Sandra Rose-Meierhöfer

Behavioral and physiological responses of young horses to different weaning protocols: a pilot study.

In this study, effects of weaning on behavioral and physiological stress parameters in young horses (foals) were determined. Foals were weaned either simultaneously without the presence of adult horses (group A, n = 6), or in the presence of two adult females familiar but unrelated to the foals (group B, n = 5), or weaned consecutively by removing two mother horses per day (group C, n = 6). Behavior, locomotion, salivary cortisol concentration, beat-to-beat (RR) interval, heart rate variability (HRV) and weight were determined. Group A foals lost weight for 2 days (mean ± SEM) − 8.3 ± 1.6 kg, p < 0.05. Weaning was followed by increased vocalization which was least pronounced in foals of group B (p < 0.05). Locomotion was most pronounced on weaning day in foals of group A and lowest in group B (p < 0.05). Weaning increased salivary cortisol concentration on the day of weaning in groups A and B and for 2 days in group C (p < 0.05). The RR interval decreased most pronouncedly in group A foals (p < 0.05). There were no consistent changes in HRV. Based on cortisol release and behavior, weaning is associated with stress but this was least pronounced in foals weaned in the presence of two familiar but unrelated adult female horses.

Physiological and behavioral stress parameters in calves in response to partial scrotal resection, orchidectomy, and Burdizzo castration

Establishing artificial cryptorchids by partial scrotal resection without removing the testicles is a technique for castration of bull calves that recently has gained new interest. In contrast to orchidectomy and Burdizzo castration, the stress response of calves to shortening of the scrotum is unknown. In this study, partial scrotal resection in bull calves was compared with orchidectomy, Burdizzo castration, and controls without intervention (n=10 per group, ages 56 ± 3 d). Procedures were performed under xylazine sedation and local anesthesia. We hypothesized that partial scrotal resection is least stressful. Salivary cortisol, heart rate, heart rate variability, behavior, and locomotion were analyzed. Cortisol concentration peaked 60 min after start of the procedures. Cortisol release was at least in part xylazine induced and none of the experimental procedures released additional cortisol. Heart rate increased in calves of all groups with initial handling, but immediately after xylazine sedation decreased to 30% below initial values and was not modified by surgical procedures. The heart rate variability variables standard deviation of beat-to-beat interval and root mean square of successive beat-to-beat differences increased when calves were placed on the surgery table but effects were similar in calves submitted to surgeries and control calves. Locomotion increased, whereas lying time decreased in response to all surgeries. Locomotion increase was most pronounced after orchidectomy. Plasma fibrinogen concentrations increased after orchidectomy only. With adequate pain medication, orchidectomy, Burdizzo castration, and partial scrotal resection do not differ with regard to acute stress and, by inference, pain. Partial scrotal resection when carried out under xylazine sedation and local anesthesia thus is an acceptable castration technique in bull calves.

Development of a Control System for the Teat-End Vacuum in Individual Quarter Milking Systems

Progress in sensor technique and electronics has led to a decrease in the costs of electronic and sensor components. In modern dairy farms, having udders in good condition, a lower frequency of udder disease and an extended service life of dairy cows will help ensure competitiveness. The objective of this study was to develop a teat-end vacuum control system with individual quarter actor reaction. Based on a review of the literature, this system is assumed to protect the teat tissue. It reduces the mean teat-end vacuum in the maximum vacuum phase (b) to a level of 20 kPa at a flow rate of 0.25 L/min per quarter. At flow rates higher than 1.50 L/min per quarter, the teat-end vacuum can be controlled to a level of 30 kPa, because in this case it is desirable to have a higher vacuum for the transportation of the milk to the receiver. With this system it is possible for the first time to supply the teat end with low vacuum at low flow rates and with higher vacuum at increasing flow rates in a continuous process with a three second reaction-rate on individual quarter level. This system is completely automated.

The effects of quarter-individual milking in conventional milking parlours on the somatic cell count and udder health of dairy cows.

