A Field Study of Serum,Colostrum, Milk Iodine,and Thyroid Hormone Concentrations in Postpartum Draft Mares and Foals

Iodine, thyroxine (T4) and triiodothyronine (T3) are required for normal fetal growth, maturation, and neonatal survival. There is a lack of robust information on iodine levels found in colostrum, milk, and serum of mares and foals after a healthy pregnancy. Our objective was to characterize colostrum, milk, and serum iodine levels in healthy postpartum mares and foals (n = 10) and explore relationships with thyroid hormone concentrations. Colostrum, milk, and jugular blood samples from draft breed mares and foals with an estimated average iodine daily intake of 39 mg per mare during pregnancy were obtained at Day 0 (foaling date) and/or 10 days later. Parameters studied were (1) mare basal concentrations of serum: TT3, TT4, and iodine; (2) iodine in colostrum at Day 0 and milk iodine (Day 10); and (3) foal basal: TT3, TT4, and serum iodine (Days 0 and 10). Median ± median error colostrum iodine levels (165 ± 15.1 μg/L) were higher than milk (48 ± 5.6 μg/L; P = .007) levels. Median ± median error foal serum iodine (268.5 ± 7.6 μg/L), TT4 (1,225 ± 47.8 nmol/L), and TT3 (14.2 ± 1.1 nmol/L) at foaling date were higher than at 10 days (serum iodine: 70 ± 3.6 μg/L; TT4: 69.6. ± 20.4 nmol/L; and TT3: 5.4 ± 0.3 nmol/L). In conclusion, equine mammary tissue concentrates iodine beyond plasma levels, making colostrum and milk a significant source of iodine. Foal serum iodine levels are high in the neonatal period and are positively correlated with TT4, which is important for neonatal adaptation.     

Effect of a Limited Iodine Diet on Iodine Uptake by Thyroid Glands in Hyperthyroid Cats

Background

The effect of feeding a limited iodine diet on radioactive iodine uptake in the thyroid glands of hyperthyroid cats is unknown.

Objectives

To determine how feeding limited dietary iodine affects radioactive iodine uptake by the thyroid glands of hyperthyroid cats.

Animals

Eight geriatric cats with spontaneous hyperthyroidism.

Methods

Prospective study of eight client owned hyperthyroid cats fed a commercially available iodine limited diet for 6 months. Clinical signs were evaluated and TT4 and fT4 were measured during consumption of the diet. Uptake of ¹²³I was determined before and 8–16 weeks after exclusive consumption of the diet.

Results

Clinical signs of hyperthyroidism resolved in all cats, but there was no significant increase in body weight. TT4 and fT4 decreased into the reference range by 8–16 weeks in all cats. Mean TT4 before consumption of the diet was 9.7 μg/dL (SD 5.2) and after consumption of the diet was 3.1 μg/dL (SD 0.9). Scintigraphy revealed unilateral uptake of isotope in 5 cats and bilateral uptake in 3 cats. Mean percentage uptake of ¹²³I by the thyroid gland at 8 hours after isotope administration was 16.2 (SD 11.8) before diet consumption and 34.6 (SD 11.7) 8–16 weeks after exclusive consumption of the diet. The percentage increase was variable between cats (38–639%).

Conclusions and clinical importance

Limited iodine diets increase iodine uptake in the autonomous thyroid glands of hyperthyroid cats. Further studies are necessary to determine if consumption of a limited iodine diet changes sensitivity of the thyroid gland to ¹³¹I treatment.     

Long-term Treatment of Insulin-insensitive Mares with Cabergoline: Effects on Prolactin and Melanocyte Stimulating Hormone Responses to Sulpiride and on Indices of Insulin Sensitivity

