Abstract: We examined whether very young dairy calves are able to discriminate between two people, and whether they use the colour of clothing or other indices to do so. During the familiarisation phase, one person (the familiar rewarder), who always wore the same colour clothes, gave milk, spoke gently and patted the calves in their individual pen for 6 days each week. During the test phase, the calf had to make a choice in an Y-maze placed in front of the gate of its stall. When the calves chose the familiar rewarder, they received 200 ml of milk as reinforcement. When they made the incorrect choice, they received nothing and were returned to their stall. On each test day, the calves made eight choices. The criterion of success was that the calf made at least six correct choices in eight trials on each of two consecutive test days (P<0.021 by the binomial law). The first experiment was carried out with fourteen 1-week-old male and female Holstein calves to see if calves could approach a person, who changed position in the maze, in order to obtain a feed reward. The familiar rewarder wore the same clothes as during the period of familiarisation and was in one arm of the Y-maze. The other arm was empty and the position of the familiar rewarder in the maze was randomised. Eleven of the 14 calves reached the criterion for success, after only three tests. The second experiment, carried out with five 2-week-old calves, examined whether the calves can differentiate the familiar rewarder (wearing the same clothing as during the period of familiarisation) from another person (the non-rewarder) wearing clothes of a different colour. The criterion of success was reached by all five calves. The third experiment was carried out with seven 2-week-old calves. It examined whether the calves can differentiate the familiar rewarder and the non-rewarder, when the two people are wearing clothes of the same colour (i.e. the same colour worn by the familiar rewarder during the phase of familiarisation). None of the calves were able to reach the criterion of success within a limited number of four test days. Often, calves would always choose the same arm of the maze. The fourth experiment was carried out on six 1-month-old calves. It was similar to experiment 3 with the difference that the familiar rewarder and the non-rewarder both wore the same colour clothes, but which were not the same colour as worn during the phase of familiarisation. Only one calf achieved the criterion of success within two test days. Results demonstrated that colour cues help very young calves to discriminate between two people, when these people wear different colour clothing. Some calves may be able to use other indicators than the colour of clothing. The Y-maze method is an promising way of examining calves' abilities to recognise people.

Abstract: Serological examination of 420 domestic animals for the presence of antilegionella antibodies indicates their high exposure to legionellae. On examination by the microagglutination reaction with a serum dilution of 1:64 or more the highest positive values were recorded in horses which reacted with antigens of L. pneumophila 1-14 in 36.2% and with antigens of another 19 types of legionellae in 47.8%. In pigs positive values recorded in 16.2% and in 21.1%; in cattle in 3.8% and 29.5%, in sheep in 7.5% and 11.3% and laboratory rabbits were quite negative. The importance of these findings with regard to the possible role of animals in the ecology of legionellae is obscure.

Abstract: The response of female tabanids to natural attractants was studied in the Monjoros Forest along the Nature Park Kopacki rit in eastern Croatia. Tabanids were caught in canopy traps baited with either aged cow, horse, sheep, or pig urine and also in unbaited traps. Tabanids were collected in a significantly higher numbers in traps baited with natural attractants compared to unbaited traps. The number of females of Tabanus bromius, Tabanus maculicornis, Tabanus tergestinus, and Hybomitra bimaculata collected from canopy traps baited with cow urine and traps baited with other natural attractants differed significantly. Females of Haematopota pluvialis were also collected more frequently in canopy traps baited with aged cow urine than in those with aged horse urine, but this difference was not significant. However, the number of females of Haematopota pluvialis collected from canopy traps baited with other natural attractants (sheep and pig urine) differed significantly when compared with aged cow urine baited traps. Canopy traps baited with aged cow urine collected significantly more Tabanus sudeticus than did traps baited with aged pig urine. Finally, the aged cow urine baited canopy traps collected 51 times more tabanids than unbaited traps, while aged horse, aged sheep, and aged pig urine baited traps collected 36, 30, and 22 times as many tabanids, respectively, than unbaited traps.

Abstract: Yearling beef bulls, representing different Bos indicus and Bos taurus breeds, were given two sexual performance assessments (libido score, number of services, time to first mount and time of sexual inactivity) at four test periods (January, April, July and October) in 1991 (Trial 1) and 1992 (Trial 2) at the Subtropical Agricultural Research Station, Brooksville, Florida. Breed and test period, as well as their interactions, influenced most results. Sexual performance assessments generally improved with age in Bos taurus breeds, but not in Bos indicus. The temperate Bos taurus breeds (Angus and Hereford) were most sexually active, the tropically adapted Bos taurus breeds (Senepol and Romosinuano) intermediate and the two Bos indicus breeds (Brahman and Nellore x Brahman) were least active. Service rates were generally low. Seasonal patterns in sexual performance were not apparent, with breed and year differences occurring. Although breeds showed consistent test results, the failure of Bos indicus bulls to service in any test, indicates either sexual immaturity, or inadequate procedures for assessment of sexual performance in this breed group.