The objective of this study was to examine the quarter health status of quarter-individually and conventionally milked cows. The MultiLactor®, a quarter-individual milking system (MULTI), has single guided tubes which provide milking on the quarter level with a low system vacuum level (37 kPa), sequential pulsation and periodic air inlet. The conventional milking system (CON) was equipped with a milking cluster where the system vacuum level was adjusted to 40 kPa. A total of 84 German Holstein cows, randomly divided into two groups, were included in the study. Over a period of 32 trial weeks, quarter foremilk samples were taken every week to determine somatic cell count (SCC). Bacteriological examinations and udder palpation were conducted at three different times. During the trial period, median SCC of quarter foremilk samples in both groups did not exceed the threshold value of 100,000 cells/ml. The results of the F test showed that the milking system (P = 0.0587) and days in milk (DIM) (P = 0.8066) had no significant effects on the quarter health status. On the other hand, lactation (P = 0.0396), quarter health status in the previous week (P < 0.0001) and trial week (P = 0.0061) affected quarter health status significantly. The estimated probabilities of the occurrence of a suspicious quarter (SCC > 100,000 cells/ml) were 19.97% (CON) and 31.72% (MULTI). However, the test of differences in the Least Square Means (LSM) showed no significant differences (P = 0.0585) between CON and MULTI. The estimated probability of quarters becoming suspicious during the first lactation was 12.51% for both groups. With an increasing number of lactation, the probability of a quarter becoming suspicious clearly increased (2nd lactation: 32.73% and 3rd lactation: 36.19%). The results also showed that the percentage of quarters with bacteriological findings revealed a stronger increase over time for MULTI than for CON.

The Usability of a Pressure-Indicating Film to Measure the Teat Load Caused by a Collapsing Liner.

Prevention of damage to the teat and mastitis requires determination of the teat load caused by a collapsing liner. The aim of this study was to test a pressure-indicating film designed to measure the pressure between a collapsing liner and artificial teats. The Ultra Super Low and the Extreme Low pressure-indicating films were tested on two types of artificial teat. The experiments were performed with a conventional milking cluster equipped with round silicone liners. For each teat and film type, 30 repetitions were performed. Each repetition was performed with a new piece of film. Kruskal-Wallis tests were performed to detect differences between the pressure values for the different teats. The area of regions where pressure-indication color developed was calculated to determine the most suitable film type. Both film types measured the pressure applied to both artificial teats by the teat cup liner. Thus, the pressure-indicating films can be used to measure the pressure between a collapsing liner and an artificial teat. Based on the results of the present investigation, a pressure-indicating film with the measurement ranges of both film types combined would be an optimal tool to measure the overall pressure between an artificial teat and a collapsing liner.

The influence of different milking settings on the measured teat load caused by a collapsing liner

Abstract Milking machine settings such as the machine vacuum, pulsation rate, and pulsation ratio influence teat tissue and teat condition, but there remains a lack of knowledge about the teat-liner interface and the pressure applied to the teat tissue by the teat cup liner during milking. The aim of the present study was to determine the influence of different milking settings on the teat-liner interface with the help of a pressure-indicating film. The Extreme Low Prescale film by Fujifilm and a hollow artificial teat made of silicone were used to measure the influence of different machine vacuum levels (30 kPa, 40 kPa, 50 kPa), different pulsation rates (40 cycles min−1, 60 cycles min−1, 80 cycles min−1), and different pulsation ratios (60:40, 65:35, 70:30) on the teat load caused by the collapsing liner. The response surface methodology with a central composite design was used to plan the experiment. The experiment was performed with a conventional milking cluster equipped with round silicone liners. The average pressure (AP), the maximum pressure (MP), and the load (L) were used to analyse the influence of different milking settings. Analysis of covariance was used to estimate the differences between measuring areas, machine vacuum levels, pulsation rates, and pulsation ratios. Machine vacuum levels, pulsation rates, and pulsation ratios had a significant influence on the measured teat load caused by liner collapse; the higher the machine vacuum and the pulsation rate, the higher the measured values of AP, MP, and L. MP values decreased with an increase of the pulsation ratio. The pulsation ratio affected L significantly depending on the machine vacuum. The liner applied more pressure to the end of the teat compared with the whole teat barrel. In conclusion, the results of the present investigation show that different adjustments to the machine vacuum, the pulsation rate, and the pulsation ratio can significantly influence the pressure applied to the whole teat by a collapsing liner.

The Use of a Pressure-Indicating Film to Determine the Effect of Liner Type on the Measured Teat Load Caused by a Collapsing Liner

During milking the teat cup liner is the interface between the teat of a dairy cow and the milking system, so it should be very well adapted to the teat. Therefore, the aim of the present study was to determine the effect of liner type on the directly measuring teat load caused by a collapsing liner with a pressure-indicating film. The Extreme Low pressure-indicating film was used to detect the effect of six different liners on teat load. For each liner, six positions in the teat cup were specified, and six repetitions were performed for each position with a new piece of film each time. Analysis of variance was performed to detect differences between the six liners, the positions within a liner, and the measuring areas. The pressure applied to the teat by a liner depends on the technical characteristics of the liner, especially the shape of the barrel, and for all tested liners, a higher teat load was found at the teat end. In conclusion, with the help of pressure-indicating film, it is possible to determine the different effects of liner type by directly measuring teat load due to liner collapse.

