青海可可西里国家自然保护区草地牧草营养成分测定

测定了可可西里国家级自然保护区内紫花针茅草地型和高山嵩草草地型牧草,冷季9月份和4月份营养成分。结果表明,各种牧草营养成分含量随种类不同和生长季节迁移而呈现一定差异;9月份两类草地型牧草DM,CP,EE,NDF,ADF,ADL,Ash,Ca和P平均含量分别为92.20%和90.42%,5.40%和5.98%,2.90%和3.06%,48.30%和44.3%,41.40%和34.36%,3.68%和6.52%,18.85%和8.28%,1.43%和1.25%,0.38%和0.47%;4月份两类草地型牧草DM,CP,EE,NDF,ADF,ADL,Ash,Ca和P平均含量分别为94.33%和93.75%,3.69%和5.85%,1.52%和2.32%,66.82%和61.88%,47.14%和43.32%,9.14%和8.53%,13.48%和13.47%,1.38%和1.16%,0.38%和0.36%;紫花针茅草地型和高山嵩草草地型牧草CP平均含量9月份较4月份分别高出46.8%和35.5%,NDF,ADF和ADL分别降低了27.71%和28.41%,11.95%和20.68%,59.63%和23.33%;就营养品质而言,高山嵩草草地型牧草优于紫花针茅草地型牧草。     

Prion protein (PrP) gene polymorphisms associated with natural scrapie cases and their flock-mates in Ireland

The PrP genotypes associated with natural scrapie in Ireland were determined and a comparison was made between genotypes found in scrapie-infected sheep and those found in healthy animals from scrapie-infected flocks. Seven PrP genotypes were identified in scrapie-infected animals: VV(136)RR(154)QQ(171),VA(136)RR(154)QQ(171),VA(136)RR(154)QR(171),VA(136)RR(154)QH(171),AA(136)RR(154)QQ(171),AA(136)RR(154)QH(171) and AA(136)RR(154)HH(171). Of 11 scrapie-infected flocks, 15 genotypes were identified in the healthy flock-mates. The genotypes identified in scrapie-affected animals were also all identified in healthy flock-mates. In 9 of the 11 flocks studied, the genotype frequencies among scrapie-infected animals were significantly different from those among healthy flock-mates. The results show that there is a significant risk of developing the clinical signs of scrapie associated with particular PrP genotypes in the Irish sheep population. The association between the V(136)R(154)Q(171) allele and scrapie was evident, as was the association between A(136)R(154)R(171) and resistance to developing the clinical signs of scrapie. The presence of the A(136)H(154)Q(171) allele in the flocks examined resulted in a decreased risk of developing scrapie compared to the presence of the A(136)R(154)Q(171).     

Pharmacokinetics of enrofloxacin in lactating sheep

The pharmacokinetics of enrofloxacin (ENR) was investigated after its intravenous (iv) and intramuscular (im) administration in six healthy lactating sheep. After iv ENR injection (as a bolus), the elimination half-life (t(1/2beta)), the volume of distribution (Vd(area)), and the area under the concentration vs. time curve (AUC) were 3.30 (0.36)h, 2.91 (0.17)l/kg and 4.19 (0.18) microg h/ml, respectively. The maximum milk concentrations of ENR (C(max)), the area under the milk concentration vs. time curve (AUC(milk)) and the ratio AUC(milk)/AUC(serum) were 2.38 (0.14)microg/ml, 23.76 (2.21) microg h/ml and 5.62 (0.30), respectively. After im administration of ENR the t(1/2beta), C(max), time of C(max) (t(max)) and absolute bioavailability (F(abs)) were 3.87 (0.10)h, 0.74 (0.07) microg/ml, 0.83 (0.12)h and 75.35%, respectively. The C(max), AUC(milk) and the ratio AUC(milk)/AUC(serum) were 1.94 (0.13) microg/ml, 24.81 (2.25) microg h/ml and 8.15 (0.96), respectively.     

