Impact of feed supplement with alfa-amylase and beta-glucanase on ingestive-related biomarkers registered with real-time sensors.

The aim of this study was to investigate the impact of feed supplements with alfa-amylase and beta-glucanase (Optipartum C+ 200) on ingestive-related behaviour biomarkers registered with real-time sensors: rumination behaviours and reticulorumen parameters (pH and temperature). Cows (n=20) in the treatment group (TG) were fed with Optipartum C+ 200 (Enzymes feed supplement: Alfa-Amylase 57 Units; Beta-Glucanase 107 Units) from 21 days before calving until 30 days after calving with a feeding rate of 200 g/cow/day. Cows (n=22) in the control group (CG) were fed a feed ration without feed supplement. Measurements started from 6 days before calving and continued until 21 days after calving. The following indicators were registered: with the RumiWatch System: Rumination time; Eating time; Drinking time; Rumination chews; Eating chews; Drinking gulps; Bolus; Chews per minute; Chews per bolus. With the SmaXtec system: the temperature, pH of the contents of the cows' reticulorumens, and cows' walking activity. According to our results, feed supplementation with alfa-amylase and beta-glucanase (Optipartum C+ 200) in the TG group resulted in increases in the following parameters: 9% rumination time and eating time, 19% drinking time, 11% rumination chews, 16% eating chews, 13% number of boluses per rumination, 5% chews per minute and 16% chews per bolus. The rumination time showed a strong, positive relation with rumination chews and bolus indicators in both groups (TG and CG) (p⟨0.001); while the rumination time in both groups of cows showed an opposite direction and was negatively related to eating time and eating chews (p⟨0.05). We found a 1.28 % lower reticulorumen pH and a 0.64 % lower reticulorumen temperature in cows fed with the supplement compared with cows in the control group. Cows in TG were 8.80% more active than those in the CG group. For improvement of ingestive-related behaviour we suggest adding a feed supplement with alfa-amylase and beta-glucanase (Optipartum C+ 200).

Evaluation of biomarkers of heat stress using automatic health monitoring system in dairy cows.

The aim of this study was to evaluate biomarkers of heat stress (HS) from an automatic milking system (AMS), the relationships between measurements of the temperature-humidity index (THI), reticulorumen pH and temperature, and some automatic milking systems parameters in dairy cows (rumination time (RT), milk traits, body weight (BW) and consumption of concentrate (CC)) during the summer period. Lithuanian Black and White dairy cows (n=365) were selected. The cows were milked with Lely Astronaut® A3 milking robots with free traffic. Biomarkers were collected from the Lely T4C management program for analysis. The pH and temperature of the contents of the cow reticulorumen were measured using specific Smax-tec boluses. The farm zone's daily humidity and air temperature were obtained from the adjacent weather station (2 km away). According to this study, during HS, the higher THI positively cor- relates with milk lactose (ML), which increases the risk of mastitis and decreases CC, RT, BW, MY, reticulorumen pH, and F/P. Some biomarkers of HS can be milk yield, milk lactose, somatic cell count, concentrate intake, rumination time, body weight, reticulorumen pH, and milk fat - protein ratio. We can recommend monitoring these parameters in the herd management program to identify the possibility of heat stress.

Can reticulorumen ph, temperature and cow activity registered before calving act as biomarkers of diseases after calving?

The aim of this study was to determine if reticulorumen ph, temperature and cow activity registered before calving can serve as indicators of diseases after calving.The cows were selected according to those fitting the profile of having had two or more lactations (on average 2.9±0.13 lactations), from 60 to 0 days before and the first 30 days after calving, and being clinically healthy. The clinical examination (identification of diseases after calving) was performed from 60 days before calving to 60 days after calving. Diseases after calving were diagnosed based on clinical symptoms specific to these diseases. The pH and temperature of the contents of the cow reticulorumens and cow activity were measured using specific smaX-tec boluses manufactured for animal care.We found that the highest pH and temperature before calving can serve as biomarkers of healthy cows after calving. The lowest reticulum temperature before calving can serve as an indicator of MF after calving. A positive correlation of reticulum pH and temperature before calving can serve as biomarkers of PR. Decreasing cow activity before calving can serve as an indicator of diseases after calving. For calving prognosis, temperature of the reticulorumen can be used; it decreased 6-7 days before calving.

Inline changes in lactate dehydrogenase, milk concentration according to the stage and number of lactation periods, including the status of reproduction and milk yield in dairy cows.

