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United States Department of Agriculture

Agricultural Research Service

Research Project: ASSESSMENT OF FECAL CHEMISTRY CHANGES IN FEVER TICK INFESTED CATTLE USING NEAR INFRARED REFLECTANCE SPECTROSCOPY
2013 Annual Report


1a.Objectives (from AD-416):
Test hypothesis that cattle fever tick infestations (either Rhipicephalus (Boophilus) annulatus or R. (B.) microplus) produce fecal chemistry changes detectable by near-infrared spectroscopy (NIRS). [Null hypothesis: No detectable fecal chemistry changes occur as a consequence of tick infestation.]


1b.Approach (from AD-416):
A minimum of 6 bovines of similar breed-type and sex will be placed on a uniform diet with water free choice. Samples of any prepared ration(s) and/or forage will be bagged and frozen for future chemical analysis. Half of the animals will serve as the control group. Daily fecal samples will be collected per animal beginning no more than 4 days after the cattle have been initiated to the diet and collected for each of 3 days prior to tick infestation, throughout the tick infestation period, and until 5 days after the end of tick drop. Samples will be placed in individual zip-locked plastic bags (one per sample), labeled as to date and cow number, and frozen (-20 degrees C) for later analysis. Notes will be kept on the cohort of ticks to describe the date(s) in which most meta-nymphs emerge to adults, and when engorged females drop. All fecal samples and feed samples will be shipped or transported on ice to College Station for coordination of fecal NIRS analysis through the Grazing Animal Nutrition Laboratory. A subset of samples will be submitted blind to the GAN Laboratory for analysis and interpretation. Additional samples may be analyzed pending the outcome of the subset testing.


3.Progress Report:

Six bovines of similar breed-type and sex were placed on a uniform diet with water free choice. Samples of any prepared ration(s) and/or forage were bagged and frozen for future chemical analysis. Half of the animals served as the control group. Daily fecal samples were collected per animal beginning no more than 4 days after the cattle had been initiated to the diet, and collected for each of 3 days prior to tick infestation, throughout the tick infestation period, and until 5 days after the end of tick drop. Samples were placed in individual zip-locked plastic bags (one per sample), labeled as to date and cow number, and frozen (-20 degrees C) for later analysis. Notes were kept on the cohort of ticks to describe the date(s) in which most meta-nymphs emerged to adults, and when engorged females dropped. All fecal samples and feed samples were shipped or transported on ice to College Station for coordination of fecal NIRS analysis through the Grazing Animal Nutrition Laboratory. NIRS was able to detect tick infestation and discriminate between R. microplus and R. annulatus. Further analysis is being completed to determine how soon after infestation the presence of ticks can be measured. This may lead to rapid passive methods to detect the presence of ticks along the cattle fever tick eradication zone.


Last Modified: 10/20/2014
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