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ARS Home » Pacific West Area » Logan, Utah » Poisonous Plant Research » Research » Publications at this Location » Publication #264283
Title: Effect of body condition on consumption of pine needles (Pinus ponderosa) by beef cows

Author
item Pfister, James
item Panter, Kip
item Gardner, Dale
item Cook, Daniel
item Welch, Kevin

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/17/2008
Publication Date: 10/1/2008
Citation: Pfister, J.A., Panter, K.E., Gardner, D.R., Cook, D., Welch, K.D. 2008. Effect of body condition on consumption of pine needles (Pinus ponderosa) by beef cows. Journal of Animal Science. 86:3608-16. DOI: 10.2527/jas.2008-1000.

Interpretive Summary: We determined if cattle in low (LBC) or high body condition (HBC) would consume different amounts of green pine needles (Pinus ponderosa). Mature beef cattle were fed an alfalfa pellet diet for Trials 1 and 2; during Trials 3 and 4 cows were fed high protein and high energy diets, respectively. Trial 5 was a grazing study on rangeland during winter in South Dakota; diets were determined using bite counts. Mean body condition score (BCS 1-9 scale) was 7.5 for HBC and < 4.0 for LBC cattle during the trials. During Trial 1, LBC cattle consumed more pine needles than did HBC cattle (mean: 5.5 vs. 1.0 g/kg body weight, respectively). During Trial 2, LBC cows consumed variable, but greater amounts of pine needles than did HBC cattle (3.7 vs. 1.3 g/kg body weight, respectively). When fed a high protein/low energy diet, LBC cattle ate more pine needles than did HBC cattle. When fed a high energy/low protein diet, LBC cattle consumed more pine needles than HBC cattle for the first 3 days of the trial, and then consumption by LBC animals decreased during the last 4 days. These trials suggest that the protein/energy ratio may be an important factor in the ability of cattle to tolerate terpenes, and that cattle were not able to sustain high levels of needle consumption on a low protein diet. During the 25-day grazing trial, LBC animals selected more pine needles (up to 25% of daily bites) on some days compared to HBC cows. Weather influenced pine needle consumption as pine needle bites by LBC cattle were related to days of greater snow depth, and lower minimum daily temperatures. Both LBC and HBC cattle increased selection of pine needles from trees during cold, snowy weather, but the magnitude of the increase was greater for LBC cattle. LBC cattle consumed more pine needles than HBC cattle in all trials, except when cattle were fed a low protein diet. In summary, we recommend that pregnant cows be maintained in at least moderate to good body condition when grazing on pine-needle infested rangelands to reduce consumption and risk of abortions. We also suggest that pregnant cows in the third trimester of gestation not have access to pine needles.

Technical Abstract: We determined if cattle in low (LBC) or high body condition (HBC) would consume different amounts of green pine needles (Pinus ponderosa). Cattle (mature; open Hereford and Hereford x Angus) were fed an adequate basal diet (alfalfa pellets) for Trials 1 and 2; during Trials 3 and 4 cows were fed high protein and high energy diets, respectively. Trial 5 was a grazing study on rangeland during winter in South Dakota; diets were determined using bite counts. Mean BCS (1-9 scale) was 7.5 for HBC and < 4.0 for LBC cattle during the trials. During Trial 1, LBC cattle consumed more (P = 0.001) pine needles than did HBC cattle (mean ''SEM: 5.5 ' 0.25 vs. 1.0 ' 0.14 g qkg BW -1 d -1, respectively). During Trial 2, there was a d x treatment interaction (P = 0.001) as LBC cows consumed variable, but greater amounts of pine needles than did HBC cattle (3.7 ' 0.19 vs. 1.3 ' 0.12 g qkg BW -1 d -1, respectively). When fed a high protein/low energy diet, LBC cattle ate more (P = 0.04) pine needles than did HBC cattle. When fed a high energy/low protein diet, there was a d x treatment interaction (P = 0.001) as LBC cattle consumed more pine needles than HBC cattle for the first 3 d of the trial, and then consumption by LBC animals decreased during the last 4 d. These trials suggest that the protein/energy ratio may be an important factor in the ability of cattle to tolerate terpenes, and that cattle were not able to sustain high levels of needle consumption on a low protein diet. During the 25-d grazing trial, there was a d x treatment interaction (P = 0.001) as LBC animals selected more pine needles (up to 25% of daily bites) on some days compared to HBC cows. Weather influenced pine needle consumption as pine needle bites by LBC cattle were related (r2 = 0.60; P = 0.001) to days of greater snow depth, and lower minimum daily temperatures. Both LBC and HBC cattle increased selection of pine needles from trees during cold, snowy weather, but the magnitude of the increase was greater for LBC cattle. LBC cattle consumed more pine needles than HBC cattle in all trials, except when cattle were fed a low protein diet. In summary, we recommend that pregnant cows be maintained in at least moderate to good body condition when grazing on pine-needle infested rangelands to reduce consumption and risk of abortions. We also suggest that pregnant cows in the third trimester of gestation not have access to pine needles.