INTRODUCTORY RESEARCH ON RELATION BETWEEN BIOMETRIC RATES OF GROWING TROTTERS AND PARAMETERS OF THEIR MOVEMENT CAPACITY IN INITIAL TRAINING STAGE

Marian Kaproń¹, Iwona Janczarek¹, Anna Suska², Iwona Marchel^1
1 Department of Horse Breeding and Use, Agricultural University of Lublin, Poland
² Department of Horse Breeding and Use, Podlaska University of Siedlce, Poland

ABSTRACT

The aim of this paper is to initiate nationwide research on trotters, in this case relations between conformation traits of their body and performance features. Material for the research was provided by 60 young trotters registered in the Danish (12) and German (48) herd books of the analysed breeds. The horses were prepared in automn 2004 for taking part in races. Trotters were also subject to 23 zoometric measurements, based on which 15 indices of their body conformation were worked out. Additionally, the evaluation of movement capacity was accomplished, including 1 – step length, its frequency as well as index and speed movement velocityof the analysed horses. Trot was repeated 3 times (starting with the slowest to the fastest one) on a specially marked part of racetrack. The evaluation of relations between measurements and indices of body conformation of the analysed trotters and their movement capacity parameters indicated the following suggestions:

• both the range and number of statistically significant dependencies between biometric features of trotters and their movement capacity point to the fact that croup conformation traits and height of individual parts of young growing trotters affect (positively or negatively) their movement capacity in the initial training process,

• the above tendencies are proved by the level of dependencies of body conformation with movement capacity parameters including a great number of statistically significant relations concerning proportions in the croup conformation (indices “shoulder part length”, “index of joint croup length”), conformation traits of shoulder belt (“shoulder part length” and “selected parts of forelimb”) as well as the rate of reconformation and chest depth,

• the carried out research is of introductory character but the range of revealed dependencies fully justify its continuation for young growing trotters as well as trained in subsequent stages of their racing career.

Key words: biometric measurements, horses, movement capacity, trotters.

INTRODUCTION

The history of horse breeding in Poland [3,4,5,15] has not marked any systematic trottter races, which brought about the fact that this type of horses has not been bred on a larger scale. Currently, profound social, political and economic changes caused a far-fetched liberalism in breeding and utlizing different breeds and types of horses. Moreover, the above changes liberated the need to seek spectacular and unknown forms of utilizing horses. They also contributed to a rapid development of private breeding centres, especially in early 90s [2], riding horses in a Western style as well as training and racing attempts of trotters. Breeding of the above type of horses has been recognized by the agreement to carry on trotter breeding and issuing a herd book. However, this kind of breeeding remains at an early stage and the first races were held only in automn 2004. Nonetheless, there are several training centers for trotters of the West European origin in the regions of Pomorze Zachodnie, Warmia and Mazury, Mazowsze and Dolny Slask and two of them have been functioning since mid-90s. The trotters trained there come from breeding centres in Germany and Denmark. After having reached a certain stage of training, they are transported to either their home countries or to take part in races. It is assumed that together with getting experience and different types of promotion of West European trotter breeds, their breeding will become more and more important and are likely to be introduced by an increasing number of Polish breeders.

Taking into account the above reasons and the further development of trotter breeding in Poland, this study has attempted at the rationalization of their training methods and evaluation of their production value through the application of the assessment of relationship between certain measures and body conformation indices of analysed horses and their movement capacity.

The fundamental objective of this research is not only to initiate studies on this horse breed, which is extremely specific for Polish conditions, but also evaluate the relations between body conformation traits of young trotters in their growth and their production value. The findings will serve to provide certain indications regarding their further racing ability. Such an evaluation is significant with a view to considerable financial outlay connected with their breeding, gradual racing implemetation and further exploitation which may turn out completely unprofitable due to a lack of earlier recognition of potential abilities.

MATERIALS AND METHOD

Material for the studies was provided by 60 young trotters bred in Germany and Denmark aged between 11 and 30 months, which were prepared for harnessed trotter races in automn 2004.

