Pharmacokinetics of boldenone and stanozolol and the results of quantification of anabolic and androgenic steroids in race horses and nonrace horses

Anabolic steroids (ABS) boldenone (BL; 1.1 mg/kg) and stanozolol (ST; 0.55 mg/kg) were administered i.m. to horses and the plasma samples collected up to 64 days. Anabolic steroids and androgenic steroids (ANS) in plasma were quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The limit of detection of all analytes was 25 pg/mL. The median absorption (t1/2 partial differential) and elimination (t1/2e) half-lives for BL were 8.5 h and 123.0 h, respectively, and the area under the plasma concentration-time curve (AUCho) was 274.8 ng.h/mL. The median t1/2e for ST was 82.1 h and the was 700.1 ng.h/mL. Peak mean (X+/-SD) plasma concentrations (Cmax) for BL and ST were 1127.8 and 4118.2 pg/mL, respectively. Quantifiable concentrations of ABS and ANS were found in 61.7% of the 988 plasma samples tested from race tracks. In 17.3% of the plasma samples two or more ABS or ANS were quantifiable. Testosterone (TES) concentrations mean (X+/-SE) in racing and nonracing intact males were 241.3+/-61.3 and 490.4+/-35.1 pg/mL, respectively. TES was not quantified in nonracing geldings and female horses, but was in racing females and geldings. Plasma concentrations of endogenous 19-nortestosterone (nandrolone; NA) from racing and nonracing males were 50.2+/-5.5 and 71.8+/-4.6 pg/mL, respectively.     

金川牦牛肋数、年龄对血清、被毛矿物元素含量的影响及血清与被毛矿物元素含量的相关性

本试验旨在分析金川县牦牛血清和被毛的矿物元素含量,探讨肋数和年龄对矿物元素含量的影响,并对被毛矿物元素含量与血清中相应元素含量的相关性进行分析。采用二因素有重复试验设计,将32只公牦牛进行分组,按照肋数[14肋(n=17)和15肋(n=15)]和年龄[0(初生)~2岁(n=10)、3~4岁(n=11)、5~6岁(n=5)、7~8岁(n=6)]共分为8组。分别采集血清及被毛样品,进行矿物元素含量分析。结果表明:1)肋数、年龄对血清中的钙(Ca)、铜(Cu)、铁(Fe)、钾(K)、镁(Mg)、锰(Mn)、钠(Na)、锌(Zn)的含量均无显著影响(P0.05);年龄和肋数间无互作(P0.05)。2)肋数对被毛Ca、Cu、Fe、Mg、Mn、Na、Zn含量无显著影响(P0.05);年龄可影响被毛K含量,7~8岁被毛K含量显著高于其他年龄段(P0.05),但对被毛其他元素含量均无显著影响(P0.05),年龄和肋数间无互作(P0.05)。3)被毛Ca、Cu、Fe、Mg、Zn与血清中相应元素含量相关性极显著(P0.01),相关系数分别为0.623 0、0.539 8、0.569 2、0.468 4、0.505 3,而K、M n、Na含量的相关性则不显著(P0.05)。综合可知,金川14肋与15肋牦牛矿物元素含量无显著差异;7~8岁被毛中的K含量显著升高;牦牛被毛、血清Ca、Cu、Fe、M g、Zn含量具有显著的相关性,可由被毛代替血清测定相应的矿物元素含量。     

The influence of duration of photoperiod and hemicastration on growth and testicular and endocrine functions of boars

Yorkshire boars were used to evaluate the influence of duration of photoperiod and hemicastration on growth and testicular and endocrine functions. At 10 wk of age, 5 hemicastrate (HC) and 5 intact (I) boars were assigned to either 8 or 16 hr of light daily until 6 mo of age. Body weights were recorded biweekly throughout the experiment. Venous cannulae were placed in all boars at 6 mo of age, and serum was collected at 30 min intervals from 0800 to 2000 hr. Gonadotropin releasing hormone (GnRH) was infused at 2000 hr (50 micrograms) and at 2030 hr (250 micrograms), and samples of serum were collected until 2400 hr. The following day, all boars were castrated, and the weights and sperm content of the testes and epididymides were determined. At castration, all pigs were given implants containing testosterone. Two weeks later, pigs were again canulated, and serum was obtained at 15 min intervals for 2 hr. Growth of boars was not significantly affected by duration of photoperiod or number of testes. Duration of photoperiod did not affect weight or sperm content of testes or epididymides. Hemi-castrated boars had greater testicular (P less than .01) and capita-corpora (C-C) epididymal weights (P less than .05) and more testicular and C-C sperm (P less than .01) per testis. Neither average concentrations of luteinizing hormone (LH) nor number and amplitude of pulses of LH were affected by photoperiod treatment. However, HC boars had greater average concentrations of LH (P less than .05) than I boars (.71 +/- .05 vs .52 +/- .05 ng/ml). Hemicastrated boars in 16 hr light daily had greater concentrations of FSH in serum (P less than .05) than 8I, 8HC, and 16I boars. Intact and HC boars had similar concentrations of prolactin (PRL) and testosterone. Similarly, concentrations of PRL and testosterone were not affected by duration of photoperiod. Secretion of LH and testosterone after treatment with GnRH was not significantly affected by duration of photoperiod. In general, HC boars released more LH in response to GnRH treatment than I boars. Concentrations of LH were greater (P less than .05) in HC than I boars at .5, 1, 2, and 3 hr after GnRH and tended (P less than .10) to be elevated at 1.5, 2.5, 3.5 and 4 hr after GnRH. The FSH response to GnRH was greater (P less than .05) for 16HC than 8I, 8HC, or 16I boars.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effect of source and amount of energy and rate of growth in the growing phase on performance and carcass characteristics of early- and normal-weaned steers

