Juris Priekulis

Research in milking intervals applying different types of milking parlours

The main problem in using the AMS is that cows do not attend the AMS voluntarily. To ensure milking three or four times a day, in many farms cows are driven to the AMS several times a day. Representatives of companies recommend that it only takes place at the beginning and at the end of a workday. In such a case, cows gradually get used to milking as many times a day as it is intended. However, the question is – does this really happen? Next to the concern regarding the provision of the intended milking times a day, farmers are also worried about milking interval dispersion. Appropriate studies were carried out to see what happens in farms, where cows are driven to the AMS in the morning and in the evening only. At the same time, analogous studies were carried out in a holding, where cows were milked with milking parlour. The studies were conducted in two holdings. In the first holding, cows were milked with the AMS, but in the second – with parallel parlour. Ten cows were selected for each experimental group, and the studies lasted for 15 days. They determined the number of milking times per day (milking/day), and the distribution and dispersion of milking intervals. The results of the study showed that in practice it was possible to achieve that the AMS is attended more than 3 times a day, on the condition that only cows with a milking interval of more than 13 hours are driven to the milking site in the morning and in the evening. However, at the same time it was found that there would always be cows in a herd that have been milked both more and less than three times a day. When milking with the AMS, milking intervals vary widely, yet in 80 % of the cases they vary between 5 and 6 hours. First lactation cows (as compared to older cows) are more inert to attend the AMS, and their dispersion of milking intervals is greater. In turn, milking parlour ensures that all cows undergo the set number of milking times and it helps keep smaller fluctuations in milking intervals. If 60 to 80 cows are milked in one group, the fluctuation of the milking interval does not exceed 2 hours.

Research in milking intervals on practice farm using automated milking systems

The aim of the research is to state how the voluntary milking principle is implemented on the practice farm milking cows using automated milking systems (AMS). For the research the following tasks were set: to state the distribution and dispersion of the milking intervals as well as to determine the correlation between the yield per milking and the milking intervals. The research was performed on a good practice farm where 110 cows are milked with two DeLaval AMS. The selectively guided cow traffic to the AMS “first feeding, after milking” is used. The cows with milking permission but not milked yet are guided to the AMS in the morning and in the evening. Besides, a couple of times per day also the cows that are not milked, but for which milking is planned 3 to 4 times per day, are also guided to the AMS. The research was performed in 10 days with all 110 cows included. The input data necessary for the research were obtained from the AMS control system. pIt was stated in the research that the average yield per milking was 12.74 kg, but the average number of milking times per day for the group of the cows – 2.6 times. Besides, such parameters milking with the AMS correspond to good practice indicators. It has been stated that in 13 % of the cases of all milking times the milking intervals have been longer than 14 hours, but in 14.3 % of the cases the cows have been milked more often than the set 6 hour interval. The average relative milking interval standard error for the whole group of the cows was 5.52 %, but the average correlation coefficient for the group of the cows between the yield per milking and the milking interval – 0.24.

MANURE MANAGEMENT SYSTEMS AND NITROGEN EMISSIONS IN LATVIA

The information for the present overview on manure management in different countries was primarily gathered through a survey using Greenhouse Gas (GHG) Inventory reports. In Latvia, N2O emissions from manure management account for only 5 % of total N2O emissions. Dividing the N2O emissions by all livestock species, 75.9 % are produced by cattle, 12.67 % – by poultry, and 4.96 % – by pigs. In GHG Inventory reports, there are great differences in manure output calculations for all livestock species in different countries (V, % ≥ 20), because all livestock is included in the same group, without separating them according to age or size. Majority of the countries have adopted a significantly higher amount of excreted N with manure from dairy cows as compared to the norms set in Latvia. Especially large differences among the countries can be observed in the groups of fattening pigs and weaned piglets; therefore, additional clarifications are needed for Latvian regulations, as the normative data currently adopted in Latvia is outside the 95 % of the value range. Keywords: GHG, manure, nitrogen emission. Article DOI: http://doi.org/10.15544/RD.2015.047