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1.
J Anim Sci ; 82(7): 2175-84, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15309967

RESUMEN

Two experiments were conducted to evaluate perennial ryegrass straw as a forage source for ruminants. Experiment 1 evaluated digestion and physiological variables in steers offered perennial ryegrass straw containing increasing levels of ergot alkaloid, lolitrem B. Sixteen ruminally cannulated Angus x Hereford steers (231+/-2 kg BW) were blocked by weight and assigned randomly to one of four treatments. Steers were provided perennial ryegrass straw at 120% of the previous 5-d average intake. Before straw feeding, soybean meal was provided (0.1% BW; CP basis) to meet the estimated requirement for degradable intake protein. Low (L) and high (H) lolitrem B straws (<100 and 1,550 ppb, respectively; DM basis) were used to formulate treatment diets: 100% L; 67% L:33% H; 33% L:67% H; 100% H (DM basis). Intake and digestibility of DM and OM, and ruminal pH, total VFA, and NH3-N were not affected by increasing lolitrem B concentration. Ruminal indigestible ADF (IADF) fill increased linearly (P = 0.01) and IADF passage rate decreased linearly (P = 0.04) as lolitrem B increased. Experiment 2 evaluated performance and production by 72 Angus x Hereford cows (539+/-5 kg BW) consuming perennial ryegrass straw containing increasing lolitrem B during the last third of gestation. Cows were blocked by body condition score and randomly assigned to one of three treatments. Cows were provided perennial ryegrass straw ad libitum and supplemented with soybean meal (0.1% BW; CP basis) to meet the estimated requirement for degradable intake protein. Mixtures of a L and H lolitrem B straw (467 and 2,017 ppb, respectively) were used to formulate treatment diets: 100% L, 50% L:50% H, 100% H (DM basis). Thirteen of 24 cows on the 100% H treatment exhibited signs of ryegrass staggers and were removed from the study; nevertheless, lolitrem B concentration did not influence pre- or postcalving weight or body condition score change. These data suggest that feeding perennial ryegrass straw containing up to 1,550 ppb lolitrem B (DM basis) did not adversely affect nutrient digestion or physiological response variables in steers. However, providing straw with a lolitrem B concentration of approximately 2,000 ppb (DM basis) resulted in 54% of cows exhibiting signs of ryegrass staggers. These data suggest that blending straws with a high (>2,000 ppb) and low (<500 ppb) concentration of lolitrem B can be a successful management practice.


Asunto(s)
Bovinos/crecimiento & desarrollo , Digestión , Alcaloides de Claviceps/administración & dosificación , Contaminación de Alimentos/análisis , Lolium , Micotoxinas/administración & dosificación , Alimentación Animal , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Bovinos/metabolismo , Relación Dosis-Respuesta a Droga , Femenino , Concentración de Iones de Hidrógeno , Alcaloides Indólicos , Masculino , Distribución Aleatoria , Rumen/química , Rumen/metabolismo
2.
J Anim Sci ; 80(10): 2764-9, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12413101

RESUMEN

The Steer-a-Year course is designed to provide classroom and hands-on experience, industry-student interaction, and student group problem-solving opportunities. It is a cooperative agreement between the Department of Animal Sciences and the Oregon Cattlemen's and Cattlewomen's Associations. Steers are donated to the program by beef producers, fed a high concentrate ration to a target BW and condition, and marketed as either carcass or retail beef. After feed and management expenses are deducted, the Department of Animal Sciences retains one-half of the profit to be used for beef facilities improvements, and the other half is distributed to the donor's choice of either the Oregon Cattlemen's or Cattlewomen's Association. Approximately 30 steers have been donated to the program annually each of the past eight years. The donor receives updates regarding steer performance during the feeding period and carcass data following harvest of the animal. Students and instructors feed and manage the steers. The instructor uses classroom time to provide information to enable students to make informed management decisions. Officers are elected from within the class each term. Student officers are responsible for ensuring that cattle are managed and fed appropriately, and they lead the class in writing and sending producer updates. An evolving facet of the program is processing and marketing. Steers are sold locally through the Clark Meat Science Center. Students are encouraged to participate in a separate course in which they process the steers into retail product. In this manner, students can be involved in procurement, management, processing, and marketing. The course is challenging for the instructor since it requires management of lecture material, cattle health and feeding, producer and employee rapport, and student participation to ensure annual success of the program in terms of student learning and public relations. The course is very well received by students, most of whom have labeled it as a great learning experience.


