Karen L. Launchbaugh

Understanding Landscape Use Patterns of Livestock as a Consequence of Foraging Behavior

Abstract Many grazing-management challenges stem from poor livestock distribution resulting in overuse of some areas and low utilization of others. Managing livestock-distribution patterns requires knowledge of pasture characteristics and animal behavior patterns. Behavioral patterns result from recognizable processes that include inherited attributes, individual and social learning systems, cue-consequence specificity, predispositions toward novel stimuli, and spatial memory. Through these behavioral mechanisms, animals form and revise preferences and aversions for specific locations in their foraging landscape. To accomplish habitat selection, domestic herbivores use sight and sound cues to seek and return to high-quality foraging locations. Nested within habitat selection are learned diet preferences and aversions by which ungulate herbivores associate taste with positive or negative postingestive feedback. The deliberate and careful modification of animal attributes and habitat characteristics could yield options for adaptive rangeland management. In this article, we describe the basic principles that underlie how animals make decisions about where to forage and how long to stay in a particular habitat. We also suggest management practices designed to modify animal behavior and alter habitat-use patterns.

Can Plants Practice Mimicry to Avoid Grazing by Mammalian Herbivores

Mimicry has been suggested as a grazing avoidance mechanism for plants. This study examined the ability of a mammalian herbivore to generalize conditioned flavor aversions (CFAs) to determine if the conditions for plant mimicry exist. Nine sheep (treatment group) were averted to cinnamon on ground rice while an additional 9 sheep (control group) received cinnamon on rice with no negative post-ingestive consequences. When offered a choice between wheat and cinnamon-flavored wheat the control group ingested more (P < 0.05) cinnamon-flavored wheat (45 ± 6%) than did the treatment group (3 ± 1%) in four test periods. This implies that herbivores generalize CFAs and thus non-poisonous plants could mimic the flavor of poisonous plants to avoid grazing

Effects of breed and dietary experience on juniper consumption by goats.

Low nutritional quality and high levels of essential oils result in low consumption of juniper by goats. In this study we examined: (1) if juniper consumption could be increased by exposing goats to essential oils early in life; (2) if goat breeds (Spanish vs Angora) differed in juniper consumption; (3) if differences in juniper consumption were related to detoxification abilities of goats; and, (4) if differences in digestibility and nitrogen or energy balance could explain juniper consumption patterns. In the first experiment, Spanish and Angora goats 6-7 weeks old, were bolused every other day for 1 month with essential oils distilled from redberry juniper (Juniperus pinchotii Sudw.), while control animals received empty capsules. Goats were then offered redberry juniper branches in a 5-day acceptance trial. Spanish goats consumed more (1 < 0.01) juniper during the trial than Angoras. Goats previously dosed with essential oils ingested marginally less (0 < 0.086) juniper than controls. Liver-specific enzymes in blood serum (aspartate aminotransferase and gamma glutamyltransferase) were compared before and after acceptance testing to examine potential liver damage. Spanish goats apparently experienced less tissue damage in response to juniper consumption than Angora goats. A second experiment examined the digestion and metabolism of juniper. Spanish goats consumed more (0 < 0.01) juniper than Angora goats though Angoras digested juniper more completely; probably a result of their lower consumption. The metabolic fate of dietary nitrogen and energy was similar for both breeds and unaffected by exposure to essential oils early in life.

Overcoming food neophobia in domestic ruminants through addition of a familiar flavor and repeated exposure to novel foods

Food neophobia, observed as a decreased intake of novel foods, can cause significant livestock production losses. For example, in the transition from rangeland to feedlot, livestock are usually offered novel diets that they sample cautiously, gradually increasing intake. This familiarization period can slow weight gains and increase time to slaughter. This research examines two ways to overcome food neophobia. First, we determined if the addition of a familiar flavor would increase the acceptance of a novel food. Lambs (n = 30) were fed barley, onion-flavored barley, or onion-flavored rice twice a day for 4 days. All lambs were then offered onion-flavored rice. The lambs that had previously eaten onion-flavored barley ate more (P < 0.05) onion-flavored rice than those that had previously eaten unflavored barley. Second, we examined if repeated exposure to novel foods increased the acceptance of subsequent novel foods. Controlling for order of food offered, lambs (n = 72 total) were offered four novel foods (calf manna, corn, rice, and wheat bran) for 3 consecutive days each (12 days total). Lambs ate more (P < 0.05) of the fourth novel food than of the first novel food offered. These results indicate that flavor generalization and repeated exposure to novel foods may increase the acceptance of novel foods.

