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The effect of various levels of ractopamine hydrochloride on the performance and carcass characteristics of finishing swine 总被引：2，自引：0，他引：2
L E Watkins D J Jones D H Mowrey D B Anderson E L Veenhuizen 《Journal of animal science》1990,68(11):3588-3595
Six trials involving 888 pigs (Study 1) and three trials involving 360 pigs (Study 2) were conducted at various geographical locations in the U.S. and Canada to evaluate the effect of ractopamine hydrochloride on the performance and carcass characteristics of finishing swine. All trials were conducted using a randomized complete block design. Trial data were pooled within study for statistical analysis. Pigs averaged approximately 64.5 kg (Study 1) and 65.9 kg (Study 2) initially and had ad libitum access to a 16% crude protein corn-soybean meal or barley-soybean meal diet. Ractopamine was included in the diet at 0, 2.5, 5, 10, 20 or 30 ppm (Study 1), or at 0, 5, 10, 15 or 20 ppm (Study 2); diets were fed for an average of 45 d (Study 1) and 50 d (Study 2) to a final weight of about 104.3 kg (Study 1) and 106.6 kg (Study 2). Carcass dissection data were collected in three of the six trials in Study 1 (0, 5 and 20 ppm ractopamine) and in all three trials in Study 2 (0, 5, 10, 15 and 20 ppm ractopamine). All ractopamine levels improved (P less than .05) ADG and feed: gain (Studies 1 and 2) above those of control pigs. Ractopamine levels of 10 to 30 ppm (Studies 1 and 2) improved (P less than .05) dressing percentage over controls. Pigs fed ractopamine at 5 and 20 ppm (Study 1) and 10, 15 and 20 ppm (Study 2) had increased (P less than .05) dissected leanness compared with controls.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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DH Lowndes DB Geohegan AA Puretzky DP Norton CM Rouleau 《Science (New York, N.Y.)》1996,273(5277):898-903
Pulsed laser deposition (PLD) is a conceptually and experimentally simple yet highly versatile tool for thin-film and multilayer research. Its advantages for the film growth of oxides and other chemically complex materials include stoichiometric transfer, growth from an energetic beam, reactive deposition, and inherent simplicity for the growth of multilayered structures. With the use of PLD, artificially layered materials and metastable phases have been created and their properties varied by control of the layer thicknesses. In situ monitoring techniques have provided information about the role of energetic species in the formation of ultrahard phases and in the doping of semiconductors. Cluster-assembled nanocrystalline and composite films offer opportunities to control and produce new combinations of properties with PLD. 相似文献
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Sainfoin (Onobrychis viciaefolia Scop.) is adapted to the calcareous soils of the southern Great Plains and can provide early season forage that does not induce bloating; however, little is known about performance by ruminants grazing sainfoin. Our objective was to determine the effect of plant growth stage and grazing pressures on potential animal production from sainfoin as predicted from energy intake as a multiple of maintenance. Nitrogen-fertilized (100 kg of N/ha) Renumex sainfoin was grown under irrigation on a Pullman clay loam (fine, mixed, thermic Torretic Paleustoll) near Lubbock, TX. Light (L), medium (M), and heavy (H) grazing pressures were applied with steers grazing sainfoin that was at the bud (B), flower (F), and seed shatter (S) stages of growth. The L, M, and H pressures were grazed to remove 50, 75, and 90% of the standing plant height. Across growth stages, L, M, and H grazing pressures averaged 52, 69, and 87% removal of pregrazed herbage mass. Dry matter intake as a percentage of BW of steers averaged 3.9, 2.8, and 1.7 for L, M, and H grazing pressures. Across growth stages, predicted live weight gain for L, M, and H grazing pressures averaged .86, .67, and .03 kg/d. Our findings indicate that the multiple of maintenance method may be useful for evaluating treatments from small-plot grazing experiments. 相似文献
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Carr SN Ivers DJ Anderson DB Jones DJ Mowrey DH England MB Killefer J Rincker PJ McKeith FK 《Journal of animal science》2005,83(12):2886-2893
One hundred eighty barrows were evaluated to determine the effects of ractopamine hydrochloride (RAC) on lean carcass yields and pork quality. The pens were blocked by weight (six pens per block) with starting block weights of 69.0, 70.7, 73.8, 76.6, 78.4, and 84.3 kg. Pens within a block were assigned randomly to one of three RAC treatments so each treatment in a block was replicated twice. Treatments (as-fed basis) included control diet, 10 ppm of RAC added (R10), and 20 ppm of RAC added (R20) and ranged from 25 to 41 d depending on block. Pigs were slaughtered by blocks when block average live weights were 109 kg. Gain and feed efficiency were improved (P < 0.05) with increasing dietary concentrations of RAC, but feed intake did not differ (P > 0.05). Dressing percentage was higher (P < 0.05) for RAC-treated pigs. Subjective color, firmness, marbling scores, and Minolta L* reflection of the LM were not different (P > 0.05) among treatments. Carcass weights were heavier (P < 0.05) for pigs treated with RAC compared with control pigs and were higher for R20 than for R10. The RAC-fed pigs had greater (P < 0.05) yields (actual and percentage of HCW) of the following Institutional Meat Purchase Specification (IMPS) cuts than control pigs: trimmed, boneless ham (IMPS-402C and IMPS-402G), loin (IMPS-414), sirloin, and Boston butt (IMPS-406A). Pigs treated with RAC had a greater (P < 0.05) percentage of fat-free lean trimmings (IMPS-418) than did control pigs. Pigs treated with the R20 concentration had increased (P < 0.05) water-holding capacity compared with control