山羊诱导泌乳效果的分析

对不同日龄的山羊进行诱导泌乳 ,参试 12只羊均诱导泌乳成功 ,通过对 7月龄与 10月龄羊的泌乳量比较 ,发现差异极显著 ,山羊泌乳期长短的个体差异极大 ,与正常泌乳进行比较 ,泌乳时间短 ,泌乳量较低     

奶牛人工诱导泌乳技术

在奶牛生产中,经常遇到有些奶牛因患不孕症长期不能正常发情配种受胎,导致奶牛不产奶,造成较大经济损失。采取有效措施治疗奶牛不孕症,是降低奶牛淘汰率,提高养牛经济效益的重要措施。 人工诱导奶牛泌乳技术就是通过治疗和利用不孕牛,注射外源性激素,激发其生理机能变化,使停产奶牛产奶     

奶山羊流产后激素诱导泌乳试验

用激素诱导泌乳的方法对 8只怀孕中后期因饲养原因而流产的奶山羊进行诱导泌乳试验。结果表明 ,试验奶山羊基本达到了正常泌乳的水平 ,经F检验 ,日均泌乳量与正常分娩组之间差异不显著 ,但和对照组之间差异极显著。说明该方法安全可靠 ,具有明显的经济效益     

人工诱导不孕奶牛泌乳的体会

在奶牛养殖业中 ,有些奶牛因患生殖系统或其他方面的疾病而暂时或终生失去了繁殖能力 ,不能产奶 ,给养牛户造成了一定损失。为减少损失 ,采用激素处理的方法 ,先后对 8头不孕牛进行了诱导泌乳处理。1　材料方法供试牛 :本场干奶 1个月以上不孕荷斯坦奶牛8头。药品 :苯甲酸雌二醇 ,上海第 9制药厂生产 ,批号 90 0 60 2 ,剂型为灭菌油溶液 ,每支含量 1 mg/ml。黄体酮 ,浙江仙居制药厂生产 ,批号 980 31 5 ,剂型为灭菌油溶液 ,每支含量 1 0 mg/ml。利血平 ,上海医科大学红旗制药厂生产 ,批号 970 1 1 4,剂型为灭菌水溶液 ,每支含量为 1 mg/ml。…     

奶山羊注产后激素诱导泌乳试验

用激素诱导泌乳的方法对8只怀孕中后期因饲养原因而注产的奶山羊进行诱导泌乳试验。结果表明，试验奶山羊基本达到了正常泌乳的水平，经F检验，日均泌乳量与正常分娩组之间差异不显著，但和对照组之间差异极显著。说明该方法安全可靠，具有明显的经济效益。     

人工诱导黑白花处女牛泌乳试验

将１７头１６月龄以来,体重不低于３４０ｋｇ的黑白花处女牛,主要依据体重相近的原则分为５组,用５种诱服方法进行人工诱导泌乳试验,结果：５组牛诱乳有效率和成功率均达１００％,１７头牛３０５ｄ头匀总产奶量为２１５０．０２ｋｇ,日均产权７．０５ｋｇ,其中以使用人工诱乳注射＋利血平的第５组产奶量最高,３０５ｄ头均总产奶３３５８．３８ｋｇ,日均产奶１１．０１ｋｇ,显著高于１组,４组牛的产奶量（Ｐ〈０．０５）,     

用诱乳激素包埋剂诱导奶牛泌乳的研究

将６头经产不孕无奶母牛分２组,另３头未配种处女牛为１组,进行包埋剂诱导泌乳试验,并国这两种牛各设一对照组进行针剂诱导泌乳,结果表明：各试验组第１泌乳月日均产奶都在１ｋｇ以上,诱乳有效率为１００％,而全泌乳期产奶量,除２头牛有意外情况外,日均产奶都在上３ｋｇ以上,诱乳成功率为１００％各试验组和对照组牛产奶量地显著差异（Ｐ〉０．０５）,尤其是处女牛在配种前诱乳,抢一个泌乳期并不影响配种受胎,用包埋剂诱     

