This study aims to investigate the relationship between human behaviour, buffalo behaviour and prevalence of oxytocin injection at milking. The research was carried out on 17 buffalo farms. On each farm the stockperson's behaviour toward the buffaloes and the buffaloes' behaviour were observed during one afternoon's milking. Stockperson's behaviour was observed from collection of the animals in the waiting area to exit from the milking parlour. The following variables were recorded: number of positive, neutral and negative interactions. The number of steps and kicks were recorded from the entrance to the milking parlour to the removal of cups whenever the stockperson was less than 0.5 m from the animal. The prevalence of oxytocin injection at milking was recorded on two separate occasions with a 5-month interval to obtain a measure of the long-term consistency of this variable. Significant correlations were found between stepping and kicking, stepping and prevalence of oxytocin injection, kicking and prevalence of oxytocin injection and stockperson positive interactions and kicking. These results indicate that stockperson behaviour is related to buffalo behaviour at milking and the latter to the use of oxytocin injections. In addition, prevalence of oxytocin injection proved to be highly reliable when re-tested five months later.

This research paper addresses the hypothesis that oxytocin (OT) could be released during suckling and during milking with and without the presence of a calf and that this release could be regulated by maternal behaviour. Plasma concentration patterns of OT and cortisol (CORT) were measured in six Tunisian dromedary camels during 2 suckling episodes, 2 manual milking episodes with calves beside the mother and 2 machine milking episodes without calves present. Various patterns of OT release were observed between each camel including specific two peak release patterns. Higher plasma OT concentrations were found during the suckling and hand-milking episodes with simultaneous suckling of calves, than during the machine milking episodes without calves. Exclusive mechanical milking episodes also evoked significant mean OT release, although greatly reduced compared to suckling and hand milking. The low basal levels and classical CORT release patterns suggested non-stressful management practices were used and there were very limited differences in udder stimulation between managements. The OT release induced by exclusive suckling and suckling together with hand-milking gives a reference point for what a good milk ejection stimulation is in camels. The important and specific reduction of OT release during machine milking without the calf present could be a physiological consequence of the maternal behaviour (selectivity for the own young) and to a lesser extent explained by a lower stimulation by machine milking.

This research communication describes the influence of diet, mammary quarter position and milking process on the temperature of teats and udder of cows fed diets containing different lipid sources. Five primiparous cows were fed diets containing cottonseed, sunflower seed, soybeans or soybean oil as a source of lipids and a reference diet without the inclusion of lipid sources in a 5 × 5 Latin Square design. Milk yield was determined in the last five days of each period. Milk samples were collected for SCC analysis on the last two days of each experimental period. The images of the mammary gland were obtained using an infrared camera and were analyzed with appropriate computer software. Milk yield was 14.8% higher for cows fed soybeans as a source of lipids. Diets and somatic cell counts did not influence the temperature of teats and udder. The milking process reduced the temperature of teats and udder by 0.79°C. Rear teats and rear quarters had higher surface temperatures than front teats and fore quarters. Changes in temperature of teats and mammary quarters occurred as a function of the milking process and quarter position. However, the diet and the SCC did not influence the temperature of teats and mammary quarters in this experiment.

Mastitis is one of the most prevalent and costly diseases in dairy cattle. Key components for adequate mastitis control are the detection of early stages of infection, as well as the selection of appropriate management interventions and therapies based on the causal pathogens associated with the infection. The objective was to characterize the pattern of electrical conductivity (EC) in milk during intramammary infection, considering specific mastitis-causing pathogen groups involvement. Cows (n = 200) identified by an in-line mastitis detection system with a positive deviation ≥15% in the manufacturer’s proprietary algorithm for EC (high electrical conductivity (HEC)) were considered cases and enrolled in the study at the subsequent milking. One control (CON) cow, within normal ranges for EC, was matched to each case. A composite milk sample was collected aseptically from each cow for bacteriological culture. Milk yield (MY) and EC were recorded for each milking during ±7 days relative to enrollment. Milk cultures were categorized into gram positive (GP), gram negative (GN), other (OTH) and no growth (NOG). Data were submitted for repeated-measures analysis with EC as the dependent variable and EC status at day −1, bacteriological culture category, parity number, stage of lactation and days relative to sampling as main independent variables. Average (± standard error (SE)) EC was greater in HEC than in CON cows (12.5 ± 0.5 v. 10.8 ± 0.5 mS/cm) on the day of identification (day −1). Milk yield on day −1 was greater in CON than in HEC (37.6 ± 5.1 v. 33.5 ± 5.2 kg). For practical management purposes, average EC on day −1 was similar for the different bacteriological culture categories: 11.4 ± 0.6, 11.7 ± 0.5, 12.3 ± 0.8 and 11.7 ± 0.5 mS/cm in GN, GP, OTH and NOG, respectively. Parity number was only associated with day −1 EC in HEC group, with the greatest EC values in parity 3 (12.3 ± 0.3 mS/cm), followed by parity 2 (11.9 ± 0.2 mS/cm), parity >3 (11.6 ± 0.5 mS/cm) and primiparous cows (11.2 ± 0.2 mS/cm). An effect on EC for the interaction of day relative to identification by pathogen gram category was observed. The same interaction effect was observed on daily MY. Overall, the level of variation for MY and EC between- and within-cows was substantial, and as indicated by the model diagnostic procedures, the magnitude of the variance in the cows in the CON group resulted in deviations from normality in the residuals. We concluded that characteristic temporal patterns in EC and MY in particular pathogen groups may provide indications for differentiation of groups of mastitis-causing pathogens. Further research to build detection models including EC, MY and cow-level factors is required for accurate differentiation.