One hundred eighty-four Angus x Simmental steers (initial BW 161.7 +/- 3.4 kg) were used to determine whether different sources and amounts of energy in the growing phase could extend the growth curve and maintain high amounts of intramuscular fat deposition in early-weaned steers. Steers were allotted by source, age, and BW to one of four growing-phase (119 to 259 d of age) regimens. For three regimens, steers were weaned at 119 d of age and either 1) fed (DM basis) a 50% grain diet ad libitum (ALC); 2) limit-fed a 70% grain diet to achieve a gain of 0.8 kg/d from 119 to 192 d of age, and 1.2 kg/d from 193 to 259 d of age (LFC); or 3) fed a 60% haylage diet ad libitum from 119 to 192 d of age, and a 25% haylage diet ad libitum from 193 to 259 d of age (ALF). For the fourth regimen, steers were normal-weaned at 204 d of age and fed a silage diet from 205 to 259 d of age (NW). From 260 d of age to slaughter, all steers consumed a 70% grain (DM basis) diet. Limit-fed and ALF steers spent the most, and NW the least amount of time (P < 0.01) in the feedlot to achieve a target fat depth of 1.27 cm. Ad libitum-fed steers were the youngest (331 d), and NW the oldest (383 d) at slaughter (P < 0.01). Overall ADG was greatest for ALC and least for NW steers (P < 0.01). Overall, ALF steers consumed the most DM (P < 0.01). While in the feedlot, LFC and ALC steers were more efficient in converting feed to BW gain (P < 0.01) than ALF and NW steers. Normal-weaned had the least and ALC the greatest (P < 0.01) fat depth at 260 d of age. Consequently, NW steers produced the heaviest, and ALC the lightest (P < 0.01) carcasses at slaughter. Normal-weaned steers had the largest, and ALC and LFC steers had the smallest longissimus muscle area (P < 0.06). Growing phase dietary treatments did not affect (P > 0.20) yield grade. Marbling score did not differ (P > 0.35), but laboratory analysis revealed that ALC steers had the lowest percentage of fat (P < 0.02) in the longissimus muscle. Shear force was greatest (P < 0.08) for steaks from ALC and LFC steers, and least for steaks from ALF and NW steers. Feeding steers the ALC diet from 119 to 260 d of age hastened physiological maturity, decreased marbling scores, and decreased muscle tenderness compared with forage feeding (ALF, NW). Limit-feeding a high-grain diet also hastened physiological maturity and decreased muscle tenderness but did not decrease marbling scores. Source and amount of energy affected partitioning of fat deposition.     

肉鸡腹水症对组织钙磷分布及钙磷利用率的影响

本试验研究了肉鸡腹水症(PHS)对组织钙磷分布及饲料钙磷利用率的影响。120只1日龄艾维茵(AA)肉鸡随机分成2组,即对照组和试验组,每组6个重复,每个重复10只鸡。试验组采用低温(LAT)和饲粮添加三碘甲腺原氨酸(T3,1.5mg/kg)诱导产生腹水症。试验期为21d。试验结果表明:1)14日龄时,试验组肉鸡的心脏、肝脏、十二指肠中钙含量与对照组相比,有增加趋势,胫骨、血清钙有下降趋势,但差异均不显著(P>0.05)。试验组肉鸡的心脏磷含量极显著低于对照组(P<0.01),十二指肠磷含量显著高于对照组(P<0.05)。饲料中钙磷利用率,试验组极显著低于对照组(P<0.01)。2)21日龄时,试验组肉鸡的心脏、肝脏中的钙含量显著高于对照组(P<0.05)。十二指肠、胫骨、血清中的钙含量两组间无显著差异(P>0.05)。十二指肠、血清磷含量试验组显著高于对照组(P<0.05),其余组织磷含量两组间无显著差异(P>0.05)。饲料中钙磷利用率,试验组极显著低于对照组(P<0.01)。3)血清碱性磷酸酶含量14、21日龄试验组和对照组差异均不显著(P>0.05)。     

