Localization of Insulin‐Like Growth Factor‐I (IGF‐I) and IGF‐I Receptor (IGF‐IR) in Equine Testes     

MJ Yoon  T Berger  JF Roser 《Reproduction in domestic animals》2011,46(2):221-228

The insulin‐like growth factor‐I (IGF‐I) is a key regulator of reproductive functions. IGF‐I actions are primarily mediated by IGF‐IR. The main objective of this research was to evaluate the presence of IGF‐I and IGF‐I Receptor (IGF‐IR) in stallion testicular tissue. The hypotheses of this study were (i) IGF‐I and IGF‐IR are present in stallion testicular cells including Leydig, Sertoli, and developing germ cells, and (ii) the immunolabelling of IGF‐I and IGF‐IR varies with age. Testicular tissues from groups of 4 stallions in different developmental ages were used. Rabbit anti‐human polyclonal antibodies against IGF‐I and IGF‐IR were used as primary antibodies for immunohistochemistry and Western blot. At the pre‐pubertal and pubertal stages, IGF‐I immunolabelling was present in spermatogonia and Leydig cells. At post‐pubertal, adult and aged stages, immunolabelling of IGF‐I was observed in spermatogenic cells (spermatogonia, spermatocyte, spermatid, and spermatozoa) and Leydig cells. Immunolabelling of IGF‐IR was observed in spermatogonia and Leydig cells at the pre‐pubertal stage. The immunolabelling becomes stronger as the age of animals advance through the post‐pubertal stage. Strong immunolabelling of IGF‐IR was observed in spermatogonia and Leydig cells at post‐puberty, adult and aged stallions; and faint labelling was seen in spermatocytes at these ages. Immunolabelling of IGF‐I and IGF‐IR was not observed in Sertoli cells. In conclusion, IGF‐I is localized in equine spermatogenic and Leydig cells, and IGF‐IR is present in spermatogonia, spermatocytes and Leydig cells, suggesting that the IGF‐I may be involved in equine spermatogenesis and Leydig cell function as a paracrine/autocrine factor.  相似文献   

益生素在养猪生产中是否有效     

M.Kenny  H.Smidt  E.Mengheri  B.Miller  朱勇文 《国外畜牧学(猪与禽)》2011,31(2):33-36

在食品中加入某些活的微生物早已被证明对人类健康有积极的影响,这一方法已拓展到食品动物生产领域,且已涉及到许多微生物菌种,特别是乳酸菌、芽孢杆菌和酿酒酵母菌。对益生素兴趣的增加基本上是由于微生物耐药性问题的出现,同时自禁止在动物生产中使用抗生素后,益生素被认为是一种可减少病原菌感染并可提高猪、尤其是断奶期间仔猪的健康。然而,仍有必要阐明益生素在猪生产中的作用及潜在作用机制。在评价益生菌功效时,必须考虑所用的特定菌株和治疗猪对应的生长阶段。在实际的养猪生产中,重复益生素的功效还存在问题,因为维持其活性对它们的有益功效极为关键,但利用常规的饲料加工技术难以实现。益生素微生物能够被有效投喂的一种情况是在利用液体发酵饲料的生产系统中。液体饲料可以用活的野生乳酸菌进行发酵,也可将特定分离株作为＂启动子＂刺激其发酵,后一种方法对发酵的可重复性及其速度有益处。养猪场的微生物应用条件对其发挥正常功效很可能是至关重要的。给利用非理想条件饲养的猪饲喂益生素,所增加的经济效益远大于采用最佳福利条件和管理措施饲养的猪。如果猪出生时使其肠道内建立一个有益的微生物菌群,就有可能会产生较为健康的猪。实现这一效果的最有效方法是给母猪服用益生素,这提供了一个扩大益生菌的手段,使新生仔猪的生活环境中到处都是值得拥有的有益菌株。相比之下,它也许足以在仔猪断奶前后向其提供一个有支持作用和保护作用的肠道菌群,因为就某些肠道菌群的不稳定和损失来说,此时期是一个重要的决定性时刻。  相似文献   

Genetic associations between feed efficiency measured in a performance test station and performance of growing cattle in commercial beef herds     

Crowley JJ  Evans RD  Mc Hugh N  Pabiou T  Kenny DA  McGee M  Crews DH  Berry DP 《Journal of animal science》2011,89(11):3382-3393