Asunto(s)
Crianza de Animales Domésticos/educación , Bovinos , Aprendizaje Basado en Problemas/métodos , Estudiantes , Agricultura/educación , Alimentación Animal , Crianza de Animales Domésticos/métodos , Animales , Curriculum , Manipulación de Alimentos , Humanos , Masculino , Oregon
3.
J Anim Sci ; 79(2): 493-9, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11219460

RESUMEN

Live weight gains of light and heavy calves grazing Plains Old World bluestem at three stocking rates were evaluated during the summers of 1997 and 1998. Initial weights of mixed-breed light-weight steers (LHT) were 141 SD = 17 kg (n = 214) in 1997 and 160 SD = 23 kg (n = 193) in 1998. Initial weights of mixed-breed heavy steers (HWT) were 265 SD = 17 kg (n = 115) in 1997 and 248 SD = 13 kg (n = 126) in 1998. Initial stocking rates for both sizes of steers were as follows: light, 392 kg of live weight/ha; moderate, 504 kg of live weight/ha (increased to 616 kg live weight/ha in 1998); and heavy, 840 kg of live weight/ ha. Averaged gain and gain/hectare are reported as stocking rate by steer type within year. Heavy steers had greater ADG than LHT steers during both years. Forage intake, expressed as a percentage of BW, was greater (P = 0.05) for LHT (3.1%) than for HWT (2.8%) calves. Grazing time (min/d; 1998 only) was greater (P = 0.05) for LHT (665) than for HWT (624) steers. Forage CP and in vivo digestible organic matter (DOM) were slightly greater (P < 0.05) in pastures grazed by HWT vs LHT cattle. Gain/hectare was greater (P < 0.05) for LHT than for HWT calves at all three stocking rates during both years. A linear decline in ADG was observed (P < 0.07) as stocking rates increased for HWT steers in 1997 and LHT steers in 1998. However, ADG did not decline with increasing stocking rate for LHT calves during 1997 or HWT calves during 1998. Forage intake was not different among stocking rates in either 1997 or 1998. Grazing time was greatest (P < 0.05) for steers in the moderate and heavy stocking rates. Forage in vivo DOM decreased (P < 0.05) as stocking rate increased. Both LHT and HWT steers had lower (P < 0.05) ADG at all three stocking rates during 1998 compared with 1997. Despite lower ADG, LHT steers had greater gain/hectare than HWT steers during both 1997 and 1998.


Asunto(s)
Crianza de Animales Domésticos/métodos , Peso Corporal/fisiología , Bovinos/fisiología , Poaceae/metabolismo , Animales , Bovinos/crecimiento & desarrollo , Ingestión de Alimentos/fisiología , Heces/química , Masculino , Valor Nutritivo , Oklahoma , Distribución Aleatoria , Análisis de Regresión , Rumen/metabolismo , Rumen/fisiología , Aumento de Peso
4.
J Anim Sci ; 78(3): 726-34, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10764081

RESUMEN

Two digestion studies were conducted to evaluate the use of pretanned leather shavings as a component of a protein supplement. In Exp. 1, the in situ and in vitro disappearance of pretanned leather shavings and soybean meal was evaluated. Results revealed that less than 18.4% of the pretanned leather shavings was solubilized and disappeared when exposed to McDougall's buffer for 48 h, but there was 90.0% disappearance with 48-h exposure to a .1 N HCl/pepsin treatment and 97.0% disappearance with exposure to a two-stage digestion. In situ disappearance following 72 h in the rumen allowed 6.8% disappearance. Thus, leather shavings seem to be relatively indigestible in the rumen, but postruminal digestion may be possible. In Exp. 2, six Angus x Holstein steers, fitted with ruminal and duodenal cannulas, were used in a replicated 3 x 3 Latin square to evaluate ruminal and digestion effects of the following supplements combined with fescue hay at 1.7% of BW (DM basis): no supplementation (control); supplementation intraruminally with soybean meal at .07% of BW (as-fed basis); and supplementation intraruminally with a combination of soybean meal and pretanned leather shavings (17:8 ratio) at .05% of BW (isonitrogenous to soybean meal; as-fed basis). Ruminal fluid passage rate was greater and fluid turnover time was shorter in steers fed leather shavings than in those fed soybean meal (P = .10). Ruminal pH was lower (P = .04) for supplemented steers than for control steers and ruminal NH3 N concentration was greater (P = .01) in steers fed soybean meal than in those fed leather shavings. Total VFA concentration was increased (P = .02) by supplementation. Supplementation with soybean meal increased (P < .05) ruminal molar proportions of butyrate, valerate, and isovalerate compared with leather shavings. Duodenal OM flow and OM disappearing in the intestines were increased by supplementation (P < .10), but not by the type of supplement fed (P > .10). Ruminal digestion of OM and total tract OM digestion were unaffected (P > .10) by supplementation and the type of supplement fed. Flow and digestion of NDF were unaffected (P > .10) by the treatments. Flow of N and the quantity of N disappearing in the intestines were increased (P < .05) by supplementation but did not differ (P > .10) between supplementation groups. Microbial N flow, N utilization for net microbial protein synthesis, and ruminal N disappearance were unaffected (P > .10) by supplementation and the type of supplement provided. Combining pretanned leather shavings with soybean meal seemed to have no deleterious effects on digestion or fermentation and to allow for escape of some N to the lower tract.