The main experiment assessed whether the inhibitory effects of the dopamine agonist, cabergoline, on prolactin and α-melanocyte stimulating hormone (MSH) concentrations would persist throughout a longer-term administration (65 days). The possible effect of cabergoline on insulin sensitivity was also studied. Ten mares known to be insulin insensitive were allotted to two groups (treated vs. control). An insulin challenge, a glucose tolerance test, and a sulpiride challenge were administered before treatment. On day 0, treated mares (n = 5) received an injection of 5 mg cabergoline in slow-release vehicle; control mares (n = 5) received an equivalent vehicle injection. Injections were repeated every 10 days for a total of seven injections. Sulpiride challenges were done 1 day before each cabergoline treatment to assess possible refractoriness to the treatment. Behavior and hair coat density were also monitored. Plasma prolactin was suppressed (P < .01) to undetectable levels in mares receiving cabergoline; control mares had robust prolactin responses to each sulpiride injection. There was no indication of refractoriness to cabergoline over time. Plasma MSH concentrations after sulpiride were also suppressed (P < .05) by cabergoline. After treatment, neither the glucose response to insulin nor the insulin response to glucose differed (P > .1) between groups. No behavioral changes were noted because of treatment. Weight of hair samples indicated that cabergoline perturbed (P < .05) winter coat growth. It is concluded that 5 mg of cabergoline in slow-release vehicle administered every 10 days is an effective way of delivering dopaminergic activity to mares that results in no noticeable detrimental effects and no refractoriness to the drug.     

日粮中添加大豆黄酮对鹌鹑生产性能和血液中激素水平的影响

本试验采用了 3个生产阶段的蛋用鹌鹑。 35日龄开产期蛋用鹌鹑日粮中添加 3mg/kg大豆黄酮 ,鹌鹑的产蛋率和血液中T3 水平均发生显著性提高 (P <0 0 5 )。 7月龄蛋用鹌鹑日粮中添加 3mg/kg大豆黄酮 ,可显著提高鹌鹑的产蛋率 (P <0 0 5 )和血液中T3 水平 (P <0 0 5 ) ;而日粮中添加 6mg/kg大豆黄酮则使鹌鹑的产蛋率显著下降 (P <0 0 5 )。 12月龄蛋用鹌鹑日粮中添加 6mg/kg大豆黄酮 ,鹌鹑的产蛋率提高 10 3% (P <0 0 1) ;血液中T3 、T4和IGF 1水平分别提高 34 8% (P <0 0 1)、2 7 6 % (P <0 0 5 )和 30 8% (P <0 0 5 )。本次研究结果表明 ,日粮中添加一定剂量大豆黄酮能显著增加开产期、高峰期和后期蛋用鹌鹑的产蛋率 ,并影响其内分泌机能     

不同精粗比全混合日粮对湖羊生长性能、血清激素浓度和屠宰性能的影响

本试验旨在研究不同精粗比全混合日粮对湖羊生长性能、血清激素浓度和屠宰性能的影响。选择体重相近、体况良好且健康的湖羊羔羊40只,随机分为4组,每组10只(公母各占1/2)。4组试验羊分别饲喂精粗比为70∶30(试验Ⅰ组)、60∶40(试验Ⅱ组)、50∶50(试验Ⅲ组)和40∶60(试验Ⅳ组)的全混合日粮。试验期为70 d,其中预试期为14 d,正试期为56 d。结果显示:1)正试期第14天和第35天,试验Ⅰ组羔羊平均日增重(ADG)极显著高于试验Ⅲ和Ⅳ组(P<0.01);正试期第35天和第56天,试验Ⅱ组羔羊体重(BW)显著高于试验Ⅳ组(P<0.05)。2)正试期第14天,试验Ⅱ组羔羊体斜长以及试验Ⅰ组羔羊胸围和管围均显著高于试验Ⅳ组(P<0.05);正试期第35天,试验Ⅰ组羔羊胸围和管围均显著高于试验Ⅳ组(P<0.05),试验Ⅰ组羔羊血清瘦素(LEP)浓度显著高于试验Ⅱ组(P<0.05);正试期第56天,试验Ⅰ组羔羊血清生长激素(GH)和四碘甲状腺原氨酸(T4)浓度显著高于试验Ⅳ组(P<0.05),试验Ⅱ组羔羊血清三碘甲状腺原氨酸(T3)浓度显著高于试验Ⅲ和Ⅳ组(P<0.05)。3)试验Ⅱ组羔羊宰前活重、胴体重、屠宰率、后腿重和背膘厚均极显著高于试验Ⅳ组(P<0.01),试验Ⅱ组羔羊肋肉厚、心脏和肝脏重量均显著高于试验Ⅳ组(P<0.05)。综上所述,在本试验条件下,育肥湖羊饲喂精粗比为60∶40的全混合日粮可获得最佳的生长性能和屠宰性能。     