Influence of range site on diet selection and nutrient intake of cattle.

It is common in range science to base stocking rate estimates on range sites as units of forage production. However, little is known about how diet composition, quality, and intake may differ by range site. This study examines the influence of 2 range sites on the diet selection and nutrient intake of cattle. A sandy loam (SL) and a clay loam (CL) range site were compared in 4 seasonal, trials on an Acacia dominated, mixed-brush savanna on the Texas Rio Grande Plains. Diet composition and quality, and nutrient intake of cattle were determined throughout each 16-21 day trial using esophageally fistulated cattle and daily dosing with ytterbium acetate. The range sites differed widely in proportions of grass, forb, and browse biomass. Cattle generally selected similar diets and adjusted diets to increasing grazing pressure and decreasing forage availability in a similar manner regardless of site, except in fall when cattle selected more browse on the SL site where herbaceous forage was severely limited. Fecal output of cattle differed between sites only in fall when cattle on the SL site had lower fecal output than cattle on the CL site. Cattle on the site of lower herbaceous mass (SL site) generally achieved higher diet quality and nutrient intake during the growing season, when herbaceous forage was readily available because of greater access to green forage. Therefore, the SL site yielded higher diet quality at low grazing pressure during the growing season. Conversely, the CL site, because of its greater herbaceous mass, yielded higher nutrient intake in the fall and at high levels of grazing pressure.

The Effect of Targeted Grazing and Biological Control on Yellow Starthistle (Centaurea solstitialis) in Canyon Grasslands of Idaho

Abstract Yellow starthistle (Centaurea solstitialis L.) is an invasive weed of significant importance on rangelands in the western United States. Field experiments were conducted in 2003 and 2004 to determine the effect of targeted grazing on yellow starthistle growth and bud production, and on the efficacy of four established biological control seed-head–feeding insects, which included three species of weevils and one fly species. We tested sheep and cattle grazing at three yellow starthistle growth stages—rosette, bolting, and late bud—at a site where all four biocontrol agents were established. The timing of grazing had a greater impact on yellow starthistle growth and bud production than the type of grazing animal. In comparison to the control, grazing at the rosette and bolting stage resulted in shorter plants both years of the study, but increased the number of buds following grazing at the bolting stage and at the rosette stage in 2003. Negligible seed production across treatments, in 2003, precluded detection of treatment effects. However, in 2004, grazing at the rosette and bolting stages resulted in a greater number of seeds per plant compared to the control and the late bud stage, which were similar. Results indicated that the timing of grazing did not negatively impact biocontrol efficacy. Eustenopus villosus adult injury and total insect larval damage were similar to control plants following each grazing treatment both years, indicating potential compatibility between targeted grazing and biocontrol for integrated management of yellow starthistle.

