Behavioural responses related to increasing core body temperature of grazing dairy cows experiencing moderate heat stress.

Exposure to direct solar radiation, high ambient temperature, lack of wind movement, coupled with own metabolic heat production, makes grazing dairy cows vulnerable to heat stress. In pastures, it would be beneficial to monitor heat stress by observable changes in behaviour. We hypothesised that grazing dairy cows exhibit behavioural changes due to increasing heat load in temperate climate. Over two consecutive summers, 38 full-time grazing Holstein dairy cows were investigated in 12 experimental periods of up to 3 consecutive days where the cows were repeatedly exposed to various levels of moderate heat load determined by the comprehensive climate index (CCI). The CCI defines the ambient climate conditions, combining air temperature, relative humidity, solar radiation and wind speed. Vaginal temperature (VT) was automatically measured as an indicator of heat stress. In addition, as a less invasive method, we investigated if reticular temperature (RET) can be indicative of heat stress on pastures. Walking activity, lying-, feeding, and ruminating durations were recorded continuously with sensors. Respiration rate (RR), proximity to and competition at the water trough, social licking, self-licking, inter-individual distance, and fly intensity were directly observed. Data were analysed in the morning (0900-1100 h) and during the hottest time of day when cows were on pasture (1230-1430 h). The VT and RET showed similar patterns in relation to the CCI, suggesting that RET can be suitable for continuous monitoring of heat stress on pastures. In the morning, the cow's VT and RET did not relevantly react to the CCI. During the period 1230-1430 h, the cow's mean VT (mean vaginal temperature (VTMEAN); range: 37.7-40.3 °C) and mean RET (mean reticular temperature; range: 37.0-41.1 °C) were positively related to the mean CCI (mean comprehensive climate index) in this period (mean ± SD: 25.9 ± 5.71 °C). For cows with greater VTMEAN, an increased mean RR and decreased durations of walking, lying, feeding, and ruminating were found. These cows were also more likely to be in proximity to the water trough and to have small inter-individual distances. Changes in these traits seem to reflect behavioural adaptations to heat stress in a temperate climate and could be used to detect the heat stress in individual dairy cows on pastures.

Short-term physiological responses to moderate heat stress in grazing dairy cows in temperate climate.

Even in temperate climate regions, an increase in ambient temperature and exposure to solar radiation can cause heat stress in lactating dairy cows. We hypothesised that grazing dairy cows exhibit short-term physiological changes due to increasing heat load under moderate climate conditions. Over two consecutive summers, 38 lactating Holstein dairy cows were studied in a full-time grazing system. Data were collected in 10 experimental periods of up to three consecutive days with a moderate comprehensive climate index (CCI). The individual animals' vaginal temperature (VT), heart rate, and locomotor activity data were automatically monitored with sensors. Blood samples and proportional whole milk samples were collected at afternoon milking. The concentrations of beta-hydroxybutyrate, glucose, non-esterified fatty acids, urea nitrogen, plasma thyroxine and triiodothyronine were analysed in blood plasma, and fat, protein, lactose, urea nitrogen, cortisol, Na+, K+, and Cl- concentrations were analysed in milk. The daily distribution of VT recordings greater than 39 °C showed a circadian rhythm with a proportion of recordings of 2% and lower during the night and a percentage of 10% or higher in the afternoon. The cows' maximal daily vaginal temperature (VTMAX) between 0830 and 1430 h was positively related to the mean daily CCI in the same time period (CCIMEAN; mean and SD 23.6 ± 5.4 °C). Cows with greater VTMAX had an increased mean heart rate, plasma glucose and milk cortisol concentrations and decreased concentrations of plasma thyroxine and triiodothyronine. The concentration of Na+ in milk was lower, and the concentration of K+ in milk tended to be higher in cows with increased VTMAX. For beta-hydroxybutyrate, non-esterified fatty acids and urea nitrogen concentrations in plasma and fat and lactose concentrations in milk no relationships were found in terms of increasing VT. For milk urea nitrogen and protein concentrations, the proportion of total variance explained by inter-individual or -period variance was high. In conclusion, changes observed in milk and blood likely reflected short-term physiological responses to moderate heat stress. In particular, milk cortisol and Na+ may be useful traits for timely monitoring of heat stress in individual cows because their inter-individual variances were relatively small and samples can be collected non-invasively.

Agonistic behaviour of dairy goats and sheep during feeding - A pilot study on Swiss farms with mixed rations.