Colostrogenesis during an induced lactation in dairy cattle

Colostrum immunoglobulin G (IgG) is of major importance for the newborn calf because epitheliochorial placentae do not provide transport in utero. The formation of colostrum occurs in the later stages of pregnancy. Our objectives were to induce lactation in non‐pregnant dairy cows and (i) to determine the changes of IgG in serum and mammary secretions during the induction process and (ii) to establish α‐lactalbumin (αLA) and prolactin (Prl) alterations to monitor the changing mammary epithelial tight junction status and development pattern. Estradiol‐17β (E2) and progesterone (P4) injections in a 1–7 days series were combined with a 3‐day injection series (day 21–23) of dexamethasone (DEX). Blood and both front quarter secretion samples were collected daily. Milking started 24 days after the start of the experiment. Results show that the mammary secretory IgG1 was increased at >7 days after the start of steroid injections and depicted a bimodal pattern reaching a high of 16 mg/ml at 21 day compared with 3.2 mg/ml in the serum. There was a small increase in secretory IgG2 that did not correlate with tight junction status, but never reached the serum concentration. The injections of DEX resulted in constriction of tight junctions. Secretory αLA was immediately increased with steroid injections, dropped precipitously after 7 days and then began a steady increase until the start of milking. Changes in serum αLA are related to mammary tight junctions while serum Prl gradually increased from 30 to >60 ng/ml after the steroid injections stopped. These results provide insights into the mechanisms and timing of colostrogenesis during an induced lactation protocol.     

Changes in nutrient balance,methane emissions,physiologic biomarkers,and production performance in goats fed different forage-to-concentrate ratios during lactation

The objective was to determine the effect forage-to-concentrate (F:C) ratio and stage of lactation on methane emissions, digestibility, nutrient balance, lactation performance, and metabolic responses in lactating goats. Twenty Murciano-Granadina dairy goats were used in an experiment divided into 3 periods: early (30 d), mid (100 d), and late (170 d) lactation. All goats were fed a diet with 35:65 F:C (FCL) during early-lactation. Then, 1 group (n = 10 goats) remained on FCL through mid- and late-lactation while the other group (n = 10 goats) was fed a diet with 50:50 F:C at mid-lactation (FCM) and 65:35 (FCH) at late lactation. A greater proportion of concentrate in the diet was associated with greater overall intake and digestibility (P < 0.05). Energy balance was negative in early-lactation (−77 kJ/kg of BW^0.75, on average) and positive for FCL at mid- and late-lactation (13 and 35 kJ/kg of BW^0.75, respectively). Goats fed FCM and FCH maintained negative energy balance throughout lactation. Plasma concentrations of non-esterified fatty acids at mid-lactation were greater for FCM than FCL (680 mEq/L), and at late-lactation concentrations were greater for FCH and FCL (856 mEq/L). A similar response was detected for plasma β-hydroxybutyrate. Methane emission was greater (P < 0.05) for FCM than FCH (1.7 g CH₄/d). This study demonstrated that differences in F:C across stages of lactation lead to distinct metabolic responses at the level of the rumen and tissues.     

高精料诱导的SARA对泌乳期山羊血液和瘤胃液中皮质醇的影响

选择7只装有永久性瘤胃瘘管的泌乳中期山羊,2×2拉丁方设计,分别饲喂精粗比为6∶4和4∶6的饲料,通过饲喂精粗比6∶4饲料建立泌乳期山羊瘤胃亚急性酸中毒(subacute ruminal acidosis, SARA)模型,研究SARA时山羊血液和瘤胃液中皮质醇浓度、肝脏皮质醇受体(glucocorticoid receptor, GR)mRNA表达及其他相关指标的变化。结果表明,精粗比6∶4日粮饲喂2周后成功诱导SARA状态(SARA组),采食后瘤胃液pH值低于5.8持续时间约6 h,而精粗比为4∶6组山羊瘤胃液pH均高于6.0 (对照组)。高精料日粮处理对瘤胃pH和乳酸以及瘤胃液和血浆内的脂多糖、皮质醇浓度有显著性影响(P<0.05),采食前SARA组山羊瘤胃液中乳酸浓度显著高于对照组(P<0.05),采食后0~4 h乳酸含量下降,6~10 h时逐渐增加并极显著高于对照组(P<0.01);2组间瘤胃液中脂多糖浓度无显著性差异(P>0.05),SARA组血浆脂多糖浓度在采食前和采食后6 h均显著高于对照组(P<0.05);采食前SARA组山羊血液中皮质醇浓度高于对照组(P=0.05),但采食后6 h两组间无显著差异(P>0.05); 2组山羊瘤胃液中皮质醇浓度在采食后2,4和6 h分别显著高于对照组(P<0.05),但在采食前和采食后10 h无显著差异(P>0.05)。Real-time PCR结果显示,SARA组山羊肝脏中GR mRNA表达显著下调(P<0.05)。本研究结果显示,泌乳期山羊发生SARA时糖皮质激素水平升高,负反馈下调肝脏GR的表达水平,提示SARA时机体处于应激状态,可能引起肝脏的物质代谢和营养物质重分配的改变。     