The aim of the present study was to investigate inline lactate dehydrogenase (LDH) dynamic changes based on different cow factors - different number and stages of lactation, milk yield, and the status of reproduction in clinically healthy dairy cows. In the Herd Navigator system, LDH activity levels (µmol/min per litre) were measured using dry-stick technology. A total of 378 cows were selected. According to their reproductive status, the cows were classified as belonging to the following groups: Fresh (1 - 44 days after calving); Open (45 - 65 days after calving); Inseminated (1 - 35 days after insemination); Pregnant (35 - 60 days after insemination and pregnant). According to their productivity, the cows were classified into the following groups: ⟨15 kg/day, 15 - 25 kg/day, 25 - 35 kg/day and >35 kg/day. The cows were milked with a DeLaval milking robot (DeLaval Inc. Tumba Sweden) in combination with a Herd Navigator analyser (Lattec I/S. Hillerød Denmark). In conclusion inline dynamic changes in the milk LDH concentration may increase together with the rise in the lactation period frequency. The highest LDH level determinated in the group of the fresh cows ranged from 5 to 10 DIM, while the highest LDH concentration level was found in the fresh cow milk. Thus, there was a positive relationship between the milk concentration of LDH and the milk yield.

Biomarkers from automatic milking system as an indicator of subclinical acidosis and subclinical ketosis in fresh dairy cows.

The objective of this study was to determine the association between subclinical acidosis (SARA) and subclinical ketosis (SCK) with biomarkers from an automatic milking system (AMS) measuring in relation to rumination time (RT), milk yield (MY), bodyweight (BW), milk temperature, the milk fat-to-protein ratio, and the electrical conductivity of milk at the udder quarters-level which can be read in fresh dairy cows. During the course of the study, all of the fresh dairy cows (n=711) were examined according to a general clinical investigation plan. The cows were selected for 1-30 days of milk (DIM) and were milked using Lely Astronaut® A3 milking robots with free traffic. Rumination time shows a statistically significant positive correlation with milk yield (milk temperature) and is negatively correlated with the fat and protein ratio. Healthy cows demonstrated the highest level of rumination time and the lowest milk temperature. The average BW for these cows was 1.64% lower than for the SARA group and the BW kg was 2.10% higher than SCK cows. MY was 14.01% lower in comparison with SARA and 6.42% higher in comparison with SCK. According to these results, some biomarkers from the AMS have an association with SARA and SCK. However, further research with a higher number of cows is needed to confirm this conclusion.

Rumination time as an indicator of stress in the first thirty days after calving.

The objectives of this study were to examine the option of being able to use rumination time (RT) as a form of stress indicator in the first thirty days after calving, and to determine the relationship between rumination time, blood cortisol levels, and lactate concentration levels in dairy cows during the first thirty days after calving. Ninety cows which produced milk (DIM) within 1-30 days were selected and categorised into the following groups: the first group (1) fell within 1-7 days after parturition (dpp) (n=30); the second group (2) fell within 8-14dpp (n=30); and the third group (3) fell within 15-30dpp (n=30) after calving. The cows were milked using Lely Astronaut® A3 milking robots with free traffic. The blood samples were tested using the fluorescence enzyme immunoassay method for cortisol analysis. Lactate concentrations were tested with a Lactate Pro2 ®. The RT increased during all of the exploratory periods (with readings between 1.12-4.90%). A decrease was also observed in the lactate levels (by 1.10 times) and cortisol levels (by 1.98 times, p⟨0.05) of cows which fell within the 8-14dpp group, when compared to an average of 1-7dpp in the previous study period (15-30dpp). However, lactate concentrations increased (by 1.84 times, p⟨0.05) as well as cortisol levels (by 2.09 times, p ⟨0.01) when compared with a figure between 8-14 dpp on the average. The results obtained indicate that, RT increased during all exploratory periods, while a decrease by 1.10 times and 1.98 times was observed in lactate levels and cortisol levels, respectively. During the entire period of the study RT was positively correlated with the lactate concentration levels, and negatively correlated with cortisol levels. Within a period of 1-14 days, a negative correlation was determined with lactate levels along with a 15-30dpp-positive correlation coefficient. In conclusion, RT can be used as a kind of stress indicator for cows in the first thirty days after calving; however, further research is required to ascertain this conclusion.

Can rumination time and some blood biochemical parameters be used as biomarkers for the diagnosis of subclinical acidosis and subclinical ketosis?

