Because of concerns about the impact of grazing management on surface water quality, a 3-yr study was conducted to determine grazing management and microclimate impacts on cattle distribution relative to a pasture stream and shade. Three treatments, continuous stocking with unrestricted stream access (CSU), continuous stocking with restricted stream access (CSR), and rotational stocking (RS), were evaluated on six 12.1-ha cool-season grass pastures stocked with 15 fall-calving Angus cows (Bos taurus L.) from mid-May through mid-October of each year. On 2 d ? mo 21 from May through September of each year, a trained observer in each pasture recorded cattle position and activity every 10 min from 0600 to 1800 hours. In years 2 and 3, position of one cow per pasture was recorded with a Global Positioning System (GPS) collar at 10-min intervals 24 h ? d 21 for 2 wk ? mo 21 from May through September. In week 2 of collar deployment in May, July, and September, cattle had access to off-stream water. Ambient temperature, black globe temperature, relative humidity, and wind speed were recorded at 10-min intervals and temperature humidity (THI), black globe temperature humidity (BGTHI), and heat load (HLI) indices were calculated. Based on GPS collars, mean percentage of time cows in CSU pastures were in the stream (1.1%) and streamside zone (10.5%) were greater (P , 0.05) than cows in CSR (0.2% and 1.8%) or RS (0.1% and 1.5%) pastures. Based on GPS collar data, off-stream water did not affect the percentage of time cattle in CSU or CSR pastures spent in the stream. Probabilities that cattle in CSU and CSR pastures were in the stream or riparian zones increased (P , 0.05) as ambient temperature, black globe temperature, THI, BGTHI, and HLI increased. Rotational stocking and restricted stream access were effective strategies to decrease the amount of time cattle spent in or near a pasture stream. Resumen Debido a preocupaciones sobre el impacto del manejo del pastoreo sobre la calidad del agua superficial, se realizó un estudio de 3 añ os para determinar el impacto del manejo del pastoreo y del microclima sobre la distribución del ganado en relación a la sombra y la corriente de agua. Se utilizaron tres tratamientos: Pastoreo continuo-sin restricción al acceso a la corriente de agua (CSU), pastoreo continúo con restricciones al acceso a la corriente de agua (CSR), y pastoreo rotacional; se evaluaron en seis potreros de 12.1 ha de gramíneas de crecimiento invernal utilizando 15 vacas Angus (Bos taurus L.) de mediados de Mayo hasta mediados de Octubre en cada añ o. En el 2 d-mes de Mayo hasta Septiembre de cada añ o un observador entrenado en cada potrero registró la posición y la actividad del ganado cada 10 minutos desde 0600 hasta las 1800 horas. En los añ os 2 y 3, se registró la posición y la actividad de una vaca/potrero utilizando collares con GPS a intervalos de 10 min cada 24 h-d-1 durante dos semanas-mes desde Mayo hasta septiembre. En la semana 2 de la implementación de los collares en Mayo, Julio, y septiembre el ...

Nonpoint source (NPS) pollution of water resources may occur from congregation of cattle near streams or ponds. Therefore, relationships of physical characteristics, shade distribution, and tall fescue (Festuca arundinacea Schreb.) prevalence in coolseason grass pastures to the temporal/spatial distribution of grazing cattle were evaluated in two studies on beef cow/calf farms. Global positioning system (GPS) collars recorded the location of 2-3 cows per pasture at 10-min intervals for 5-14 d in the spring, summer, and fall annually. Pasture botanical composition was visually assessed annually. In Study 1, cow location was recorded on five pastures ranging in size from 13 ha to 125 ha with 1.9-3.8% of the pasture area in a stream or pond (water source) and 2-30% of the pasture area within 30.5 m of the water source (waterside zone) for 3 yr. Shade covered 27-73% of the pasture area with 3-64% of shade located within waterside zone. In Study 2, cow location was recorded in three pastures with areas of 8 ha, 10 ha, and 15 ha with 17.8%, 43.4%, and 14.7% of the total area and 28%, 73%, and 68% of the total shade in the waterside zone for 1 yr. In Study 1, proportions of cow observations within the waterside zone increased with decreasing pasture area (r 2 ¼0.61) and increasing proportions of the total pasture area (r 2 ¼0.37) and shade (r 2 ¼0.29) within the waterside zone. In Study 2, proportion of cow observations in the waterside zone increased as the proportion of total area (r 2 ¼0.62) and shade (r 2 ¼0.42) in the waterside zone increased. Results imply more restrictive measures to minimize the risks of NPS pollution of water resources may be most effective in smaller and narrow pastures. Resumen La contaminación de origen no identificado (NPS) de los recursos hídricos, puede ocurrir debido a la congregación del ganado cerca de los arroyos o estanques. Por lo tanto, las relaciones de las características físicas, distribución de la sombra y la incidencia de Festuca alta (Festuca arundinacea Schreb.) en potreros con gramíneas de crecimiento invernal en la distribución temporal/espacial del pastoreo del ganado se evaluaron en dos estudios en una granja de vaca-becerro. Collares de sistema de posicionamiento global (GPS) registraron la ubicación de 2 a 3 vacas por potrero a intervalos de 10 minutos de 5 a 14 en la primavera, verano y otoño anualmente. La composición botá nica de los potreros se evaluó visualmente cada año. En el estudio 1, conducido durante tres años, la ubicación de las vacas se registró en cinco potreros con un rango de 13 a 125 hectáreas de extensión, con 1.9 a 3.8% de la superficie del potrero en arroyos o estanques (fuente de agua) y 2 a 30% de la superficie del potrero dentro de 30.5 m de distancia de la fuente de agua (zona de agua) para 3 años. Los sombreaderos cubrieron de 27 a 37% del á rea del potrero con 3 a 64% de la sombra ubicada dentro de la zona del agua. En el estudio 2, la ubicación de las vacas se registró en tres potreros con á reas de 8, 10, y 15 hectá reas con 17.8, 43.4 y 14...

