Decreased ACTH secretion during prolonged transportation stress is associated with reduced pituitary responsiveness to tropic hormone stimulation in cattle

The present study examined the effect of transportation stress on hypothalamic–pituitary–adrenal axis responsiveness to tropic hormone stimulation and on abundance of corticotropin releasing factor (CRF) receptor R1 (CRFR1) and arginine vasopressin (AVP) receptor V3 (V3) mRNAs in the anterior pituitary (AP) of cattle. Holstein steers were transported for 10 h or used as non-transported controls (NTC). Blood samples were collected at start of transportation and every 1–2 h thereafter. To test AP responsiveness to tropic hormones, animals were challenged (i.v.) with CRF (0.5 μg/kg), AVP (1 μg/kg) or CRF plus AVP immediately after end of transportation and blood samples collected every 30 min for 3 h. The AP of animals transported for 0, 4 or 10 h were harvested for mRNA analyses. Plasma ACTH in transported animals increased within 1 h and remained elevated for 6 and 8 h versus NTC and 0 h values, respectively. Plasma concentrations of cortisol increased in response to transportation and remained elevated throughout the transport period. Injection of CRF or AVP to NTC animals increased plasma ACTH, but ACTH secretion in response to CRF or AVP was dramatically reduced in transported animals. ACTH secretion following co-injection of CRF and AVP tended to be less in transported animals, but was almost 100% greater than when secretagogues were administered separately. Despite decreased AP responsiveness to CRF and AVP, AP CRFR1 and V3 mRNAs were increased after 10 h transportation. Results indicate decreased AP responsiveness to CRF and AVP may regulate duration of ACTH secretion in response to transportation stress in cattle.     

Bovine C-terminal octapeptide of RFamide-related peptide-3 suppresses luteinizing hormone (LH) secretion from the pituitary as well as pulsatile LH secretion in bovines

Gonadotropin-inhibiting hormone (GnIH), observed in quail as a member of the RFamide neuropeptide family, suppresses luteinizing hormone (LH) secretion from the avian pituitary. Rats and cattle have an active gene of another member of the RFamide neuropeptide family, termed RFamide-related peptide-3 (RFRP-3), although bovine RFRP-3 is different from that of rats in both length and amino-acid sequence. A single injection of GnIH or RFRP-3 inhibited LH secretion in rodents, which continued for various periods. This study was conducted to evaluate the effects of bovine C-terminal octapeptide of RFRP-3 (RFRP-3-8) on LH secretion from cultured anterior pituitary (AP) cells of cattle, and the effects of RFRP-3-8 injections on pulsatile LH secretion in castrated male calves. The suppressive effect of RFRP-3-8 on LH secretion from AP cells was observed in the presence of gonadotropin-releasing hormone (GnRH), but not in the absence of GnRH in culture media. In another experiment collecting blood samples serially from castrated male calves with repeated intravenous injections of RFRP-3-8 (n = 6) or saline (n = 6), the RFRP-3-8 group showed suppressed LH pulse frequency during the injection period (P < 0.05); however, the RFRP-3-8 group showed no difference from the saline group in all measures of LH secretion in the postinjection period. In conclusion, our results suggested that RFRP-3-8 suppresses LH secretion from cultured AP cells, as well as LH pulse frequency in cattle.     

Localization of putative pituitary stem/progenitor cells in female dairy cattle

Research on sex-determining region Y-box 2 (SOX2)-positive pituitary stem/progenitor cells, as a source of hormone-producing cells, is progressing rapidly in rodents. However, the stem/progenitor cells supplying hormone-producing cells that are essential for growth, reproduction, and lactation in bovines have not yet been identified. In this study, we characterized SOX2-positive cells in the pituitary gland of dairy cattle (Holstein heifers) after sexual maturity. Immunofluorescence analysis revealed that the localization pattern of SOX2-positive cells in the dairy cattle pituitary gland was similar to that observed in the rodent pituitary gland; the marginal cell layer (MCL), dense cell clusters, and single cells scattered in the parenchyma of the anterior lobe. Furthermore, most of the SOX2-positive cells were positive for the pituitary stem/progenitor cell niche markers E-cadherin and cytokeratin 8+18, which have been reported in rodents. In addition, in the MCL of the anterior lobe, there was a subpopulation of SOX2-positive cells positive for paired-related homeobox 1 and 2, whereas negative for S100β. Moreover, in the parenchyma of the anterior lobe, co-localization of SOX2 and pituitary hormones was infrequent. In summary, this study reveals the localization of putative pituitary stem/progenitor cells positive for SOX2 in dairy cattle. These results provide valuable information to support further investigation of cell supply in the dairy cattle pituitary gland.     

