Letters to the editor

Extract

In order to utilize spring growth efficiently under a system of grassland farming, a New Zealand dairy farmer endeavours to calve as many cows as possible within a four to six weeks' period. To maintain this calving pattern, herd members must conceive by 70 to 80 days after calving. Consequently normal postparturient uterine involution, together with a minimum of delay in the onset of ovarian activity and oestral cyclicity, is of vital importance. A study of these phenomena may be very rewarding in helping to achieve optimal reproductive efficiency.     

Letters to the editor

Extract

Sir,—A 7-month-old lamb was presented for slaughter, one of a line of 460. The animal was in good condition and, except for a moderately enlarged abdomen, no abnormalities could be detected on ante-mortem examination.     

Equine rhinopneumonitis virus infection in New Zealand

Abstract

Extract

Sir,—Japanese workers (Matumoto el al., 1965 Matumoto, M., Ishizaki, R. and Shimuzu, T. 1965. Serologic survey of equine rhinopneumonitis virus infection among horses in various countries. Arch, f. Viruslorsch., 15: 609–624.  [Google Scholar]) have examined 388 horse sera from 17 countries including New Zealand and have found evidence of a high incidence of infection with equine rhinopneumonitis virus. The New Zealand material was supplied between 1957 and 1960, by Dr J. D. Manning, then of the National Health Institute, Wellington.     

Letter to the editor

Extract

Sir, — In the course of research on infectious bronchitis (IB) in chickens in New Zealand, one strain of IB virus was seleted and attenuated as a local vaccine virus and produced in limited quantities at Massey University for trial purposes.     

A 3.3-Ma impact in argentina and possible consequences

Enigmatic glassy materials (escorias) and red bricklike materials (tierras cocidas) occur at a restricted stratigraphic level (the top of the Chapadmalal Formation). Materials from one locality near Mar del Plata are attributed to a mid-Pliocene impact event with a radiometric and magnetostratigraphic age of 3.3 million years ago (Ma). An extinction of endemic fauna (including the glyptodonts and flightless cariamid birds) correlates with the unit containing the impact glasses. Moreover, the age of the glasses is coincident within dating uncertainties with a pulselike change in the oxygen isotope marine record in the Atlantic and Pacific Oceans just before the late Pliocene deterioration of the climate.     

Phytophthora disease of alder (Alnus glutinosa) in France: investigations between 1995 and 1999

A severe decline of alder associated with an undescribed Phytophthora species was identified for the first time in England in 1993. No generalized decline of alder was reported in France before 1990. The first diebacks and mortalities of common alder were observed at the beginning of the 1990s, but the so‐called alder Phytophthora was not isolated in France until 1996. First, a synthesis about alder declines that were known in France before 1995 is presented. Then, a survey was established in north‐eastern France; 108 sites were visited and the alder Phytophthora was isolated from 57 of them. All the main rivers were found to be affected and damage levels are significant along some of them. The frequency of the alder Phytophthora and other fungi isolated from declining alders is discussed. Finally, information on other alder declines in France is presented region by region, and a map summarizes the known distribution of the disease. The alder Phytophthora is quite common and widespread in France, with western and north‐eastern France being especially affected; however, the number of diseased or dead trees varies greatly from one site to another. All records are from Alnus glutinosa; other Alnus species were seldom seen in the surveys.