Adrenocorticotropic hormone-induced secretion of cortisol in goats is inhibited by androgen

In a previous study, it was found that there are sex differences in goats with respect to the levels of cortisol secretion induced by transportation stress. We also found that treatment of castrated male goats with dihydrotestosterone (DHT) suppressed the increase in plasma cortisol concentration following transportation, but did not suppress the secretion of adrenocorticotropic hormone (ACTH). This suggests that androgen might block ACTH ‐ induced cortisol secretion. In order to examine this hypothesis, the effects of androgen on ACTH‐induced cortisol secretion in goats were investigated. First, castrated male goats were treated with testosterone (T), DHT or cholesterol (cho) for 21–25 days. Cho was used as a control for T and DHT treatment. Then, plasma cortisol concentrations were compared among the hormonal treatments after ACTH injection. Subsequently, the distribution of androgen receptors in the caprine adrenal gland was investigated. There were no differences in the basal cortisol concentrations among the hormonal treatments. However, plasma cortisol concentrations after ACTH injection were significantly lower in T ‐ and DHT ‐ treated goats than in cho ‐ treated goats. Androgen receptors were present in 60% of the cells in the zonae fasciculata and reticularis of the adrenal cortex, the regions that secrete glucocorticoids. These results suggest that androgen may act directly on the adrenal cortex to suppress cortisol secretion induced by ACTH.     

非常规蛋白饲料原料对泌乳山羊氮代谢和微生物蛋白合成的影响

文章旨在研究不同蛋白质来源精饲料对泌乳山羊氮代谢及微生物蛋白合成的影响.试验选择平均初始体重为(43.62±2.35)kg的泌乳期山羊72头,随机分为3组,每组4个重复,每个重复6头.各组分别饲喂以豆粕、大豆浓缩蛋白和豆科植物(银合欢)为基础的精料,试验为期8周.结果:大豆浓缩蛋白组尿液和尿素氮排泄量较豆科植物组显著提...     

Effects of photoperiod on salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relation between salsolinol (SAL)‐induced prolactin (PRL) release and photoperiod in goats. A single intravenous (i.v.) injection of SAL was given to adult female goats under short (8 h light, 16 h dark) or long (16 h light, 8 h dark) photoperiod conditions at two different ambient temperatures (20°C or 5°C), and the PRL‐releasing response to SAL was compared to that of thyrotropin‐releasing hormone (TRH) or a dopamine (DA) receptor antagonist, sulpiride. SAL, as well as TRH or sulpiride, stimulated the release of PRL promptly after each injection in both 8‐ and 16‐h daily photoperiods at 20°C (P < 0.05). The area under the response curve (AUC) of PRL for the 60‐min period after injections of saline (controls), SAL, TRH and sulpiride in the 16‐h daily photoperiod group was greater than each corresponding value in the 8‐h daily photoperiod group (P < 0.05). There were no significant differences in the AUC of PRL among the values produced after the injection of SAL, TRH and sulpiride in 16‐h daily photoperiod group; however, the values produced after the injection of TRH were smallest among the three in the 8‐h daily photoperiod group (P < 0.05). The PRL‐releasing responses to SAL, TRH and sulpiride under a short and long photoperiod condition at 5°C resembled those at 20°C. These results show that a long photoperiod highly enhances the PRL‐releasing response to SAL as well as TRH or sulpiride in either medium or low ambient temperature in goats.     

Effects of heat exposure on nutrient digestibility, rumen contraction and hormone secretion in goats

The present study investigated changes in nutrient digestibility, rumen fermentation, behavior and hormone (growth hormone (GH), insulin and insulin‐like growth factor‐1 (IGF‐1)) secretion among goats (three male goats) in a hot environment (H, 35 ± 1.2°C; relative humidity (RH), 80 ± 7.2%; 13 days), in a thermoneutral environment (T, 20 ± 0.6°C; RH, 80 ± 3.4%; 20 days), and in a thermoneutral environment accompanied by the same restricted diet as provided in the hot environment (TR, 20 ± 0.6°C; RH, 80 ± 3.4%; 20 days). The following results were obtained: rectal temperature and water intake were higher in the H treatment than in the T treatment or TR treatment, while hay consumption was lower. Crude protein, neutral detergent fiber and acid detergent fiber digestibility was highest in H treatment. The concentrations of acetic acid and butyric acid in the rumen was also highest in the H treatment. Time spent eating in the H treatment was also the highest, followed in order by T treatment and TR treatment. Ruminating time was lower in H treatment than in T treatment or TR treatment, and reposing time was highest in the TR treatment. When eating and ruminating, the amplitude values of the rumen contraction were lowest in the H treatment, as was the frequency of rumen contraction. Excretion of plastic particles was faster in T treatment and TR treatment than H treatment. Heat exposure was associated with world lowered concentrations of total volatile fatty acids and acetic acid in plasma. The plasma glucose concentration was highest in the T treatment, followed in order by TR treatment and H treatment. The plasma GH concentration was lowest in the H treatment, while the plasma insulin was highest in the H treatment. The IGF‐1 concentration was highest in the H treatment, followed in order by T treatment and TR treatment. In conclusion, heat exposure in goats decreased feed intake and rumen contraction, but increased digestibility. However, when goats in a thermoneutral environment received the same restricted feeding as they received in the hot environment, digestibility increased without a change in rumen contraction. Between the H treatment and TR treatment, the changes in digestibility were accomplished by coordinate changes in hormone secretion in order to maintain body homeostasis.     