According to the past reports, the utility value of monitoring rumination time (RT) around the time at which calving takes place and, in particular, during the first week of lactation, is a way of identifying in a timely fashion those cows that are at a greater level of risk when it comes to developing disease in early lactation. Recent reports have focused on the role of minerals in disease resistance in ruminants, but little is known about the concentrations blood parameters in dairy cows with subclinical acidosis and subclinical clinical ketosis. According this we hypothesised that rumination time and some blood biochemical parameters (including cortisol and lactate) can serve as biomarkers for subclinical acidosis (SARA) and subclinical ketosis (SCK). Accordingly, the aim of the current study was to determinate the impact of subclinical acidosis and ketosis on rumination time and some blood biochemical parameters. For the current study, of a total of 225 fresh dairy cows (between one and sixty days after calving) a general clinical examination produced a selection of 93 cows: ten of these were diagnosed with SARA, thirteen had SCK and seventy were clinical healthy cows. Rumination time (RT), body weight (BW), and milk yield (MY) were registered with the help of Lely Astronaut® A3 milking robots. It was determining the concentrations of blood serum albumin (Alb), total protein levels (TP), glucose (Glu), urea (Urea), calcium (Ca), phosphor (Phos), iron (Fe), alaninaminotranspherase (ALT), aspartataminotranspherase (AST), Gammagliutamyltranspherase (GGT), and creatinine (Cre). RT decreases and blood lactate rates increase in cases of SARA and SKC, while in cases of SARA the total blood protein levels increased and in the SCK group it decreased.A similar trend of differences between the SARA group and the SCK group in terms of healthy cows could be found in changes in blood urea, glucose, Ca, Mg, P, and Fe. Cows in the SCK group showed statistically higher ALB content levels, while the activity of AST and Crea was at a lower level. According to this, rumination time, and some blood biochemical parameters can be used as biomarkers in the diagnosis ofsubclinical acidosis and ketosis. Future studies, however, are needed so that these results can be compared across a greater number of animals.

Changes in the real-time registration of milk ß-hydroxybutyrate according to stage and lactation number, milk yield, and status of reproduction in dairy cows.

This study investigated changes in the real-time measured levels of milk ß-hydroxybutyrate according milk yield, lactation number and status of reproduction in dairy cows. A total of 378 cows were selected. According to their reproductive status the cows were classified as belonging to the following groups: Fresh (1 - 44 days after calving. n=43). Open (45 - 65 days after calving. n=78), Inseminated (1 - 35 days after insemination. n=133). Pregnant (35 - 60 days after insemination and pregnant (relatively pregnant) (n=124). The cows were milked with DeLaval milking robot (DeLaval Inc., Tumba, Sweden) in combination with a Herd Navigator (Lattec I/S. Hillerød. Denmark) analyser. We observed that milk ß-hydroxybutyrate (BHB) had a tendency of increasing with an increase of lactation number. The average BHB in multiparous cows was 11.111% higher in com- parison with primiparous cows (p⟨0.001). We found higher BHB concentration in the multipa- rous cows in all reproduction status groups (p⟨0.001). A strong positive statistically significant (p⟨0.001) relationship has been found between BHB and the average milk yield within all groups of primiparous cows although we found a statistically unreliable coefficient of correlation (from -0.202 to 0.057) between highest milk yield and BHB in primiparous and multiparous cows.

Changes in reticulorumen content temperature and pH according to time of day and yearly seasons.

The monitoring of rumen content temperature can be useful for the evaluation of cow health condition and heat. The aim of this research was to evaluate the influence of the circadian rhythm (time of day) and season on reticulorumen acidity (pH) and temperatures (RT) in lactating dairy cows. The research was performed on ten 2nd - lactation, clinically healthy Lithuanian Black and White fresh dairy cows (up to 1 day after calving). The cows were milked twice daily at 05:00 and 17:00. The cows were kept in a loose housing system, and were fed a feed ration throughout the year at the same time, balanced according to their physiological needs. Cow feeding took place every day at 06:00 and 18:00. The pH and temperature of the contents of cow reticulorumens were measured using specific smaXtec boluses manufactured for animal care. The temperature starts rising 6 hours after the evening feeding and milking, whereas 1 hour after the morning milking, it starts decreasing. The lowest temperature observed in the springtime was 38.81±0.001, and the highest was in autumn 39.17±0.001. The pH starts decreasing 3 hours after the morning feed, whereas 4 hours after the evening feed, it starts increasing. The lowest pH was observed in the summertime - 5.99±0.001, and the highest was in autumn and springtime - 6.18±0.001. In conclusion the reticulorumen temperature in lactating cows was found to be influenced by the circadian rhythm and season. The acidity of the reticulorumen content changes similar to the temperature. The pH of the reticulorumen contents was also found to be influenced by the circadian rhythm and season.