Effect of a Nonsurgical Embryo Transfer Procedure and/or Altrenogest Therapy on Endogenous Progesterone Concentration in Mares

Endogenous progesterone levels may decline after transcervical embryo transfer in some mares. Progestogen therapy is commonly used to support endogenous progesterone levels in embryo transfer recipient mares or those carrying their own pregnancy. The goal of this study was to determine the effects of the transcervical transfer procedure and/or altrenogest therapy on luteal function in mares. Mares were assigned to one of six treatment groups: group 1 (untreated control; n = 7 cycles), group 2 (sham transfer, no altrenogest; n = 8 cycles), group 3 (sham transfer plus altrenogest; n = 8 cycles), group 4 (pregnant, no altrenogest; n = 9 mares), group 5 (pregnant plus altrenogest; n = 9 mares), and group 6 (nonpregnant plus altrenogest; n = 10 cycles). Mares in groups 4-6 were bred and allowed an opportunity to carry their own pregnancy. Blood samples were collected for 22 days beginning on the day of ovulation. Sham embryo transfer (groups 2 and 3, combined) did not result in a decline in endogenous progesterone levels compared with control mares (group 6). However, sham embryo transfer did result in luteolysis and an abrupt decline in endogenous progesterone levels in one of the 16 (6.2%) sham-transferred mares. Altrenogest therapy in sham-transferred mares (group 3) was associated with lower endogenous progesterone levels on days 10, 12, and 13 postovulation when compared with sham-transferred mares that did not receive altrenogest (group 2). Administration of altrenogest to pregnant mares (group 5) was associated with lower concentrations of endogenous progesterone from days 14 to 18 and on day 21 compared with endogenous progesterone levels in pregnant mares not administered altrenogest (group 4). In conclusion, a transcervical embryo transfer procedure can cause luteolysis in a low percentage of mares. Altrenogest therapy may be associated with a reduction in endogenous progesterone secretion, presumably mediated by a reduction in pituitary luteinizing hormone (LH) release and a decrease in luteotropic support.     

甘草次酸对青年母猪生长性能、抗氧化能力及生殖激素浓度的影响

本试验旨在研究甘草次酸对青年母猪生长性能、抗氧化能力及生殖激素浓度的影响。选用(124±7)日龄、平均体重为(61.00±3.03)kg的健康长×大二元青年母猪64头,按日龄、体重相近的原则随机分为4个组,分别为对照组(基础饲粮)、玉米赤霉烯酮组(基础饲粮+1 mg/kg玉米赤霉烯酮)、甘草次酸组(基础饲粮+400 mg/kg甘草次酸),玉米赤霉烯酮+甘草次酸组(基础饲粮+1 mg/kg玉米赤霉烯酮+400 mg/kg甘草次酸),每组4个重复,每个重复4头母猪。预试期5 d,正试期28 d。结果表明:1)与对照组相比,玉米赤霉烯酮组青年母猪阴户发育异常,阴户长、宽及面积极显著增加(P<0.01)。2)甘草次酸组和玉米赤霉烯酮+甘草次酸组青年母猪的平均日采食量和平均日增重均显著高于对照组和玉米赤霉烯酮组(P<0.05)。3)与对照组相比,玉米赤霉烯酮组青年母猪的粗脂肪消化率显著增加(P<0.05),钙和磷消化率显著降低(P<0.05);甘草次酸组的粗纤维和粗脂肪消化率显著增加(P<0.05),钙和磷消化率极显著增加(P<0.01);玉米赤霉烯酮+甘草次酸组的粗脂肪消化率显著增加(P<0.05)。4)与对照组相比,玉米赤霉烯酮组青年母猪的血清吻素(Kp)、雌二醇(E2)、促黄体素(LH)浓度极显著增加(P<0.01),甘草次酸组的血清Kp和E2浓度显著增加(P<0.05),玉米赤霉烯酮+甘草次酸组的血清Kp、E2和LH浓度极显著增加(P<0.01)。5)玉米赤霉烯酮组青年母猪的血清丙二醛(MDA)含量显著高于对照组和甘草次酸组(P<0.05);与玉米赤霉烯酮组相比,玉米赤霉烯酮+甘草次酸组的血清MDA含量显著降低(P<0.05),血清乳酸脱氢酶(LDH)活性极显著降低(P<0.01)。综上所述,饲粮中添加甘草次酸可改善青年母猪的生长性能和抗氧化能力,影响生殖激素浓度,具有缓解玉米赤霉烯酮对青年母猪繁殖危害的作用。     