稻草与不同饲料混合在体外消化率上的组合效应研究

以体外干物质消化率(IVDMD)对鲁梅克斯K-1(Rumex patientia,RP)、紫云英(Astragalus sinicus,AS)、高丹草(Sorghum hybrid Sudangrass,SHS)、苏丹草(Sorghumsudanense,SS)、矮象草(Pennisetumpurputeumcv.mott,PPM)、苜蓿(Medicagosativa,MS)、木薯干草(CH)、稻草(RS)、氨化稻草(ARS)与木薯渣(CR)的品质进行了评定。IVDMD(%)自高到低的排序为:CR(77.63)、RP(61.32)、MS(55.26)、AS(54.91)、CH(52.97)、SHS(40.24)、PPM(38.70)、ARS(36.88)、SS(34.15)、RS(26.63)。除AS与MS外,各种饲料间的IVDMD差异显著(P0.05)。本研究将组合效应值(AE)定义为混合饲料实测IVDMD与各单个饲料IVDMD加权和值之差。分别以RS、ARS作为低、中等品质基础秸秆饲料,再分别添补RP、AS、SHS、SS、PPM、MS与CH(RS还补饲ARS),共6个组合。结果表明,任一组合均观察到正组合效应,以添补MS的最大;CH作为添补料其效果要好于禾本科牧草,与豆科牧草相似;对低质秸秆基础饲料的补饲较对中等品质的组合效应明显。     

Measurements of the acid-binding capacity of ingredients used in pig diets

: Some feed ingredients bind more acid in the stomach than others and for this reason may be best omitted from pig starter foods if gastric acidity is to be promoted. The objective of this study was to measure the acid-binding capacity (ABC) of ingredients commonly used in pig starter foods. Ingredients were categorised as follows: (i) milk products (n = 6), (ii) cereals (n = 10), (iii) root and pulp products (n = 5), (iv) vegetable proteins (n = 11), (v) meat and fish meal (n = 2), (vi) medication (n = 3), (vii) amino acids (n = 4), (viii) minerals (n = 16), (ix) acid salts (n = 4), (x) acids (n = 10). A 0.5 g sample of food was suspended in 50 ml distilled de-ionised water with continuous stirring. This suspension was titrated with 0.1 mol/L HCl or 0.1 mol/L NaOH so that approximately 10 additions of titrant was required to reach pH 3.0. The pH readings after each addition were recorded following equilibration for three minutes. ABC was calculated as the amount of acid in milliequivalents (meq) required to lower the pH of 1 kg food to (a) pH 4.0 (ABC-4) and (b) pH 3.0 (ABC-3). Categories of food had significantly different (P < 0.01) ABC values. Mean ABC-4 and ABC-3 values of the ten categories were: (i) 623 (s.d. 367.0) and 936 (s.d. 460.2), (ii) 142 (s.d. 79.2) and 324 (s.d. 146.4), (iii) 368 (s.d. 65.3) and 804 (s.d. 126.7), (iv) 381 (s.d. 186.1) and 746 (s.d. 227.0), (v) 749 (s.d. 211.6) and 1508 (s.d. 360.8), (vi) 120 (s.d. 95.6) and 261 (s.d. 163.2), (vii) 177 (s.d. 60.7) and 1078 (s.d. 359.0), (viii) 5064 (s.d. 5525.1) and 7051 (s.d. 5911.6), (ix) 5057 (s.d. 1336.6) and 8945 (s.d. 2654.1) and (x) -5883 (s.d. 4220.5) and -2591 (s.d. 2245.4) meq HCl per kg, respectively. Within category, ABC-3 and ABC- 4 values were highly correlated: R2 values of 0.80 and greater for food categories i, iv, v, vi, vii and viii. The correlation between predicted and observed ABC values of 34 mixed diets was 0.83 for ABC-4 and 0.71 for ABC-3. It was concluded that complete diets with low ABC values may be formulated through careful selection of ingredients. The final pH to which ABC is measured should matter little as ABC-3 and ABC-4 are highly correlated.     

