苏尼特羊妊娠后期限制饲养对其羔羊初生重的影响

基于妊娠后期胎儿生长最快的特点 ,研究在妊娠 90d将 4 5只平均体重为 4 1 4 5kg±3 81kg、体况中等、胎次为 2～ 3的苏尼特经产妊娠母羊随机分为四个营养水平组 (每天每千克代谢体重 0 2 0、0 33、0 4 4、0 86MJ) ,目的在于研究在妊娠后期 (90～ 15 0d)不同限制程度饲养能量水平对羔羊初生重的影响。结果表明不同饲养能量水平导致四组羔羊平均初生重分别为 2 80 1、3 375、3 6 98、3 6 6 6kg ,其中后三组羔羊初生重间无显著差异 (P >0 0 5 ) ,而 0 2 0MJ组显著 (P <0 0 5 )降低其初生重。在限制饲养期间 ,不同组别母羊净失重不同 ,依次为 11 13、7 2 3、4 4 2、0 93kg ,分别占妊娠 90d各组母羊净重的 2 7 9%、17 9%、11 3%、2 4 %。可见在妊娠后期母体失重达到试验开始时母体净重的17 9% ,仍不影响羔羊初生重 ,达到 2 7 9%时仍能完成妊娠。这表明苏尼特羊对低能量是有很强的适应性的     

甘肃高山细毛羊母羊妊娠后期补饲效果研究

根据甘肃高山细毛羊母羊妊娠后期营养缺乏状况,配制出中等能量中等蛋白质补饲料 Ⅰ、低能量高蛋白质补饲料 Ⅱ和高能量低蛋白质补饲料 Ⅲ 3种补饲料。选择健康、体重相近的妊娠后期母羊60只,随机分为A、B、C、D 4组,每组15只,每个重复1只羊,A、B、C组为试验组,分别补饲饲料Ⅰ、Ⅱ和Ⅲ;D组为对照组,按牧民传统方式饲养,试验期共68 d。试验结果表明,A、B、C补饲组母羊平均日增重分别为102、109和114 g/d;A、B、C补饲组羔羊初生重分别为4.09、3.91和 4.40 kg,均显著高于对照组。补饲料Ⅲ对试验羊血清葡萄糖(glucose)、甘油三酯 (triglyceride)和尿素氮(blood urea nitrogen)浓度有显著影响(P<0.05);补饲料Ⅱ对试验羊血清总蛋白(total protein)、谷草转氨酶(aspartate transaminase)浓度有显著影响。补饲组试羊瘤胃液总氮、瘤胃液蛋白氮含量显著高于对照组(P<0.05)且A组显著高于其他各组,B组瘤胃液尿素氮浓度显著高于其他各组(P<0.05)。试验组瘤胃液挥发性脂肪酸(volatile fatty acid)浓度和丙酸摩尔比显著高于对照组(P<0.05);试验组瘤胃液中乙酸/丙酸显著低于对照组(P<0.05)。3种补饲料对试验羊瘤胃液pH和瘤胃液氨态氮影响均不显著(P>0.05)。     

不同营养水平限制饲养对妊娠期蒙古绵羊生长激素受体(GHR)mRNA表达水平的影响

为了阐明不同营养水平限制饲养妊娠期母羊后,在不同生长阶段对蒙古绵羊生长激素受体(GHR)mRNA表达水平的影响,研究根据GenBank中绵羊的GHR序列,设计1对预计扩增产物为395 bp的引物,采用RT-PCR技术检测了蒙古绵羊在不同营养水平条件下肝脏和背最长肌中GHR mRNA表达量的变化。结果表明:在限制采食阶段,低营养水平组即营养限制组(RG1组)和阈值组(RG2组)肝脏的GHR mRNA表达水平低于正常营养的对照组(CG组),而背最长肌的GHR mRNA表达水平高于对照组,说明限制营养对绵羊GHR水平的影响具有组织特异性。在补偿生长结束阶段,RG1组和RG2组绵羊的肝脏和背最长肌中GHR mRNA表达水平均恢复到对照组水平。     

Effects of maternal nutrition on udder development during late pregnancy and on colostrum production in Scottish Blackface ewes with twin lambs

