More lambs from feed and chemical treatments

The ovulation rate, or the number of eggs shed per ovulating ewe, represents the upper limit of the capacity of a flock of ewes toproduce lambs. Several methods can be used to increase ovulation rates and lambing percentages of ewes, including selection for better breeding, feeding and the use of chemicals. The potential for improving the reproductive performance of Western Australia\u27s ewe flocks by the use of different approaches to breeding was discussed by L.G. Butler and R.P. Lewer in the Journal of Agriculture in 1983. This article mainly discusses the research conducted by the Department of Agriculture\u27s Sheep and Wool Branch on the supplementary feeding of ewes with sweet narrow-leafed lupin seed (Lupinus augustifolius) and the more recent investigations of the technique of immunisation to change the levels of some of the sex hormones in ewes. Both methods can increase ovulation rates and subsequent lambing percentages

Recommendations for management of flocks during joining

THE age or experience of the ram, the number of ewes it has to serve and the management of the ram and ewe flock at mating time all influence the lamb-marking percentage. These are the findings of a systematic research programme conducted over the period 1963 to 1955 by Dr. R. J. Lightfoot,* in collaboration with Mr. J. A. C. Smithf (1966) and continued by the author in the years 1967 to 1969

Twinning increases production

Many breeders claim that twinning causes too many losses among Merino lambs and does not favour breeding for twin lamb production. But recent experiments have proved otherwise and agricultural scientists now agree that . . . TWINNING INCREASES PRODUCTION THE low marking percentages regularly recorded for Merino flocks suggest that the Merino is a relatively infertile breed. Certainly, lambing percentages are low when compared with those of most British breeds of sheep

Lamb mortality on agricultural research stations

Progress report of a study of lamb losses in experimental flocks on Department of Agriculture research stations in the agricultural areas. THE major barrier to increased production by the West Australian sheep and wool industry is the shortage of sheep in the agricultural areas of the State, and much research has been directed towards overcoming this shortage

Observations on the mating behaviour of rams

TO work efficiently in commercial flocks, rams must mate with and fertilise relatively large numbers of ewes, often over short periods of mating. The importance of mating behaviour is obvious. Despite this, little is known of the mating behaviour of rams under commercial situations. A series of experiments in 1968 at Badgingarra Research Station was designed to investigate this and other aspects of mating behaviour

Mating weaners does not affect future ewe performance

Maiden ewes in Western Australia are usually mated in their second year because of supposed ill-effects of earlier mating on the ewe\u27s future production. Mating at a younger age however, providing there was no reduction in future performance, would provide for an extra lamb drop and thus increase the lifetime output of ewes. Information from various sources indicated that weaners could be successfully mated providing their bodyweights were satisfactory. This trial was carried out to test the results of mating weaners under Western Australian conditions

Lupinosis and rates of stocking of lupin stubbles

Lupin stubbles provide valuable summer sheep feed but under some conditions the fungus Phomopsis rossiana (for which lupins are the host plant) produces a toxin that causes lupinosis. Results from research at Badaingarra Research Station over the 1973-74 and 1974- 75 summers have shown that sheep liver damage associated with lupin stubble grazing is likely to be more severe at high than low stocking rates

Growth and wool production of Merino wethers after treatment with testosterone

The results were variable with there being no response to the testosterone treatment of the weaners in year 2 which were weaned onto dry feed. In the other two years, the weaners grazed at the lower stocking rates were heavier and there appeared to be a general increase in the weight of those injected with testosterone. However, the level of response was not consistent and in year 3 there was no response while the sheep grazed green feed for four months or so following weaning

Amplified Sediment waves in the Irish Sea (AmSedIS)

Exceptionally high, straight-crested and trochoidal sediment waves have recently been observed on shelf seas world-wide, and reach heights of up to 36 m in the Irish Sea. It is uncertain how the interplay between geological, biogeochemical and hydrodynamic processes influences the migration and extreme growth of these sediment waves. The AmSedIS project thus sets out to (1) investigate the role of sediment granulometry and sedimentavailability on both “extreme” and “normal” sediment wave development and (2) investigate the potential association of methane derived carbonate formation with extreme sediment wave growth. The preliminary findings are: (1) The crests of unusually high and trochoidal sediment waves still migrate over several meters per year and they consist of coarser, more poorly sorted sediments in comparison to the "normal" sediments waves; (2) Methane seepage is not considered a factor in extreme sediment wave development; (3) The excess of mobile sediment supply seems to allow for "extreme" sediment wave growth, and is linked to palaeo-tunnel valleys and the finer sediments that fill them or with converging sediment transport pathways; (4) The variation in sediment from sediment wave trough to crest to trough will form the basis for more advanced numerical modelling