Effect of hCG in the Presence of hCG Antibodies on the Follicle, Hormone Concentrations, and Oocyte in Mares

Follicle blood flow, follicular-fluid and plasma hormone concentrations, and oocyte quality were studied 30 h after an ovulation-inducing hCG treatment when the pre-ovulatory follicle was 32 mm. Mares were grouped as positive (n = 16) and negative (n = 44) for hCG antibodies before the experimental hCG treatment. Percentage of the follicle wall with blood flow signals was less (p < 0.05) in the antibody positive group than in the negative group. The concentrations of follicular-fluid oestradiol and free IGF1, and plasma oestradiol were greater (p < 0.001), and follicular-fluid progesterone (p < 0.001) and plasma LH (p < 0.02) were less in the antibody-positive group than in the negative group. For recovered oocytes at 30 h (n = 37), the antibody-positive group had fewer (p < 0.001) mature (MII) oocytes than the antibody-negative group. Results were attributable to highly effective neutralization of the hCG in the antibody-positive group.     

补喂不同水平雌马酚对母绵羊生长性能、血浆中雌马酚含量与生殖激素水平以及抗氧化能力的影响

本试验旨在研究补喂不同水平雌马酚对绵羊生长性能、血浆中雌马酚含量与生殖激素水平以及抗氧化能力的影响。试验选取年龄为2岁、平均体重为(36.73±2.42)kg的健康、体况相近的哈萨克母羊20只,随机分为4组,分别为对照组、试验Ⅰ组、试验Ⅱ组、试验Ⅲ组,每组5只羊。各组试验羊在相同的饲养条件下饲养,在此基础上,试验Ⅰ组、试验Ⅱ组、试验Ⅲ组每日每只分别补喂10、25、50 mg雌马酚,进行为期14 d的饲养试验。结果表明:1)与对照组相比,每日每只母绵羊补喂50 mg雌马酚可以显著或极显著提高平均日增重、平均日采食量(P<0.05或P<0.01),显著降低料重比(P<0.05)。2)补喂雌马酚后血浆中雌马酚含量呈先上升后下降趋势,在2.0~3.0 h时达到峰值。3)试验Ⅰ组血浆中睾酮(T)水平显著或极显著高于对照组和试验Ⅲ组(P<0.05或P<0.01),试验Ⅱ组也显著高于对照组(P<0.05),但与试验Ⅰ组和试验Ⅲ组无显著差异(P>0.05);试验Ⅰ组和试验Ⅱ组血浆中双氢睾酮(DHT)水平显著高于对照组和试验Ⅲ组(P<0.05)。4)血浆总抗氧化能力(T-AOC)与过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性均以试验Ⅱ组最高,丙二醛(MDA)含量以试验Ⅱ组最低,与对照组的差异均达到显著或极显著水平(P<0.05或P<0.01)。由此得出,在本试验条件下,每日给每只母绵羊补喂50 mg雌马酚可以显著提高绵羊的生长性能;补喂雌马酚后2.0~3.0 h,母绵羊血浆中雌马酚含量达到峰值,并且随着补喂剂量的提高,血浆中高含量雌马酚的跨峰时间(即维持血浆高含量雌马酚的持续时间)也延长。每日给每只母绵羊补喂10和25 mg雌马酚可显著提高血浆中T和DHT水平。每日给每只母绵羊补喂25 mg雌马酚可显著提高机体抗氧化能力,效果优于补喂10、50 mg时。     