INTRODUCTION: Feeding mixed rations is a widely used practice for cattle to ensure the intake of a balanced diet and to reduce competition for food. It is unknown, whether mixed rations have the same advantages for small ruminants because they differ from cattle in their feeding and social behaviour. In this observational pilot study, an array of feeding and social behaviour of dairy goats and sheep fed ad libitum with mixed rations on Swiss farms was investigated. Twelve dairy goat and 12 dairy sheep farms feeding mixed rations were visited once during the winter feeding period. Data on the feeding management, feeding place design and the composition of the mixed rations were collected. The number of animals feeding simultaneously and the number and type of agonistic interactions during feeding were assessed by direct observations for 6 hours after the morning feed-distribution. The feeding management and the composition of the mixed rations were very heterogeneous among farms. The feed rations were mostly well balanced in relation to energy and protein and covered the requirements for the daily production of about 2,5 kg of milk. In terms of feeding simultaneously, sheep were more synchronous than goats. The mean number of agonistic interactions per feeding place within 6 hours were 3,8 in goats and 1,8 in sheep; thus, the probability to observe agonistic behaviour is higher in goats than in sheep. Goats and sheep also differed in the frequency of types of agonistic interactions. Overall, the occurrence of agonistic interactions between animals during feeding decreased with higher numbers of feeding places per animal and longer periods of time since the feed distribution. To conclude, when feeding mixed rations, agonistic interactions related to feeding are more frequent in goats but also occur in sheep to a considerable extent. They can be decreased by offering more feeding places.

INTRODUCTION: L'alimentation avec des rations mixtes est une pratique largement utilisée pour les bovins afin de garantir l'apport d'une alimentation équilibrée et de réduire la concurrence pour la nourriture. On ignore si les rations mixtes présentent les mêmes avantages pour les petits ruminants, car ils diffèrent des bovins en matière de comportement alimentaire et social. Dans cette étude observationnelle pilote, un éventail de comportements alimentaires et sociaux de chèvres et de moutons laitiers nourris ad libitum avec des rations mixtes dans des fermes suisses a été étudié. Douze exploitations de chèvres laitières et 12 exploitations de moutons laitiers, utilisant des rations mixtes, ont été visitées une fois pendant la période d'alimentation hivernale. Des données sur la gestion de l'alimentation, la conception du lieu d'alimentation et la composition des rations mixtes ont été recueillies. Le nombre d'animaux s'alimentant simultanément et le nombre et le type d'interactions agonistiques pendant l'alimentation ont été évalués par des observations directes pendant 6 heures après la distribution matinale des aliments. La gestion de l'alimentation et la composition des rations mélangées étaient très hétérogènes entre les exploitations. Les rations alimentaires étaient généralement bien équilibrées en termes d'énergie et de protéines et couvraient les besoins pour la production quotidienne d'environ 2,5 kg de lait. En termes d'alimentation simultanée, les moutons étaient plus synchrones que les chèvres. Le nombre moyen d'interactions agonistiques par place d'alimentation dans les 6 heures était de 3,8 chez les chèvres et de 1,8 chez les moutons ; la probabilité d'observer un comportement agonistique est en conséquence plus élevée chez les chèvres que chez les moutons. Les chèvres et les moutons diffèrent également dans la fréquence des types d'interactions agonistiques. Dans l'ensemble, l'occurrence des interactions agonistiques entre les animaux pendant l'alimentation a diminué avec un nombre plus élevé de places d'alimentation par animal et des périodes plus longues depuis la distribution des aliments. En conclusion, lors de la distribution de rations mixtes, les interactions agonistiques liées à l'alimentation sont plus fréquentes chez les chèvres mais se produisent également dans une large mesure chez les moutons. Elles peuvent être réduites en offrant davantage de places d'alimentation.

Effects of the anti-sucking device «SuckStop Müller¼ on calf behavior.