A multistate cooperative study was conducted to study the current issue of tail length in docked lambs and its relationship to incidence of rectal prolapse. A total of 1,227 lambs at six locations were randomly allocated to two or three tail dock treatments: 1) short--tail was removed as close to the body as possible, 2) medium--tail was removed at a location midway between the attachment of the tail to the body and the attachment of the caudal folds to the tail, and 3) long--tail was removed at the attachment of the caudal folds to the tail. Short-docked lambs had a greater (P < 0.05) incidence of rectal prolapse (7.8%) than lambs with a medium (4.0%) or a long (1.8%) dock. Female lambs had a higher (P < 0.05) incidence of rectal prolapse than male lambs. At two stations, lambs were finished either in a feedlot on a high-concentrate diet or on pasture with no grain supplementation. At one station, with a very low incidence of rectal prolapse, there was no difference in incidence between lambs finished in the feedlot or on pasture; however, at the station with a relatively high incidence of rectal prolapse, lambs in the feedlot had a higher (P < 0.05) incidence than lambs on pasture. The half-sib estimate of heritability for the incidence of rectal prolapse was low (0.14). The results of this study strongly implicate short dock length as a cause of rectal prolapse in lambs finished on high-concentrate diets. Furthermore, the results of this study and the only other study known conducted on this issue strongly suggest that docking lambs at the site of the attachment of the caudal folds to the tail will result in a negligible incidence of rectal prolapse.

-Our objective was to estimate the sensitivity and specificity of the agar-gelimmunodiffusion test (AGID), the ELISA, and the skin test for the detection of Mycobacterium avium subspecies paratuberculosis (MAP) in sheep using Bayesian methods without a gold standard. Fourteen flocks (2 465 sheep) were used. Five flocks (450 sheep) were considered MAP non-infected and 9 flocks (2 015 sheep) had sheep infected with MAP. Sheep were skin tested and blood was collected for AGID and ELISA testing. Results were analyzed using a Bayesian 3-test in 1-population model fitted in WinBUGS. The model allowed for dependence (correlation) between the two serologic tests, but these two tests were assumed to be conditionally independent of the skin test. The estimated specificity was 99.5% (95% PI of 98.9-99.9%) for the AGID; 99.3% (98.4-99.8%) for the ELISA using an optical density measured cutoff of 0.20; 99.2% (98.1-99.8%) using a cutoff of 0.15; 97.5% (95.8-98.7%) using a cutoff of 0.10; and 98.7% (97.3-99.5%) for the skin test. The estimated sensitivities were 8.3% (6.2-10.7%) for the AGID; 8.0% (6.0-10.4%), 10.6% (8.3-13.1%), and 16.3% (13.5-19.4%) for the ELISA using the cutoffs 0.20, 0.15, and 0.10 respectively; and 73.3% (62.3-85.8%) for the skin test. The skin test was specific in non-infected populations and sensitive in infected populations, although in some cases a positive skin test might represent MAP exposure rather than infection. The AGID and ELISA were specific but lacked sensitivity. The AGID and ELISA consistently identified two different populations of infected sheep with only moderate overlap between positive test results.

and Implications Real-time ultrasound measures of body composition were collected on 85 head of market sheep by 3 ultrasound technicians and subsequent measures were collected on the carcasses of these sheep. This study may help to establish reasonable expectations for ultrasound certification statistics within the sheep industry. Based on these data, it appears that reasonable standards for a sheep ultrasound certification program would be: UFAT-bias <= 0.10 in., SEP <= 0.10 in., SER <= 0.10 in., correlation >= 0.60; UREA-bias <= 0.50 in. 2 , SEP <= 0.50 in. 2 , SER <= 0.50 in. 2 , and correlation >= 0.50. If an ultrasound certification program were started within the sheep industry it may be possible for sheep breeders to more effectively work toward meeting consumer demands in terms of product composition.