低蛋白质饲粮添加蛋氨酸和赖氨酸对离乳期梅花鹿生长性能和血清生化指标的影响

本试验旨在研究低蛋白质饲粮中添加蛋氨酸(Met)和赖氨酸(Lys)对离乳期梅花鹿仔鹿生长性能和血清生化指标的影响.选择16只健康3月龄雄性梅花鹿,随机分为4个组,每组4个重复,每个重复1只.各组限量饲喂4种不同饲粮:对照组(Ⅰ组)饲喂16.28％粗蛋白质(CP)的高蛋白质饲粮,试验组饲喂13.40％CP添加0.23％Lys并分别添加0(Ⅱ组)、0.06％(Ⅲ组)、0.12％(Ⅳ组)Met的低蛋白质饲粮,试验期为56 d.结果表明:1)Ⅱ组平均日增重(ADG)最低,Ⅱ、Ⅲ、Ⅳ组ADG随饲粮Met水平增加而增加,Ⅳ组ADG与Ⅰ组基本相同.2)Ⅰ组56 d血清白蛋白(ALB)含量显著高于Ⅱ、Ⅲ组(P＜0.05),56 d血清总蛋白(TP)含量显著高于Ⅱ组(P＜0.05),28 d血清尿素氮(UN)含量极显著高于Ⅳ组(P＜0.01),56 d血清葡萄糖(GLU)含量极显著低于Ⅱ、Ⅲ组(P＜0.01),血清天冬门氨酸氨基转移酶(AST)活性显著高于Ⅳ组(P＜0.05),28 d血清碱性磷酸酶(AKP)活性显著或极显著高于Ⅱ、Ⅲ组(P＜0.05或P＜0.01).3)Ⅱ、Ⅲ、Ⅳ组相比,Ⅳ组28 d血清UN含量显著低于Ⅱ组(P＜0.05),Ⅳ组28 d血清AKP活性显著高于Ⅱ、Ⅲ组(P＜0.05),但血清球蛋白(GLB)、TP含量随饲粮Met水平升高而增加,血清AST、丙氨酸氨基转移酶(ALT)活性和UN含量随饲粮Met水平升高而降低.由此可见,在13.40％CP的饲粮中添加Lys和Met,仔鹿的ADG可达到16.28％ CP饲粮的水平,饲粮中添加0.12％Met有利于仔鹿生长和代谢平衡.     

The Effect of Cloprostenol on the Incidence of Multiple Ovulation and Anovulatory Hemorrhagic Follicles in Two Mares: A Case Report

Reproductive records of the entire lives of two mares with abnormally high incidence of multiple ovulation and hemorrhagic anovulatory follicles were analyzed retrospectively. Chi-square analysis was used to test statistically the effect of cloprostenol, a prostaglandin F2 analog, on the incidence of multiple ovulations, hemorrhagic anovulatory follicles, and its ultrasonographic appearance. A total of 319 estrous cycles during a 17-year period were analyzed. Cycles induced with cloprostenol were more likely (P < .000) to develop hemorrhagic anovulatory follicles than spontaneous cycles. The incidence of multiple ovulation was higher in induced cycles than in spontaneous cycles in one of the two mares.     

Effect of Follicle Size and Follicle-Stimulating Hormone on Ovulation Induction and Embryo Recovery in the Mare

The timing of ovulation is an important component to many equine breeding strategies. The action of luteinizing hormone on ovulation induction has been recognized; however, potential effects of follicle-stimulating hormone (FSH) have been less defined. Objectives of this study were to determine whether (1) mares could be induced to ovulate follicles ≤30 mm; (2) equine FSH (eFSH) has a positive effect on ovulation induction, and (3) ovulation of small follicles would affect embryo recovery. Light-horse mares (n = 12) between 4 and 10 years of age were assigned to treatments when they had a dominant growing follicle with a mean diameter of 24, 28, or 35 ± 2 mm and endometrial edema. Treatments were (1) H35, human chorionic gonadotropin (hCG) at 35 ± 2 mm; (2) F35, eFSH at 35 ± 2 mm; (3) H28, hCG at 28 ± 2 mm; (4) FH28, eFSH and hCG at 28 ± 2 mm; (5) D28, deslorelin (gonadotropin-releasing hormone [GnRH] analog) at 28 ± 2 mm; (6) FH24/H24, hCG or eFSH and hCG at 24 ± 2 mm. Mares’ reproductive tracts were scanned at 24 ± 2-hour intervals after treatment to detect ovulation. Mares were inseminated, and embryos were collected. Numbers of mares that ovulated within 48 ± 2 hours after treatment were: H35, 8/8 (100%); F35, 8/14 (57%); H28, 7/12 (58%); FH28, 9/12 (75%); D28, 3/7 (43%) and FH/H24, 4/14 (29%). The number of mares that ovulated in 48 ± 2 hours for H35 was not different from that for FH28 but was higher (P < .05) than all other groups. Embryo recovery rates, diameters, developmental stages, and morphology scores were not different for mares ovulating 48 hours or less versus more than 48 hours after treatment or among treatment groups. Results of this study demonstrate that follicles ≤30 mm can be induced to ovulate with no effect on embryo recovery or quality, as assessed by stereomicroscopy.     