Effects of leptin and leptin peptide amide on the release of luteinizing hormone, growth hormone and prolactin from cultured porcine anterior pituitary cells

The present study was carried out to determine whether leptin or leptin (116–130) peptide amide (lep (116–130)), an active fragment of the native protein in rats, is able to stimulate the release of luteinizing hormone (LH), growth hormone (GH) or prolactin (PRL) from cultured porcine anterior pituitary (AP) cells in vitro. The AP cells were obtained from 6 month‐old pigs and were incubated for 3 h with 10^?11?10^?7 mol/L leptin or lep (116–130) after being cultured in Dulbecco's modified Eagle's medium for 3–4 days. Leptin significantly increased the concentration of LH and GH in the culture medium at concentrations of 10^?8 and 10^?7 mol/L, respectively, compared with the controls (P < 0.05). Leptin did not increase the concentration of PRL in the culture medium. In contrast to these results, no effects of lep (116–130) on the release of LH, GH or PRL were seen in the cultured cells. These results suggest that leptin stimulates the release of LH and GH by acting directly on porcine AP cells, and that a fragment of leptin protein comprising amino acids 116–130 is not associated with the secretion of hormones in pigs.     

Has bovine somatotropin (BST) an effect upon drug disposition? Comparative studies in goats and cattle with sulphadimidine and antipyrine after parenteral administration of BST,zeranol and proligestone

Daily subcutaneous BST injection in lactating cows, bulls and castrated male dwarf goats did not induce significant changes in the pharmacokinetic parameters of antipyrine (AP) and sulphadimidine (SDD). Similarly, no changes were obtained after injection of slow-release BST formulations in lactating cows and non-lactating female goats. In contrast to androgenic hormones, both zeranol and proligestone had no effect upon the disposition of AP and SDD, although both synthetic hormones did induce enhanced plasma somatotropin concentrations. In goats, metabolic effects induced by zeranol and BST included significant reductions in plasma urea values, whereas plasma creatinine levels were somewhat lower after daily BST administration.     

贵州地方黄牛种业现状、存在问题及对策

贵州优良黄牛种资源丰富,包括关岭黄牛、威宁黄牛、黎平黄牛、思南黄牛、务川黑牛5个优良地方品种。近年来黄牛种业发展较好,带领着当地人推进脱贫攻坚战。但在美好的景象之下我们也要看到它存在着品种退化、管理技术落后、技术人员不足等问题。本文就贵州地方黄牛种业现状、存在问题展开论述,进一步探讨了贵州地方黄牛种业发展方向,为其持续发展提供了详细对策。     

牛主要抗病候选基因的研究进展

牛抗病基因与其自身的抗病性和免疫能力有一定的相关性,因此研究相关抗病基因对提高牛自身免疫能力和选育优良后代有重要意义,文章着重介绍了国内外关于天然抗性相关巨噬细胞蛋白1（natual resistant macrophage protein 1,Nramp1）、主要组织相容性复合物（major histocompatibility complex,MHC）、甘露糖结合凝集素（maflnan binding lectin,MBL）、Toll样受体（Toll-like receptors,TLR）及干扰素基因（interferon,IFN）与牛某些疾病相关性的研究进展,及其是否可用于后代育种的分子标记,如MHC与奶牛的乳房炎密切相关;牛TLR4基因的外显子1760 C>T突变中的CC基因型可作为奶牛乳房炎抗性筛选中的分子标记等。笔者认为研究这些抗病基因可更深层次了解牛的抗病机制,同时借助先进的技术手段如分子标记、基因工程等,可更好的选育出抗病后代,抗病基因在育种中的应用将是未来研究抗病性和免疫能力的主要方向。     