Blood levels of hormones and metabolites, erythrocytes and leukocytes and respiration and pulse rate of heifers after alpage

High-altitude grazing, at or above the timberline in summer months continues to be important in alpine regions of Europe, where about 80% of young stock spend much of the three summer months on these pastures. Apart from direct utilization of these resources and saving of feed in the home farms, alped cattle are said to have greater longevity and better growth, i.e. they display compensatory growth. K& uuml ; nzi et al. (1988), S uttner (1980) and R uhland (1983) reported that heifers which spent one or two summers on alpine pastures, have, as cows in intra-herd comparisons, about one lactation more than homegrown heifers. Compensatory growth after alpage was reported by these authors, by B ianca (1977), W eilenmann -B ossart (1988) and other authors. The effects of alpine sojourn on physiological and biochemical traits were investigated by B ianca and E spinosa (1975), B ossart et al. (loc. cit.), K rippl et al. (1961) and S uttner (1980). This investigation concerns the comparative effects of alpine pasture and farm feeding on subsequent physiological and biochemical traits.     

生物炭与化肥配施对紫色土肥力与微生物特征及油菜产量品质的影响

研究不同梯度的生物炭与常规施肥、减量施肥相配合对紫色土肥力与微生物特征及油菜产量品质的影响,为实际生产中制定生物炭与化肥的配施方案提供理论参考。依托西南地区特有的紫色土,采用裂区试验设计,试验处理包括:B₀F₁ (不施生物炭+减量肥)、B₀F₂(不施生物炭+全量肥)、B₁F₁(低量生物炭+减量肥)、B₁F₂(低量生物炭+全量肥)、B₂F₁(高量生物炭+减量肥)、B₂F₂(高量生物炭+全量肥)。结果表明:生物炭改良后的土壤全碳、全氮、全钾、阳离子交换量(CEC)、pH显著高于B₀处理,且F₁各土壤肥力指标水平与F₂相近。生物炭的输入提升了土壤微生物Shannon多样性指数(H)、Simpson 优势度指数(D)、碳源利用丰富度指数(S),促进了根际微生物对糖类、氨基酸类、羧酸类、聚合物类、酚酸类碳源的利用程度。生物炭有效提高了油菜产量,在F₁水平下,生物炭的施用显著降低籽粒中芥酸、硫苷、亚麻酸的含量,提升了高油酸、油酸、黄籽度水平。冗余分析(RDA)结果显示,对油菜品质指标的重要性排序为:全钾>全碳>全氮>全磷>CEC>pH。其中,全钾、全碳、全氮、全磷对籽粒品质有显著影响(P<0.05)。总之,生物炭与化肥联合施用可显著改善土壤肥力状况,提升土壤微生物活性,促进了微生物对碳源的利用程度。生物炭的施用量以35 t·hm^-2为宜,可有效弥补化肥减量后的养分亏缺,促进油菜增产和籽粒品质的改良。     

T细胞的发育分化及胸腺激素的作用

胸腺既是免疫器官,又是内分泌器官。胸腺是T淋巴细胞发育、分化和成熟的场所。原胸腺细胞,经过前胸腺细胞、CD4-CD8-双阴性细胞、CD4 CD8 双阳性细胞以及CD4 CD8-或CD4- CD8 两个单阳性胸腺细胞亚群共5 个阶段,发育分化为成熟的T淋巴细胞。胸腺微环境是T淋巴细胞发育分化的重要条件。胸腺上皮细胞分泌产生的胸腺激素在T淋巴细胞发育分化过程中起重要作用。文章着重综述了T淋巴细胞发育分化过程及胸腺激素的生化性质和生物学功能。     

Effect of chromium picolinate and chromium propionate on glucose and insulin kinetics of growing barrows and on growth and carcass traits of growing-finishing barrows