Asunto(s)
Alimentación Animal , Bovinos/metabolismo , Fibras de la Dieta/metabolismo , Nitrógeno/metabolismo , Rumen/metabolismo , Curtiembre , Animales , Digestión , Fermentación , Poaceae , Glycine max
5.
J Anim Sci ; 78(3): 735-41, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10764082

RESUMEN

Twelve ruminally cannulated steers (Angus x Holstein; average initial BW = 533 +/- 3.28 kg) were randomly allotted to one of three treatments (four steers/treatment) to evaluate the use of pretanned leather shavings as a component of a protein supplement for steers grazing dormant intermediate wheatgrass (Thinopyrum intermedium Host). Steers were allotted to one of three treatments: 1) no supplement (control); 2) supplementation intraruminally at 0700 with soybean meal at .2% of BW (as-fed basis); 3) supplementation intraruminally with soybean meal and pretanned leather shavings (17:8 ratio, respectively) at .16% of BW (as-fed basis). Supplements were formulated so that intakes were isonitrogenous and were placed intraruminally once daily (0700). Sampling periods were conducted February 3 to 16 and February 17 to March 5, 1995. In situ organic matter disappearance of the soybean meal supplement was greater (P > .05) than that of the leather shavings supplement at all incubation times (1, 3, 6, 9, 12, 24, and 48 h). Data suggested that pretanned leather shavings within the leather shavings supplement were only 25% degradable within the rumen. Forage OM intake (control = 12.7, soybean meal = 12.7, and leather shavings = 13.4 g/kg of BW), grazing time, and grazing efficiency were not altered (P > .10) by supplementation or type of supplement provided but did increase between the February and March samplings. Total intake was increased (P = .09) with supplementation and reflected the addition of the protein supplements. Particulate and fluid passage estimates were unaffected (P > .10) by the supplements; however, gastrointestinal fill increased (P = .01) between the February and March samplings. Ruminal pH was lower (P = .04) and ruminal NH3 N concentration was greater (P = .02) for supplemented steers than for control steers, and supplementation treatments did not differ (P > .10). Total VFA concentrations were increased (P = .01) by supplementation but were not affected by type of supplement provided (P > .10). Ruminal molar proportions of acetate and propionate and the ratio of these two VFA did not differ (P > .10) between supplementation types. Nonetheless, supplementation increased molar proportions of butyrate (P = .04), valerate (P = .02), and isovalerate (P = .05), and leather shavings supplementation increased (P = .10) isobutyrate proportions over those in steers supplemented with soybean meal. Combining pretanned leather shavings with soybean meal seemed to have no deleterious effects on forage intake, digesta passage, grazing behavior, or ruminal fermentation and seemed to provide effects similar to those of soybean meal alone.


Asunto(s)
Alimentación Animal , Bovinos/metabolismo , Fibras de la Dieta/metabolismo , Suplementos Dietéticos , Conducta Alimentaria , Nitrógeno/metabolismo , Rumen/metabolismo , Curtiembre , Animales , Digestión , Fermentación , Cinética , Poaceae , Glycine max
6.
J Anim Sci ; 78(12): 3144-54, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11132829

RESUMEN

Prairie hay supplemented with various amounts of corn and soybean meal was fed to steers in two experiments. Effects of supplementation on hay OM intake, digestion, and ruminal fermentation and kinetics were measured. A preliminary study was conducted to attain accurate values for OM intake and digestibility of prairie hay to be used in ration formulation using the NRC (1996) level 1 model. Ten steers (284 +/- 9 kg) given ad libitum access to chopped prairie hay (75% NDF, 6% CP) were supplemented with dry-rolled corn (0.75% of BW/d) plus soybean meal (0.25% of BW/d). Hay OM intake was 1.85% of BW and hay OM digestibility was 48%. Based on results from the preliminary study, eight ruminally cannulated beef steers (317 +/- 25 kg) received a sequence of eight different supplementation combinations (2 x 4 factorial arrangement of treatments). These supplements consisted of dry-rolled corn at either 0 or 0.75% of BW (DM basis) daily combined with one of four amounts of added soybean meal to provide between 0 and 1.3 g of degradable intake protein (DIP)/kg of BW. After supplements had been fed for 10 d, feces were collected for 4 d. Intake of hay and total OM increased quadratically (P < 0.01) in response to added DIP with or without supplemental corn. Hay OM digestibility increased quadratically (P = 0.03) as DIP was added when corn was fed in the supplement. Intake of digestible OM was greater (P < 0.01) with than without corn supplementation. Increasing DIP increased (P < 0.01) digestible OM intake regardless of whether corn was fed. Inadequate ruminally degraded protein in grain-based supplements decreased forage intake, digestibility, and energy intake of cattle fed low-quality prairie hay. Providing adequate supplemental DIP to meet total diet DIP needs seemed to overcome negative associative effects typically found from supplementing low-quality forages with large quantities of low-protein, high-starch feeds.