INTRODUCTION: When cross-sucking persists beyond calf-hood, it represents an important problem in dairy heifers and cows. It can cause teat injuries and severe mastitis and lead to significant economic losses. The «SuckStop Müller,¼ a novel anti-sucking device, is designed to give the calf a negative feedback when cross-sucking on a conspecific. The aim of this study was to assess whether wearing a SuckStop would result in behavioral changes other than cross-sucking and thus, impair welfare in the short- and longer-term. Sixteen group-housed calves were observed in groups of four on five days, before and after fitting the SuckStop: day -2, day -1, day 0, day 1, and day 9. Maintenance behaviors (e.g., feeding, drinking, lying) were recorded using instantaneous scan sampling. In addition, the frequency of contact behaviors (e.g., exploring the feeding fence, touching own body) was recorded by means of continuous focal animal observations. Contact behaviors were classified as «impaired¼ or «normal¼ depending on whether or not the calf flinched in response to the contact. Finally, the number of visits to the milk and concentrate feeders was extracted from the computer-controlled feeding system. Fitting a SuckStop resulted in a higher proportion of observations spent lying and less exploration behavior on day 0 and day 1 than on day -2, day -1, and day 9. On day 0 and day 1, 6,3 % of exploration behaviors were classified as impaired, compared to 0,4 % (day -2, day -1) before and 0,2 % (day 9) after fitting the SuckStop. On day 9, all calves had superficial ulcerations on the nasal septum. In four calves, these ulcerations were moderately severe, whereas all other calves had slight ulcerations. In summary, the calves habituated quickly to this novel anti-sucking device. Follow-up studies are necessary to assess the long-term relevance of tissue alterations in the nasal septum for calf welfare as well as the effect of the SuckStop on cross-sucking behavior.

INTRODUCTION: Lorsque la succion croisée persiste au-delà de l'âge de veau, elle représente un problème important chez les génisses et les vaches laitières. Elle peut provoquer des blessures aux trayons et des mastites graves et entraîner ainsi des pertes économiques importantes. Le «SuckStop Müller¼, un nouveau dispositif anti-succion, est conçu pour donner au veau un feedback négatif lorsqu'il suce un congénère. L'objectif de cette étude était de déterminer si le port d'un SuckStop pouvait entraîner des changements de comportement autres que la succion croisée et, par conséquent, nuire au bien-être à court et à long terme. Seize veaux logés en groupe ont été observés par groupes de quatre pendant cinq jours, avant et après la pose du SuckStop: jour ­2, jour ­1, jour 0, jour 1 et jour 9. Les comportements d'entretien (par exemple se nourrir, boire, se coucher) ont été enregistrés à l'aide d'un échantillonnage par balayage instantané. En outre, la fréquence des comportements de contact (par exemple, explorer le râtelier, toucher son propre corps) a été enregistrée au moyen d'observations continues de chaque animal. Les comportements de contact ont été classés comme «altérés¼ ou «normaux¼ selon que le veau a tressailli ou non en réponse au contact. Enfin, le nombre de visites aux distributeurs de lait et de concentré a été extrait du système d'alimentation contrôlé par ordinateur. L'installation d'un SuckStop a entraîné une proportion plus élevée d'observations de comportements couchés et moins de comportements d'exploration le jour 0 et le jour 1 que le jour ­2, le jour ­1 et le jour 9. Le jour 0 et le jour 1, 6,3 % des comportements d'exploration ont été classés comme déficients, contre 0,4 % (jour ­2, jour ­1) avant et 0,2 % (jour 9) après la pose du SuckStop. Au jour 9, tous les veaux présentaient des ulcérations superficielles sur la cloison nasale. Chez quatre veaux, ces ulcérations étaient modérément graves, tandis que tous les autres veaux présentaient de légères ulcérations. En résumé, les veaux se sont rapidement habitués à ce nouveau dispositif anti-suceur. Des études de suivi sont nécessaires pour évaluer la pertinence à long terme des altérations tissulaires de la cloison nasale pour le bien-être des veaux ainsi que l'effet du SuckStop sur le comportement de succion croisée.

Performance of goats in a detour and a problem-solving test following long-term cognitive test exposure.

Cognitive research in long-lived species commonly involves using the same animals in different experiments. It is unclear whether the participation in cognitive tests can notably alter the performance of individuals in subsequent conceptually different tests. We therefore investigated whether exposure to cognitive tests affects future test performance of goats. We used three treatment groups: goats with long-term exposure to human-presented object-choice tests (for visual discrimination and reversal learning tests + cognitive test battery), goats that were isolated as for the test exposure but received a reward from the experimenter without being administered the object-choice tests, and goats that were isolated but neither received a reward nor were administered the tests. All treatment groups were subsequently tested in two conceptually different cognitive tests, namely a spatial A-not-B detour test and an instrumental problem-solving test. We tested dairy goats, selected for high productivity, and dwarf goats, not selected for production traits, each at the same two research sites. We did not find notable differences between treatments with respect to the goats' detour or problem-solving performance. However, high variation was observed between the research sites, the selection lines, and among individuals, highlighting potential pitfalls of making accurate comparisons of cognitive test performances.

