Implanting young bulls with zeranol from birth to four slaughter ages: III. Growth performance and endocrine aspects     

D G Gray  J A Unruh  M E Dikeman  J S Stevenson 《Journal of animal science》1986,63(3):747-756

Seventy-two Simmental bull calves were assigned randomly either to a zeranol implanted (I) or nonimplanted (NI) control group. Within 3 d after birth, bulls assigned to the I treatment were implanted with 36 mg zeranol and reimplanted every 84 d until slaughter. Calves were weaned at 7.2 mo, preconditioned for 2 wk, and assigned within treatment to slaughter ages 12.0, 13.8, 15.7 and 17.4 mo. Blood samples were taken bimonthly from 8.3 to 16.6 mo of age. Weight gains, feed:gain ratios and slaughter and carcass weights were similar (P greater than .10) for I and NI bulls for the total feeding period. Weight gains for NI bulls were larger (P less than .05) from 7.7 to 9.5 mo and from 11.3 to 12.2 mo of age, whereas gains for I bulls were greater from 12.2 to 14.1 mo. Serum estradiol-17 beta (E2) and testosterone (T) concentrations were higher (P less than .05) for NI bulls at 8.3, 9.2, 10.2, 11.1, 12.1 and 13.0 mo. However, at 13.9 and 14.8 mo, E2 concentrations were higher (P less than .10) for I bulls. A similar, but nonsignificant (P greater than .10), trend was noted for T concentrations of I bulls at 13.9 and 14.8 mo. Rapid increases in E2 concentrations were observed from 8.3 to 9.2 mo in NI bulls, but from 12.1 to 13.9 mo in I bulls. Similarly, T concentrations increased rapidly from 8.3 to 10.2 mo in NI bulls, but from 12.1 to 14.8 mo in I bulls. Peak concentrations of T and E2 for NI bulls were observed near 11 and 13 mo, respectively, whereas peak T and E2 levels were delayed in I bulls until near 14 mo. Periods of greater weight gains for both NI and I bulls corresponded to rapidly increasing E2 and T concentrations. Serum thyroxine concentrations were lower (P less than .05) for I bulls at 13.9 mo but similar to NI bulls at all other ages. Serum insulin concentrations were higher (P less than .05) for I bulls than for NI bulls at 8.3, 10.2, 11.1 and 12.1 mo. Regardless of treatment, insulin concentrations increased with increasing age. Carcasses from I bulls were fatter (P less than .05) and tended (P = .09) to have smaller ribeye areas/100 kg carcass. Fat thicknesses for both treatments increased (P less than .05) from 13.8 to 15.7 mo. Skeletal maturity scores, 9-10-11th rib bone percentages and femur measurements indicated an increased skeletal maturation in I bulls.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

Haematological and biochemical reference values for the koala (Phascolarctos cinereus)     

PM. CANFIELD  ME. O'NEILL†  EF. SMITH† 《Australian veterinary journal》1989,66(10):324-326

Haematological and biochemical reference values were established from 45 clinically healthy koalas. Statistical analysis revealed no significant differences for sex and season of sampling. Immature koalas had significantly higher alkaline phosphatase and inorganic phosphate values, and significantly lower total protein concentrations due to low globulins values. Enzyme reference values tended to be wide and could limit their usefulness in detecting disease. In the reference values for leukocytes, neutrophils and lymphocytes, the inclusion of low values which were not actually seen may interfere with the detection of reduced levels due to disease.  相似文献   

Influence de la densité et de la période de concurrence de Solanum nigrum L. sur la tomate de semis direct, en relation avec le désherbage     