Effects on udder development and colostrum production of changing the level of ewe nutrition were investigated. Udder weights at term were derived from their linear dimensions and yields of colostrum were obtained by hand milking on three occasions between one and 18 hours after birth. The linear dimensions of the udder increased progressively in all animals between 100 days of gestation and term (about 145 days), but udder development was retarded significantly within three days of the onset of underfeeding at 105 days of gestation. Underfeeding reduced the total yield of colostrum during the first 18 hours after birth by decreasing the prenatal accumulation of colostrum and its subsequent rates of secretion. Improving the ewe's nutrition from one hour after birth tended to increase the secretion rates of colostrum between 10 and 18 hours. Refeeding previously underfed ewes to high levels from about five days before birth had no effect on udder growth but did increase the prenatal accumulation of colostrum and its subsequent rates of secretion to levels which, when corrected for differences in udder weight, were similar to those of ewes which were fed well throughout. Calculations revealed that by ignoring udder growth the Agricultural Research Council recommendations for the energy requirements of pregnant ewes underestimate the cost of tissue synthesis during the last four weeks of pregnancy by about 100 per cent.     

Pharmacokinetics of penicillin-G in ewes and cows in late pregnancy and in early lactation

Concentrations of penicillin-G in serum were determined after single intravenous doses of potassium penicillin-G (10 mg/kg body wt) to ewes and cows in late pregnancy and in early lactation. Penicillin-G in serum was analysed by a microbiological method and pharmacokinetic parameters were calculated by model-independent methods. Serum concentrations were lower in early lactation than in late pregnancy in both ewes and cows. The differences were statistically significant at most sampling times in ewes but only during the first hour in cows.
Weight corrected values of clearance and volume of distribution were significantly higher in early lactation than in late pregnancy in both ewes and cows. Mean residence time and elimination-half life were shorter in lactating than in pregnant ewes, however for the latter parameter the difference was not statistically significant. Neither of these parameters changed in cows.
It is concluded that in both ewes and cows pharmacokinetic parameters of penicillin-G are altered from late pregnancy to early lactation but that these changes have little practical impact and do not call for a revised dosage regime of the studied drug.     

Influence of protein supplementation during late pregnancy and lactation on the resistance of Santa Ines and Ile de France ewes to Haemonchus contortus

This experiment aimed to evaluate the effect of periparturient metabolizable protein (MP) nutrition on resistance to Haemonchus contortus in single rearing Ile de France and Santa Ines ewes. The restriction-fed iso-energetic diet was calculated to provide either 0.8 (low MP diet) or 1.3 (high MP diet) times MP, from three weeks before parturition until eight weeks into lactation. The ewes were experimentally infected with 1000 H. contortus infective larvae (L3) three times a week (Mondays, Wednesdays and Fridays), starting five weeks before the predicted date for parturition until a total of 15,000 L3 had been administered. While both breeds showed elevated fecal egg counts (FEC), these values were significantly lower for Santa Ines ewes than Ile de France ewes, but were independent of level of MP feeding. The latter also did not affect lamb weight gain and ewe body weight variation in each breed. Packed cell volume and total plasma protein for Santa Ines in all periods were significantly higher than those for Ile de France ewes (P<0.01) but were not affected by nutrition. In contrast, levels of serum IgG and IgA antibodies against somatic H. contortus infective larvae and adult antigens were similar between breeds but higher in animals that received high MP diets (P<0.05). The reduced body score of ewes at the beginning of the experiment probably influenced their high susceptibility to incoming larvae. Since, unexpectedly, MP scarcity was not achieved in this experiment, our data support the view that Santa Ines ewes are more resistant to H. contortus than Ile de France ewes.     

Effect of supplementation with concentrates and lasalocid during late pregnancy and lactation on productivity of Rambouillet ewes and development of wool follicles in their lambs

A total of 64 Rambouillet ewes was utilized in this study. Ewes were fed a 50:50 mixture of alfalfa and prairie hay ad libitum and either no concentrates (C), .4 kg concentrates . head-1 X d-1 (S) or .4 kg concentrates containing 73 ppm lasalocid . head-1 X d-1 (SL) during the last 50 d of pregnancy and through 60 d of lactation. A total of 163 skin samples was obtained from the mid-side region of the lambs at birth, 1 and 2 mo of age, and follicle traits were estimated by histological techniques. Wool growth per unit area (100 cm2) was estimated by clipping wool from both right and left mid-sides of all ewes 60 d postpartum. Birth weight of single lambs did not differ (P greater than .20) among treatments. Twin lambs of supplemented ewes were heavier (P less than .01) at birth than those of control ewes and the difference between S and SL groups was not significant. Compared with the control, concentrate supplementation with or without lasalocid increased (P less than .01) postnatal lamb survival and ewe productivity, expressed as kilograms of lamb weaned per ewe lambed. The C, S and SL groups weaned 12.50, 18.52 and 20.72 kg/ewe lambed (P less than .01), respectively. Maternal concentrate supplementation did not influence secondary to primary wool follicle ratio (Sf/Pf) of single lambs (P greater than .20). Twin lambs of the S ewes tended to have higher Sf/Pf than controls. The SL twins had intermediate Sf/Pf values (P greater than .20).(ABSTRACT TRUNCATED AT 250 WORDS)     

Strangulation of the duodenum by the uterus during late pregnancy in two cows.

