Variability of fundament traits in primiparous simmental heifers

Visual evaluation and recognition of dairy traits of cows are preliminary indicators of milk yield, longevity, and reproductive ability of the individual animal, which is very important from the aspect of the economics of milk production. The deficiencies in the fundament traits lead to poor production, poor health and premature culling of cows from the herd. The paper examines the frequency of preferred scores of a certain trait in the first calving heifers according to the housing method (animals reared by individual agricultural producers and farm animals) and their origin (domestic and imported animals), as well as the impact of these two factors on the observed properties. Four fundament traits were analysed: the position of the hind legs, the development of the hocks/joints, the pastern joints and the height of the feet on a total of 954 first-calving Simmental heifers. Observed by the housing method, the higher frequency of the preferred scores for all of the fundament traits, was achieved by the farm cows, while according to the origin of the cows, the higher frequency of the preferred scores for all of the fundament traits was realized by imported animals in relation to domestic cows. The influence of the factors of the housing method and origin of animals examined by χ2 test on all the tested linear scores (frequency of scores) of the fundament traits was statistically very significant (p≤0.001), while the analysis of the variance (F test) determined high significance (p≤0.001) of the interaction between the origin and housing method on the height of the feet, as well as significant effect (p≤0.05) on the position of the hind legs, while on other linear scores of the fundament traits it did not exhibit statistical significance (p>0.05).


Introduction
The evaluation of the exterior of animals is based on knowledge of the structure and function of individual organs as well as the most important relationships between the individual parts of the body.
Assessment of body development of cattle is a critical evaluation of whether the affected animal, by its overall appearance and individual parts of the body, can guarantee good health and high production, or longevity. Inclusion of a linear type score, contributes to the estimation of the cow's breeding value, which positively reflects on the overall results of the selection and the success of production (Pantelić et al., 2006).
Linear assessment includes the evaluation of each trait in its biological extremes, according to the scale ranging from 1 to 9 in the scorecard, and it should be emphasized that the highest score (9) is not the most favourable for each trait, because for some traits the average grades (5) is the best (Petrović and Pantelić, 2015).
A minimum set of feet and leg traits required in an effective selection program include the results or measurements of one or more feet traits and the assessment of the leg traits. The combination of angles, length and diagonals of the hind feet seems to be the best combination that allows the ease and precision of scoring or measurement and predictive values for the lameness traits of the feet. In fact, some data suggest that only the diagonal of the feet is sufficient measurement (Boelling, 1994;McDaniel and Vilk, 1996). Which traits of the hind legs should be included is not so well established. Most programs use the position of the rear legs -side view, which primarily reflects the angle of the hock joint. Boelling (1994) finds that it is more related to locomotion results than to feet measurements. Other data show that the position of the hind legs is more informative for the prediction of survival (McDaniel et al., 1993), although less hereditary than the side view. When available, estimates of locomotive properties look like useful predictors. The actual incidence of lameness should be included when present, but the studies do not compare its value with respect to the indirect selection based on scores for feet and leg traits and locomotion results.
By studying the incidence of deformity of the extremities of the Simmental cows depending on the type of bedding, Stojanović et al. (2018) reached the following results: of the total number of studied cows 3.45% had "X" front leg position, 14.8% had "X" position of the hind legs. The convergent position of the front legs was recorded in 35.86%, and divergent in 8.28% of animals. The convergent position of the hind legs was established in 16.55% of cows, and divergent in 2.76%. The forward protruding position of the front legs was recorded in 4.14% of cows, inducted position in 11.03%, and a broad position in 4.14% of animals. The sickle position of hind legs was recorded in 17.24% of the cows, and 7.59% of animals were post-legged. The pronounced soft front leg pasterns were Variability of fundament traits in... 315 determined in 7.59% of the cows, and the soft pasterns of the hind legs in 33.79% of the total number of estimated cows. The observed changes in the joints in the shape of swellings were recorded in 1.38% of cattle on the carpal joint and 2.76% on the tarsal joint. The affected blade and body joint (scurry shoulder) was recorded in 43.45% of the total number of cows. The body weight of Busha cows in the area of the Pirot district amounted to 226.07 kg, the height to withers 104.33 cm, the height to rump 104.12 cm, pelvis width 32.52 cm, breast depth 53.97 cm, breast girth 130.48 cm, and body length 119.67 cm.
By studying correlations between the milk performance and the fundament traits, results obtained show mainly negative correlations (Boelling and Pollott, 1997). Their results suggest that lameness will increase as a result of the selection on increased milk yields, unless taking into account the traits of the fundament. Uribe et al. (1995) find that genetic correlations of production with "troubleshooting of leg problems" ranged from 0.20 to 0.27 and indicate that longterm selection on yield has probably reduced the problems that arise in the fundament traits. Foot and leg disorders were correlated with milk performance in the United States, r = 0.48 (Lions et al., 1991) and the Netherlands r = 0.26 (Groen et al., 1994).