J. P. CAUSSANEL  X. BRANTHÔME  J. MAILLET  A. CARTERON 《Weed Research》1990,30(5):341-354

Effects of density and period of competition by Solanum nigrum L. on direct seeded tomatoes in relation to weed control The effects of density and period of competition from Solanum nigrum L. were measured in direct seeded tomatoes given weed control treatments currently used in south-east France. S. nigrum emerging after a diquat treatment at the 2–3 leaf stage of the crop and thinned to low densities (<12.8 plants ha^?1) at the 5–6 leaf stage of the crop caused significant yield loss if left to compete with the crop until harvest. Yield reduction was smaller if the same weed densities were present only until the onset of flowering. The regression curves of yield on weed density differed as annual climatic variations affected sowing date and plant growth; a comparison between years was made using the relation ‘crop yield × weed biomass/crop biomass’. Significant interactions between weed density and period of competition were found with yield of both green and red fruit. For late sown crops with low densities of S. nigrum two weed control treatments at the 5–6 leaf stage and at the onset of flowering were sufficient to prevent yield loss.  相似文献   

Effects of packaging atmospheres on beef instrumental tenderness, fresh color stability, and internal cooked color     

Grobbel JP  Dikeman ME  Hunt MC  Milliken GA 《Journal of animal science》2008,86(5):1191-1199

Fresh meat color is a major factor influencing the purchase of meat products by consumers, whereas tenderness is the primary trait determining overall eating satisfaction of consumers. The objectives of this research were to determine the effects of packaging atmosphere on fresh beef color stability, cooked color, and tenderness. Longissimus lumborum muscles (n = 14 pairs) from USDA Select, A-maturity carcasses were assigned to either 14-d tenderness measurement or to display and then to 18-d [80% O(2), 20% CO(2) (HiO(2)) modified atmosphere packaging (MAP)] or 28-d [vacuum package (VP) and ultra low (ULO(2)) plus CO MAP blends] tenderness measurement. Loins were then fabricated on d 7 postmortem into 2.54-cm-thick steaks. Steaks 8 to 10 caudal to the first 7 steaks were bisected, assigned to a packaging treatment, and used for internal cooked color. One full steak was used for initial tenderness. Packaging treatments were as follows: vacuum-packaging (VP); 80% O(2), 20% CO(2) (HiO(2)); 0.4% CO, 35% CO(2), 64.6%N(2) (ULO(2)CO); 0.4% CO, 99.6% CO(2) (ULO(2)COCO(2)); 0.4% CO, 99.6% N(2) (ULO(2)CON(2)); or 0.4% CO, 99.6% Ar (ULO(2)COAr). Steaks packaged in HiO(2) MAP were in dark storage (2 degrees C) for 4 d, and all other steaks were in dark storage for 14 d. Steaks were displayed under fluorescent lighting (2,153 lx; 3,000 K) for 7 d, with instrumental color measured on d 0 and 7 of display. Trained color panelists (n = 10) assigned color scores. Steaks for Warner-Bratzler shear force and cooked color were cooked to 70 degrees C. Steaks packaged in the 4 ULO(2) MAP blends with CO had no change (P > 0.05) or increased (P < 0.05) a* values for fresh color. Steaks packaged in VP or the 4 ULO(2) MAP blends with CO had little or no surface discoloration. Steaks packaged in HiO(2) MAP discolored faster (P < 0.05) and 56% more (P < 0.05) than those in any other packaging treatment. There were no differences (P > 0.05) in Warner-Bratzler shear force on d 14 postmortem. Steaks packaged in HiO(2) MAP were less tender (P < 0.05) than the other treatments at the end of display but had 10 d less aging due to a shorter dark storage period. Steaks packaged in HiO(2) had the lowest (P < 0.05) a* values for internal cooked color of all packaging treatments. Steaks packaged in ULO(2)COCO(2) and VP had intermediate a* values, whereas those packaged in ULO(2)COAr, ULO(2)CO, and ULO(2)CON(2) had the greatest (P < 0.05) a* values for internal cooked color. Ultra-low oxygen packaging treatments had longer fresh color stability than steaks packaged in HiO(2) MAP and equal or better tenderness. Packaging atmospheres altered the internal cooked color, with steaks packaged in HiO(2) MAP exhibiting premature browning.  相似文献   

Biochemical and Protein Profile of Alpaca (Vicugna pacos) Uterine Horn Fluid During Early Pregnancy          下载免费PDF全文

ME Argañaraz  SA Apichela  R Zampini  J Vencato  C Stelletta 《Reproduction in domestic animals》2015,50(1):121-128

