Assessment of limits for racing speed in the Italian trotter population

The current world record for trotter is 68.0 s/km, that is better than the estimates of record limit reported in literature (68.2 s/km for males and 69.1 s/km for females in Swedish Trotters): this is way the record limit was investigated in Italian Trotter using the same methodology applied to Swedish Trotter. The best racing times of 30'587 3-5 year old Italian Trotters, recorded between January 1st, 1992, and October 31th, 2009, have been log transformed to check for trends and asymptotic limit: a positive trend is present, and limits of 61.8 s/km and 62.8 s/km have been respectively estimated for males and females. The Generalized Extreme Value theory, applied to the 3-year old winners of the Italian Trot Derby, estimates a limit of 64.7 s/km. These results indicate that the limit for racing speed is still far from actual values

Estimation of Genetic Parameters for Peak Yield, Yield and Persistency Traits in Murciano-Granadina Goats Using Multi-Traits Models

This paper studies parameters of a lactation curve such as peak yield (PY) and persistency (P), which do not conform to the usual selection criteria in the Murciano-Granadina (MG) breed, but are considered to be an alternative to benefit animal welfare without reducing production. Using 315,663 production records (of 122,883 animals) over a period of 24 years (1990–2014), genetic parameters were estimated with uni-, bi- and multivariate analysis using multiple trait derivative free restricted maximum likelihood (MTDFREML). The heritability (h2)/repeatability (re) of PY, yield (Y) and P was estimated as 0.13/0.19, 0.16/0.25 and 0.08/0.09 with the uni-trait and h2 of bi- and multi-traits analysis ranging from 0.16 to 0.17 of Y, while that of PY and Y remained constant. Genetic correlations were high between PY–Y (0.94 ± 0.011) but low between PY–P (–0.16 ± 0.054 to –0.17 ± 0.054) and between Y–P (–0.06 ± 0.058 to –0.05 ± 0.058). Estimates of h2/re were low to intermediate. The selection for Y–PY or both can be implemented given the genetic correlation between these traits. PY–P and Y–P showed low to negligible correlation values indicating that if these traits are implemented in the early stages of evaluation, they would not be to the detriment of PY–Y. The combination of estimated breeding values (EBVs) for all traits would be a good criterion for selection

Optimization of the Performance Test Length for theSella ItalianoStallion

The Sella Italiano stallions are selected by 100-day perfomance test, but many breeders organisations use station test of shorter length. In twelve editions, 17,394 ten-point scores both for character and gaits, and 6291 scores for jumping were assigned to 314 candidate stallions. By means of the comparison of univariate EBVs, calculated from the complete dataset or from the reduced subsets, a dataset lasting only from 33rd day to 78th day of the training period was selected: it included less than 70% of the original data. The subset was validated by 3-trait AM BLUP: there were no evident effects on the estimates of variance component or ratio, and the aggregated selection index for the three traits showed a 99% rank correlation with the official index. These findings demonstrate that the training period could be reduced without affecting the genetic progress in the Sella Italiano breed

Analysis of founders and performance test effects on an autochthonous horse population through pedigree analysis: structure, genetic variability and inbreeding.

The Maremmano is an autochthonous Italian horse breed, which probably descended from the native horses of the Etruscans (VI century B.C.); the Studbook was acknowledged in 1980, and it includes 12 368 horses born from that year up to 2015. The aim of this study was to evaluate the effect of the selection program on the genetic variability of the Maremmano population; the analysis was performed using both the 'Endog v 4.8' program available at http://webs.ucm.es/info/prodanim/html/JP_Web.htm and in-house software on official pedigree data. Four Reference Populations were considered, and the most important one was the population of the 12 368 Maremmano horses officially registered in the National Studbook. The pedigree completeness of this population was very good because it was more than 90% at the third parental generation and more than 70% at the fifth generation; the pedigree traced back to a maximum of 10.50 generations with an average of 3.30 complete generations and 5.70 equivalent complete generations. The average generation interval was 10.65±4.72 years, with stallions used for longer periods than mares. The intervals ranged from 10.15±4.45 (mother-daughter) to 10.99±4.93 (father-daughter). The effective number of founders (f e) was 74 and the effective number of ancestors (f a) was 30 so that the ratio f e/f a was 2.47. The founder genome equivalents (f g) was 13.72 with a ratio f g/f e equal to 0.18. The mean of the genetic conservation index was 5.55±3.37, and it ranged from 0.81 to 21.32. The average inbreeding coefficient was 2.94%, with an increase of 0.1%/year, and the average relatedness coefficient was 5.52%. The effective population size (N e) computed by an individual increase in inbreeding was 68.1±13.00; the N e on equivalent generations was 42.00, and this value slightly increased to 42.20 when computed by Log regression on equivalent generations. The analysis confirmed the presence of seven traditional male lines. The percentage of Thoroughbred blood in the foals born in 2015 was 20.30% and has increased 0.21%/year since 1980; in particular, it increased more than twice (0.51%/year) until 1993 and afterwards slightly fluctuated. The pedigree analysis confirmed the completeness of genealogical information and the traditional importance that breeders gave to the male lines; although the genetic diversity of Maremmano seemed to be not endangered by the selection program, some effects on the population structure were found and a more scientific approach to genetic conservation should be incorporated in the selection plans

the use of a random regression model on the estimation of genetic parameters for weight at performance test in appenninica sheep breed