Two Swiss Braunvieh cows in late pregnancy underwent surgery because of a rare form of ileus due to strangulation of the duodenum at its caudal flexure by the gravid uterus. The whole uterus had passed through a gap between the mesoduodenum and duodenum and with increasing weight had led to strangulation of the duodenum. This was possible since the mesoduodenum and both walls of the greater omentum adjacent to its caudal edge were not connected with the duodenum, probably due to a congenital inhibitory malformation. A transsection and an end-to-end anastomosis of the duodenum were necessary in both cases since it was impossible to retract the gravid uterus through the defect. Postoperative recovering was uneventful in both cows, which were discharged after seven and five days respectively and calved normally about two months later. Copyright Harcourt Publishers Ltd.     

Use of injectable vitamin E and selenium-vitamin E emulsion in ewes and suckling lambs to prevent nutritional muscular dystrophy

Forty-eight Blackbelly X Dorset, 27 Finnish, 26 Finnish X Dorset, 28 Rambouillet and 8 Dorset Suffolk-sired lambs were used in this experiment. Three weeks before lambing, one-half of the ewes received a selenium emulsion (Se-E) containing .05 mg selenium and 3.7 IU of vitamin E/kg body weight (BW). A 2 X 3 X 2 factorial arrangement was used; lambs from either treated or nontreated ewes were randomly assigned irrespective of breed to one of six treatment combinations consisting of 0 or .025 mg/kg BW selenium (Se) injected at birth or two .025 mg/kg BW Se injections, one at birth and one 2 to 3 wk later, and two levels of injectable Vitamin E (E; 0 and 100 IU) given at birth. Both lambs and ewes were provided access to 75% concentrate diets supplemented with Se and E at recommended NRC levels. Plasma activity of creatine phosphokinase (CPK) was highest at 1 d of age and exhibited decreases (P less than .001) over time. In lambs, the E injection tended to decrease plasma activity of CPK. Plasma glutathione peroxidase activity was lowest at 1 d of age and increased over the course of the experiment but was unaffected by treatments (P less than .05). Plasma tocopherol concentration decreased (P less than .01) with time, with E therapy tending to increase tocopherol concentration. Differences in mean plasma tocopherol concentrations among breeds were also observed (P less than .01). Selenium concentration increased over time and with the E injection (P less than .01). An interaction between ewe and lamb Se-E treatments also was observed (P less than .10), with nontreated lambs from nontreated ewes exhibiting lower Se concentrations than treated lambs from injected ewes. An increase in lamb plasma Se concentration was noted in response to Se-E treatments (P less than .001). In the ewes, plasma tocopherol concentration was lower while Se concentration was higher at 18 d than at 1 d postpartum (P less than .01 and P less than .001, respectively). Milk Se concentration was lower at 18 d than at 1 d (P less than .001) and was higher (P less than .10) in Se-E-treated ewes.     

The body composition and metabolic status of twin- and triplet-bearing ewes and their fetuses in late pregnancy

This study investigated the body composition and metabolic status of twin- and triplet-bearing ewes and their fetuses in late pregnancy. The aim was to identify factors that could explain the lower survival rates of triplet lambs compared with twin lambs. Ten twin- and 10 triplet-bearing ewes and their fetuses were euthanased on either day 139 or 140 of pregnancy and fetal and placental measurements recorded. The weights of the gravid uterus (P < 0.01) and mammary gland (P < 0.05) were significantly heavier (although not proportionally), in triplet-bearing than twin-bearing ewes (21.10 vs. 16.85 and 1.08 vs. 0.80 kg respectively). There were no other differences in the weight of ewe organs or in metabolite concentrations. The number of cotyledons per triplet fetus was significantly (P < 0.001) less compared to twins although this was countered by a tendency for greater (P = 0.05) individual cotyledon weight, resulting in no differences in either total fetal membrane plus cotyledon or total cotyledon weights.