South American camelids show high embryo loss rate, during the first 60 days of pregnancy. One of the factors which may be related to this situation is that over 98% of the embryos implant in the left uterine horn (LUH) even though both ovaries contribute similarly to ovulation. There is scarce information about the uterine environment of female camelids at any physiological state that could explain the capability of the LUH to attract the embryo and maintain pregnancy. We describe, for the first time, the biochemical and protein profile of uterine fluid (UF), addressing the right and LUH environment in non‐pregnant and pregnant alpacas. Different substrates, electrolytes and metabolites were assayed in both uterine horn fluids. Small changes were observed in glucose and total protein levels, which were more noticeable during pregnancy. In addition, 10 specific proteins were found in the left horn fluid in 5‐week‐pregnant alpacas, and two protein bands were identified in non‐pregnant alpaca right horn fluid. These results would provide basic information for identification of possible markers for pregnancy diagnosis, reproductive diseases and hormone‐treated animals evaluation and hence contributing to improve the pregnancy rate.  相似文献   

Effects of sequential feeding of β-adrenergic agonists on cull cow performance, carcass characteristics, and mRNA relative abundance     

Weber MJ  Dikeman ME  Unruh JA  Jaeger JR  Murray L  Houser TA  Johnson BJ 《Journal of animal science》2012,90(5):1628-1637

The objectives of this study were to determine the effects of supplementation with a single β-adrenergic agonist (β-AA) or a sequence of β-AA on cow performance, carcass characteristics, and mRNA relative abundance of cull cows implanted and fed a concentrate diet. Sixty cull cows were implanted with Revalor-200 (200 mg of trenbolone acetate and 20 mg of estradiol) and assigned to 1 of 4 treatments (n = 15/treatment): CON = fed a concentrate diet only; RH = supplemented with ractopamine-HCl for the last 25 d before slaughter; ZH = supplemented with zilpaterol-HCl for 20 d before a 3-d withdrawal before slaughter; RH + ZH = supplemented with RH for 25 d, followed by ZH for 20 d before a 3-d withdrawal before slaughter. Ractopamine-HCl was supplemented at a dose of 200 mg·animal(-1)·d(-1), and ZH was supplemented at 8.33 mg/kg (100% DM basis) of feed. All cows were fed a concentrate diet for 74 d. Each treatment had 5 cows per pen and 3 replicate pens. Body weights were collected on d 1, 24, 51, and 72. Muscle biopsies from the LM were collected on d 24, 51, and at slaughter from a subsample of 3 cows per pen. Carcass traits were evaluated postslaughter. The 2 ZH treatments averaged 15.3 kg more BW gain, 0.20 kg greater ADG, and 7.8 cm(2) larger LM area than CON and RH treatments, and 21 kg more HCW than CON, but these differences were not significant (P > 0.10), likely due to a sample size of n = 15/treatment. The sequence of RH followed by ZH tended to optimize the combination of HCW, LM area, percent intramuscular fat, and lean color and maturity compared with the ZH treatment. Abundance of β(2)-adrenergic receptor (AR) mRNA was not altered in the RH + ZH treatment during RH supplementation from d 24 to 51 of feeding. However, the abundance of β(2)-AR mRNA increased (P < 0.05) the last 23 d of feeding for the RH treatment and tended (P = 0.10) to increase in ZH cows during ZH supplementation. For all cows, abundance of type IIa myosin heavy chain (MHC-IIa) mRNA decreased (P < 0.05) after 24 d of feeding. Abundance of MHC-IIx mRNA increased (P < 0.05) for ZH and RH + ZH treatments the last 23 d of feeding during ZH supplementation. Although few significant differences were observed in performance or carcass traits, mRNA quantification indicated that β-AA supplementation elicited a cellular response in cull cows. Implanting and feeding cull cows for 74 d, regardless of β-AA supplementation, added economic value by transitioning cows from a cull cow to what is referred to in industry as a white cow market in which cows have white fat resulting from grain feeding.  相似文献   

Effects of age, weight, and fat slaughter end points on estimates of breed and retained heterosis effects for carcass traits     