Two experiments were conducted to determine the effects of dietary Cr tripicolinate (CrPic) or Cr propionate (CrProp) on growth, carcass traits, plasma metabolites, glucose tolerance, and insulin sensitivity in pigs. In Exp. 1, 36 barrows (12 per treatment; initial and final BW were 20 and 38 kg) were allotted to the following treatments: 1) corn-soybean meal basal diet (control), 2) as 1 + 200 ppb Cr as CrPic, or 3) as 1 + 200 ppb Cr as CrProp. Growth performance data were collected for 28 d, and then 23 pigs (seven, eight, and eight pigs for treatments 1, 2, and 3, respectively) were fitted with jugular catheters and a glucose tolerance test (500 mg glucose/kg BW) and an insulin challenge test (0.1 IU of porcine insulin/kg BW) were conducted. Both CrPic and CrProp decreased (P < 0.05) ADG and ADFI but did not affect gain:feed (P > 0.10). Fasting plasma glucose, total cholesterol, urea N, insulin, and high-density lipoprotein cholesterol:total cholesterol concentrations were not affected (P > 0.10) by either Cr source. Pigs fed CrPic had lower (P < 0.02) fasting plasma NEFA concentrations than control pigs, but plasma NEFA concentrations of pigs fed CrProp were not affected (P > 0.10). During the glucose tolerance test, glucose and insulin kinetics were not affected by treatment (P > 0.10). During the insulin challenge test, glucose clearance was increased (P < 0.01) in pigs fed CrProp but not affected (P > 0.10) in pigs fed CrPic. Glucose half-life was decreased (P < 0.03) in pigs fed CrPic or CrProp, but insulin kinetics were not affected (P > 0.10). In Exp. 2, 48 barrows (four replicates of four pigs per replicate; initial and final BW were 23 and 115 kg) were allotted to the same dietary treatments in a growing-finishing study. Average daily gain, ADFI, and gain:feed were not affected (P > 0.10) by treatments. Carcass length tended (P = 0.10) to be greater in pigs fed CrPic than in pigs fed CrProp, but other carcass measurements were not affected (P > 0.10). Glucose kinetics from the insulin challenge test indicate that both CrPic and CrProp increase insulin sensitivity and that both Cr sources are bioavailable.     

Genetic and phenotypic relationships of feed intake and measures of efficiency with growth and carcass merit of beef cattle

Feed intake and efficiency of growth are economically important traits of beef cattle. This study determined the relationships of daily DMI, feed:gain ratio [F:G, which is the reciprocal of the efficiency of gain (G:F) and therefore increases as the efficiency of gain decreases and vice versa, residual feed intake (RFI), and partial efficiency of growth (efficiency of ADG, PEG) with growth and carcass merit of beef cattle. Residual feed intake was calculated from phenotypic regression (RFIp) or genetic regression (RFIg) of ADG and metabolic BW on DMI. An F1 half-sib pedigree file containing 28 sires, 321 dams, and 464 progeny produced from crosses between Alberta Hybrid cows and Angus, Charolais, or Alberta Hybrid bulls was used. Families averaged 20 progeny per sire (range = 3 to 56). Performance, ultrasound, and DMI data was available on all progeny, of which 381 had carcass data. Phenotypic and genetic parameters were obtained using SAS and ASREML software, respectively. Differences in RFIp and RFIg, respectively, between the most and least efficient steers (i.e., steers with the lowest PEG) were 5.59 and 6.84 kg of DM/d. Heritabilities for DMI, F:G, PEG, RFIp, and RFIg were 0.54 +/- 0.15, 0.41 +/- 0.15, 0.56 +/- 0.16, 0.21 +/- 0.12, and 0.42 +/- 0.15, respectively. The genetic (r = 0.92) and phenotypic (r = 0.97) correlations between RFIp and RFIg indicated that the 2 indices are very similar. Both indices of RFI were favorably correlated phenotypically (P < 0.001) and genetically with DMI, F:G, and PEG. Residual feed intake was tendentiously genetically correlated with ADG (r = 0.46 +/- 0.45) and metabolic BW (r = 0.27 +/- 0.33), albeit with high SE. Genetically, RFIg was independent of ADG and BW but showed a phenotypic correlation with ADG (r = -0.21; P < 0.05). Daily DMI was correlated genetically (r = 0.28) and phenotypically (r = 0.30) with F:G. Both DMI and F:G were strongly correlated with ADG (r > 0.50), but only DMI had strong genetic (r = 0.87 +/- 0.10) and phenotypic (r = 0.65) correlations with metabolic BW. Generally, the phenotypic and genetic correlations of RFI with carcass merit were not different from zero, except genetic correlations of RFI with ultrasound and carcass LM area and carcass lean yield and phenotypic correlations of RFI with backfat thickness (P < 0.01). Daily DMI had moderate to high phenotypic (P < 0.01) and genetic correlations with all the ultrasound and carcass traits. Depending on how RFI technology is applied, adjustment for body composition in addition to growth may be required to minimize the potential for correlated responses to selection in cattle.     