It has been well established that milk yield is affected both by milking frequency and due to the removal of residual milk, but the influence of a combination of these factors is unclear. In this study, four mid-lactation cows were used in a 4 × 4 Latin square design to test the hypothesis that the effects of more frequent milking and residual milk removal on milk yield and composition are additive and alter milk fatty acid composition. Treatments comprised two or four times daily milking in combination with (or without) residual milk removal over a 96 h interval preceded by a 2 d pretreatment period and followed by a 8 d washout in each 14 d experimental period. Milk was sampled at each milking for the analysis of gross composition and SCC. Samples of available and residual milk collected on the last milking during each treatment period were collected and submitted for fatty acid composition analysis. Increases in milking frequency and residual milk removal alone or in combination had no effect on milk yield or on the secretion of lactose and protein in milk. However, residual milk removal during more frequent milking increased milk fat yield. Milking treatments had no major influence on the fatty acid composition of available milk, but resulted in rather small changes in the relative abundance of specific fatty acids, with no evidence that the additive effects of treatments were due to higher utilisation of preformed fatty acids relative to fatty acid synthesis de novo. For all treatments, fat composition of available and residual milk was rather similar indicating a highly uniform fatty acid composition of milk fat within the mammary gland.

Oxytocin release, milking characteristics, and teat condition were investigated with reduced claw vacuum and pulsation settings compared to milking at regular settings with or without pre-stimulation. The reduced vacuum and pulsation settings during low milk flow are expected to protect the teat tissue before the occurrence of milk ejection at the start of milking, and at the end of milking during a potential overmilking period, i.e. at a milk flow <200 g/min. Seven cows were machine-milked either after a 60 s manual pre-stimulation, or without pre-stimulation and reduced vacuum and pulsation settings, or at full vacuum and normal pulsation during the start of milking. Plasma oxytocin (OT) concentration increased similarly in response to manual pre-stimulation and to both milking with reduced, or with full vacuum and pulsation settings, however delayed by 1 min if the cluster was attached without pre-stimulation. In all treatments OT concentrations remained elevated throughout milking. Milk flow curves were mostly non-bimodal at milkings after manual pre-stimulation and bimodal at milkings without pre-stimulation. The main milking time was shorter and average milk flow was higher during milking after pre-stimulation, but did not differ between treatments without pre-stimulation. Milk yields and peak flow rates were not affected by treatments. Either reduced or full vacuum settings were again applied during an intended overmilking from 200 to 100 g/min of milk flow towards the end of milk harvest. Pre-milking teat ultrasound cross sections were recorded one day before the experiment started. Post-milking ultrasound cross sections were performed at 15 min after each experimental milking. Teat wall thickness was increased after milking as compared to pre-milking but did not differ among treatments. In conclusion, OT release and milking performance are similar if milking is performed with pre-stimulation, or without pre-stimulation but reduced claw vacuum and b-phase during low milk flow.