鲁西黄牛妊娠周期血清生殖及相关激素变化规律研究

[目的]为了进一步提高鲁西黄牛的繁殖性能,有必要对妊娠周期中生殖及相关激素的分泌规律进行研究。[方法]利用放射性免疫法对空怀期、妊娠3个月、妊娠6个月、围产期以及分娩后母牛血清中雌二醇、孕酮、催乳素、游离T3（甲状腺素）和IGF-Ⅰ（胰岛素样生长因子-Ⅰ）等激素浓度进行测定。[结果]随妊娠时间的延长,体重、胸围、腰角宽、尻长、髋宽和管围等体尺指标都逐渐增加,并且体重与游离T3含量有极显著的相关关系。妊娠早期循环血液中雌二醇含量很低,到妊娠中期开始增长,围产期达到高峰。而孕酮分泌量在妊娠早期逐渐上升,妊娠中期稍有下降,到围产期时又逐渐增加并达到高峰。IGF-Ⅰ含量在整个妊娠周期中一直保持上升趋势。催乳素含量在妊娠6个月以前增加不明显,直到围产期时分泌量开始迅速增加,分娩后持续上升。[结论]通过对鲁西黄牛妊娠周期血清生殖及相关激素的检测,为以后进一步提高其繁殖性能提供依据。     

Effect of Deslorelin and/or Human Chorionic Gonadotropin on Inducing Ovulation in Mares During the Transition Period Versus Ovulatory Season

The objective of this study was to compare the rate of ovulation when deslorelin and/or human chorionic gonadotropin (hCG) was administered in mares in both the transition period and the ovulatory season. A total of 200 Paint Horses, Quarter Horses, and crossbred mares were used during the transition season (July to September) and the ovulatory season (October to February) of the southern hemisphere. The animals were divided into four groups. In the control group (n = 72), mares received 1 mL of saline; in deslorelin group (n = 171), 1.5 mg of deslorelin was administered by intramuscular (IM) injection; in hCG group (n = 57), 1,667 IU of hCG was administered IV; and in hCG + deslorelin group (n = 438), 1.5 mg of deslorelin (IM) and 1,667 IU of hCG (IV) were administered. The drugs were administered after follicles ≥35 mm in diameter were identified and grade III uterine edema was observed. At 48 hours after application, ultrasonography was performed to detect ovulation. During the transition period, the ovulation rates were 4.3% (control), 78.6% (deslorelin), 50% (hCG), and 73.3% (hCG + deslorelin). During ovulatory season, the ovulation rates were 16.4% (control), 68.8% (deslorelin), 60% (hCG), and 73% (hCG + deslorelin). There was no significant difference (P > .05) in the ovulation rate between the groups or the periods, except that the control group was lower than all others. Furthermore, both hCG and deslorelin are viable options for inducing ovulation during the transition period before ovulation season.     

Effect of Repeated Cabergoline Treatment on the Vernal Transition and Hair Shedding of Mares (Year 1) and a Subsequent Comparison of the Effect of Starting Date on Prolactin Suppression (Year 2)

