Life Sciences Commons^™

Sheep Updates 2006 - Part 2, Darryl Smith, Kathryn Kemper, David Rutley, R. R. Woolaston, D. J. Brown, K. D. Atkins, A. E. Casey, A. J. Ball, David Hopkins, David Stanley, Leonie Martin, Arthur Gilmour, Remy Van De Ven, Geoff Duddy, Steve Semple, David Kessell, Andrew Thompson

Sheep Updates

This session covers six papers from different authors:

GENETICS

1. Novel selection traits - what are the possible side effects?, Darryl Smith, Kathryn Kemper, South Australian Research and Development Institute, David Rutley, University of Adelaide.

2. Genetic Changes in the Australian Merino since 1900, Sheep Genetics Australia Technical Committee, R.R. Woolaston Pullenvale, Queensland, D.J. Brown, Animal Genetics and Breeding Unit*, University of New England, K.D. Atkins, A.E. Casey, NSW Department of Primary Industries, A.J. Ball, Meat and Livestock Australia, University of New England

3. Influence of Sire Growth Estimated Breeding Value (EBV0 on Progeny Growth, David Hopkins, David Stanley, Leonie …

Bovine Respiratory Disease In Feedlot Cattle: Environmental, Genetic, And Economic Factors, G. D. Snowder, L. Dale Van Vleck, L. V. Cundiff, G. L. Bennett

Department of Animal Science: Faculty Publications

The objective of this study was to characterize genetic, environmental, and economic factors related to the incidence of bovine respiratory disease (BRD) in feedlot calves. Records from 18,112 calves representing 9 breeds (Angus, Braunvieh, Charolais, Gelbvieh, Hereford, Limousin, Pinzgauer, Red Poll, and Simmental) and 3 composite types (MARC I, MARC II, and MARC III) over a 15-yr period (1987 to 2001) were evaluated. Disease incidence was observed and recorded by station veterinary and technical staff. The incidence of BRD varied across years, with the annual observed incidence ranging from 5 to 44%. From 1987 to 1992, the annual average incidence …

Shearing Lambs Improves Growth Performance During Periods With Elevated Thermal Load, Jake J. Herrig, Simone M. Holt, J.A. Daniel

South Dakota Sheep Research Reports, 2006-07

The purpose of this study was to determine if average daily gain (ADG) is improved in shorn lambs versus non-shorn lambs in the summer months in the upper Midwestern United States. Forty-nine purebred Hampshire and Columbia ram (n = 10 Hampshire and 4 Columbia) and ewe (n = 22 Hampshire and 13 Columbia) lambs were grouped by breed, sex, age (104 ± 1.7 days of age), and initial weight (109 ± 3.5 lbs) into shorn (n=26) and non-shorn (n=23) groups. After shearing (3 June 2004), shorn sheep had approximately 0.1 inches of wool-cover. Lambs were weighed 1, 29, and 57 …

Demographic Feedback Between Clonal Growth And Fragmentation In An Invasive Seaweed, Jeffrey T. Wright, Andrew R. Davis

Faculty of Science - Papers (Archive)

Many abundant plants, invertebrates, and seaweed are clonal, and this allows the formation of high-density aggregations, foraging, and the placement of modules into new space, and rapid rates of expansion. For these species, population density and rates of expansion are functions of recruitment of asexual modules and post-recruitment vegetative growth and survivorship. In this study, we provide the first experimental test of the relative importance of these two processes in determining the abundance of a clonal seaweed using Caulerpa taxifolia, an invasive green alga that spreads rapidly and reaches very high abundance. We asked two main questions: What is …

Effects Of Husbandry Parameters On The Life-History Traits Of The Apple Snail, Marisa Cornuarietis: Effects Of Temperature, Photoperiod, And Population Density, John Aufderheide, Ryan Warbritton, Nadine Pounds, Sharon File-Emperador, Charles Staples, Norbert Caspers, Valery E. Forbes

Valery Forbes Publications

These experiments are part of a larger study designed to investigate the influence of husbandry parameters on the life history of the apple snail, Marisa cornuarietis. The overall objective of the program is to identify suitable husbandry conditions for maintaining multigeneration populations of this species in the laboratory for use in ecotoxicological testing. In this article, we focus on the effects of photoperiod, temperature, and population density on adult fecundity and juvenile growth. Increasing photoperiod from 12 to 16 h of light per day had no effect on adult fecundity or egg hatching and relatively minor effects on juvenile growth …

Post-Weaning Performance Of Steers From Varying Calving And Weaning Strategies In Montana, E. E. Grings, W. A. Phillips, R. E. Short, H. Mayeux, R. K. Heitschmidt

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The impact of varied calving and weaning times on post-weaning production of steer calves was evaluated in a 3- yr study. Steers (approximately 12 steers per calving-weaning treatment per year) born in late winter or early spring were weaned at 190 or 240 d of age, and steers born in late spring were weaned at 140 or 190 d of age after grazing with their dams on native range. Steers were pen-fed a growing diet until approximately 375 kg BW. They were then moved to an individual feeding facility and fed a higher-energy diet. Steers were allotted to harvest dates …

Effects Of Removal And Remixing Of Heavyweight Pigs On Performance To Slaughter Weights, M. C. Brumm, L. J. Johnston, D W. Rozeboom

Haskell Agricultural Laboratory (Northeast Research and Extension Center)

An experiment was conducted to determine the effects of heavyweight pig removal and remixing on performance. The experiment used a total of 450 pigs (31 kg initial BW) that were sorted and remixed at a mean replicate BW of 73 kg. Treatments were 15 pigs/pen from initial BW to slaughter (15S), 20 pigs/pen from initial BW to time of sort and remix, then reduced to 15 pigs/pen (20/ 15), and 15 pigs/pen from time of sort and remix to slaughter, comprised of the 5 heaviest pigs from each of three 20/15 pens per replicate (15M …

The Biology Of Canadian Weeds. 133. Cuscuta Campestris Yuncker, C. Gronovii Willd. Ex Schult., C. Umbrosa Beyr. Ex Hook., C. Epithymum (L.) L. And C. Epilinum Weihe, Mihai Costea, François J. Tardif

Biology Faculty Publications

Cuscuta spp. (dodders) are rootless, holoparasitic herbs with filiform stems attached to the host by numerous haustoria. In Canada, Cuscuta gronovii is the most common native species of the genus followed by Cuscuta campestris and C. umbrosa. Cuscuta epithymum and C. epilinum, both introduced species in Canada, occur occasionally. Infestation by Cuscuta spp. can result in serious yield losses and dodders are listed as noxious weeds in British Columbia, Ontario and Québec, and as restricted weeds in Alberta. These plants have evolved special adaptations to ensure their success: germination occurs late in the season when potential hosts are …