Animal & Range Sciences
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The curricula in animal science provide students with a firm foundation in the biological and natural sciences, animal breeding, reproductive physiology, nutrition, and livestock production and management. Natural Resources & Rangeland Ecology focuses on managing the interaction of livestock, and wildlife and their rangeland habitats. Emphasis is placed on soil, water and vegetation attributes which influence habitat ecology and management of livestock and wildlife.
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Item Habitat Relations of Mule Deer in the Texas Panhandle.(1985-11-27) Koerth, Benjamin H.; Sowell, Bok F.; Bryant, Fred C.; Wiggers, Ernie P.Telemetric observations of mule deer (Odocoileus hemionus) does were used to determine seasonal relationships between deer use and availability of habitats on two study areas in the Panhandle region of west Texas. Juniper breaks was the only type used in greater proportion than its availability on the Canadian River study area (CRSA). On the Clarendon study area (CSA) mule deer shifted seasonal preferences between riparian, cultivated fields, and juniper breaks. Annual and seasonal home ranges were considerably larger on the CSA. Larger home ranges and variability in seasonal use of the habitat types on the CSA were attributed largely to the presence of cultivated winter grain fields. Shifts in home ranges coincided with the season when production in the cultivated fields was highest and native forage availability was lowest. Comparisons of indirect deer observations (pellet groups and bed sites) with random measurements within each habitat type characterized deer use sites as east and north facing slopes, located close to a canyon rim, and receiving light livestock and human use. The placement of cultivated grain fields could be used to influence overall range use and attract deer to or away from localized sites. Also, consideration should be given to directing heavy livestock and human traffic away from sites that are used by mule deer.Item Protein Supplementation and 48-Hour Calf Removal Effects on Range Cows(1992-03) Sowell, Bok F.; Wallace, Joe D.; Parker, Eugene E.; Southward, Morris G.In 1984, 99 Angus × Hereford cows (4- to 6-yr-olds) were assigned randomly to a 4-yr, 2 × 2 factorial study. Treatment assignment was permanent, and no new cows were added during the study. By 1987, 71 cows remained, and over-all, 335 complete cow-calf data sets were used. Main effect treatments were beginning time (prepartum [PRE] vs postpartum [POST]) for crude protein (CP) supplementation (twice weekly feeding of 41% CP cottonseed meal pellets at 1.58 kg • $\text{cow}^{-1}$ • $\text{feeding}^{-1}$) and temporary calf removal (48 hour [48-H] vs 0 hour [CONT]) just before the breeding season. For analyses, sex of calf was included as a third main effect (2×2×2) and year was included as a random factor; the 4-way interaction served as the testing term for repeated measures over years. Year was the dominant source of variation for most traits; we attributed this mainly to different amounts and timing of precipitation among years. Very few interactions were observed. The PRE supplemented cows had reduced (P<0.01) spring body weight losses and higher prebreeding body condition scores (4.9 vs 4.5; P<0.01) compared with POST cows. Reproductive performance did not differ between PRE and POST cows. Use of 48-H calf removal vs CONT did not influence (P>0.10) reproductive traits measured. Likewise, 48-H treatment did not impair health or reduce weaning weights of calves. In a separate, within-year analysis used to examine age of dam effects, productivity of 4-yr-old cows during 1984 was slightly below that of older cows for some traits. Cow age effects were not detected in other years. We conclude that control cows in our study were approaching optimum fertility and production levels in concert with their environment and that improvement beyond these levels with the treatments imposed was unlikely.Item Application of Feeding Behaviour to Predict Morbidity of Newly Received Calves in a Commercial Feedlot.