The absolute weight of many organs were significantly (P < 0.05) heavier in twin fetuses than in triplet fetuses. However, after correction for fetal body weight the only differences observed were significantly (P < 0.05) lighter, by approximately 10%, semitendinosus muscle, liver and heart weights in triplet compared to twin fetuses (6.2 vs. 5.6, 88.9 vs. 80.4, 33 vs. 30 g respectively). The fetal fructose concentrations were significantly (P < 0.05) lower in triplet than in twin fetuses.

The mean weight of the lightest triplet fetus within each triplet set was 31% lighter than that of the heaviest triplet (P < 0.05), resulting in significantly (P < 0.05) lighter absolute weights of most fetal measurements taken. However, after correction for fetal body weight these differences disappeared. Within twin sets, the mean weight of the lightest fetus was only 16% lighter (P < 0.05) than its heavier counterpart but there were no significant differences in absolute organ weights. When corrected for fetal body weight, the lightest twin fetus had significantly (P = 0.05) greater kidney weights and tended to have heavier heart (P = 0.07) and lungs (P = 0.07). It is unknown why the relative organ weight relationships between the heaviest and lightest differ between twin and triplet fetuses.

In conclusion this study has identified three factors which may contribute to the lower survival rates observed in triplet-compared to twin-born lambs; low fructose concentrations, lighter fetal weights, especially in one fetus within each triplet set, and maternal mammary gland increases that are not proportional to the increase in numbers of fetuses. While these findings are not novel, there were no other factors identified that could account the lower survival rates reported in triplet-born lambs compared to twins. The other only other significant differences identified were the proportionally lighter livers and hearts in triplets although the possible effects of these on survival is unknown.     

Comparison of estrus induction and subsequent fertility with two different intravaginal devices in ewes during the non-breeding season

Two experiments were conducted to compare the effect of estrus induction by controlled internal drug release (CIDR) and intravaginal cream containing 500 mg progesterone (P cream) in ewes during the non-breeding season. In the first experiment, twenty-four ewes were randomly grouped for two treatments with the different intravaginal devices for 12 days: Group A was the CIDR group and Group B was the P cream group. Blood was collected from all treated ewes, and progesterone (P(4)), estradiol 17-beta (E(2)) and luteinizing hormone (LH) concentrations were measured by enzyme immunoassay. In the second experiment, the conception rates from natural mating, estrus-detected AI (inseminated 12 h after estrus detection), or fixed-time AI (inseminated 42 h after removal of an intravaginal device) in 127 ewes treated with CIDR or P cream were compared. In Experiment 1, the rate of estrus induction and the time of estrus onset after device removal were 91.7% and 36.3 +/- 15.7 h in Group A, and 100% and 35.0 +/- 12.6 h in Group B, respectively. There were no significant differences between the devices. The mean plasma P(4) concentration in Group B was significantly (P < 0.01) lower than Group A between day -9 and day -1 (Day 0: the day of device removal). However, no significant differences were found in the mean E(2) concentrations of the two groups after treatment. The mean time of estrus onset in ewes with an observed LH surge and the time of LH surge after treatment were 23.3 +/- 8.7 h and 30.3 +/- 5.0 h for Group A and 27.6 +/- 6.5 and 26.3 +/- 8.0 h for Group B, respectively, and there were no significant differences. However, a significant difference (P < 0.05) was found in the mean time from the time of estrus onset to LH surge between Group A (6.4 +/- 6.7 h) and Group B (-1.3 +/- 4.1 h). In Experiment 2, the conception rates for natural mating, estrus-detected AI, and fixed-time AI were 55.0, 29.4, and 25.0% for Group A and 40.7, 25.0, and 42.1% for Group B, respectively, and there were no significant differences. These results suggest that the effect of induction of estrus and ovulation and the rate of conception after treatment were comparable to CIDR even though the plasma P(4) concentration of the P cream method tended to be low during the insertion period.     

日粮不同能量和蛋白水平对多浪羊繁殖性能及血液生化指标的影响

试验于2009年3月至2010年3月在喀什地区麦盖提县多浪羊繁育基地进行,研究日粮不同能量和蛋白水平对多浪羊繁殖性能及血液生化指标的影响。90只母羊分为第Ⅰ组、第Ⅱ组和第Ⅲ组共3个组进行试验,3组均饲喂不同能量和蛋白水平的日粮,分别计算春季和秋季3个组的繁殖性能指标值,并检测血清中TP、ALB、GLB、ALP、BUN、GLU、TG和LDH的含量。结果发现,提高日粮能量水平对多浪羊春季发情率的提高有明显效果,但日粮高能量水平对受胎率和双羔率的提高均无效果;高蛋白水平日粮对多浪羊春季与秋季的发情率、受胎率和双羔率的提高没有明显效果;多浪羊春季血清中BUN含量高于秋季,秋季血清中ALP含量高于春季。从血液生化指标分析可以看出,秋季的繁殖性能比春季好。     