Comparative study of behavioural and milking traits in cows milked with a conventional or individual quarter milking system (Multilactor®) and with different milking persons

Abstract The aim of this study was to investigate the influence of a new type of milking system on the behaviour of cows during milking by comparing a conventional milking system (CON) with an individual quarter milking system (MUL), MultiLactor®. Sixty-eight dairy cows were observed during their milking times (32 cows in CON, 36 cows in MUL) using video recordings to analyse their behavioural traits. The udder preparation duration, milking duration and milk yield were also evaluated. No significant differences were found between the CON and the MUL regarding cows’ head posture (P=0.38), body posture (P=0.85), number of steps (P=0.08) and number of kicks (P=0.56). However, the milk yield was lower (P=0.02), just as the udder preparation duration (P<0.01) and milking duration (P=0.01) were shorter in the CON compared to the MUL. In addition, in regard to the milking person, differences were displayed in the head posture of the milked cows, kick-off or loss of teat cup or milking cluster, and frequency of udder preparation. In conclusion, the investigated milking systems did not markedly influence the behaviour of dairy cows; however, udder preparation duration, milking duration and milk yield were significantly greater for the MUL than for the CON. However, the milking person appears to have a greater impact on the behaviour of the cows than the milking system.

Evaluation of teat-end vacuum conditions as affected by different pulsation settings in a quarter-individual milking system

The objective of this study was to determine the effect of pulsation on the teat-end vacuum behaviour in a quarterindividual milking system (QIMS). To meet this objective, simultaneous (SIM), alternating (ALT) and sequential (SEQ) pulsation were tested in a laboratory milking parlour. In the pulsation system SEQ four pulsators, instead of one (as in SIM) or two (as in ALT), are used. Unlike in SIM and ALT, the pulsation in each quarter is started individually. After pulsation is started in quarter one, pulsation will begin in the following quarters, each with a time delay of 25 % of the pulse duration with respect to the start of the previous quarter. Tests were performed at various flow rates (0.8 to 6.0 l/min) with the help of the wet-test method and the teat-end vacuum behaviour was observed. The lowest vacuum fluctuation of 4.4 kPa was recorded under SIM pulsation as well as the lowest vacuum reduction of 1.3 kPa. Both values were recorded at a flow of 4 l/min during the suction phase (b-phase). For SEQ and ALT pulsation, higher levels of vacuum reduction and fluctuation were measured during the suction phase at a flow rate of 4 l/min (SEQ: 7.6 / 1.8 kPa and ALT: 9.0 / 1.9 kPa). Consequently, it was concluded that SIM pulsation is the most appropriate pulsation setting when optimization for low vacuum reduction and fluctuation during the suction phase is demanded.

Short communication: Dipping efficiency and teat dip residues in milk using an automatic dipping system

Prototypes of the automatic-dipping system Apollo were tested with the IQ milking cluster (GEA Farm Technologies GmbH, Bönen, Germany) to determine the teat-dip residues in the milk and the dipping performance (number of dipped teats) of the system compared with manual (hand) dipping. A laboratory trial and a field trial at a dairy farm were performed to determine the iodine level in the milk when an iodine-based teat dip was used. In the laboratory trial, the mean difference between the 53 paired samples (sampling upstream and downstream of the cluster) was 18.9 ± 3.18 μg of iodine/kg. A field trial at a 300-cow commercial dairy farm consisted of taking 2 sets of individual cow milk samples 6 wk apart. Three weeks before the second test day, the iodine-based teat dip was replaced by an iodine-free teat dip. The mean difference between the 2 sets of 55 samples was 25.1 ± 5.22 μg/kg. Compared with manually applying an iodine-based teat dip, the increase in the iodine content resulting from the use of the tested cluster with automatic dipping was very low and would not be an issue of food safety. The dipping performance tests were completed on the same 300-cow commercial dairy farm as the field iodine level trial was performed. In total, 4,541 teats from 307 cows were observed on 4 consecutive days, showing a 91.6 ± 1.3% success rate.