Goats work for food in a contrafreeloading task.

Contrafreeloading (CFL) is the phenomenon when animals work for a resource although an identical resource is available for free. Possible explanations for CFL are that animals seek context for species-specific behaviours or to control their environments. We investigated whether goats show CFL and whether breeding for productivity traits has altered its occurrence. In a manipulation task, we compared two selection lines: 27 Nigerian dwarf goats, not bred for productivity traits, and 30 dairy goats, bred for high milk yield. Over 10 trials, each goat could perform one of three behaviours: not participating in the trial, feeding for free from an open door, or opening a sliding door for a feed of similar value. The results were analysed using an Item Response Tree (IRTree) generalized linear mixed model (GLMM). The fitted probabilities to participate were > 0.87 over all trials in both selection lines. For dwarf goats, the probability of choosing the closed door, and thereby demonstrating CFL, increased from 0.30 in Trial 1 to 0.53 in Trial 10. For dairy goats, this probability was constant at approximately 0.43. Unlike dwarf goats, dairy goats were faster to approach the closed compared to the open door. Overall, our results suggest that both selection lines were similarly interested in CFL.

On-chip free beam optics on a polymer-based photonic integration platform.

This paper presents on-chip free beam optics on polymer-based photonic components. Due to the circumstance that waveguide-based optics allows no direct beam access we use Gradient index (GRIN) lenses assembled into the chip to collimate the beam from the waveguides. This enables low loss power transmission over a length of 1432 µm. Even though the beam propagates through air it is possible to create a resonator with a wavelength shift of 0.002 nm/°C, hence the allowed deviations from the ITU-T grid (100 GHz) are met for ± 20 °C. In order to guarantee reliable laser stability, it is necessary to implement optical isolators at the output of the laser. This requires the insertion of bulk material into the chip and is realized by a 1050 µm thick coated glass. Due to the large gap of the free-space section, it is possible to combine different resonators together. This demonstrates the feasibility of an integrated wavelength-meter.

Head orthesis therapy in infants with unilateral positional plagiocephaly: an interdisciplinary approach to broadening the range of orthodontic treatment.

OBJECTIVE: Unilateral positional plagiocephaly is the most common deformity of the head in infants. As part of a prospective controlled clinical study, the pathomorphology of the positional plagiocephaly in early infancy was examined. The goal was to use noninvasive three-dimensional (3D) imaging to generate, for the first time ever, a standard database of infants without head deformities, to quantify the asymmetry of the positional plagiocephaly, and to evaluate the effectiveness of functional growth control using head orthesis. PATIENTS AND METHODS: In the present study, 3D soft-tissue data of the entire head were collected from a total of 40 infants: 20 with positional plagiocephaly (6.0 ± 0.97 months) and 20 infants without a head deformity (6.4 ± 0.3 months). Functional growth was controlled using a custom-made head orthesis. To evaluate the therapy, pre- and posttherapeutic scans were evaluated in three dimensions. RESULTS: Compared with the control group, infants with positional plagiocephaly demonstrated a reduced maximum length of the head, an increased head height, a shift in the ear axis as well as asymmetric anterior and posterior volumes of the neurocranium in lateral comparisons. Therapy using head orthesis led to a significant improvement of the asymmetry, with a reduction of the diagonal difference and an adjustment of the posterior volumes. CONCLUSION: Conservative growth control of extrinsically deformed infant skulls represents an interdisciplinary medical expansion of the orthodontic therapeutic spectrum. To prevent potential effects of positional plagiocephaly on the viscerocranium, head orthesis therapy is advisable in infancy.

Complex monolithic and InP hybrid integration on high bandwidth electro-optic polymer platform.

We report on the monolithic integration of multimode interference couplers, Bragg gratings, and delay-line interferometers on an electro-optic polymer platform capable of modulation directly at 100 Gb/s. We also report on the hybrid integration of InP active components with the polymer structure using the butt-coupling technique. Combining the passive and the active components, we demonstrate a polymer-based, external cavity laser with 17 nm tuning range and the optical assembly of an integrated 100 Gb/s transmitter, and we reveal the potential of the electro-optic polymer technology to provide the next generation integration platform for complex, ultra-high-speed optical transceivers.

Influence of weaning method on health status and rumen development in dairy calves.

