2016 Research Journal Add Two Articles
July 1, 2016

Two new articles have been posted to the 2016 edition of the Sheep and Goat Research Journal.

In the first article, Sex of Littermate Twin Affects Lifetime Ewe Productivity, authors J. Alison Brown, David P. Kirschten, Gregory S. Lewis and J. Bret Taylor state that ewe productivity is synonymous with annual litter-weight weaned (LWW) per ewe exposed to rams for breeding, and LWW is largely a function of the number of lambs born and weaned. Selecting for LWW should increase litter size and numbers of ewe-ram co-twins. Thus, historical records were used to determine whether the sex of co-twins affected lifetime productivity of twin-born ewes. U.S. Sheep Experiment Station lambing records from 1991 through 1997 were queried to identify twin-born ewes that were reared with their biological dams and retained in the breeding flock. Based on the data, it was concluded that ewes born as a co-twin to a ram had an advantage over ewes born as a co-twin to a ewe. This advantage amounted to 15.55 kg in lifetime litter-weight weaned per-ewe exposed.

The next study evaluated performance and health parameters associated with gastrointestinal parasite control when lambs and meat-goat kids were finished on a mixed sward of orchard grass, red clover and white clover with and without supplemental whole cottonseed. In the article, Selective Deworming Effects on Performance and Parameters Associated with Gastrointestinal Parasite Management in Lambs and Meat-Goat Kids Finished on Pasture, authors K.E. Turner, D.P. Belesky, K.A. Cassida, A.M. Zajac and M.A. Brown determined that using FAMACHA© as a means to identify haemonchus contortus-induced anemia resulted in a mean 56-percent reduction in doses of dewormer administered compared to a theoretical monthly dosing of each animal. By considering the use of breed groups resistant to or having high resilience to internal parasites and coupling with the use of the FAMACHA© system to determine the need to deworm individual animals, producers can improve livestock performance and reduce overall cost of production.

The full articles are available at www.sheepusa.org/ResearchEducation_ResearchJournal.