The examined trotters were subject to zoometric measures, in compliance with the methodology used for half-bloods and racehorses [10], obtaining 23 measures of certain body parts and distances between their morphological points. All the measurements were based on common principles [16] to determine their height at withers, backcrupper and tail base, chest depth and girth, skew body length, length of leg, shoulder, forearm, foreshank and hindshank, croup as well as width of shoulders and croup. It was also suggested in the studies to utilize the distance between certain body points of horses, like hip point-hip joint, hip joint – knee joint, hip joint- point of buttock, hip joint-hock joint, knee joint-hock joint. This method of determining distances has been characterised in the earlier study [7].

Proportions in body conformation of the trotters were analysed by means of the so-called “body conformation index” including: reconformation, chest depth, boniness, croup width and length, shoulder width and eurysomy which have been so far used in numerous studies [15]. They were completed by own indices such as “shoulder part length”, “selected parts of forelimb”, “croup size”, “joint croup length”, “croup triangle” and “hindlimb length”. The formulas of the analysed indices were given in the earlier work [7] connected with the evaluation of relationship between conformation properties and movement capacity of half-blood stallions.

The evaluated trotters, harnessed to training trolleys were tested for their movement capacity on a flat, sandy, 30-metre long racetrack, measuring 5 steps of each horse. The distance was determined based on the length of the distance covered by each trotter starting with the trace of hoof tip of interior leg (after beginning the first step) to the sixth step.

The tested trotters covered the track 3 times. The pace of the trot increased from the slowest to the fastest possible due to a low training advance. The first ride was called “slow”-17-18 kmph, the second “medium”-27-28 kmph, and third “fast”-37-42 kmph. In order to boost the reliability of the analyses, average parameters of movement capacity were established on the basis of average values from the 3 rides.

The evaluated movement capacity parameters included: one step length (in meters with 0.01 m acccuracy) in all 3 rides and step frequency (number of steps per minute).

Both biometric rates of tested trotters and their movement capacity parameters were statistically analysed using simple characteristics. The relationship between examined biometric and movement traits were estmated by means of simple correlations.

RESULTS

Parameters of statistical characteristcs of measures (Table 1) and indices of body conformation of young, growing trotters indicate a phenotype levelling of tested trotters, due to relatively low varibility coefficients (V). Their values are definitely lower than 15%, which is considered the upper limit of variability of statistically analysed traits: in fact, the V values do not exceed 10% in most cases. It should be noted that V – values are low related to the body conformation index (Table 2), where none of them exceeded 10%. The observed tendencies prove the need to analyse biometric conformation traits of young growing trotters, mainly because of their considerable phenotype levelling.

An equally high degree of homogeneity was not stated in relation to the analysed parameters of movement capacity (Table 3) of the tested trotters. The main reason for that seems to be their introductory character and low degree of training advance. Nevertheless, in a vast majority of cases, V-values do not exceed 15% in relation to such parameters as :step length and its frequency as well as step index. Fairly considerable V-values were noted for movement velocity of the tested trotters, which can be explained by their training ability. Yet, in none of the cases do they reach 30%.

The analysis of relationship between biometric traits of trotters and their movement capacity points to frequent and repeated statistically significant positive links (Table 4). The greatest number of highly significant and significant correlations was found on analysing step length in all 3 trot types and a considerably smaller number related to other movement parameters and not to any trot type. The greatest number of statistically significant correlations pertained to the so-called “height biometric traits” (height at withers, back, crupper and tail head). In a slow trot they reached between 0.312* and 0.417**, in medium from 0.361** to 0.444** and fast from 0.349** to 0.445**. The average relationship value for the 3 trot types was between 0.378** and 0.498**. It should be noted that the height at tail head showed the most frequent and highest level of relationship with step length (slow trot 0.417**, medium 0.418**, fast 0.445**), step frequency (slow trot 0.345, average –0.278) and index(slow trot 0.288**, medium 0.363**, average 0.270*). The analysed tendency would indicate the fact that less sloping and more horizontal croups of young growing trotters influence have a greater impact on movement capacity parameters. Some variable relationships also occurred in the case of chest depth and step frequency in slow (–0.311*), medium (–0.282*) and average trot (–0.288*) as well as step legth in medium (0.287*), fast (0.274*) and average trot (0.306*). To a smaller degree, this also affected skew body length having a positive influence on step length in fast trot (0.307*).

The croup conformation of young trotters is clearly related to their step length in all analysed cases, as it amounts to 0.303* in slow trot, 0.435** in medium trot and 0.367** in fast trot (0.433* combined). Croup width had a negative influence on step frequency in average trot (–0.281).