Material and methods
The basic data on the traits of the fundaments, as well as the data on the origin of all examined cows, were collected in cooperation with the farm "Lazar" Blace housing a number of animals included in this research. For animals housed on individual farms, data on these traits were collected in cooperation with breeding organizations, which implement the breeding program in the area of Toplica district.
The total number of animals (n = 954) used in the analysis of morphometric traits were divided into two groups based on the housing method, and two groups based on origin, in the following way: Based on the housing method: Group 1: animals reared by individual producers (n = 504); Group 2: animals reared on the farm (n = 450); Based on the origin: Group 1: animals of domestic origin (n = 718); Group 2: imported animals (n = 236).
All of the properties of the fundament were evaluated linearly after the first calving: the position of the hind legs, the development of the hocks, the pastern joints and the height of the hoof.
The processing of collected data consisted in determining the frequency for each assessment individually, the frequency of the preferred scores for all the traits of the fundament and the comparison of the received frequencies by groups.
Subsequently, the influence of the housing method (applied χ2 test) and the influence of the origin (χ2 test applied) on the frequency of linear scores for each property of the fundament was examined, while the analysis of variance examined the influence of the housing method and origin, as well as their interaction with all linear scores, in the following model with a fixed influence on the housing method and origin and their interaction: Yij=µ+Ni+Pj+NPij+eijk • Yij: examined trait, • µ: population average for given trait, • Ni: fixed effect of i housing method (i=1,2), • Pj: fixed effect of j origin (j=1,2), • NPij: effect of interaction between factors (housing method and animal origin), eij: random error For statistical data processing and application of the specified model, the software SPSS Statistics for windows, Version 23.0 was used.

Results and Discussion
Based on the results shown in Table 1, it can be concluded that the majority of animals had preferable scores for studied trait, with animals reared on the farm (79.56%) and animals originating from import (83.05%) had a higher frequency of desirable scores compared to animals reared by individual producers (60.12%), and animals of domestic origin (64.76%). The effect of animal origin and housing method was statistically very significant (p≤0.001) on the frequency of the rear leg assessment, examined by the χ2 test. By variance analysis (F test), significant influence (p≤0.05) of origin and interaction of origin and housing method was determined.The frequency of preferable scores for the development of the hock joints was twice as high in farm animals compared to the first-calving heifers reared by individual producers and amounted to 49.33%. A higher percentage of preferred scores was also recorded in imported animals (40.25%) compared to animals of domestic origin (33.85%).
On the basis of the χ2 test of the independence of the trait, a statistically very significant correlation (p≤0.001) of the origin and score for the development of the hock joints was established in the first place, as well as the housing method and scores for the same trait. The variance analysis (F test) showed a high significance of the housing method (p≤0.001), while the origin of the animal and the interaction of origin and housing method did not have a statistically significant effect (p> 0.05) on the development of the joints. By analysing the pastern joints and the height of hoofs, according to the groups (Table 2), the lowest percentage of cows with favourable scores for pastern joints were cows grown by individual producers (52.78%), then cows of domestic origin (63.37%), (74.15%) and the highest percentage with favourable scores for the pastern joints were cows reared on the farm (80.89%).
By testing the frequencies using the χ2 test, it was found that there was statistically very significant variation (p≤0.001) for pastern joints influenced by the method of rearing of cows and their origin. By analysing the variance (F test), a highly significant influence of the rearing method was determined (p≤0.01), significant influence of the animal origin (p≤0.05), while the interaction of origin and housing did not have a statistically significant effect (p> 0.05) on the pastern joints.
The frequency of the preferred scores for the observed trait was considerably higher in farm animals (67.11%), than in the animals reared by individual producers, where only 18.25% of first calvers obtained preferred scores. If the observed population is viewed on the basis of animal origin, it can be noted that the frequency of preferred scores was slightly higher for the imported animals (41.95%), than for the animals of domestic origin, where 41.09% of first calving heifers received preferred scores for the height of the hoofs.
The influence of the animal origin and the method of housing was statistically very significant (p≤0.001) on the frequency of scores for the height of the hoofs, examined by the χ2 test. By variance analysis (F test), a very significant influence (p≤0.001) of the way of housing, the origin of the animals and their interaction was also determined. Housing x Origin F=19.328*** p=0.000 ***-p≤0.001; ** -p≤0.01; * -p≤0.05; nz -p>0.05

Conclusion
By examining the fundament traits in the first calving heifers of Simmental breed observed according to the method of housing, the higher frequency of the preferred scores for all the fundament traits was recorded for farm cows, while in regard to the origin, a higher frequency of the preferred scores for all fundament properties was recorded in imported cows compared to cows of domestic origin. The influence of the factors of housing method and origin on all tested linear estimates (frequency of estimation) of the fundament traits, examined by χ2 test, was statistically very significant (p≤0.001), while the analysis of the variance (F test) determined high significance (p≤0.001) of the effect of origin and housing method on the height of hoofs, as well as significance (p≤0.05) of the effect on the position of the hind legs, while on other linear scores of the fundament traits it did not exhibit statistical significance (p> 0.05).
Genetic improvements in fundament traits are unlikely to prevent all foot problems, but the choice of animals with preferred scores for the height of hoofs, pastern joints, the development of the hock joints, and the position of the hind legs can reduce their incidence in the herd. By examining the scores of the fundament traits, it can be concluded that their significance lies in the longevity of the cows and, consequently, on the livestock production.