Effect of wheat and high-moisture sorghum grain fed singly and in combination on ruminal fermentation, solid and liquid flow, site and extent of digestion and feeding performance of cattle

Two experiments were conducted to determine how varying the proportion of wheat (W) and high-moisture sorghum grain (SG) in 80% grain dies would affect ruminal fermentation, liquid and solid flow, site and extent of digestion (Exp. 1) and feeding performance of cattle (Exp. 2). In Exp. 1, three ruminal, duodenal and ileal cannulated steers (average weight 295 kg), fed at 1.54% of body weight, were used in a six-period crossover design. Treatments were: W, 50W:50SG (W:SG) and SG. Increasing wheat level decreased ruminal pH, molar proportion of acetate, and acetate:propionate ratio (P less than .05) and increased (P less than .05) L-lactate concentration, molar proportions of propionate and valerate and total volatile fatty acid concentration. Ruminal liquid dilution and outflow rates were faster (P less than .05) and retention time was shorter (P less than .05) for the W diet. Duodenal and ileal liquid flow increased (P less than .05), and solid flow decreased (P less than .05), as dietary level of wheat increased. Apparent ruminal digestion (% of intake) of dry matter (DM) and organic matter (OM) was greater (P less than .01) with the wheat-containing diets. Intestinal DM and OM digestion (percent of intake) was higher (P less than .05) with the SG and W:SG diets. Ruminal, small intestine, large intestine and total tract starch digestion (percent of intake) was 93.5, 5.6, .7, 99.8, 71.5, 20.4, 5.7, 97.6; and 48.0, 32.5, 10.5, 91.0 with the W, W:SG and SG diets, respectively. In Exp. 2, group-fed (24 pens) steers (avg initial weight 341 kg) were fed ad libitum once daily for 121 d. Treatments were: W, 67W:33SG, 33W:67SG and SG. Rates of gain (kg/d) with the W (1.32), 67W:37SG (1.33) and 33W:67SG (1.30) diets were similar (P greater than .05), but faster (P less than .05) than those with the SG diet (1.16). Feed intake was lower (P less than .01) with the W and 67W:33SG diets, but the wheat-containing diets were utilized more efficiently (P less than .01). Increasing the proportion of wheat in sorghum grain feedlot diets improved cattle performance by optimizing ruminal and post-ruminal digestion.     

Effect of season and location on semen quality and serum concentrations of luteinizing hormone and testosterone in Brahman and Hereford bulls

Hereford bulls from Montana (MH; n = 15) and Nebraska (NH; n = 15) and Brahman bulls from Texas (BB; n = 18) were relocated to one of three locations (LOC): Montana (MT), Nebraska (NE) or Texas (TX). All bulls were pubertal at the time of relocation in late May 1984. Semen was collected by electroejaculation within 1 wk after relocation and at 90-d intervals beginning in November 1984 through early February 1986. Bulls were given a GnRH challenge (200 micrograms i.m.) during the same week of semen collections. Bulls also were bled for 8 h at 20-min intervals in the fall of 1984 and the spring and fall of 1985 to determine endogenous concentrations of LH and testosterone. Season affected sperm concentration in all breeds (P less than .05) with decreases during the winter in BB and during the summer in NH and MH bulls. Brahman bulls had lower percentage of live cells (LIVE) than NH and MH bulls did (P less than .0001). Brahman bulls decreased in LIVE during the winter (P less than .001). Area under the LH curve after GnRH was lower (P less than .005) in BB than in MH and NH. Brahman bulls in MT had greater (P less than .02) area under the LH curve and lower (P less than .06) area under the testosterone curve than did BB in TX or NE during the winter. There was no seasonal fluctuation in LH or testosterone response to GnRH in NH or MH bulls at any LOC. Area under the endogenous LH curve was lowest (P less than .04) in BB. Basal endogenous testosterone concentration was greater (P less than .03) in NH than in MH or BB. Area under the endogenous testosterone curve was lower (P less than .03) in MH than in NH or BB. These results indicate that BB exhibit seasonal fluctuations in semen quality. This was not so apparent in semen quality traits of Hereford bulls. There also was a seasonal influence in BB on both endogenous testosterone and GnRH-stimulated LH and testosterone concentrations. Compared with Hereford bulls, Brahman bulls had lower endogenous and GnRH-stimulated concentrations of LH.     

植酸酶和柠檬酸对肉鸡生产性能及钙、磷利用率的影响

试验以正常营养水平饲粮为对照 ,研究在低营养水平饲粮中添加植酸酶 (0、 30 0g/t)、柠檬酸 (0、 0 5% )对肉鸡生产性能和钙、磷利用率的影响。试验用 2 2 5羽 1日龄黄羽肉鸡随机分为 5个处理 ,每处理 3个重复 ,每重复 1 5只鸡进行 6周试验。结果饲粮营养水平降低 6 %可导致肉鸡日增重 (ADG)和饲料利用率下降 (P <0 0 5) ;在低营养水平日粮中 ,添加 30 0g/t植酸酶、 0 5 %柠檬酸 ,ADG和料肉比 (F/G)与正常营养水平饲粮组差异不显著 (P >0 0 5) ;各处理组的血清Ca、P、AKP活性及胫骨Ca、P差异不显著 (P >0 0 5) ;腿病发生率各处理组差异不显著 (P >0 0 5)。添加 30 0g/t植酸酶、 0 5 %柠檬酸的处理组P排泄量显著低于对照组 (P <0 0 5)。植酸酶与柠檬酸合用能进一步提高生产性能和钙、磷利用率 ,能达到正常营养水平饲粮的效果。植酸酶与柠檬酸合用存在协同效应     