Clostridia in the milk can lead to late blowing, a cheese defect. Clostridia are ubiquitous, deriving from both the farm environment and the feed ingested by the cows, and are transferred into the milk through faecal contamination. Our aim was to investigate the effect of different in-parlour practices on the content of anaerobic spore-forming bacteria in milk, and to monitor the variation in spore content in the feed and environment. The experiment, conducted in an experimental dairy during autumn, was repeated in exactly the same way for two consecutive years. The experimental design applied three different milking routines in three consecutive 7-d periods: forestripping alone (F); forestripping and post-dipping (F+Post); pre-dipping, wiping, forestripping and post-dipping (Pre+F+Post). Teat skin swabs and samples of feed, faeces, bedding materials and milk were collected for microbiological analyses. The dietary forage of the lactating cows included maize silage, which, in both years, was found to have the highest level of clostridial spore contamination. Pre-dipping with a detergent/emollient solution, and drying with a disposable paper towel, proved much more efficient in reducing spore contamination than forestripping alone, both on the teats (1·30 vs. 2·20 log10 MPN/swab; P < 0·001) and in the milk (1·82 vs. 2·47 log10 MPN/L, P < 0·02), while post-dipping had little influence on spore count. The standard plate count in milk was significantly lower with Pre+F+Post treatment than with F (3·80 vs. 4·51 log10 CFU/mL, P < 0·01). The teat preparation procedure did not influence the lactic acid bacterial levels in the milk, which is very positive in that decreased lactic acid bacterial content can lessen raw milk cheese quality.

Experiments were designed to investigate the suitability of a combination of a short manual teat stimulation with a short latency period before teat cup attachment to induce and maintain oxytocin release and milk ejection without interruption. In Experiment 1, seven dairy cows in mid lactation were manually pre-stimulated for 15, 30 or 45 s, followed by either 30 s or 45 s of latency period. It was shown that all treatments induced a similar release of oxytocin without interruption until the end of milking. In particular, the latency period of up to 45 s did not cause a transient decrease of oxytocin concentration. In Experiment 2, milking characteristics were recorded in seven cows each in early, mid, and late lactation, respectively. Because the course of milk ejection depends mainly on the degree of udder filling, individual milkings were classified based on the actual degree of udder filling which differs between lactational stages but also between morning and evening milkings. All animals underwent twelve different udder preparation treatments, i.e. 15, 30, or 45 s of pre-stimulation followed by latency periods of 0, 30, 45, or 60 s. Milking characteristics were recorded. Total milk yield, main milking time and average milk flow rate did not differ between treatments if the degree of udder filling at the start of milking was >40% of the maximum storage capacity. However, if the udder filling was <40%, main milking time was decreased with the duration of a latency period up to 45 s, independent of duration of pre-stimulation. Average milk flow at an udder filling of <40% was highest after a pre-stimulation of 45 s followed by a latency period of another 45 s. In contrast, average milk flow reached its lowest values at a pre-stimulation of 15 s without additional latency period. However, average milk flow after a 15-s pre-stimulation increased with increasing latency period. In conclusion, a very short pre-stimulation when followed by a latency period up to 45 s before teat cup attachment remains a suitable alternative for continuous stimulation to induce milk ejection.

Attaching the milking machine to the cow is the last remaining major repetitive task that the worker in a modern milking parlour has to perform. Several groups of research workers are developing robotic systems for this purpose. The task for the robot of locating the cow's teats and attaching the machine is complicated by morphological differences between cows and the need to allow the cow freedom to move during the operation. This paper reviews the progress that has been made.

In studies of bovine mastitis, it has been repeatedly confirmed that milking is associated with entrance of microorganisms into the mammary gland (International Dairy Federation, 1987; Bramley, 1992). As different husbandry practices apply between cattle and dairy sheep (cows are machine milked, ewes are usually hand milked), results from cows may not always apply to ewes. The objective of this investigation was to determine whether there were differences in bacterial flora populations in the teat duct and mammary secretion of ewes before and after milking.

The aim of the study was to determine the role of opioids modulating the release of prolactin (PRL) in response to milking in sixteen Brown-Swiss dairy cows. Two experiments were carried out to measure the dose-related effect of morphine and the effect of the opioid antagonist naloxone (NAL), with or without morphine. In the first experiment, six cows were injected (via catheter) on 3 consecutive days after the control milking (0 mg) with 21, 70 and 210 mg morphine-HCl 10 min before the start of the morning milking. The second experiment was divided into two parts. In the first part, four cows were injected after control morning milking with 210 mg morphine, 10 min before the start of the following morning milking. This was followed on the next day by an application of 210 mg NAL (15 min before the start of milking) and 210 mg morphine. In the second part, after control milking for 1 d, six cows were injected with 210 mg NAL 10 min before milking. Morphine at the highest dose tended to stimulate basal PRL levels in the first and second experiments (P<0·10). PRL increased in response to machine milking but morphine did not stimulate its release further. NAL alone, or when given with morphine did not influence the release of PRL in response to machine milking. However, NAL was effective in suppressing the increase in basal levels of PRL caused by morphine. In conclusion, although morphine tended to stimulate basal levels of PRL before milking, the release of PRL during milking seemed not to be regulated by opioids.