Seasonal Change in Forage Value of Rangeland Weeds in Northern Idaho

Abstract Prescribed grazing is an effective tool for controlling some rangeland weeds. Forage quality of eight nonnative rangeland weeds common to northern Idaho was determined. Five collection sites were established for each weed species: rush skeletonweed, meadow hawkweed, houndstongue, sulfur cinquefoil, yellow starthistle, Dalmatian toadflax, hoary cress, and tansy ragwort. Plants were collected at rosette, bolt, flower, and seed set stages; dried and separated into leaves, stems, flowers, or seed; and analyzed separately for crude protein (CP), neutral detergent fiber (NDF), and mineral content (ash). As expected, plants became more fibrous as they matured because stems increased in NDF value throughout the season and the leaf ∶ stem ratio of most weeds we examined decreased throughout the season. In general, the weeds we examined expressed only moderate fiber levels, beginning the season with NDF values near 34% in the rosette stage and becoming near 52% NDF in the seed set stage. CP values were near 25% in the rosette stage for houndstongue, rush skeletonweed, and hoary cress whereas other weeds we examined had about 15% CP in the rosette. As the season advanced, all plants lost protein content and ended the season with CP values from 5 to 8% at seed set. Ash values declined for all species as the season progressed. Our results indicate that these weeds have forage values similar to many native plants and could be reasonable forage resources for livestock. We did not examine the content of secondary compounds in these weeds that may render them unpalatable and limit their forage value. Nomenclature: Dalmatian toadflax, Linaria dalmatica (L.) P. Mill. LINDA; hoary cress, Lepidium draba (L.) Desv. LEDRD; houndstongue, Cynoglossum officinale L. CYWOF; meadow hawkweed, Hieracium caespitosum Dumort. HIECA; rush skeletonweed, Chondrilla juncea L. CHOJU; sulfur cinquefoil, Potentilla recta L. PTLRC; tansy ragwort, Senecia jacobeae L. SENJA; yellow starthistle, Centaurea solstitialis L. CENSO

Forage Availability and Body Condition Affect Intake of Lupine (Lupinus leucophyllus) by Grazing Cattle

Abstract The genus Lupinus is an important group of plants with a number of species worldwide that are toxic to grazing livestock. The objective of this study was to examine the effect of body condition and the relationship between forage availability and consumption of lupine (Lupinus spp.) by grazing cattle (Bos taurus). Five cows in low body condition (LBC) and 4 in high body condition (HBC) grazed a common pasture in central Washington, with abundant velvet lupine (Lupinus leucophyllus) during an 18-d grazing period. Cows in LBC and HBC began ingesting lupine on d 1 and 4, respectively. For LBC cows compared with HBC cows, the ingestion rate of lupine was greater (3.2 vs. 2.5 mean bites/min, respectively; P

Age and body condition of goats influence consumption of juniper and monoterpene-treated feed.

Abstract Redberry juniper (Juniperus pinchotii Sudworth) is an invasive, evergreen tree that is rapidly expanding throughout western and central Texas. Goats will consume some juniper on rangelands; however, intake is limited. The objective of our research was to determine how the age and body condition of goats influence their consumption of juniper and an artificial feed containing 4 monoterpenes. Two separate experiments were conducted. Experiment 1 examined the intake of redberry juniper foliage and used 39 goats either young (2 yr) or mature (> 6 yr). One-half of each age group was fed appropriate basal rations to reach either a high (HBC) or low body condition (LBC). Goats in LBC ate more (P < 0.01, 8.6 g · kg−1 body weight [BW] ± 0.7 SE) juniper than those in HBC (2.3 g · kg−1 BW ± 0.3 SE), and young animals consumed more (P < 0.05, 7.2 g · kg−1 BW ± 0.7 SE) juniper than mature goats (3.9 g · kg−1 BW ± 0.5 SE) across body condition treatments. In experiment 2, 36 goats, either young (2 yr) or mature (> 6 yr) and in either HBC or LBC, were offered a synthetic ration treated with 20.8 g · kg−1 of 4 monoterpenes found in redberry juniper. Goats in LBC ate more (P < 0.01, 25.3 g · kg−1  BW  ± 1.0 SE) of the terpene-treated feed than those in HBC (17.5 g · kg−1 BW ± 0.7 SE), and young animals ate more (P < 0.05, 22.5 g · kg−1 BW ± 0.8 SE) than mature goats (20.3 g · kg−1 BW ± 0.8 SE) across body condition treatments. Total intake as a proportion of body weight was also affected by body condition. Age and body condition are important factors that influence intake of chemically defended plants. A better understanding of how these attributes affect diet selection will aid livestock producers in improving grazing management.

Rangeland Inventory as a Tool for Science Education

Program pairs range professionals, teachers and students together to conduct vegetation measurements and teach inquiry -based science DOI:10.2458/azu_rangelands_v26i1_hankins