Effect of bypass fat supplementation on productive performance and blood biochemical profile in lactating Murrah (Bubalus bubalis) buffaloes

The study investigated the effect of dietary supplementation of bypass fat on productive performance and blood biochemical profile of lactating Murrah buffaloes (Bubalus bubalis). Fifteen multiparous buffaloes (2-4 lactation) of early to mid lactation were divided in three homogenous groups T(1) (control), T(2), and T(3) of five each. The animals in T(1) were fed with a basal diet consisting of a concentrate mixture, green sorghum, and wheat straw as per requirements, while the animals in group T(2) and T(3) were fed with same ration supplemented with 0.7 % (100?g/day) and 1.4 % (200?g/day) bypass fat (on dry matter intake (DMI) basis), respectively. The feed intake, milk yield, and milk composition were not influenced by supplemental bypass fat. However, fat-corrected milk (6.5 %) yield was higher (P?相似文献   

Pharmacokinetic evaluation of tramadol and its major metabolites after single oral sustained tablet administration in the dog: a pilot study

The study evaluated the pharmacokinetics of tramadol and its major metabolites O-desmethyltramadol (M1), N-desmethyltramadol (M2) and N-O didesmethyltramadol (M5) following a single oral administration of a sustained release (SR) 100mg tablet to dogs. Plasma tramadol concentration was greater than the limit of quantification (LOQ) in three dogs, M1 was quantified only in one dog while M2 and M5 were quantified in all of the dogs. The median values of C(max) (maximum plasma concentration), T(max) (time to maximum plasma concentration) and T(1/2) (half-life) for tramadol were 0.04 (0.17-0.02)mirog mL(-1), 3 (4-2) and 1.88 (2.211-1.435)h, respectively. M5 showed median values of C(max), T(max) and T(1/2) of 0.1 (0.19-0.09)microg mL(-1), 2 (3-1) and 4.230 (6.583-1.847)h, respectively. M2 showed median values of C(max), T(max) and T(1/2) of 0.22 (0.330-0.080)microg mL(-1), 4 (7-3) and 4.487 (6.395-1.563)h, respectively. The findings suggest that the SR formulation of tramadol may not have suitable pharmacokinetic characteristics to be administered once-a-day as an effective and safe treatment for pain in the dog.     

Effects of prostaglandin F(2alpha) and nitric oxide on the secretory function of bovine luteal cells

The objective of the present study was to investigate the influence of prostaglandin F(2alpha) (PGF (2alpha)) and nitric oxide (NO) on production of steroids and PGs by culturing bovine luteal cells obtained from ovaries on days 8-12 of the estrous cycle with a nitric oxide (NO) donor (Spermine NONOate), and a NO synthase inhibitor (N(G)-nitro-L-arginine methyl ester dihydrochloride: L-NAME). When the cells were exposed for 24 h to PGF(2alpha) (10(-7)-10(-5) M), production of progesterone (P(4)) increased significantly at all doses used (P<0.05). Moreover, PGF(2alpha) stimulated PGF(2alpha) production (P<0.01), depressed testosterone (T) production (P<0.05), but did not affect synthesis of prostaglandin E(2) (PGE(2)). Spermine NONOate decreased P(4) production to 66%, 47% and 34% of the control concentration after treatment with 10(-5) M, 10(-4) M and 10(-3) M, respectively, but did not affect T production, and increased PGF(2alpha) synthesis (P<0.05) and PGE(2) (P<0.01) at all doses used. L-NAME increased production of P(4) (P<0.01) but did not affect (P>0.05) secretion of T, PGF(2alpha) and PGE(2). Estradiol-17beta (E(2)) was detectable on the level of sensitivity of assay and was not significantly altered by any treatments. The overall results suggest that PGF(2alpha) and NO produced locally in bovine CL play roles in the regulation of the secretory function of the bovine CL as auto/paracrine factors.     

Comparison of corn with four sorghum grain hybrids: site and extent of digestion in steers

