30. CHOMA,J. DÁVID,V.: The analysis of the diagnostic procedures with employment of biotechnological methods in dairy herds. (Diagnosztikai eljárások elemzése biotechnológiai módszerekkel tejelõ tehenészetben)

30. Choma

érk: 97.11.25.

UEVM, 04001 Kosice, Hlinkova 1/A, Slovak Republic

INTRODUCTION

In connection with the transformation of economy in our country, considerable and un-fortunately frequent undesirable changes have occurred. In some breedings, the situation has been stabilized. The management and/or owners of agricultural enterprises are actively searching the possibilities how to intensify the production and they con-sider the presented proposals very carefully.
In this connection, the endeavour to assess the situation in the field of reproduction has inspired us to process the computer outputs concerning the reproduction in more detail and to obtain a summary for a longer period of time from several herds.

MATERIALS AND METHODS

The data from three dairy cow herds in the form of summary computer output of the Reprovet program at a monthly interval, as far as possible, were included into processing. In one herd, the controlled reproduction was carried out systematically and for a long time. In other two herds, the works concerning the reproduction were ensured by a standard method.
The data about basic reproductive parameters including the herd's longevity (by means of the number of lactations) were processed into the primary tables. The values from these data were either used for the processing into a graphic form or they were used at first in relation to particular numbers (n) of respective animals to calculate the percentages and thereafter they were put into graphs.

RESULTS AND ASSESSMENT

The results obtained are depicted on the figures 1-4. For briefness sake, tables are not presented.
Figure 1 shows the gradual growth of originally very low number of parturitions for the herd RR that, however, did not reach values of both other herds despite the fact that there was a tendency of gradual decrease in the natality per a breeding cow. According to this indicator, the order of herds is unequivocal - SM2, SM1, and RR.

Figure 1.

Development of the average number of lactations with controlled reproduction (RR) and with standard method (SP);
values + 2,0 !
From Figure 2 it can be seen that the data in neither herd are complete for less than two years. In a herd with controlled reproduction (herd RR), a datum for one month is missing, in herd No. 1 with standard method (herd SM1) for four months and in herd No. 2 with standard method (herd SM2) for seven months. The initial mean value of the number of insemination per pregnancy (or insemination index) in herd RR was basically at an acceptable level. In the course of 3 to 5 months after RR began to be used, it slightly deteriorated and throughout the whole period left it has not changed too much. In both herds with standard method, the initial insemination index exceeded the value of 2.2 and it varied considerably in a course of time. The total dynamics is evident from the figure. In both herds with standard method, there is an obvious decreasing tenden-cy at the end of the first year. At the end of the second year, on the other hand, there was an increase in particular in herd SM2.

Figure 2.

The number of insemination per pregnancy in three herds with controlled reproduction (RR) and with standard method (SP);
values + 1,0 !
The initial values of the interval between herds (Figure 3) in comparison with the insemination index are completely different. They are the worst in the herd RR, quite good in the herd SM1 and almost ideal in the herd SM2. After initial 3 to 5 month slight decrease in the herd RR, in further seven months the interval with slight interruption was basically always longer and thereafter it gradually decreased to an ideal state. In both further herds, on the contrary, there was a tendency of permanent deterioration. The deterioration in the herd SM2 persisted by March of the second year with sub-sequent improvement. In herd SM1, however, the state was permanently deteriorating by September of the second year.

Figure 3.

The changes in parturition - insemination interval in three herds with controlled reproduction (RR) and with standard method (SP);
values + 50,0 !
Open days (Figure 4) at highest initial value for a herd SM2 showed a tendency to deteriorate slightly throughout the whole period of observation. In more detailed charac-terization after the period of interrupted lengthening in the first year (March to Novem-ber), during the summer months of the second year it was basically at the initial level and it has repeatedly deteriorated at the end of the year. In the herd SM1, the tendency of deterioration was marked particularly in the course of the first year (by October). From November to March of the second year it decreased (to less than a half of the original March-October increase), then it lengthened again to the highest value for this herd in August. In the herd RR after the initiation of the use of biotechnical methods, the service-period has been lengthening by the end of June. Thereafter, practically by February of the next year, it has been shortening at first markedly, and then slightly. The subsequent lengthening peaked in April and it persisted by June. In next months, gradual shortening to an ideal length can be seen. In comparison with previous year, however, it was slower.

Figure 4.

The changes in open days in three herds with successful use of controlled reproduction (RR) and with standard method (SP);
values + 80 !
When assessing the results as a whole it can be stated that the reproductive situation of the herd RR was improving. The development of the state of open days as well as the number of insemination per pregnancy were satisfying. On the other hand, the reproduction in herds SM1 and SM2 has deteriorated in all parameters observed except for the insemination index that is a bit better at the end of the second year than at the beginning. This is, however, negligible to its real value. The effect of successful, systematic use of biotechnical methods in the first herd is beyond any doubt. It does not explain, however, all deviations recorded. The processing of other available data about these herds will be certainly helpful in a better assessment of graphically presented results and in understanding them better. The work on these subjects continues.
The results obtained indicate that after the initiation of the use of biotechnical methods, instead of an improvement, on the contrary, the deterioration of reproductive parame-ters may occur; in our case it lasted 3 to 4 months. Obviously, also the season of the year has contributed to the deterioration as the value of open days has worsened in the second year as well although a month earlier and in a lesser extent. On Figures (Nos. 3, 4, and 2) the similar deteriorations can be seen that last, however, a bit longer (5 to 7 months ) and sometimes are interrupted. At assessing the suggested and introduced measures these phenomena may participate in "false positivity or false negativity" of the obtained results and their interpretation. These may occur in particular at the assessments for a short period.

CONCLUSION

In the present study, the results of the course of basic reproductive functions are pro-cessed based on summary monthly outputs of computer program of Reprovet, namely in two herds with a standard method and in a herd with the use of biotechnical methods. The number of insemination per pregnancy, parturition first insemination interval, open days, and production viability of herds have been observed. The results show a tendency of a deterioration of reproductive parameters with standard method and, on the contrary, an improvement with the intensive reproductive care. The approach used in this study enables to obtain the clear knowledge and after processing of further data, also detailed real bases about the situation in a herd.