Two studies were conducted to determine efficacy of cabergoline for suppressing prolactin (PRL) and the possible effects on vernal transition in mares. In experiment 1, six mares each received either vehicle or cabergoline (5 mg, intramuscularly) every 10 days for 12 treatments beginning February 4, 2013. Blood samples were drawn regularly, and mares were challenged with sulpiride periodically to assess PRL suppression. Weekly hair samples were obtained to determine shedding. Prolactin was suppressed (P < .05) by cabergoline, but suppression waned in spring. There was no effect (P > .05) of treatment on day of first ovulation, luteinizing hormone, or follicle stimulating hormone. Hair shedding was generally suppressed (P = .05). In 2014 (experiment 2), eight of the same 12 mares were used in a similar experiment to determine if the rise in PRL observed in experiment 1 was due to refractoriness to cabergoline or perhaps another factor. Treatment began on April 6, 2014, corresponding to the increase in PRL in treated mares in experiment 1. Mares were treated with cabergoline or vehicle until June 5. Prolactin was suppressed (P < .05) by cabergoline, and the pattern of apparent escape from suppression was similar to year 1. We conclude that (1) cabergoline at this dose alters hair shedding but does not alter the time of first ovulation in mares and (2) relative to our previous reports of cabergoline treatment in the fall, there is a seasonal effect on the ability of this dose of cabergoline to suppress unstimulated PRL secretion.     

Preliminary Observations on the Concentrations of Serum Luteinizing Hormone and Follicle-stimulating Hormone during Gestation in Bactrian Camels (Camelus bactrianus)

The concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in the serum of the Bactrian camel (Camelus bactrianus) throughout pregnancy were analysed by radioimmunoassay. The samples were withdrawn at intervals of half a month. The serum LH concentrations varied significantly between 2.2±0.9 and 20.3±18.8 ng/ml during the pregnancy, with the highest value on the day of artificial insemination, which indicated that a preovulatory LH peak appeared. Thereafter, the LH concentration tended to fall, reaching a fairly constant low level by the eighth month of pregnancy. The serum FSH concentrations varied between 7.0±0.2 and 28.9±0.4 ng/ml during gestation, with the peak value being reached at 4.5 months, followed by a marked drop to 7.0±0.2 ng/ml at 7.5 months.     

The Effect of Combined Therapy With Captopril, Furosemide, and a Sodium-Restricted Diet on Serum Electrolyte Concentrations and Renal Function in Normal Dogs and Dogs With Congestive Heart Failure

Captopril, furosemide, and a sodium-restricted diet were administered to 6 normal dogs and 10 dogs with congestive heart failure. Serum electrolyte concentrations and renal function were monitored in both groups. In the normal dogs, no clinically meaningful changes in serum electrolyte, urea nitrogen, or creatinine concentrations developed during therapy with a sodium-restricted diet and 4 weeks each of furosemide alone, captopril alone, or furosemide plus captopril. Three of 6 normal dogs on furosemide and a sodium-restricted diet had at least one serum potassium concentration above the reference range during the 4 weeks of observation. One normal dog on captopril, furosemide, and a sodium-restricted diet developed azotemia, and 2 dogs had serum potassium concentrations above the reference range during the 4 weeks of observation. Ten dogs with congestive heart failure were treated with captopril, furosemide, a sodium-restricted diet, and digoxin.
Etiopathogenesis of the heart failure included valvular insufficiency (n = 6), dilated cardiomyopathy (n = 3), and dilated cardiomyopathy and dirofilariasis (n = 1). Serum electrolyte concentrations and renal function were monitored for 5 consecutive weeks in 7 of the 10 dogs and for 17 weeks or longer in 6. Two dogs were euthanized after 4 weeks because of acute decompensation of heart failure, and one dog developed severe azotemia and uremia. Six of 10 dogs with congestive heart failure had at least one serum potassium concentration above the reference range sometime during the 5 weeks of observation, although the changes in the mean serum potassium concentrations were not statistically significant. Four of 10 dogs with congestive heart failure developed azotemia sometime during the 5 weeks of observation.     