The intravenous administration of johnin in the diagnosis of paratuberculosis in practice

The diagnostic value of the intravenous injection of 1.6 or 3.2 ml of johnin was evaluated in a total of 116 cattle. The sensitivity was 84% with clinically suspect cattle. A general reaction occurred frequently as well as elevation of body temperature (average 1.47 degrees C). The observance of a general reaction was a good additional source of information when evaluating the test. There was no significant difference in elevation of temperature between the cattle injected with 1.6 ml and those injected with 3.2 ml. A combination of diagnostic techniques such as the complement fixation test, intravenous johnin test, microscopic examination of the faeces and a biopsy examination of the rectal mucosa were necessary, in order to confirm the diagnosis of Johne's disease. In this manner a diagnosis can be confirmed with clinically suspect cattle in 96% of the cases. The sensitivity of the intravenous johnin test was considerably lower in cases of non-clinical Johne's disease.     

Genetic effects on beef heifer puberty and subsequent reproduction.

Significant genetic variation exists within and between breeds of beef cattle for age at puberty (AP). In general, faster-gaining breed groups of larger mature size reach puberty at a later age than do slower-gaining breed groups of smaller mature size; breeds selected for milk production reach puberty at younger ages than do those breeds not selected for milk production. Heterosis, independent of heterosis effects on weight, influences most measures of puberty in females and scrotal circumference (SC) in males. Crossbred heifers reach puberty at younger ages and heavier weights than their straightbred counterparts. Scrotal circumference has been shown to be an excellent indicator of AP in yearling bulls. Furthermore, a favorable genetic relationship exists between SC in bulls and AP of female offspring. Beef cattle breeders may take a direct approach to breeding for AP and subsequent reproduction by directly selecting for measures of fertility such as SC. However, an indirect approach, involving selection for an array of traits that provide an appropriate "genetic environment" for the expression of fertility (i.e., size, milk production, calving ease) may be preferred. Although seedstock producers are limited to making change through within-breed selection, commercial producers can take advantage of both within- and between-breed selection as well as crossbreeding to achieve the same goal.     

母牛体内生殖激素变化规律的研究进展

生殖激素是对母牛繁殖活动起直接调节作用的激素,因此对其进行精准测定,掌握生殖激素的变化规律对生产上提高母牛繁殖效率具有重要意义。但在动物体内大部分生殖激素的含量是极其微量的,所以选择准确灵敏的测定方法非常重要。本文论述生殖激素的生物测定法、受体分析法、免疫测定法（放射免疫测定和酶免疫测定）的优缺点,同时对各生殖激素的来源、生理作用和变化规律,及各激素之间的相关性分析做阐述,将对研究母牛的生殖生理,提高母牛繁殖效率,促进高产、高效、优质的牛业生产,加快牛业繁殖改良进程有着极其重要的意义。     

牛子宫复旧调控机制及促进子宫复旧方法的研究进展

牛产后子宫复旧延迟会延长繁殖间隔，降低繁殖率。子宫复旧涉及产后子宫组织退化、修复与子宫肌层的重塑，其中干细胞、细胞因子与非编码RNA以及雌激素与孕激素等参与调控产后子宫组织修复与再生。同时，维生素与葡萄糖类物质、中药制剂、免疫调节因子等绿色、无公害防治方法能够有效促进牛产后子宫复旧。本文就牛产后子宫复旧调控机制及促进子宫复旧方法的最新研究进展进行归纳总结，以期为研究动物产后子宫复旧的分子调控机制及研发促进子宫复旧新方法提供一定参考。     

2013年国外肉牛营养价值评定的研究进展

文章从精饲料营养和粗饲料营养两个方面综述了2013年国外肉牛营养价值评定的研究进展.精饲料营养主要包括蛋白质原料（亚麻籽、葵花籽、棉籽和油菜籽）、蛋白质水平、能量饲料以及精饲料对肉牛和犊牛的综合评价四个方面;粗饲料营养主要包括粗饲料品种和青贮饲料两个方面的研究.文章对上述研究成果进行了总结分析,以期为我国内年产业的快速发展提供一些借鉴.     