Asunto(s)
Bovinos/metabolismo , Carbohidratos de la Dieta/metabolismo , Digestión , Glycine max , Rumen/metabolismo , Zea mays , Alimentación Animal , Animales , Suplementos Dietéticos , Ingestión de Alimentos , Ingestión de Energía , Heces/química , Fermentación , Concentración de Iones de Hidrógeno , Masculino , Rumen/química
7.
Home Healthc Nurse ; 18(8): 524-30; quiz 531, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11951305

RESUMEN

Guided imagery is a therapeutic technique that allows a person to use his or her own imagination to connect their body and mind to achieve desirable outcomes such as decreased pain perception and reduced anxiety. This article describes the use and application of guided imagery for clients in the home and the benefits to the agency. A step-by-step approach to teaching clients how to use guided imagery is included.


Asunto(s)
Ansiedad/terapia , Servicios de Atención de Salud a Domicilio , Cuidados Paliativos al Final de la Vida , Imágenes en Psicoterapia/métodos , Manejo del Dolor , Anciano , Femenino , Humanos , Selección de Paciente , Resultado del Tratamiento
8.
J Anim Sci ; 77(2): 291-9, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10100656

RESUMEN

Fall-weaned crossbred steer calves (n = 300; 184 +/- 2.9 kg) received either no implant (Control) or were implanted with Synovex-C (SC = 10 mg estradiol benzoate + 100 mg progesterone), Synovex-S (SS = 20 mg estradiol benzoate + 200 mg progesterone), or Revalor-G (RG = 8 mg estradiol-17beta + 40 mg trenbolone acetate) to determine the effects of implants on weight gain during winter grazing on dormant tallgrass prairie, subsequent grazing and finishing performance, and carcass characteristics. Steers grazed two dormant tallgrass prairie pastures from October 16, 1996, until March 29, 1997 (164 d), and received 1.36 kg/d of a 25% CP supplement that supplied 100 mg of monensin/steer. Following winter grazing, all steers were implanted with Ralgro (36 mg zeranol) and grazed a common tallgrass prairie pasture until July 17 (110 d). After summer grazing, all steers were implanted with Revalor-S (24 mg estradiol-17beta + 120 mg trenbolone acetate), and winter implant treatment groups were equally allotted to four feedlot pens. Steers were harvested November 17, 1997, after a 123-d finishing period. Daily gains during the winter grazing phase averaged .28, .32, .32, or .35 kg/d, respectively, for Control, SC, SS, or RG steers and were greater (P < .01) for implanted steers than for Controls. Summer daily gains were similar (1.05 +/- .016 kg/d; P > or = .61) for all treatment groups. Feedlot daily gains were also similar (1.67 +/- .034 kg/d; P > or = .21), with implanted steers weighing 14 kg more than Control steers (P = .05) at harvest, despite similar management during summer grazing and feedlot phases. Control steers tended (P = .06) to have lower yield grades. There were no differences (P = .99) in marbling between implanted and nonimplanted steers. Steers implanted during the wintering phase had increased skeletal and overall (P < .01) carcass maturities compared with nonimplanted steers, which resulted in more "B" and "C" maturity carcasses. Because carcass maturity score affects quality grade, the increased maturities of implanted steers resulted in a $9.04 decrease in carcass value/100 kg (P < .01) compared with Controls. The results of this study indicate that growth-promoting implants are efficacious for cattle wintered on dormant native range despite low daily gains. This increased weight is maintained through the summer grazing and feedlot phases; however, the benefit of the increased weight may be offset by decreased carcass quality grade and value due to increased carcass maturity.


Asunto(s)
Crianza de Animales Domésticos/métodos , Bovinos/crecimiento & desarrollo , Metabolismo Energético , Aumento de Peso , Anabolizantes/administración & dosificación , Anabolizantes/farmacología , Alimentación Animal , Animales , Composición Corporal/efectos de los fármacos , Combinación de Medicamentos , Metabolismo Energético/efectos de los fármacos , Estradiol/administración & dosificación , Estradiol/análogos & derivados , Estradiol/farmacología , Masculino , Progesterona/administración & dosificación , Progesterona/farmacología , Estaciones del Año , Acetato de Trembolona/administración & dosificación , Acetato de Trembolona/análogos & derivados , Acetato de Trembolona/farmacología , Aumento de Peso/efectos de los fármacos
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