Effects of melatonin on salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the effect of melatonin (MEL) on the salsolinol (SAL)‐induced release of prolactin (PRL) in goats. Female goats were kept at 20°C with 16 h of light, 8 h of darkness, and orally administered saline or MEL for 5 weeks. A single intravenous (i.v.) injection of saline (controls), SAL, thyrotropin‐releasing hormone (TRH) or a dopamine receptor antagonist, sulpiride, was given to the goats 3 weeks after the first oral administrations of saline or MEL, and the responses were compared. The mean basal plasma PRL concentrations in the control group were higher for the saline treatments than MEL treatments (P < 0.05). SAL as well as TRH and sulpiride stimulated the release of PRL promptly after each injection in both the saline‐ and MEL‐treated groups (P < 0.05). The area under the response curve of PRL for the 60‐min period after the i.v. injection of SAL, TRH and sulpiride in the saline‐treated group was greater than each corresponding value in the MEL‐treated group (P < 0.05). These results show that daily exposure to MEL under a long day length reduces the PRL‐releasing response to SAL as well as TRH and sulpiride in goats.     

二花脸母猪泌乳期乳中乳铁蛋白分泌规律的研究

应用我们已建立的酶联免疫吸附分析 (ELISA)方法 ,研究二花脸母猪泌乳期乳中乳铁蛋白 (Lactoferrin,Lf)的分泌规律。采集分娩后的4头二花脸母猪在泌乳起始 48h内的连续乳样 (每小时采样 1次 )进行测定。结果显示 :刚分娩时乳中Lf浓度最高 ,为 1 2 66 59μg/mL ;随后开始下降 ,前 2 0h内下降较快 ,2 0h之后下降变缓 ;至第 48h ,浓度降为第 1小时的 53 %。对处于泌乳期前 30d内的 4头二花脸母猪连续乳样 (每天采集 1次 )和 1 0 2头二花脸母猪散点乳样 (每天随机采样 )的测定结果表明两者Lf的分泌规律基本相似 :分娩第 1天 ,Lf浓度最高 ;1周内迅速下降 ,第 7天降至第 1天的 2 5 % ;1周后下降缓慢 ;2周后趋于平稳。     

Alterations in the jejunum of young goats caused by feeding soy protein‐based diets

This study was designed to investigate whether soy protein or soy protein supplemented with indispensable amino acids (AA) change the protein expression pattern and utilization of pre‐cursors for RNA biosynthesis in jejunal mucosa in relation to casein and whether these changes affect mucosal cell growth. Kids were fed comparable diets based on cow`s milk, of which 50% of crude protein were replaced by either casein (CAS), soy protein (SP) or soy protein supplemented with indispensible AA (SPA) for 34 days (n = 4/group). Jejunal tissue was collected 5 h after adding a single dose of ¹⁵N‐RNA to the diet, in order to determine morphology, protein repertoire by two‐dimensional gel electrophoresis and matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometry, and RNA biosynthesis by isotope ratio‐mass spectrometry. In mid‐jejunum, morphological alterations induced by partial replacement of casein with soy protein were accompanied by changes in mucosal proteins related to generation of the cytoskeleton and in pathways for mucosal RNA biosynthesis, resulting in a smaller re‐utilization of dietary RNA pre‐cursors and in an increased activity of enzymes involved in nucleic acid breakdown. Soy protein supplemented with indispensible aminoacids tended to revise mucosal growth retardation with no impact on salvage of dietary RNA pre‐cursors for mucosal RNA biosynthesis, but changes in cytoskeleton generation. Feeding soy protein with supplementation of indispensible AA does not ameliorate soy protein effects on mucosal morphology and RNA metabolism in the jejunum in a significant manner.