Estimations of repeatability and heritability of egg albumen antimicrobial activity and of lysozyme and ovotransferrin concentrations

1. The repeatability and heritability of growth inhibition by egg albumen of two major pathogenic bacteria, a Gram-negative (Salmonella Enteritidis) and a Gram-positive (Staphyloccocus aureus) and of two antimicrobial albumen proteins, lysozyme and ovotransferrin, were estimated in commercial pedigree hens. 2. Repeatability was evaluated in 100 egg-type hens at the beginning, middle and end of the laying cycle on eggs collected for 3 weeks. Heritabilities were estimated at 36 to 40 weeks of age on 400 pedigree hens (2 eggs/hen), which were the offspring of 25 sires each mated with 4 dams. Ovotransferrin and lysozyme were quantified by ELISA. Salmonella Enteritidis (S.E.) and Staphyloccocus aureus (S.A.) were inoculated into a sample of sterilised albumen and enumerated after incubation. 3. Total protein content in albumen decreased with age of laying hens, whereas there were increases in lysozyme or ovotransferrin concentrations and in the bacteriostatic effect of albumen. 4. Repeatability for bacterial growth in albumen ranged from 0.29 to 0.39 for the number of S.E. (log cfu/ml) one day post inoculation (p.i.) but was lower and more variable at 5 d p.i. or for S.A. number. It ranged from 0.27 to 0.38 for S.E. and S.A. number at the mid period of the laying cycle. Repeatabilities were low and variable for total egg albumen protein or lysozyme and ovotranferrin concentrations (0 to 0.22). 5. Negative phenotypic correlations were observed between lysozyme concentrations and S.E. number but that between lysozyme and S.A. number was not significant. 6. Heritabilities were low (0.01 to 0.09) for protein traits. They were 0.11 for S.A. number and 0.16 for S.E. number one day p.i. 7. It appears to be more efficient to select on global bacterial growth than on specific antimicrobial proteins. The most promising trait is the number of S.E. one day p.i.     

Influence of L-Carnitine on Performance and Ruminal and Blood Metabolites of Grazing Calves and Finishing Lambs

Three experiments were conducted to study the influence of level and type of L-carnitine (LC) on performance and rumiasl and plasma metabolites of weanling calves and finishing lambs. Weanling calves (84) grazing dormant dallisgrass-bermudagrass forage were fed a 20% CP supplement to provide 0, 0.5, 1, or 2 g of ruminally unprotected (RUP) LC per calf daily in Exp. 1. There was a linear increase (P=0.01) and cubic response (P=0.03) to RUP LC in growth rate and quadratic changes (P=0.01) in plasma ammonia N (PAN) and plasma urea N (PUN). In Exp. 2, 32 lambs were individually fed 14% CP diets containing 0, 50, 100, or 200 ppm RUP LC or ruminally protected (RP) LC in a 2 × 4 arrangement of treatments. Lambs gained BW faster (P=0.03) and more efficiently (P=0.07) as the LC level increased to 100 ppm and then declined at 200 ppm (quadratic response). Longissimus area decreased (P=0.03), and fat cover tended (P=0.15) to decline, at 50 and 100 ppm LC and increased at 200 ppm (linear and quadratic response). Ruminal ammonia N levels were reduced at 50 ppm LC but increased at greater LC levels (linear, quadratic, and cubic response, P=0.02). Plasma carnitine concentrations increased (P=0.01) as the dietary level of LC increased. Protected LC was more effective than RUP LC in increasing growth rate (P=0.06) and reducing PAN (P=0.1). In Exp. 3, 16 wether and 16 ewe lambs were individually fed corn-based or soybean hull-based diets with 0 or 100 ppm RP LC in a 2 × 2 arrangement of treatments. Lambs fed RP LC gained BW faster and more efficiently (P=0.04) than lambs that were not fed LC. Lambs fed corn-based and soybean hull-based diets responded similarly to RP LC; however, performance was greater (P=0.03) for lambs fed the corn-based diet. Gender of lambs did not influence the response to diet or RP LC. Supplementing the diet with 100 ppm RP LC reduced (P=0.01) ruminal pH and ammonia N. Plasma carnitine concentrations were increased (P=0.01), and PAN was decreased (P=0.04) by feeding 100 ppm RP LC. Ruminnaly unprotected and RP LC were effective in improving growth rate in ruminants; the latter appeared to be more effective in finishing lambs. L-carnitine reduced ruminal ammonia N and plasma glucose and, in some cases, PAN and PUN.     