Measures such as shoulder width, chest girth, leg length, forearm length and foreshank length rarely showed a relationship with movement capacity of young trotters in different trot types; a highly significant level was only found for the correlation between leg length with average trot speed (0.325**) and chest girth with step length in fast trot (0.370**).

Very interesting tendencies were found on evaluating the relationship between measures of croup conformation and movement parameters in different trot types. The distance “hip joint – knee joint” (giving approximate length of thigh bone) is negatively highly significantly correlated with step length (slow trot – 0.685**, medium – 0.466**, fast – 0.350** and average – 0.583**) , and positive relationships are related to movement speed (slow trot 0.424**, medium 0.490**, fast 0.439**). Distance “hip joint – knee joint” also indicated a negative relationship with the step index in all trot types (slow – 0.709**, medium – 0.445, fast – 0.369). The other measure, significantly related to movement capacity parameters, is the distance “hip joint – point of buttock”, which positively influenced step length in slow (0.583**), medium (0.590**), fast (0.306) and average trot (0.579**). It influenced negatively movement velocity: in slow trot (–0.426**), medium (–0.503**) and fast (–0.376*) as well as average (–0.533**). The analysed distance also affected negatively movement velocity in slow (–0.323*), medium (–0.408*) and average trot (–0.313*). It had a positive influence on step index in slow trot (0.568**), medium (0.513**) and fast (0.275*). A slightly smaller number of relationships was found for the influence of the distance “hip joint – hock joint” on individual parameters of movement capacity of trotters. It was stated that the greatest number of relationships within this measure was related to parameters in medium trot – step length (0.367*), step index (0.327*), step frequency (–0.320*) and velocity (0.281*). A fewer number was established for slow trot (step length 0.308*), step index (0.312*), average trot (step length 0.348**) and step frequency (–0.326**).

The results of estimated relationship between body conformation indices and their parameters of movement capacity are presented in Table 5. Their greatest number was established in relation to the “croup triangle” index in which significant relationships were determined between the analysed parameter and step length in slow trot (–0.555**) and its index (–0.549*) and medium trot (0.491** and –0.421**, respectively). They appeared in the average results of all trot types, in relation to step length (–0.474**) and movement velocity (0.485**). The only highly significant relationship established for fast trot was movement velocity in the third trot (0.423*). Additional statistically significant correlation coefficients were given also in relation to the index of “selected parts of forelimb” and and step length in slow (0.280*), medium (–0.510*), fast (–0.248*) and average trot (0.410**).The third statistically significant correlation was the one between “cumulative croup length” with step length in fast trot (0.426**) and its index (0.372**) as well as step length in average trot (means of 3 measurements). Statistically significant relations were established with referrence to “shoulder part length”, step length in slow (–0.249*) and medium trot (–0.455**). This also pertained to restructuring indices and their significant connection with step frequency in medium trot (–0.382**) and movement velocity (–0.427**) as well as chest depth with the parameters mentioned before (step frequency – 0.344** and movement velocity – 0.483**). Individual statistically significant coefficients were found in relation to chest girth (0.309*) in slow trot and boniness index (–0.273*) in medium trot.

It is impossible to compare directly the obtained results with those achieved by other authors due to the introductory character of the studies. The research carried out in foreign countries has a different character [1,12,13,16] since there are no studies availble in Poland on the connections between biometry of trotters and their performance.

CONCLUSIONS

However, this study aims at indicating tendencies which should possibly be confirmed in the following further research:

• both the range and number of statistically significant relationships between biometric traits of trotters and their movement capacity shows that croup construction traits as well as height of individual parts of young growing trotters affect considerably (in a positive or negative way) their movement capacity in the process of introductory training,

• the above trends are also confirmed by the number of connections between body conformation indices and movement capacity parameters, within which the greatest number of statistically significant relations refers to the proportions of croup conformation (“croup triangle” index, “cumulative croup length”), shoulder belt conformation traits (“shoulder part length” and “selected parts of forelimb” index). Also important are reconformation and chest depth rates,

• the research carried out so far has an introductory character but the range of revealed relationships fully justifies its continuation as far as young and growing trotters are concerned, but also in the training process of their subsequent stages of racing career.

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