In the artificial rearing of dairy calves, the same feeding plan is applied to all animals during the milk-feeding period, with individual differences attributable to development or health status rarely considered. The aim of this study was 1) to analyze whether the parameters of feeding behavior automatically recorded by a feeding computer and weight gain are suitable for predicting the health status and rumen development of male dairy calves, and 2) to compare a conventional weaning method (end of milk provision at 12 wk of age, n = 23 calves) with a concentrate-dependent weaning method (with reduction in the milk amount depending on the consumption of concentrate, n = 24). The health status of each animal was evaluated daily by a scoring list (health score), and body temperature was measured automatically during each milk intake. In addition, the number of veterinary treatments per calf was recorded. Rumen development was assessed by measuring rumen papillae in 8 rumen areas after slaughter (n = 24, half of each treatment group). During the milk-feeding period, body temperature was elevated (>/=39.5 degrees C) on 40.8 and 43.2% of all days for calves on the concentrate-dependent weaning method and the conventional weaning method, respectively. Hay and concentrate intake (but not milk intake) and weight gain were clearly affected by health status. In addition, health score and the probability of being treated by a veterinarian were significantly related to decreases in concentrate consumption. During the milk-feeding period, increased body temperature, an increased number of veterinary treatments, and decreases in milk consumption were all associated with reduced weight gain. Calves on the concentrate-dependent weaning method were weaned at an average age of 76 d, which was significantly shorter than the age at the end of milk provision for conventionally fed calves (84 d). Weight gain and health status did not differ between treatment groups. Weight gain was positively associated with papillae length. A treatment effect on rumen development could not be found. We conclude that the concentrate-dependent weaning method allows a faster physiological development without any negative impact on rumen development, weight gain, or health status; we therefore recommend its use in practice.

Effects of frequency and duration of outdoor exercise on the prevalence of hock lesions in tied Swiss dairy cows.

Injuries around the tarsal joint are common in dairy cows kept in tie stalls. This study investigated the influence of the frequency and duration of outdoor exercise on the prevalence of hock lesions in tied Swiss dairy cows. Over a 1-year period (from January to December), cows on 66 farms were examined a total of six times (once every 2 months) for the number and severity of hock lesions (hairless patches, scabs and open wounds, swellings). The prevalence of scabs and wounds (mean 2.1 scabs per cow and farm, range 0.3-4.1) was negatively associated with the duration of outdoor exercise, and positively associated with its frequency. It was also significantly affected by the time of visit and the type of bedding (straw being better than other materials). With increasing length of the lying area, the prevalence of scabs and wounds decreased. Based on the interpretation of the final model, it is suggested that a minimum of 50h spent outdoors over a 4-week period is necessary to have a marked result on the prevalence of hock lesions.

The development of intersucking in dairy calves around weaning.

Intersucking, i.e. sub-adult or adult cattle sucking at the udder of herd-members, is a problem often reported in dairy herds that leads to udder health problems. The causes of intersucking are virtually unknown, and until now all available countermeasures treat only the symptoms of this behavioural problem. We examined (I) whether intersucking occurs prior to weaning and continues thereafter, and (II) whether its establishment is related to the feeding management during weaning. On 10 dairy farms, we observed the sucking and feeding behaviour of a group of dairy calves (2-5 animals per farm, 38 in total) 1 week before and 1, 5 and 9 weeks after weaning. Calves were weaned off milk at an average age of 21 weeks (S.D. 4.7). We analysed the calves' food rations in order to estimate the adequacy of their energy density. Thirty-five (92%) of the 38 calves performed intersucking already before weaning, with the frequency being highly variable between individual calves (x(med)=5.0 bouts/day, range 0-24.7). Calves with a high intersucking activity before weaning were likely to continue intersucking after weaning (P<0.05). Before and after weaning intersucking could be observed at nearly every time of the day, but was most frequent around feeding. Calves with a long feeding duration (x(med)=260min, range 186-374) showed less frequent intersucking 1 week after weaning (P<0.05). In addition, the frequency of intersucking increased with decreasing adequacy of their rations energy density (r=-0.88, P<0.01), and the highest intersucking activity was recorded on farms with restricted availability of food. The results indicate that intersucking occurs already before weaning, and its establishment may be prevented by a ration and a feeding management that ensures an optimal transition from pre-ruminants to ruminants.

Is intersucking in dairy cows the continuation of a habit developed in early life?

