Document Type

Thesis - Open Access

Award Date

1979

Degree Name

Master of Science (MS)

Department

Animal Science

First Advisor

L. D. Kamstra

Abstract

Cattleman and veterinarian in the western states and Canada have noted the frequent occurrence of reproductive failure in cattle grazing ranges with tree stands of ponderosa pine (Pinus ponderosa). Consumption of the needles or buds from this tree have caused pregnant stock cows to abort or deliver weak calves. Retained fatal membranes are also frequently associated with pine needle abortion. Surveys conducted by the Black Hills Area Resource and Development Project in 1974 covering eight countries in western South Dakota and eastern Wyoming estimate that at least 600 calves were lost through pine needle abortion in a three year period in that area alone. Pine needle abortion is a frequent cause for economic loss to these livestock producers. Since no disease can be intelligently prevented or controlled understood it is understood, more definitive research is needed to solve the problem. Research attempts to further define the disease and to isolate the causative agent are continuing in various laboratories. Some of the investigations are designed to produce the disease at will under laboratory conditions. If the causative factor or factors are discovered and prevention is then possible, the economic benefit to ranchers and to the meat industry in general is obvious. Biological screening for the potential active factor causing the abortions is difficult. So many minute extracted fractions from pine needles require a biological testing method. A simple, inexpensive, and reproducible screening technique therefore is essential. Further fetal and maternal effects must be identified and relative intensity of each measured. Early embryonic effects, except in small laboratory animals, have not received much attention. Chick embryo bioassays are a logical choice for a screening technique. The egg produces an environment for the embryo that is free from outside contamination that could interfere with treatment results. Difficulty exists with small laboratory mammals because they usually reasorb the fetuses early after embryonic death. Cattle are the main concern with pine needle abortion, and since such as mice and rats would be disadvantageous. The primary objective of this study is to test the validity if the chick embryo bioassay screening method with pine needle isolates. An attempt is made to determine if active components appear in lipid or carbohydrate fractions.

Library of Congress Subject Headings

Abortion in animals Ponderosa pine Biological assay Chickens -- Embryos

Format

application/pdf

Number of Pages

54

Publisher

South Dakota State University

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