Four diverse sorghum hybrids (yellow, cream, hetero-yellow and red) and corn grain were dry-rolled and fed in an 85% grain diet to Angus-Hereford steers (241 kg) equipped with ruminal and double L-type duodenal and ileal cannulas to compare the effects of grain source on site and extent of digestion. Yellow (yel) has a homozygous yellow endosperm, with a yellow seed coat, whereas cream and hetero-yellow (het-yel) have a heterozygous yellow endosperm with white and red seed coats, respectively. Red has a homozygous white endosperm with a red seed coat. Diets were fed at 2% of initial BW (DM basis) in a 5 x 5 Latin square. Total digestive tract starch digestibility (%) was greater (P less than .05) for corn (92.5) than for red (84.3), yel (84.3) and het-yel (82.9) but not greater (P greater than .10) than for cream (87.9). Ruminal starch digestibility (%) was greater (P less than .10) for corn (85.8) than for sorghum hybrids (69.1). Pre-cecal starch digestibility (%) was greater (P less than .05) for corn (90.6) than for het-yel (76.2), red (74.8) and yel (74.1). Ruminal escape (%) of grain N was greater (P less than .10) for red (79.9) than for het-yel (69.2), cream (66.5) and yel (66.1), with corn (53.6) being less (P less than .10) than sorghum hybrids. Pre-cecal and total tract non-NH3 N digestibilities (%) were not altered (P greater than .10) by grain source. Hybrid of sorghum altered site and extent of starch digestion and ruminal escape of grain N; hybrids had estimated gain:feed ratios that were 81 to 93% of those of rolled corn grain.     

Rumen degradability characteristics of normal maize stover and silage, and quality protein maize silage-based diets offered to cows

Rumen degradability characteristics of dry matter (DM), organic matter (OM) and crude protein (CP) of normal maize (NM) stover (T1)-, NM silage (T2)- and quality protein maize (QPM) silage (T3)-based diets were studied using three rumen-fistulated Boran × Friesian non-lactating cows (371?±?32.00?kg) in 3?×?3 Latin Square Design. Cows were supplemented with a similar concentrate mix. In sacco degradability of DM and OM indicated that the (a) values of DM (128) and OM (114) for NM stover were lower (P?相似文献   

Fertility and hatchability in RIR and WL breeds as functionally modified by crossing them in alternate sex combinations (Gallus domesticus)

(1) Four breeding groups of Rhode Island Red and White Leghorn domestic fowl (RIR (female) x RIR (male), RIR (female) x WL (male), WL (female) x RIR (male) and WL (female) x WL (male)) were compared for fertility, hatchability, and their post-insemination sustainability, egg weight loss during incubation and uncovered yolk in abdominal cavity of dead in shell in order to understand the problems associated with the RIR breed in these respects. (2) Crossing RIR (female) with WL (male) or in reverse sex combinations did not improve fertility in comparison to pure RIR chickens and all these groups were less fertile than the pure WL. (3) Unlike fertility, hatchability in RIR improved with the change to either sex partner of the WL breed but the WL (female) x RIR (male) combination was similar to the pure WL (97.72 and 97.12%, respectively). In contrast, crossing RIR (female) with WL (male) resulted in an improvement (86.67%) as compared to pure RIR (76.67%) but still lower than the pure WL and WL (female) x RIR (male) cross. (4) Egg weight loss during incubation was more (20.16%) in pure RIR as compared to RIR (female) x WL (male) (17.13%), followed by WL (female) x RIR (male) (10.28%) and pure WL (9.57%). (5) There were more dead-in-shell embryos with yolks outside their abdominal cavity in pure RIR and their crosses as compared to pure WL breeds. (6) Fertility was sustained for longer in WL than other combinations with post-artificial insemination using constant number of spermatozoa. Fertility after a week of insemination tended to decrease more rapidly than hatchability on a fertile egg basis. (7) It is concluded that both sexes are responsible for the poor fertility in RIR but the female is responsible for poor hatchability and this poor performance is mainly due to greater egg weight loss during incubation.     

Localization and Coexistence of Calcium-Binding Proteins and Neuropeptides in the Vagal Ganglia of the Goat

