L. Migliorati

Evaluation of milk enzymes and electrolytes, plasma metabolites, and oxidative status in twin cows milked in an automatic milking system or twice daily in a conventional milking parlor.

The aim of this paper was to evaluate the effects of automatic milking (AM) on milk enzymes and minerals related to mammary epithelial integrity in comparison with twice-daily conventional milking (CM). One cow from each of 6 pairs of twins was assigned to be milked with AM or with CM throughout first lactation. Milk production was recorded and milk samples were collected at 4, 11, 18, 25, 32, and 39 wk of lactation (WOL) to determine fat and protein content, somatic cell count, pH, plasminogen (pl) and plasmin (Pl) activities, Na, K, and Cl. Body condition score was monitored; blood samples were collected to determine energy-related metabolites in the first third of lactation (14 WOL), and plasma oxidative status throughout lactation. Overall mean and standard deviation of milking frequency (MF) in AM were 2.69 and 0.88, respectively. Milk production, fat and protein contents, and somatic cell count did not differ between milking systems. The pl and pl+Pl activities were lesser in AM than in CM. Milk pH was greater in AM than in CM. Milk Na, K, Na/K ratio, and Cl did not differ across the whole lactation. Milk pH had a positive correlation with milk Pl activity (r = 0.41), Na (r = 0.37), and Cl (r = 0.40) concentration, and negative correlation with the log(10) of pl/Pl ratio (r = -0.47). The milk Na/K ratio had a positive correlation (r = 0.55) with milk Pl activity. Milking system (MS) did not seem to affect mammary epithelial permeability. The differences in enzymatic (proteolytic) activity due to the MS, probably related to daily MF, lead one to suppose that the quality of the protein fraction for the cheese-making process was preserved better with AM than with CM, even if differences in pH might negatively interfere. No difference was detected in BCS, and in plasma concentration of triglycerides and nonesterified fatty acids, whereas plasma cholesterol concentration during the first 10 WOL was lesser in AM than CM. Oxidative status, measured by plasma reactive oxygen metabolites and thiol groups, did not differ between MS throughout the whole lactation. These results suggest that early lactation of AM primiparous cows may give rise to crucial situations: for milk production, when a low MF may impair further mammary cell proliferation; for milk quality, if an irregular MF, with prolonged milking intervals, leads to an increased milk pH with increased conversion of pl to Pl.

Effects of automatic milking system on teat tissues, intramammary infections and somatic cell counts

Abstract To assess the impact of automatic milking systems (AMS) on the different aspects of milk production a research project involving both commercial and experimental dairy farms with different AMS and different management was started. This paper reports the results of a follow-up study on primiparous cows focused on assessing some markers to be used to monitor udder and teat health. Heifers were included after calving and sampled for at least 12 months. Quarter milk samples and teat measurements were taken to assess: intramammary infection (IMI) frequencies, somatic cell counts (SCC), teat thickness changes, teat skin and apex conditions. The study included 28 cows in herd A and 27 in herd B for a total number of 2344 samples. Overall, teat apex and skin conditions were maintained along the lactation. Teat skin conditions tended to decrease because of the accumulated number of milkings while lactation proceeded, but at a largely acceptable level in both herds. Teat apex conditions showed a decrease. Teat thickness changes displayed different patterns in the two herds, probably because of the different type of AMS, but in both cases a trend to decrease in thickness could be observed. The application of AMS in herd B, free from contagious pathogens, did not influence the frequency of IMI and the SCC. In herd A, characterized by the presence of Staphylococcus aureus IMI, the frequency of IMI showed a progressive increase, very likely as a consequence of the spread of infections during milking. Teat skin had no association with the frequency of IMI. Teat thickness changes outside values considered as physiological proved to be associated with decreased conditions in the teat apex score in herd A, but not in herd B. However, a decrease in teat apex score proved to be associated with an increase in IMI frequency in both herds. The results of this field trial confirm that AMS have no negative impact on IMI incidence, SCC and teat tissue conditions when the initial cow health status and overall herd management are good. In the presence of contagious pathogens, and when cows have more than 300 days in milk (DIM) the frequency of negative outcomes significantly increases and the proper control measures should be taken.