(2001-09) Quimby, W. F.; Sowell, Bok F.; Bowman, J. G. P; Branine, M. E.; Hubbert, M. E.; Sherwood, H. W.The objective of this study was to use feeding behavior of newly received steers (average initial weight 191 kg) to detect morbidity in animals in a commercial feedlot. Two separate 32 d feeding trials were conducted in Wellton, Arizona, in July and November 1996. Radio frequency technology was used to record the total time spent within 50 cm of the feedbunk (animal presence every 5.25 s times 5.25 s) in 3 h intervals from 0600 to 2400 on a daily basis for 103 and 122 male calves in trial 1 and 2, respectively. Statistical procedures based on the cumulative sums (CUSUM) of the 3 h feeding intervals were used to detect morbid animals, compared with detection of animals deemed morbid by experienced pen riders. In trial 1, the CUSUM procedure detected animal morbidity 4.5 d earlier (P < 0.001) than the feedlot personnel. In trial 2, the CUSUM procedure detected animal morbidity 3.7 d earlier (P < 0.001) than feedlot pen riders. Overall accuracy, positive predictive value and sensitivity of the CUSUM prediction method were 87, 91, and 90%, respectively. Combined trial data suggest that feeding behavior during the first 30 d cattle are in a receiving pen, as collected with radio frequency technology and analyzed with CUSUM charts, may be used to detect animal morbidity approximately 4.1 d earlier (P < 0.001) than conventional methods typically employed in commercial feedlots.Item Horses and Cattle Grazing on the Wyoming Red Desert, III.(1984-03) Plumb, G. E.; Krysl, L. J.; Hubbert, M. E.; Smith, M. A.; Waggoner, J. W.Vegetative cover losses due to trampling near watering sites in the summer and winter are compared for horses grazed alone, cattle grazed alone and horses and cattle grazed in combination. There were significant differences (p<.05) found in the rates of total cover loss as a function of distance to water in both the summer and winter. Grasses sustained heavy trampling losses in all treatments in both seasons. Forbs sustained heavy losses in all treatments during summer. Shrub losses were moderate to low in all treatments during both seasons. Total cover loss was similar in all summer and winter treatments.Item Horses and Cattle Grazing in the Wyoming Red Desert, II. Dietary Quality.(1984-05) Krysl, L. J.; Sowell, Bok F.; Hubbert, M. E.; Plumb, G. E.; Jewett, T. K.; Smith, M. A.; Waggoner, J. W.Botanical composition of horse and cattle diets from fecal analysis and nutrient quality of hand-harvested forages used by these herbivores were evaluated to assess dietary quality during the summer and winter seasons of 1981 in the Wyoming Red Desert. Dietary crude protein estimates averaged 7.5±0.1% and 9.0±0.5% during the summer for horses and cattle, respectively. Dietary crude protein estimates in the winter were lower, averaging 6.1±0% and 6.0±0% for horses and cattle, respectively. Estimated dietary calcium levels for both herbivores were high through the summer and winter, while dietary phosphorus levels appear to be deficient during both seasons. Average in vitro dry matter disappearance coefficients for horses and cattle during the summer were 52±2% and 52±2%, respectively. During the winter these values dropped to 39±1% and 40±1% for horses and cattle, respectively.Item Estimating Digestibility and Faecal Output in Lambs Using Internal and External Markers.(1988-08-01) Krysl, L. J.; Galyean, M. L.; Estell, R. E.; Sowell, Bok F.Twenty fine-wool, ruminally cannulated lambs (average weight 45–9 kg) were used in a completely random design to evaluate the ability of three internal markers to predict dry matter digestibility and two external markers to estimate faecal output. Lambs were allotted randomly to one of four diets: 100% prairie hay (PH), 100% lucerne hay (LH), 50% prairie hay:50% sorghum grain (PS) and 50% lucerne hay: 50% sorghum grain (LS). The trial consisted of a 14-day adaptation period followed by a 7-day total faecal collection period. Feed and faecal samples were subjected to 96 h ruminal fluid and 48 h acid-pepsin digestions, followed by extraction with acid detergent (IVADF) or neutral detergent (IVNDF) solution. Dry matter digestibility (DMD) calculated from feed:faeces ratios of IVADF, IVNDF and acid detergent lignin (ADL) was compared with in vivoapparent digestibility. Ytterbium-labelled forage (YLF) and dysprosium-labelled faeces (DLF) were pulse-dosed via ruminal cannulae, and faecal Yb and Dy excretion curves were fitted to a one-compartment, agedependent model for estimation of faecal output, paniculate passage rate (PPR) and mean gastrointestinal retention time. In vivoDMD in lambs fed PH was greater (P <005) than DMD calculated