This study was performed to investigate the neurochemical characteristics of the vagal ganglia of the goat by immunohistochemical methods using calbindin D-28k (CB), calretinin (CR). parvalbumin (PA), substance P (SP). calcitonin generelated peptide (CGRP) and galanin (GAL) antibodies. In the proximal vagal ganglia (jugular ganglia), CGRP- (57.1%), SP- (48.2%), GAL- (8.6%), PA- (8.7%), CB- (8.5%) and CR-like (5.3%) immunoreactive cells were observed. In the distal vagal ganglia (nodose ganglia), CGRP- (40.5%), SP- (30.20%), CB- (22.0%) and CR-like (18.10%) immunoreactive cells were present. The double immunohistochemical study showed, that in the proximal vagal ganglia, CGRP immunoreactivity was co-localized in SP- (84.8%), GAL-(100%), CB- (5.6%) and CR- (5.7%) immunoreactive cells: SP immunoreactivity was co-localized in the CGRP- (80.0%), GAL- (100%). CB- (5.3%) and CR- (5.6%) immunoreactive cells; GAL immunoreactivity coexisted in the CGRP- (4.4%) and SP- (19.8%) immunoreactive cells, but not in calcium-binding proteins (CBP)-immunoreactive cells; PA immunoreactivity was absent in the CGRP- and SP-immunoreactive cells; CB and CR immunoreactivities were seen in the CGRP-(0.8%) and SP-immunoreactive (0.9%) cells. On the other hand, in the distal vagal ganglia, CGRP immunoreactivity appeared in SP- (66.6%), CB- (1.0%) and CR- (1.2%) immunoreactive cells; SP immunoreactivities were observed in the CGRP- (44.1%), CB- (1.0%) and CR- (1.2%) immunoreactive cells; CB immunoreactivities were present in the CGRP- (0.5%) and SP- (0.8%) immunoreactive cells; CR immunoreactivities were contained in the CGRP- (0.5%) and SP- (0.8%) immunoreactive cells. These findings indicate that the goat is distinct from other mammalian species in the distribution and localization of neurochemical substances in the vagal ganglia. and suggest that these differences may be related to physiological characteristics, particular those of the ruminant digestive system.     

Prevalence of some internal parasites recovered at necropsy of Thoroughbreds born in 1982 in Kentucky

A total of 89 Thoroughbreds, 14 to 333 days old (born in 1982), were examined at necropsy for certain internal parasites during a 1-year-period, Mar 1, 1982, to Feb 28, 1983. The eyes of 73 of the horses and the cranial mesenteric arteries of 71 were examined. Specific interest was on prevalence of parasites according to month of the year and age of the horses at necropsy. Parasites recovered (first month-last month infected horse found) were as follows: Thelazia lacrymalis (eyes) immature and mature (June - February); Habronema/Draschia (lungs) immature (May - September); Habronema muscae (stomach) immature (July - February) and mature (September - February); Draschia megastoma (stomach) immature (August - December), mature (August - February), and lesions (September - February); Gasterophilus intestinalis (stomach) 2nd instars (July - February) and 3rd instars (August - February); Gasterophilus nasalis (stomach) 2nd instars (August - November) and 3rd instars (August - February); Parascaris equorum (lungs) immature (March - November), P equorum (small intestine) immature (March - February), and mature (July - February); Strongyloides westeri (small intestine) mature (March - September); Anoplocephala perfoliata (cecum) immature and mature (August - February); Strongylus vulgaris (cranial mesenteric artery) immature and mature (May - February). Other parasites recovered, but only from 1 or 2 horses each (months found in infected horses) were: Thelazia skrjabini (eyes) (October), Dictyocaulus arnfieldi (lungs) (January); Trichostrongylus axei (stomach) (October); Anoplocephala magna (small intestine) (October, November); S vulgaris (cecum) (November); Strongylus edentatus (cecum) (January); Setaria spp (abdominal cavity) (January). Influence of probable chemotherapy of the horses on prevalence of the parasites is discussed.     

Tumor necrosis factor-α inhibits the stimulatory effect of luteinizing hormone and prostaglandin E(2) on progesterone secretion by the bovine corpus luteum