Post‐glucose load changes of plasma key metabolite and insulin concentrations during pregnancy and lactation in ewes with different susceptibility to pregnancy toxaemia

Insulin resistance during late gestation may act as a predisposing factor of ovine pregnancy toxaemia (OPT). To evaluate the insulin action on energy metabolism in ewes with different susceptibilities to OPT, intravenous glucose tolerance tests (1 mmol glucose/kg body weight) were performed in 5.6 ± 0.7 year old, slightly underfed German Blackheaded Mutton ewes [high‐risk (HR) ewes] and 2.5 year old, overnourished Finnish Landrace ewes [low‐risk (LR) ewes] during mid and late pregnancy, during early lactation and during the dry period. Plasma samples were analysed for glucose, insulin, non‐esterified fatty acids (NEFA) and β‐hydroxybutyrate (β‐HB). The glucose elimination rate and the glucose‐stimulated first‐phase insulin secretion were significantly (p < 0.05) lower in the HR, in relation to the LR group combining the data of all gestational stages. The basal rate of lipolysis was significantly increased in the HR ewes during late pregnancy, but the NEFA clearance after the glucose load was similar in both groups during all reproductive stages. Plasma β‐HB concentrations decreased only in the LR ewes after the glucose load during late pregnancy. Results indicate an insulin resistance in the HR ewes regarding the glucose utilization and the ketone body formation during late pregnancy. The insulin resistance in the HR ewes may represent one predisposing factor responsible for the susceptibility to OPT. Further scientific work is necessary to elucidate whether this insulin resistance was due to breed, age or nutritional state.     

Effects of infection with Trypanosoma brucei brucei on different trimesters of pregnancy in ewes.

The effects of Trypanosoma brucei brucei infection during the first, second or third trimesters of pregnancy in 13 ewes were studied. All infected ewes were anaemic with the anaemia being most severe, moderate and least in ewes infected in the second, third and first trimesters, respectively. Weight loss occurred in all infected ewes but was most severe in ewes infected in the third trimester. Three of the four ewes infected in the first trimester died without aborting while one aborted and later died. Of the four ewes infected in the second trimester, three died without aborting while one lambed and later died. In the third trimester ewes, one aborted, two lambed and all three later died while one died without aborting. None of the lambs was viable. The control ewe lambed normally. The infection resulted in 16.7% abortion, 100% death and 33.3% neonatal deaths. This study demonstrates that T. brucei brucei has a devastating effect on pregnancy irrespective of the trimester of infection.     

Pregnancy impairs ketone body disposal in late gestating ewes: implications for onset of pregnancy toxaemia

The impact of pregnancy on ketone body disposal during a hyperketonaemic clamp was examined by tracer isotope dilution techniques in seven 12 h fasted sheep in three reproductive states, in the dry non-gestating period, late in gestation and during early lactation. After a sampling period of 60 min under basal conditions a DL-BHB racemate solution was continuously infused intravenously for 3 h at rates of 14.3-24.3 micromol/(kg min) to elevate the D-BHB concentration in blood plasma to values between 5 and 7 mmol/l. Two separate experiments were carried out with the same sheep in each of the three reproductive states. During pregnancy three ewes were pregnant with a single lamb and four ewes carried twins. Maximal D-BHB turnover rates fell significantly in late gestation by 26% relative to early lactation and by 22% when compared with the dry non-pregnant state. Reduction of maximal D-BHB disposal rate during late gestation was accompanied by a significant 297% (p<0.005) and a non-significant 49% increase in the basal BHB concentration in blood, a non-significant 10% and 4% decrease in the rate constant of D-BHB turnover and a non-significant 24% and 13% rise in the incremented increase of D-BHB concentration per unit D-BHB infusion, relative to the dry and the lactating period, respectively. Induction of hyperketonaemia significantly lowered NEFA and glycerol concentrations in blood by 67% and 57%, respectively, compared to the pre-infusional concentrations. The magnitude of this effect was the same in all reproductive states and was explained as a direct antilipolytic action of D-BHB on adipose tissue. It is concluded that the reduced ability of the late gestating ewe to utilize D-BHB promotes hyperketonaemia. Since hyperketonaemia exerts several adverse effects, e.g. on energy balance and glucose metabolism it appears that the impairment of ketone bodies disposal in late pregnancy facilitates development of pregnancy toxaemia, especially in ewes carrying twins.