from IVNDF, IVADF and ADL. In lambs fed LH and LS, in vivoDMD did not differ (P >005) from marker estimates. In vivoDMD for lambs fed PS did not differ from IVNDF or IVADF estimates but was greater than (P <005) the ADL estimate. No differences (P> 005) were observed in recovery among the three internal markers for any of the diets. Faecal output for lambs fed PH did not differ {P >005) from marker estimates but was overestimated by 15 to 20% by YLF and DLF. Faecal output for lambs fed LH was similar to the estimate from YLF, but less than (P <0–05) the estimate with DLF. For lambs fed PS, faecal output did not differ from marker estimates, but YLF and DLF values were 16% lower and 17% higher, respectively. No significant differences were observed in actual and estimated faecal output for lambs fed the LS diet. Estimates of PPR with DLF were numerically greater than YLF estimates for all diets except LS. Correspondingly, mean gastrointestinal retention time was less (P <005) for DLF compared with YLF for all diets except LS.Item Horses and Cattle Grazing in the Wyoming Red Desert(1984-01) Krysl, L. J.; Hubbert, M. E.; Sowell, Bok F.; Plumb, G. E.; Jewett, T. K.; Smith, M. A.; Waggoner, J. W.The sagebrush-grass range in southcentral Wyoming presently supports large numbers of feral horses and domestic livestock. Diets of feral horses and cattle during summer and winter grazing were evaluated using fecal analysis under 2 stocking levels in small pastures. Horses and cattle consumed primarily grasses during the summer and winter. However, shrubs and forbs were also important dietary components. Needleandthread, Sandberg bluegrass, thickspike wheatgrass, Indian ricegrass, gray horsebrush, and winterfat were the major foods of horses and cattle during the summer and winter. Dietary overlap between horses and cattle during the summer averaged 72% and increased to 84% during the winter. Horses and cattle selected foods in a similar order.Item Influence of Ruminally Dispensed Monensin and Forage Maturity on Intake and Digestion.(1993-05) Fredrickson, Eddie L; Galyean, M. L.; Branine, M. E.; Sowell, Bok F.; Wallace, Joe D.Eight ruminally cannulated crossbred steers (average weight 336 kg) grazing native blue grama (Bouteloua gracilis [H.B.K.]) rangeland were used in a repeated measures design to evaluate effects of monensin ruminal delivery devices (MRDD) and forage phenology on ruminal digestion. Three periods were assessed: mid-August (Aug.), early October (Oct.), and mid-November (Nov.). One MRDD was placed in the reticulum of 4 steers via the ruminal cannula 21 days before each period. Intake was estimated using total fecal collections. Diet samples were collected using 3 esophageally fistualted steers. Ruminal fill was measured by ruminal exacuation; rate and extent of in situ ruminal neutral detergent fiber disappearance were estimated before ruminal evacuations. Ruminal passage rates, retention time, and apparent total tract organic matter digestibility were estimated using indigestible neutral detergent fiber. In vitro organic matter disappearance of esophageal masticate did not differ (P>.05) in Aug. and Oct. (average of 53.7%), but declined (P<.05) in Nov. (48.7%), whereas organic matter digestibility was greater (P<.10) in Aug. (62.3%) than in either Oct. (55.2%) or Nov. (53.9%). Release of monensin from the bolus (68 mg day-1) was less than expected (100 mg day-1). Intake, organic matter digestibility, ruminal passage rates, retention time, pH, and ammonia were not affected (P>.10) by MRDD. In situ neutral detergent fiber disappearance at 96 hours was decreased (P<.10) by MRDD (68 vs 65% for control and MRDD, respectively). As the grazing season progressed, intake declined (P<.10), whereas ruminal fill and retention time increased (P<.05), and passage rate of indigestible neutral detergent fiber decreased (P<.05). At 48 hours in situ neutral detergent fiber was greatest (P<.05) in Aug. and least (P<.05) in Nov.Item Liquid supplementation for ruminants fed low-quality forage diets: a review(1995-09) Bowman, J. G. P.; Sowell, Bok F.; Paterson, J. A.Forty-three studies involving liquid supplementation of cattle and sheep consuming low-quality forages were identified, summarized in tabular form and reviewed. All studies that could be found containing animal gain, forage intake and (or) supplement consumption with molasses-urea supplements under grazing conditions were reviewed. Seven