围产牛外周血主要类固醇类激素与中性粒细胞功能的关系研究进展

围产牛的免疫机能与外周血类固醇类激素的水平显著相关。中性粒细胞(PMN)作为天然免疫第一道防线的重要成员,其免疫功能与自身类固醇类激素受体表达状况的相关性备受关注。通过总结国内外相关研究的新发现,对围产牛外周血中PMN功能与E、P和GC水平动态变化的相关性及其相应激素受体的信号传导作用进行系统阐述。     

The intravenous administration of johnin in the diagnosis of paratuberculosis in practice

Summary

The diagnostic value of the intravenous injection of 1.6 or 3.2 ml of johnin was evaluated in a total of 116 cattle. The sensitivity was 84% with clinically suspect cattle. A general reaction occurred frequently as well as elevation of body temperature (average 1.47° C). The observance of a general reaction was a good additional source of information when evaluating the test.

There was no significant difference in elevation of temperature between the cattle injected with 1.6 ml and those injected with 3.2 ml. A combination of diagnostic techniques such as the complement fixation test, intravenous johnin test, microscopic examination of the faeces and a biopsy examination of the rectal mucosa were necessary, in order to confirm the diagnosis of Johne's disease. In this manner a diagnosis can he confirmed with clinically suspect cattle in 96% of the cases.

The sensitivity of the intravenous johnin test was considerably lower in cases of non‐clinical Johne's disease.     

Cellular distribution of anionic antimicrobial peptide in normal lung and during acute pulmonary inflammation

Anionic peptides (APs) are small antimicrobial peptides present in human and ovine lung. In this study APs were also detected in bovine lung, and production of APs in lungs with acute inflammation induced by various stimuli was determined. The distribution and intensity of APs were determined by immunohistochemistry in lungs of 1) neonatal calves (1-3 days of age) inoculated with Mannheimia (Pasteurella) haemolytica, a known inducer of the bovine beta-defensin lingual antimicrobial peptide (LAP) or pyrogen-free saline (PFS), and 2) growing calves (3 months of age) similarly inoculated with M. haemolytica, a lipopolysaccharide (LPS) from M. haemolytica, an LPS-associated protein from M. haemolytica, or PFS. APs were also detected by western blots with the same antibody in lungs of the calves above, as well as in calves inoculated with Pseudomonas aeruginosa, and an adult cow. Anionic peptide (AP) immunoreactivity was detected in bands (approximate weights) in the western blots of lung at 28-30 (strongest signal), 31, 45, and 52-60 kd regardless of inoculum. The adult cow lacked bands at 45 kd, but it had additional bands at 64 (inconsistently) and 35-38 kd. All these band sizes are consistent with those of the western blots of human and ovine lung. The cellular distribution of APs in lung of neonatal and growing cattle was similar to that in lung of human and sheep. In lungs with acute inflammation induced by live bacteria, LPS, or protein, AP distribution and intensity were similar to those in control (PFS-inoculated) lungs and slightly decreased in bronchioles. This work demonstrates that AP is present in lung of cattle and is thereby conserved among two ruminant species and man. Distribution and intensity of AP production are not enhanced by infection or acute inflammation and are decreased in bronchioles, which suggests that AP is not induced like beta-defensins such as LAP, but, instead, is produced constitutively.     

Surgery of the abomasum.

Abomasal diseases are common in cattle. Many of these diseases can be managed surgically. This article briefly discusses the various classifications of abomasal diseases. It focuses on the surgical treatment of these diseases. Surgical principles of conventional surgery and minimally invasive techniques are discussed.     