Effect of concentrate feeding on milking frequency and milk yield in an automatic milking system

Riassunto Effetto della somministrazione di concentrato sulla frequenza di mungitura e sulla produzione di latte in un sistema di mungitura automatizzato. In un sistema robotizzato (AMS) gli animali sono maggiormente invogliati a recarsi all’area di mungitura mediante la distribuzione di concentrato. Si è voluto verificare come si comportano le vacche quando si somministra un alto vs.basso livello di concentrato in presenza o meno di sostanze appetizzanti. La prova è stata condotta su 44 bovine Frisone suddivise in 4 gruppi omogenei secondo un disegno sperimentale change over con 4 periodi affinché ogni gruppo ricevesse ciascun trattamento. Mediamente gli animali hanno consumato tutto il concentrato somministrato. La somministrazione di concentrato con appetizzanti non ha incrementato il numero di mungiture, ma ha aumentato significativamente le presentazioni all’area AMS, con effetto positivo, seppure non significativo, sulla produzione di latte. La somministrazione di diverse quantità di concentrato non ha modificato sostanzialmente i parametri controllati.

Automation in dairy cattle milking: experimental results and considerations

Abstract The results of two experimental programs financed to the Istituto Sperimentale per la Zootecnia are presented. The objective of the two Italian programs was the verify if automatic milking is a suitable practice for Italian dairy system. Results are summarised and compared to those obtained in other international projects. Results refer to animal behaviour, milk yield, milk quality an animal welfare. In a trial comparing cows milked with an automatic milking system and cows milked in a milking parlour, we observed that when the temperature and humidity are very high cows reduce their activity, have lower milking frequency and milk yield than in cold seasons. In comparison to milking parlour, automatic milking system did not increase milk yield which was affected significantly by season, stage of lactation, parity, season per treatment and parity per treatment. The causes of the negative results obtained by this group and by other international groups are discussed. We also presented the results obtained in four trials thereby four appetizers or flavourings were tested to improve efficiency of automatic milking system. Comparing the two milking systems, automatic milking determined a worsening of milk quality, but from these data is not possible to exclude the possibility to use automatic milking for Grana Padano and Parmigiano Reggiano-type cheeses. Animal welfare is not negatively influenced by automatic milking system, which has the potentiality to improve the control and care of cows.

Influence of feeding flavouring-appetizing substances on activity of cows in an automatic milking system

Abstract Cow behaviour and milk production were evaluated depending on the presence or absence of flavouring and appetizing substances in the diet. Fifty-two Italian Friesian cows were blocked according to parity, DIM, milk yield and average number of previous visits during a two-week period before the start of the trial and divided into two groups. The experimental design was a change over, with two groups and two periods lasting four weeks. The compared treatments were: concentrate with addition of flavouring and appetizing substances (FAS) or without (C). Each experimental group including low (L) (<21 kg/d), mid (M) (21-28 kg/d), and high (H) (>28 kg/d) yielding cows at which were offered 1.5, 2.5, 3.5 kg/d of concentrate, respectively, in the automatic milking system (AMS) throughout the experiment. The cows generally consumed all the distributed FAS or C concentrate. The experiment showed that cow’s behaviour was modified through the use of a appetizing component of the concentrate fed in the automatic dispenser of the AMS. Cows fed FAS concentrate increased the weekly visits without milking and milking frequency and decreased milking interval. Moreover, the use of the FAS concentrate reduced the number of milkings with intervals >11 hours by 5%. The greater milk yield of cows fed FAS could be a consequence of behaviour shift.

Effects of adsorbents in dairy cow diet on milk quality and cheese-making properties

Abstract The use of adsorbents (clinoptilolite+sepiolite) in the diet of cows was evaluated in two trials. A total of 52 Italian Friesian cows were assigned to one of two dietary treatments, control and adsorbent (CON vs. ADS). Individual and bulk milk samples were collected. On individual data, no significant difference was found between treatments in milk yield, milk fat, protein, and lactose concentrations, milk protein yield, pH, and titratable acidity, both in summer and spring. In spring only, there was a trend (P = 0.07) for a higher milk fat yield and a lower somatic cell number in ADS than in CON group. In summer only, milk clotting time was higher in ADS than in CON group (P < 0.05). On bulk milk, no significant differences in components and technological features were found between the CON and ADS groups. The bulk milk contents in total and soluble Ca were 1100 vs. 1108 mg/kg and 378 vs. 369 mg/kg for CON and ADS respectively, proving to be unaffected by treatment and suggesting a lack of interference by ADS on milk Ca availability for cheese-making process. We concluded that, for a period of 12 weeks, the addition of 1% on DM of the diet for lactating cows of non-nutritional adsorbents does not negatively affect milk yield, milk composition, and cheese-making features.