The Appenninica breed is an Italian meat sheep; the rams are approved according to a phenotypic index that is based on an average daily gain at performance test. The 8546 live weights of 1930 Appenninica male lambs tested in the performance station of the ASSONAPA (National Sheep Breeders Association, Italy) from 1986 to 2010 showed a great variability in age at weighing and in number of records by year. The goal of the study is to verify the feasibility of the estimation of a genetic index for weight in the Appenninica sheep by a mixed model, and to explore the use of random regression to avoid the corrections for weighing at different ages. The heritability and repeatability (mean±SE) of the average live weight were 0.27±0.04 and 0.54±0.08 respectively; the heritabilities of weights recorded at different weighing days ranged from 0.27 to 0.58, while the heritabilities of weights at different ages showed a narrower variability (0.29÷0.41). The estimates of live weight heritability by random regressions ranged between 0.34 at 123 d of age and 0.52 at 411 d. The results proved that the random regression model is the most adequate to analyse the data of Appenninica breed

On the use of elo rating on harness racing results in the genetic evaluation of trotter

The official results of trotters in Italian harness racings have been used to get AM-BLUP estimates of genetic parameters, EBVs and rTI of three groups of traits: speed (racing time, annual best time, best time in career between 2- and 5-year old), earnings (earnings/start, annual earnings, total earnings between 2- and 5- year old) and Elo system traits (underlying performance and final rating). The Elo system has been used for half a century in chess players rating, and it has been modified and fitted to several games and sports: it has already been used for genetic evaluation of sport horses in France. The highest heritability estimates in each group of traits have been found for best time (.430±.014), total earnings (.271±.013) and Elo final rating (.270±.008). The choice of "k", the Elo ratings updating factor, did not show a key role in affecting the results. The underlying performance heritability and repeatability have been estimated .159±.004 and .420±.007 respectively. The Elo-based systems proved to be very promising in objectively evaluating trotters

Primera valoración genética Blup en el caballo trotador español

Tras la aprobación del Esquema de Selección específico para el Caballo Trotador Español (l de septiembre de 2005), se ha realizado la primera Valoración Genética para carreras de trote con metodología BLUP modelo animal en España, en base a los resullados deportivos obtenidos por los animales de esta raza en 4.180 carreras celebradas durante los años 2003-2005. Trabajando con un total de 42.993 registros de participación pertenecientes a 1.580 animales (832 machos, 593 hembras y 155 castrados), se estimaron los parámetros genéticos y los valores de cría para los tres caracteres seleccionados: ganancias anuales (GA), mejor tiempo anual (MTPA) y porcentaje de puestos clasificado entre el primero y el cuarto (PPC). El modelo genético-estadístico empleado incluye el sexo del animal, el año de nacimiento, el año de carrera y el número de participaciones registradas cada año (covariable de GA) como efectos fijos; y el efecto aditivo directo y el efecto ambiental permanente como factores aleatorios

Exercise-induced up-regulation of MMP-1 and IL-8 genes in endurance horses

<p>Abstract</p> <p>Background</p> <p>The stress response is a critical factor in the training of equine athletes; it is important for performance and for protection of the animal against physio-pathological disorders.</p> <p>In this study, the molecular mechanisms involved in the response to acute and strenuous exercise were investigated using peripheral blood mononuclear cells (PBMCs).</p> <p>Results</p> <p>Quantitative real-time PCR (qRT-PCR) was used to detect modifications in transcription levels of the genes for matrix metalloproteinase-1 (<it>MMP-1</it>) and interleukin 8 (<it>IL-8</it>), which were derived from previous genome-wide expression analysis. Significant up-regulation of these two genes was found in 10 horses that had completed a race of 90–120 km in a time-course experimental design.</p> <p>Conclusion</p> <p>These results suggest that <it>MMP-1 </it>and <it>IL-8 </it>are both involved in the exercise-induced stress response, and this represents a starting point from which to understand the adaptive responses to this phenomenon.</p

Pre-selection of most significant SNPS for the estimation of genomic breeding values

The availability of a large amount of SNP markers throughout the genome of different livestock species offers the opportunity to estimate genomic breeding values (GEBVs). However, the estimation of many effects in a data set of limited size represent a severe statistical problem. A pre-selection of SNPS based on single regression may provide a reasonable compromise between accuracy of results, number of independent variables to be considered and computing requirements