Endocrine modulation of physiological responses to catabolic disease

Disease or endotoxemia alters the plasma concentrations of anabolic hormones, particularly growth hormone (GH) and insulin-like growth-factor I (IGF-I). In general, these hormones are inhibited during the catabolic disease state. A hypothesis has evolved that anabolic hormones might be useful in patients’ recovery under these and other catabolic circumstances. The treatment of cattle with GH has provided significant improvement in the physiological response of the animals to the subsequent injection of bacterial lypopolysaccharide (LPS), perhaps via inhibition of tumor necrisis factor (TNF) release. However, this improved response to disease was not observed with animals treated with GH and infected with one of two parasitic organisms, Sarcocystis cruzi or Eimeria bovis. Recent attempts with other anabolic hormones, estradiol and progesterone, have proven remarkably effective in improving the adaptive physiological responses of calves to either E. bovis infection or to the injection of LPS. All animals displayed signs of infection, but the intensity and duration of symptoms were reduced. Although a mechanism is not yet known, there were no effects on TNF; cortisol; the percentages of lymphocytes expressing CD2, 4, or 8 antigens; or the production of antibodies.     

张掖市肉牛产业发展路径与态势分析

本文论述了张掖市自然条件优越、饲草资源丰富、良种化程度高、发展模式先进、服务体系完善等肉牛产业发展的有利条件,并以张掖市30年来肉牛产业发展的成功经验,提出以坚持集聚发展、集约经营、产业融合、高效安全的肉牛产业发展方向,努力在规模扩展、品种改良、精深加工、品牌培育、市场开发上实现新突破,全面提升肉牛产业规模化、标准化、产业化、数字化水平,用现代科学技术和手段装备肉牛产业,大力发展肉牛饲养业,努力把张掖打造成中国西北肉牛产业第一大市。     

肉牛同期排卵-定时输精技术的应用进展

近年来,中国肉牛产业不断调整优化,母牛存栏量持续增长,但国内可繁殖肉用母牛数量持续减少,母牛受胎率普遍不高,犊牛成活率低,已成为制约肉牛产业发展的瓶颈环节。同期排卵-定时输精技术通过应用生殖激素处理调控母牛发情周期,促进母牛发情,从而提高母牛参配率,在提高母牛繁殖力中得到广泛应用,是当今家畜繁殖技术的一个重大突破。由于中国肉牛养殖集约化程度低,同期排卵-定时输精技术在肉牛上的应用尚未得到广泛重视。不同同期排卵-定时输精处理程序各有特点,在实际应用中影响同期排卵-定时输精程序处理母牛发情配种妊娠率的因素很多,如何对该技术实现进一步优化是当前面临的重大难题。国内外针对于同一生殖激素的不同浓度、不同激素组合及激素注射的间隔时间、激素的替换等做了大量的研究。文章综述了定时输精技术原理、主要程序及国内外肉牛同期排卵-定时输精技术研究进展,以期为建立高效的肉牛同期排卵-定时输精技术体系实现该技术在肉牛产业上的应用提供参考。     

Distal Interphalangeal Joint Arthrodesis in Seven Cattle Using the Acutrak Plus Screw

Objectives— To report a technique for arthrodesis of the distal interphalangeal joint (DIPJ) with two 6.5 mm Acutrak Plus (AP) compression screws from a solar approach and outcome in 7 cattle.
Study Design— Case series.
Animals— Cattle (n=7) with DIPJ arthritis.
Methods— Retrieved data from medical records of cattle that had undergone DIPJ arthrodesis using 2 AP screws via a solar approach were signalment, history, clinical signs, preoperative blood work, preoperative radiographs, complications, postoperative radiographs, and postoperative lameness evaluation. Outcomes, assessed by owner interview 6–26 months after surgery, were classified as excellent, good, or poor.
Results— Fusion of the DIPJ was evident by 6 months. All cattle returned to full function with minimal lameness and normal appearance to the distal aspect of the limb. Four thoracic limbs and 3 pelvic limbs were affected; 3 medial and 4 lateral claws. Complications included moderate lameness associated with implants (n=2) that resolved after screw removal.
Clinical Relevance— Use of the AP screw system in cattle is an excellent option for DIPJ arthrodesis with minimal postoperative morbidity and excellent return to function.