Impact of energy intake and pregnancy status on rate and efficiency of gain and backfat changes of sows postweaning

A collaborative study was conducted to evaluate factors related to determining optimal feeding and management programs for increasing net returns from marketing cull sows. A total of 269 multiparous sows averaging 192 kg of body weight were weaned, moved to individual gestation crates, and assigned to one of eight treatment combinations in a 2 x 2 x 2 factorial arrangement for a 42-d postweaning feeding experiment. Factors included limited (L) (1.8 kg/sow/d) or ad libitum (AL) access to feed during wk 1 postweaning, a corn-soybean meal (corn) or barley-sunflower meal (barley) diet, and pregnant or nonpregnant status. All sows were provided ad libitum access to feed from wk 2 to 6 postweaning. Gain and feed intake (FI) data were collected weekly for each sow and used to calculate gain:feed (G/F). Ultrasonic backfat (BF) data were collected on d 0, 21, and 42 postweaning. Sows on the AL treatment had greater FI (P < 0.05) but similar gain (P = 0.80) for the 42-d postweaning period compared to sows on the L treatment. Most of this response was due to lower sow body weight loss during wk 1 postweaning (P < 0.01) when sows were provided AL (-7.2 kg) vs L (-13.2 kg) access to feed. Sows fed the corn diet had higher gain (P < 0.01), improved G/F (P < 0.01), and increased BF (P < 0.01) over the 42-d feeding period than sows fed barley. The corn diet resulted in less sow BW loss (P < 0.01) during wk 1 (-8.8 kg) than the barley diet (-11.6 kg). Pregnant sows had higher gain, FI, G/ F, and BF (P < 0.01) than nonpregnant sows over the 42-d feeding period. Most of this advantage occurred during wk 4 postweaning when FI and gain of nonpregnant sows was lower (P < 0.01) than for pregnant sows. An economic analysis indicated that, when cull sow prices are relatively high and feed prices are moderate to low, maintaining and managing cull sows for an additional 6 wk postweaning may be economically advantageous compared to 0 or 3 wk. Pregnant sows fed the corn diet produced the greatest economic return. These results suggest that mating sows as they return to estrus postweaning and providing ad libitum access to a corn-soybean meal diet improves growth performance and feed efficiency, and may thereby provide increased returns when marketing cull sows.     

Effects of homozygosity and stress on blood and bone calcium and magnesium

SUMMARY: The effect of homozygosity (measured by inbreeding coefficient) on the concentration of serum Ca and Mg ions as well as Mg ions concentrations in whole blood and bone tissue Mg and Ca content was studied. Wild Norway rats (Rattus norvegicus Erxleben) were crossbred with albino outbred rats (Ipf:RIZ). F]-hybrids constituted the control group (0% of inbred). Using full-sibs mating, rats of 50% and 91% of inbred were reproduced. Half of each group was exposed to physical stress (PS) involving 3 d starvation, 3 h swimming and ether anaesthesia (to collect blood for examination), the other half was given only ether anaesthesia (ES). A significant (p < 0,01) linear decrease was observed in the concentration of Ca and Mg ions in serum, of Mg and Ca ions in bone tissue due to homozygosity increase, and a quadratic decrease of Mg content in whole blood. A considerable effect of the sex on Ca and Mg ion concentrations in serum, in particular under the conditions of severe physical stress was observed as well. Physical stress differentiated significantly Mg ion content in whole blood and serum. ZUSAMMENFASSUNG: Die Senkung der Konzentration von Calcium und Magnesium im Blut und im Knochengewebe bei Ratten durch Homozygotie und Stre? Bei Ratten unterschiedlichen Inzuchtgrades (%): 0, 59 und 91 wurden unter physischem Stre? (3 Tage Hungern und 3 h Schwimmen) mittels RIA die Konzentrationen von Calcium und Magnesium Ionen im Blutserum, Mg im ganzen Blut und Mg und Ca im Knochengewebe untersucht. Der Ausgangselternbestand (0% Inzucht) waren F(1) -Kreuzungen von wilden Wanderratten (Rattus norvegius Erxleben) mit Albino Ratten der nichtverwandten Linie Ipf:RIZ. Es wurde statistisch signifikante lineare Senkung der Konzentration von Ca und Mg Ionen im Blutserum, von Mg und Ca im Knochengewebe sowie (P ≤ 0,01) der Mg Konzentration im ganzen Blut unter dem Einflu? der Inzucht gefunden. Letztere folgt einem Polynom 2. Grades. Es wurde auch ein signifikanter Einflu? von Geschlecht auf Ca und Mg Ionen Konzentration im Blutserum, besonders bei dem starken physischen Stre?, beobachtet. Der physische Stre? hat gro?en Einflu? (P ≤ 0,01) auf Mg Konzentration im Blutserum sowie im ganzen Blut.     