Tumor necrosis factor-α (TNF-α) is involved in the tissue remodeling that occurs in the corpus luteum (CL) during its development and regression. This cytokine is also implicated in the regulation of reproduction by its actions on ovarian steroidogenic cells. The aim of this study was to examine the influence of TNF-α on (1) progesterone (P(4)) output by the bovine CL and on (2) the responsiveness of the CL to LH or prostaglandin E(2) (PGE(2)) in vitro. In experiment 1, CL (days 8 to 10 of the estrous cycle) were perfused by using an in vitro microdialysis system with TNF-α (0.1, 0.5, or 1 μg/mL) alone or with TNF-α (1 μg/mL) followed by LH (1000 ng/mL) or PGE(2) (2 × 10(-5) M). Basal P(4) release (P < 0.05) was increased by TNF-α (0.5 or 1 μg/mL). Moreover, TNF-α (1 μg/mL) inhibited the stimulatory effect of LH or PGE(2) on P(4) output (P < 0.05). In experiment 2, 4 h after intrauterine infusion of TNF-α (0.01 μg/mL or 1 μg/mL), CL (days 8 to 10 of the estrous cycle) were collected by colpotomy, cultured, and stimulated with LH (10 ng/mL) or PGE(2) (10(-6) M). Intrauterine infusion of TNF-α at a concentration of 1 μg/mL increased basal P(4) output by CL (P < 0.05). Moreover, the intrauterine infusion of TNF-α at a concentration of 0.01 μg/mL inhibited the stimulatory effect of LH or PGE(2) on P(4) output (P < 0.05). These results indicate that TNF-α (1) does not have an effect on the autonomous, pulsatile release of P(4); (2) increases P(4) secretion by bovine CL with increasing doses, and (3) reduces in a dose-dependent manner the responsiveness of CL to luteotropic factors both directly (after infusion to CL) and indirectly (after intrauterine infusion).     

Effect of the ratio between essential and nonessential amino acids in the diet on utilization of nitrogen and amino acids by growing pigs.

In 36 growing pigs (30 to 60 kg), N balance and amino acid (AA) composition of weight gain were measured to evaluate the interactive effect of the ratio between N from essential amino acids (EAA(N)) to nonessential amino acids (NEAA(N)) and total N level (T(N)) in the diet on N retention and utilization of N, EAA(N), NEAA(N), and AA. Nine diets composed from ordinary feedstuffs and supplemented with crystalline AA were used (three EAA(N):NEAA(N) ratios of 38:62, 50:50, and 62:38 at three T(N) levels of 18.8, 22.9, and 30.0 g/kg). Pigs were fed restrictedly, at a level of 2.8 x energy for maintenance. In all diets, EAA (including arginine) supply was according to or slightly above the recommended ratios to lysine. Measurements were done in four blocks of nine pigs each. In a concomitant slaughter experiment, the AA composition of deposited body protein was determined to estimate AA utilization. The effects of T(N) and EAA(N):NEAA(N) and their interaction for N retention and utilization were significant. Nitrogen retention increased with higher T(N) in the diet. Increasing EAA(N):NEAA(N) from 38:62 to 50:50 improved N retention only at the two lower T(N) levels. Increasing EAA(N): NEAA(N) above 50:50 failed to improve N retention significantly at any of the three T(N) levels. Lowering T(N) improved the utilization of total and digested N and of EAA(N) and NEAA(N). The increase in EAA(N): NEAA(N) consistently resulted in a lower utilization of EAA(N), but this was compensated by a higher utilization of NEAA(N). The utilization of T(N) was improved by increasing EAA(N):NEAA(N) from 38:62 to 50:50 at the two lower T(N) levels and was relatively unaffected by EAA(N):NEAA(N) at the highest T(N). However, a lower utilization of N was observed at a ratio of 62:38 at a T(N) level of 22.9 g/kg. The effects were similar for utilization of individual EAA and NEAA. Utilization of alanine, aspartic acid, and glycine was close to or >100% at the highest EAA(N):NEAA(N), which was expected because all of these AA are synthesized in pigs. Also, the utilization of arginine was >100% in most of the treatments, which confirms the semiessential character of this AA for maintenance. We concluded that the required ratio of EAA(N):NEAA(N) for optimal N retention and utilization is approximately 50:50. The EAA(N):NEAA(N) is more important at lower dietary protein levels. This study indicates that EAA(N): NEAA(N) can be increased up to 70:30 without lowering the utilization of N. Thus, deaminated EAA(N) was efficiently utilized for the synthesis of NEAA(N).     