不同饲粮能量结构对后备母猪初情日龄、血清代谢产物和激素浓度的影响

本试验旨在探讨不同饲粮能量结构对后备母猪初情日龄、血清代谢产物和激素浓度的影响。选用90头体况相近、平均体重为(61.97±4.37)kg的长白×大白杂交后备母猪,根据体重相近的原则均衡分成3组,每组5个重复,每个重复6头。3组母猪饲喂3种不同能量结构的等能等氮饲粮,其中组1饲粮含有49.70%淀粉、2.81%粗脂肪(EE)和8.95%中性洗涤纤维(NDF),组2饲粮含有43.52%淀粉、5.68%EE和12.53%NDF,组3饲粮含有37.13%淀粉、8.73%EE和16.02%NDF。预饲5d后开始试验,在猪群第1个个体出现发情后的1个月结束试验,试验期68d。结果表明:随着饲粮淀粉水平的降低和EE、NDF水平的增加,后备母猪背膘厚呈下降趋势,但组间差异不显著(P>0.05);初情日龄以组1最小,但3组间差异不显著(P>0.05);发情率组1和组2比组3均提高10百分点,但组间差异不显著(P>0.05)。不同饲粮能量结构对后备母猪血清甘油三酯(TG)、总胆固醇(TC)和葡萄糖(GLU)浓度无显著影响(P>0.05)。血清胰岛素样生长因子-Ⅰ(IGF-Ⅰ)、瘦素(Leptin)、促黄体素(LH)浓度组1显著高于组3(P<0.05),血清促性腺激素释放激素(GnRH)浓度组1显著高于组2和组3(P<0.05)。血清胰岛素(INS)、雌二醇(E2)和促卵泡素(FSH)浓度各组间无显著差异(P>0.05)。综上可知,过多降低后备母猪饲粮淀粉水平并增加EE、NDF水平,会影响血清中代谢激素IGF-Ⅰ、Leptin和生殖激素GnRH、LH的分泌,不利于初情期启动。     

新疆家蚕抗菌肽对雏鸡生长性能及血清激素、理化指标的影响

将240只1日龄南宁麻花鸡随机分成4组.对照组饮用自来水,3个试验组的饮水中分别添加0.5、1.5、3.5 mL/L抗菌肽.试验期为56d.结果表明:与对照组相比,1.5、3.5 mL/L添加量的试验组雏鸡增重效果显著(P＜0.05),试验组血清总蛋白浓度差异不显著(P＞0.05),尿素氮水平下降显著(P＜0.05),血清胰岛素样生长因子-1(IGF-1)水平显著升高.在28日龄,试验组的三碘甲状腺原氨酸(T3)浓度高于对照组,差异不显著(P＞0.05),甲状腺素(T4)水平下降显著(P＜0.05);在56日龄,试验组的T3水平显著降低(P＜0.05),但T4水平高于对照组,差异显著(P＜0.05).     

高脂饲料中添加发酵桑叶对杂交鳢生长性能、体组成及血清生化指标的影响

本试验旨在研究高脂饲料中添加发酵桑叶对杂交鳢生长性能、体组成及血清生化指标的影响。选用体质健壮、平均体重为10g的杂交鳢360尾,随机分成3个组,每个组设4个重复,每个重复30尾。各组投喂在高脂饲料中分别添加0(对照组)、7.5%和15.0%发酵桑叶的试验饲料。试验期8周。结果表明:1)与对照组相比,15.0%发酵桑叶组杂交鳢的特定生长率(SGR)和蛋白质效率(PER)显著降低(P0.05),饲料系数(FCR)显著增加(P0.05);7.5%发酵桑叶组杂交鳢的SGR、PER和FCR无显著差异(P0.05)。各组杂交鳢的摄食率(FR)无显著差异(P0.05)。2)与对照组相比,7.5%和15.0%发酵桑叶组杂交鳢的全鱼粗脂肪含量以及肝体比、脏体比和肠脂比显著降低(P0.05),15.0%发酵桑叶组杂交鳢的肝脏脂肪含量显著降低(P0.05)。各组杂交鳢的全鱼粗灰分、粗蛋白质以及肌肉脂肪含量均无显著差异(P0.05)。3)与对照组相比,15.0%发酵桑叶组杂交鳢的血清谷草转氨酶和谷丙转氨酶活性以及总胆固醇、甘油三酯含量显著降低(P0.05);7.5%和15.0%发酵桑叶组杂交鳢的血液葡萄糖含量显著降低(P0.05)。各组杂交鳢的血清总蛋白含量均无显著差异(P0.05)。由此可见,高脂饲料中添加7.5%发酵桑叶不会影响杂交鳢的生长性能,而添加15.0%发酵桑叶会抑制杂交鳢的生长,但有利于肝脏健康,改善机体的糖脂代谢。