Morulas and blastocysts comprised 84.4% of the recovered oocytes/embryos. Only 5.2% of these were of poor quality. Of the transferred embryos, 65.1% developed into lambs and 91.3% of the recipients lambed. The ewe lambs were as suitable as donors and recipients as the older ewes .