Intersucking, i.e., cattle sucking the udder of heifers or cows, is a frequent problem in dairy herds and may lead to udder damage, mastitis, milk loss, and culling of breeding animals. Using epidemiological methods, we conducted an observational cross-sectional study to investigate risk factors for intersucking in Swiss dairy cows. We asked 114 randomly selected dairy farmers about a broad spectrum of environmental factors possibly associated with intersucking, such as housing conditions, management, and feeding of calves, heifers, and cows. Thirty of the 114 farms were confronted with intersucking in cows. The mean proportion of intersucking cows per farm was 1.6%. From a total of 3077 cows (Swiss Brown Cattle, Simmental, and Holstein Friesian) we recorded 49 cows that had performed or were currently intersucking. In 69% of these cows, intersucking had been observed as heifers. Using path analysis and multivariable stepwise backward logistic and linear regression analyses, we revealed that the most important risk factor for intersucking cows was the presence of intersucking heifers on a farm (odds ratio = 7.8). The results suggest that intersucking in cows is the continuation of a habit that was already established in a cow's subadult life. This emphasizes the importance of looking not only at the animal's current environmental situation but also considering its entire life history for the prevention of behavioral problems.

Factors associated with intersucking in Swiss dairy heifers.

Intersucking is a problem that may lead to udder damage, mastitis, milk loss, and culling of breeding animals. To analyse the risk factors for intersucking in dairy heifers in Switzerland, we asked 130 randomly selected dairy farmers about a broad spectrum of environmental factors that might be associated with intersucking (such as housing conditions, management, and the feeding of calves and heifers). In total, 2768 heifers (Swiss Brown Cattle, Simmental and Holstein Friesian) were included of which 303 had ever performed intersucking. Data at the farm level were analysed using path analysis (linear and logistic regression). Two outcome variables were considered: the occurrence of intersucking on the farm and the proportion of intersucking heifers above the cut-off of 7.2%. Farms where calves had no access to barnyard or pasture, where calves were reared in pens in enclosed buildings, where heifers after weaning were not restrained while feeding, where heifers after weaning received <0.5kg concentrate per day, and where heifers after weaning were fed > or =40% maize silage (dry-matter ratio) were most likely to have intersucking heifers.

Die konstanz der melkordnung von ziegen in großen gruppen.

UNLABELLED: ZUSAMMENFASSUNG: An zwei großen Ziegengruppen (Gehörnte und Hornlose) wurde geprüft, ob es eine Melkordnung gibt. Die Tiere wurden in einem landwirtschaftlichen Betrieb in Oberbayern in Laufställen gehalten. Zunächst wurde für jede Herde die Soziale Rangordnung ermittelt und für jedes Tier ein Dominanzindex errechnet. Gleichzeitig wurde über Wochen hinweg bei 17 Melkvorgängen (Gehörnte) bzw. 20 Melkvorgängen (Hornlose) die Melkordnung ermittelt. Die Untersuchung führte zu folgenden Ergebnissen: 1 . Der Platz in der Melkordnung schwankte individuell sehr viel weniger, als es bei zufälliger Wahl zu erwarten gewesen wäre. Viele Tiere nahmen bei jedem Melkvorgang annähernd denselben Platz in der Melkordnung ein. 2 . Eine Platzkonstanz bestand vor allem am Anfang und am Ende der Melkordnung. 3 . Es konnte kein Zusammenhang zwischen Melkordnung und Sozialer Rangordnung gefunden werden. 4 . Geißen mit höherer Milchleistung nahmen im allgemeinen frühere Plätze in der Melkordnung ein, als es zufälliger Verteilung entsprochen hätte. 5 . Zwischen gehörnten und hornlosen Tieren bestanden in allen Aspekten nur geringfügige Unterschiede. 6 . Es ist denkbar, daß die Melkordnung weniger von meßbaren Merkmalen als von Gewohnheitsbildung abhängt. SUMMARY: Equality of ranking of goats at milking The existence of rank order at milking was investigated in two large groups of horned and polled goats, respectively. First, social rank was determined and an index of dominance constructed for each animal in each herd. Simultaneously, the ranking at milking was observed 17 times for horned and 20 times for the polled goats, respectively: 1 . The ranking at milking shows less than random variation. At each milking, animals assume roughly the same position. 2 . Uniformity of ranks was particularly evident at the beginning and at the end of milking. 3 . No connection was evident between social rank and milking rank. 4 . Higher yielding goats entered the milking parlour significantly earlier. 5 . Little differences in this behaviour seemed to exist between horned and polled goats. 6 . Ranking seems to be influenced by habits more than by measurable traits.