Ríos-Utrera A  Cundiff LV  Gregory KE  Koch RM  Dikeman ME  Koohmaraie M  Van Vleck LD 《Journal of animal science》2006,84(1):63-87

The influence of different levels of adjusted fat thickness (AFT) and HCW slaughter end points (covariates) on estimates of breed and retained heterosis effects was studied for 14 carcass traits from serially slaughtered purebred and composite steers from the US Meat Animal Research Center (MARC). Contrasts among breed solutions were estimated at 0.7, 1.1, and 1.5 cm of AFT, and at 295.1, 340.5, and 385.9 kg of HCW. For constant slaughter age, contrasts were adjusted to the overall mean (432.5 d). Breed effects for Red Poll, Hereford, Limousin, Braunvieh, Pinzgauer, Gelbvieh, Simmental, Charolais, MARC I, MARC II, and MARC III were estimated as deviations from Angus. In addition, purebreds were pooled into 3 groups based on lean-to-fat ratio, and then differences were estimated among groups. Retention of combined individual and maternal heterosis was estimated for each composite. Mean retained heterosis for the 3 composites also was estimated. Breed rankings and expression of heterosis varied within and among end points. For example, Charolais had greater (P < 0.05) dressing percentages than Angus at the 2 largest levels of AFT and smaller (P < 0.01) percentages at the 2 largest levels of HCW, whereas the 2 breeds did not differ (P > or = 0.05) at a constant age. The MARC III composite produced 9.7 kg more (P < 0.01) fat than Angus at AFT of 0.7 cm, but 7.9 kg less (P < 0.05) at AFT of 1.5 cm. For MARC III, the estimate of retained heterosis for HCW was significant (P < 0.05) at the lowest level of AFT, but at the intermediate and greatest levels estimates were nil. The pattern was the same for MARC I and MARC III for LM area. Adjustment for age resulted in near zero estimates of retained heterosis for AFT, and similarly, adjustment for HCW resulted in nil estimates of retained heterosis for LM area. For actual retail product as a percentage of HCW, the estimate of retained heterosis for MARC III was negative (-1.27%; P < 0.05) at 0.7 cm but was significantly positive (2.55%; P < 0.05) at 1.5 cm of AFT. Furthermore, for MARC III, estimates of heterosis for some traits (fat as a percentage of HCW as another example) also doubled in magnitude depending on different levels of AFT end point. Rational exploitation of breeds requires special attention to use of different end points and levels of those end points, mainly for fat thickness.  相似文献   

乌冈栎种群天然更新研究     

谢春平  方彦  方炎明 《林业资源管理》2011,(1)

种群更新对维持种群的稳定和发展具有极其重要的意义。通过野外实地调查,对不同地区乌冈栎种群的更新情况进行了分析,结果如下:1)大多数地区乌冈栎种群的幼苗结构呈倒金字塔型,说明乌冈栎种群的更新存在一定的困难;但在乌冈栎顶级群落中,由于仍存在一定数量的幼树,短期内的更新仍能继续进行;2)从乌冈栎幼苗空间分布格局来看,林窗或林缘处呈聚集分布,而林冠下呈均匀分布,这与乌冈栎幼苗生长的需光性有极大的关系;3)乌冈栎的萌发实验表明,1～2个月的沙藏处理有利于提高萌发率,而萌发过程中鼠害和虫蛀是限制出苗率的主要原因之一;4)乌冈栎种子的传播除靠重力外,啮齿类动物对它的影响最大,他们之间存在一定的权衡关系。为了提高乌冈栎种群的天然更新率,适当干扰地开辟林窗是较佳的途径。  相似文献   

Effects of different packaging atmospheres and injection-enhancement on beef tenderness, sensory attributes, desmin degradation, and display color   总被引：1，自引：0，他引：1  

Grobbel JP  Dikeman ME  Hunt MC  Milliken GA 《Journal of animal science》2008,86(10):2697-2710

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Tissue distribution,shedding and environmental detection of infectious bursal disease virus genome following infection of meat chickens at two ages          下载免费PDF全文

JMKGK Jayasundara  SW Walkden‐Brown  AFMF Islam  ME Katz  KG Renz 《Australian veterinary journal》2018,96(5):167-175

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