Successful Low Dose Insemination of Flow Cytometrically Sorted Ram Spermatozoa in Sheep

The fertility of ram spermatozoa that had undergone flow cytometric sorting (MoFlo SX) and cryopreservation was assessed after low-dose insemination of synchronized Merino ewes. Oestrus was synchronized with progestagen-impregnated pessaries, PMSG and GnRH treatment. Ewes (n = 360) were inseminated with 1 x 10(6), 5 x 10(6) or 15 x 10(6) motile sorted frozen-thawed (S(1), S(5), or S(15) respectively) or non-sorted frozen-thawed (C(1), C(5) or C(15) respectively) spermatozoa from three rams. An additional group of ewes were inseminated with 50 x 10(6) motile non-sorted frozen-thawed spermatozoa (C(50)) to provide a commercial dose control. The percentage of ewes lambing after insemination was similar for C(50) (24/38, 63.2%), C(15) (37/54, 68.5%), S(15) (38/57, 66.7%), S(5) (37/56, 66.1%) and S(1) (32/52, 61.5%) groups (p > 0.05), but lower for C(5) (19/48, 39.6%) and C(1) (19/55, 34.5%) treatments (p < 0.05). This study demonstrates sorted ram spermatozoa are equally fertile to non-sorted spermatozoa even when inseminated at 2% of the dose. Furthermore, at very low artificial insemination doses (1 or 5 million motile) the fertility of sorted ram spermatozoa is superior to non-sorted spermatozoa inseminated in equal numbers. These results have significance for the future commercialization of sex-preselection technology in sheep as a reduction in the minimum effective sperm number will allow a corresponding decrease in the associated cost per dose.     

谷氨酰胺对黄颡鱼幼鱼抗氧化能力和非特异性免疫力的影响

本试验旨在研究谷氨酰胺对黄颡鱼幼鱼抗氧化能力及非特异性免疫力的影响。选取平均体重为(2.49±0.04)g的黄颡鱼幼鱼240尾,随机分为4组,每组3个重复,每个重复20尾。4组试验鱼分别饲喂谷氨酰胺添加量为0(对照)、0.1%、0.2%、0.4%的等氮等能试验饲料。试验期为10周。结果表明:饲料中添加0.2%的谷氨酰胺可以显著提高黄颡鱼幼鱼的血清总蛋白、球蛋白、甘油三酯、高密度脂蛋白和低密度脂蛋白含量(P0.05);各组黄颡鱼幼鱼的血清谷丙转氨酶、谷草转氨酶和碱性磷酸酶活性差异不显著(P0.05);饲料中添加0.1%的谷氨酰胺可以显著提高黄颡鱼幼鱼肝脏中过氧化氢酶、谷胱甘肽过氧化物酶及肌肉中超氧化物歧化酶、谷胱甘肽过氧化物酶的活性(P0.05);随着饲料中谷氨酰胺添加量的增加,头肾巨噬细胞的吞噬指数呈升高趋势,且0.2%和0.4%组较对照组显著升高(P0.05),但0.2%和0.4%组间差异不显著(P0.05)。由此可见,饲料中添加0.1%~0.2%的谷氨酰胺能够提高机体的抗氧化能力和非特异性免疫力。     

伊氏锥虫安锥赛抗药性相关基因-TbTA1的分析

为探讨伊氏锥虫对安锥赛抗药性的分子机理，以布氏锥虫对砷剂药物抗药性相关的TbTA1基因设计引物，以55℃、57℃、60℃、63℃和65℃不同退火温度，分别从伊氏锥虫敏感株的cDNA和基因组DNA中扩增出TbTA1基因的全长序列，但是从安锥赛抗药株伊氏锥虫的cDNA和基因组DNA中都未扩增出TbTA1基因，这表明基因TbTA1可能与伊氏锥虫安锥赛抗药性的产生有关。伊氏锥虫与布氏锥虫的，TbTA1基因序列比较，它们有10个碱基不同，即第88位的G（T.e）-A（T.b）、第144位的T（T．e）-C（T．b）、第224位的C（T．e）-T（T．b）、第471位的C（T.e）-T（T.b）、第472位的A（T．e）-G（T.b）、第549位的G（T．e）-T（T．b）、第1008位的C（T．e）-T（T.b）、第1033位的A（T．e）-G（T．b）、第1293位的A（T．e）-G（T．b）和第1384位的T（T．e）-C（T．b），其中有5个碱基所编码的氨基酸不同，即Val^30（T.e）Ile（T．b）、Ala^75（T．e）-Val（T．b）、Ile^158（T．e）-Val（T．b）、Thr^345（T．e）-Ala（T．b）和Ser^462（T.e）-Pro（T．b），这表明伊氏锥虫与布氏锥虫的TbTA1差异可能是它们的种间差异。