studies were found which compared forage intake or animal performance by animals fed hay or straw and molasses-urea supplements with unsupplemented animals. Molasses-urea supplements did not increase forage intake or animal performance compared with unsupplemented animals in five of the seven studies. Thirteen studies were identified which evaluated performance of grazing animals receiving molasses-urea supplements compared with unsupplemented animals. Seven of these 13 grazing studies reported improved live weight change when animals received molasses-urea supplements. Only two grazing studies were found which evaluated forage intake by animals consuming molasses-urea supplements and compared it with unsupplemented animals. Both studies found no effect. Five of six studies identified that compared molasses-urea supplements with dry supplements, forage intake or animal live weight change were not increased by molasses-urea supplements over dry supplements. Most authors concluded that feeding molasses-urea supplements to grazing ruminants was not as profitable as feeding dry supplements; however, few studies reported economic data. Studies demonstrated that level of molasses and nitrogen influenced animal performance. Asynchrony between molasses and nitrogen resulted in animal weight loss. Most positive animal responses were seen with a combination of high levels of molasses and nitrogen. However, these results may have been influenced by supplement formulation. Performance and intake results were confounded by pasture condition, forage quality, animal variation and supplement delivery system. In four studies that measured supplement intake by individual animals, between 1 and 20% of experimental animals refused to consume any molasses-urea supplement. Quantification of supplement intake and animal feeding behavior has not been adequately addressed in the literature.Item TmpL, a transmembrane protein required for intracellular redox homeostasis and virulence in a plant and an animal fungal pathogen(2009-11) Kim, Kwang-Hyung; Willger, Sven D.; Park, Sang-Wook; Puttikamonkul, Srisombat; Grahl, Nora; Cho, Yangrae; Mukhopadhyay, Biswarup; Cramer, Robert A.; Lawrence, Christopher B.The regulation of intracellular levels of reactive oxygen species (ROS) is critical for developmental differentiation and virulence of many pathogenic fungi. In this report we demonstrate that a novel transmembrane protein, TmpL, is necessary for regulation of intracellular ROS levels and tolerance to external ROS, and is required for infection of plants by the necrotroph Alternaria brassicicola and for infection of mammals by the human pathogen Aspergillus fumigatus. In both fungi, tmpL encodes a predicted hybrid membrane protein containing an AMP-binding domain, six putative transmembrane domains, and an experimentally-validated FAD/NAD(P)-binding domain. Localization and gene expression analyses in A. brassicicola indicated that TmpL is associated with the Woronin body, a specialized peroxisome, and strongly expressed during conidiation and initial invasive growth in planta. A. brassicicola and A. fumigatus DtmpL strains exhibited abnormal conidiogenesis, accelerated aging, enhanced oxidative burst during conidiation, and hypersensitivity to oxidative stress when compared to wild-type or reconstituted strains. Moreover, A. brassicicola DtmpL strains, although capable of initial penetration, exhibited dramatically reduced invasive growth on Brassicas and Arabidopsis. Similarly, an A. fumigatus DtmpL mutant was dramatically less virulent than the wild-type and reconstituted strains in a murine model of invasive aspergillosis. Constitutive expression of the A. brassicicola yap1 ortholog in an A. brassicicola DtmpL strain resulted in high expression levels of genes associated with oxidative stress tolerance. Overexpression of yap1 in the DtmpL background complemented the majority of observed developmental phenotypic changes and partially restored virulence on plants. Yap1-GFP fusion strains utilizing the native yap1 promoter exhibited constitutive nuclear localization in the A. brassicicola DtmpL background. Collectively, we have discovered a novel protein involved in the virulence of both plant and animal fungal pathogens. Our results strongly suggest that dysregulation of oxidative stress homeostasis in the absence of TmpL is the underpinning cause of the developmental and virulence defects observed in these studies.