pigs. Purge loss decreased linearly (P < 0.05) with increasing RAC compared with control for 14-d aged, non-enhanced loins. Warner-Bratzler shear (WBS) force values measured for nonenhanced chops were greater for RAC-treated pigs than for control pigs with a low dose response (P = 0.001). Enhanced chop (salt and phosphate injection) WBS values did not differ (P > 0.05) among dietary treatments. Trained sensory evaluation panel results for tenderness decreased in a low-dose plateau response fashion for nonenhanced chops (P = 0.004). Tenderness of enhanced chops decreased linearly (P = 0.04) with increasing RAC concentrations. No differences (P > 0.05) were found in juiciness or flavor of enhanced or nonenhanced chops. Feeding RAC to late-finishing swine resulted in faster growing, more efficient animals with increased boneless subprimal yields, and it had little effect on pork juiciness and flavor. 相似文献
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Effect of monensin, estradiol controlled release implants and supplement on performance in grazing steers 总被引：1，自引：0，他引：1
J F Wagner H Brown N W Bradley W Dinusson W Dunn N Elliston J Miyat D Mowrey J Moreman L C Pendlum 《Journal of animal science》1984,58(5):1062-1067
Five trials in five locations in the United States involving 512 steers were conducted to evaluate the effect of monensin [200 mg/d in .9 kg of supplement (Ru mensin )] and estradiol-controlled release implants ( Compudose ) administered alone and in combination on average daily gain (ADG) in steers on pasture. The effect of energy supplementation on rate of gain was also evaluated in these same trials. The initial weight of steers averaged 250 kg and the average duration of the five trials was 124 d. Estradiol-controlled release implants increased ADG by 15.6% (.095 kg/d; P less than .0001) and monensin increased ADG by 8.1% (.054 kg/d; P less than .05). The combination of estradiol-controlled release implant and monensin increased ADG by 27.4% (.168 kg/d). Treatment responses were additive relative to ADG response, with no interaction observed between the treatments. Nine-tenths kilograms of an energy supplement/d increased ADG by 12.4% (.073 kg/d; P less than .01). 相似文献
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AT Le Souëf M Barry DH Brunton R Jakob-Hoff B Jackson 《New Zealand veterinary journal》2013,61(6):340-344
CASE HISTORY: An adult female Duvaucel's gecko (Hoplodactylus duvaucelii) from a threatened species breeding programme presented due to a prolonged gestation period and distended abdomen.CLINICAL AND PATHOLOGICAL FINDINGS: The gecko was in lean body condition with an irregularly shaped, firm mass in the coelomic cavity. Radiographically there was a diffuse radio-opacity within the coelomic cavity with cranial displacement of the right lung field. Ultrasonography revealed a round homogenous abdominal mass of medium echogenicity with an echogenic capsule. Haematology showed a leucocytosis with a moderate left shift in heterophils and toxic changes. Bilateral ovariectomy was performed to remove two ovarian granulomas and Salmonella enterica subspecies houtenae (IV) was cultured from the ovarian tissue. The gecko recovered well from the surgery, regained weight and remained in good health 3 years following the surgery.DIAGNOSIS: Pre-ovulatory stasis and ovarian granulomas associated with infection with Salmonella enterica subsp. houtenae.CLINICAL RELEVANCE: The surgery described in this case resulted in recovery of the gecko, which despite its loss of reproductive capability is of value as an education animal. This is the first report of pre-ovulatory stasis and ovarian granulomas associated with infection with Salmonella enterica in a Duvaucel's gecko and is also the first reported case of pre-ovulatory stasis in a viviparous lizard species. The case adds to knowledge regarding potential reproductive pathology in lizards, which is particularly important information for managers of captive lizard breeding programmes. 相似文献
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B Alexander G Coppola GF Mastromonaco E St. John ER Reyes DH Betts WA King 《Reproduction in domestic animals》2008,43(2):207-211
Early pregnancy diagnosis and monitoring play an important role following embryo transfer in sheep. The aims of the current study were to investigate (i) the pattern of serum progesterone profiles in sheep carrying somatic cell nuclear transfer (SCNT)‐derived (clone) pregnancies, and (ii) the frequency of pregnancy loss during development following SCNT embryo transfer. Sheep SCNT embryos were made using standard nuclear transfer techniques. Day 7 embryos were surgically transferred to oestrus‐synchronized recipients (n = 27). As a control, normal fertile ewes (n = 12) were bred by natural breeding. Serum was collected from all the ewes on the day of estrus (day 0 sample), 7 days post‐estrus (day 7 sample) and 19 days post‐estrus (day 19 sample) and every 10 days thereafter until lambing or pregnancy loss occurred. Serum progesterone (P4) was assessed using enzyme immunoassay. Pregnancy was confirmed by ultrasound scanning on day 35 of pregnancy followed by subsequent scanning every 10 days. In control ewes, pregnancy rate on day 35 was 83.3% (10/12), whereas in the ewes that received SCNT embryos, it was 22.2% (6/27; p < 0.05). The day 45 pregnancy rate in the control ewes was 83.3%, whereas in the SCNT embryo recipients it was 11.0% (p < 0.05). Hormone analysis revealed that SCNT embryo recipients exhibited a significantly lower P4 profiles at different time points in pregnancy compared to controls (p < 0.05). This study highlights the use of serum progesterone in combination with ultrasound for the investigation of embryo loss and crucial times during development of normal and SCNT embryos in sheep. Further, the serum P4 levels directly reflect the degree of placental development in these two groups. 相似文献