The International Standards Organization (ISO) produces international standards for milking equipment. These describe the minimum specifications of design, installation, maintenance and testing of milking machines (BS ISO, 1996). Often these standards are adopted and exceeded by national standards. Standards are rarely mandatory and in some countries variations in interpretation and even disagreement can lead to differences in operating conditions of the milking machine.

A survey of plant test results in the UK (Berry & Scrivens, 1997) showed that, on annual or biannual testing, more than 75% of plants failed to meet the then existing standard (BS5545, 1988). In the UK, most types of plant installed since 1994 meet the newest ISO standard (BS ISO, 1996). However, one type of plant has many features different from all other types. This is a type of plant whose major variations include a smaller claw bowl volume (150 ml), a narrower long milk tube diameter (13·5 mm), 8 mm milk pulse tube, greater cluster weight (approximately 3·5 kg) and simultaneous pulsation used on a plant with milk lift and milking at an installed system vacuum of 47–48 kPa. The majority of parlours installed with this equipment at the time of this study had no form of indexing (see below).

A study has been undertaken to assess 20 new installations for compliance with the ISO requirements (BS ISO, 1996), performance in a static test, milking performance, cow behaviour and the effects on teat condition. Compliance to standards and static test results have been reported elsewhere (Ohnstad, 1997), with no plant proving entirely satisfactory. Some plants had major problems with vacuum level, pulsation characteristics and large air leaks. The physical operation of the milking plant has important implications for cow behaviour and welfare and also ergonomics of the milking operation. The effects on teat condition have already been reported (Hillerton et al. 2000). Here the effects on cow behaviour and milking performance are assessed. Comparisons have been made in line with the International Dairy Federation recommendations (IDF, 1997) to examine the performance and interactions of the cow, the machine and the operator in evaluating the milking process.

Milk producers in Malaysia make extensive use of crossbred Sahiwal Friesian dairy cattle. These animals have, however, been found susceptible to lactation failure. A survey of cows in an experimental herd of F1 Sahiwal Friesian animals indicated that, in 30% of animals, milk yield decreased to negligible levels within the first 8 weeks post partum. Lactation failure was associated with a progressive increase in the amount of residual milk left in the udder after normal milking. By week 3 of lactation, residual milk volume was significantly greater than that in animals that, based on previous lactation history, were not susceptible to lactation failure, and accounted for up to 30% of milk available at the morning milking. The cellular consequences of residual milk accumulation were evident in the activities of acetyl-CoA carboxylase, fatty acid synthetase and galactosyltransferase, key enzyme markers of cellular differentiation, which decreased in glands undergoing lactation failure and were lower than values measured in tissue of control cows. Mammary cell number, estimated by tissue DNA content, was also reduced in animals undergoing lactation failure. These indices of mammary development indicate that lactation failure is the result of premature involution in susceptible animals. Premature involution is a predictable consequence of progressive milk stasis in failing lactation, and attributable to an increase in autocrine feedback by inhibitory milk constituents. The progressive increase in residual milk is, on the other hand, unlikely to be attributable to impaired mammary development. Measurements of milk storage during milk accumulation showed no differences between control and lactation failure cows in the distribution of milk between alveolar and cisternal storage compartments. We conclude that lactation failure in Sahiwal Friesian cows is due to a failure of milk removal, and probably the result of an impaired milk ejection reflex rather than to the glands' milk storage characteristics.

The present study was performed to find out how dairy cow behaviour and the level of the adrenocortical hormone cortisol were influenced by feeding in relation to milking The experiment was designed as a Latin square and performed on 24 primiparous and multiparous Swedish Red and White dairy cows. Each treatment period lasted for 21 days, including 11 days when the cows became accustomed to the new routines. The cows were exposed to three treatments: feeding 1·5 h before milking (FBM), feeding exactly at the same time as milking (FDM) and feeding 1·5 h after milking (FAM). Recordings of individual behaviour were made with instantaneous direct observation of each cow. For the statistical analyses the recordings were divided into two groups: 0 to 1·5 h after feeding and 0 to 1·5 h after milking. Results with a P-value below 0·05 were regarded as statistically significant. The interesting findings in this study were: (a) 0 to 1·5 h after feeding, the percentage of lying was higher in FDM and the percentage of lying while ruminating was higher in FDM; (b) 0 to 1·5 h after milking, the cows in FAM had a significantly lower percentage of social interactions and a significantly higher percentage of oral activity; and (c) feeding-related level of cortisol stayed higher 30 to 60 min after feeding in FAM compared with FBM and FDM, whereas milking-related cortisol secretion tended to be lower in FDM than in FBM and FAM These results demonstrate that feeding during milking may be an important management routine, also for dairy cow behaviour.