Interest in selection for improved feed efficiency is increasing, but before any steps are taken toward selecting for feed efficiency, correlations with other economically important traits must first be quantified. The objective of this study was to quantify the genetic associations between feed efficiency measured during performance testing and linear type traits, BW, live animal value, and carcass traits recorded in commercial herds. Feed efficiency data were available on 2,605 bulls from 1 performance test station. There were between 10,384 and 93,442 performance records on type traits, BW, animal value, or carcass traits from 17,225 commercial herds. (Co)variance components were estimated using linear mixed animal models. Genetic correlations between the muscular type traits in commercial animals and feed conversion ratio (-0.33 to -0.25), residual feed intake (RFI; -0.33 to -0.22), and residual BW gain (RG; 0.24 to 0.27) suggest that selection for improved feed efficiency should increase muscling. This is further evidenced by the genetic correlations between carcass conformation of commercial animals and feed conversion ratio (-0.46), RFI (-0.37), and residual BW gain (0.35) measured in performance-tested animals. Furthermore, the genetic correlations between RFI and both ultrasonic fat depth and carcass fat score (0.39 and 0.33, respectively) indicated that selection for improved RFI will result in leaner animals. It can be concluded from the genetic correlations estimated in this study that selection for feed efficiency will have no unfavorable effects on the performance traits measured in this study and will actually lead to an improvement in performance for some traits, such as muscularity, animal price, and carcass conformation. Conversely, this suggests that genetic selection for traits such as carcass quality, muscling traits, and animal value might also be indirectly selecting for more efficient animals.  相似文献   

Effect of sire breed and genetic merit for carcass weight on the transcriptional regulation of the somatotropic axis in longissimus dorsi of crossbred steers     

Keady SM  Kenny DA  Keane MG  Waters SM 《Journal of animal science》2011,89(12):4007-4016

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Pasture and forage crop systems for non-irrigated dairy farms in southern Australia. 1. Physical production and economic performance     

D.F. Chapman  S.N. Kenny  D. Beca  I.R. Johnson 《Agricultural Systems》2008

The dairy industry in southern Australia relies on perennial ryegrass pasture to supply 60–70% of the diet of lactating cows. Improvements in the amount and quality of home-grown forage used for dairy cow feeding are critical for further productivity gains in the industry. A modeling approach was used to estimate the effects of changing the forage system on farm business profit. Base models (using 100% of farm area in perennial ryegrass pasture) were constructed for above-average (Top 40%) and high performing (Top 10%) farm types typical of two locations: Terang in southwest Victoria and Ellinbank in Gippsland, eastern Victoria. These models were then re-simulated using different forage base options such as: oversowing annual ryegrass, winter crops (annual ryegrass monoculture, winter cereal grown for whole crop silage), summer crops (grazing brassicas, maize), combinations of these (double cropping), or summer shoulder pasture (notionally based on tall fescue) on between 10% and 100% of farm area.  相似文献   

Effects of Superoxide Disrnutase and Allopurinol on the Survival of Acute Island Skin Flaps     

Im MJ  Manson PN  Bulkely GB  Hooper JE 《Veterinary surgery : VS》1985,14(3):234-234

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Flood plain staggers, a tunicaminyluracil toxicosis of cattle in northern New South Wales     

CA BOURKE  MJ CARRIGAN  SCJ LOVE 《Australian veterinary journal》1992,69(9):228-229

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An outbreak of listerial myelitis in sheep     

JT SEAMAN  MJ CARRIGAN  FA COCKRAM  GI CARTER 《Australian veterinary journal》1990,67(4):142-143

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A review of cases submitted to Murdoch University for immunodiagnostic testing: 1978–1989     

WJ PENHALE  MJ DAY†  AD LINES  RP McKENNA 《Australian veterinary journal》1990,67(4):148-149

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Experimental evidence that tryptamine alkaloids do not cause Phalaris aquatica sudden death syndrome in sheep     

CA BOURKE  MJ CARRIGAN  RJ DIXON† 《Australian veterinary journal》1988,65(7):218-220

The acute toxicity for sheep of 3 alkaloids that occur in Phalaris acquatica was examined by intravenous and oral administration. The lowest tested dose rates that produced clinically observed signs were, for 5-methoxy dimethyltryptamine, 0.1 mg/kg body weight intravenously and 40 mg/kg orally; for gramine, 10 mg/kg intravenously and 500 mg/kg orally; and for hordenine, 20 mg/kg intravenously and 800 mg/kg orally. All induced the clinical signs observed in the nervous form of phalaris toxicity, but none induced the cardiac, sudden death, syndrome.  相似文献