Identification of subpopulations of bovine mammary-gland phagocytes and evaluation of sensitivity and specificity of morphologic and functional indicators of bovine mastitis

The number and function of bovine mammary-gland phagocytes were assessed in 8 lactating cows, each tested at least twice within an 8-mo period (total number of observations, 20). Macrophages and polymorphonuclear (PMN) cells were evaluated by conventional cytology, flow cytometry, fluorescent microscopy, and somatic-cell count (SCC). Phagocytosis was evaluated from the uptake of fluorescent beads and expressed as median fluorescence intensity (MFI). Two major subpopulations of phagocytes, of low or high MFI (LFI or HFI), were observed, and there were up to 4 sub-subpopulations within the HFI subpopulation of both macrophages and PMN cells. Fluorescent microscopy identified phagocytes containing up to 4 beads per cell. Cows showing ≤ 72.3% phagocytes by cytology were regarded as non-mastitic (11 observations), and those showing ≥ 80.7% phagocytes were considered to be mastitic (8 observations). Phagocyte MFI was negatively associated with mastitis; that is, the higher the MFI, the lower the SCC. The percentage of HFI PMN cells was the only indicator of mastitis with 100% sensitivity and specificity. Thus, bovine mammary-gland phagocytes consist of several subpopulations of different phagocytic ability, whose assessment more adequately predicts bovine mastitis than do morphologic indicators.     

Isolation and Culture of Ovine and Bubaline Small and Large Pre-antral Follicles: Effect of Cyclicity and Presence of a Dominant Follicle

Studies were conducted to examine the effects of the cyclicity and the presence of a dominant follicle (DF) in ovary on the recovery and in vitro growth of pre-antral follicles (PFs) in sheep and buffalo. Small pre-antral follicles (SPFs, 100–250 μm) and large pre-antral follicles (LPFs, 250–450 μm) were isolated from slaughterhouse ovaries in the breeding seasons by a mechanical and enzymatic method. The sheep and buffalo PFs were cultured in vitro for 6 and 15 days, respectively, and examined for their growth, survival and antrum formation rates and growth rates of oocytes in cultured pre-antral follicles. The follicles of the sheep and buffalo were recovered and cultured simultaneously within replicates. The recovery rates (number per ovary) of both SPFs and LPFs were significantly (p < 0.05) higher in cyclic ewes (SPFs: 22.0 ± 3.3 vs 12.1 ± 2.6 and LPFs: 16.0 ± 3.6 vs 9.2 ± 1.8) and buffaloes (SPFs: 9.2 ± 1.3 vs 4.1 ± 1.0 and LPFs: 10.3 ± 2.7 vs 5.4 ± 0.7) compared with those recovered from acyclic ones. Presence of a DF in ovary significantly (p < 0.05) reduced the recovery rates of LPFs in ewes (9.06 ± 2.7 vs 16.4 ± 3.8) but had no effect in buffalo. Cyclicity of animals or follicular dominance had no effects on in vitro growth, survival and antrum formation rates and growth rates of oocytes in cultured PFs of SPFs and LPFs in both sheep and buffalo. The in vitro growth, survival and antrum formation rates of LPFs and growth rates of oocytes in cultured LPFs were significantly (p < 0.05) higher than those observed in SPFs in both sheep and buffalo. The overall recovery and growth rates of the PFs were lower in buffaloes compared with ewes.     

奶牛子宫内膜炎致病菌的分离与鉴定及耐药性分析

本试验通过对山东省4个大型奶牛场的60头子宫内膜炎患牛进行调查、采样,并用常规方法对细菌进行分离、培养、鉴定。共分离到细菌59株,其中分离率最高的是埃希氏大肠杆菌10株(16.95%)、葡萄球菌属8株(13.6%)、芽孢杆菌属6株(10.2%)、链球菌属5株(8.5%)(其中溶血性链球菌2株)、棒状杆菌属5株(8.5%)、不动杆菌属5株(8.5%)、双球菌5株(8.5%)、肠杆菌属4株(6.8%)、沙门氏菌3株(5.1%)、克雷伯氏杆菌属2株(3.4%)、耶尔森菌属2株(3.4%)、摩拉杆菌属1株(1.7%),而且分离到了梭菌属3株(严格厌氧菌)。药敏试验分析结果显示,大多数致病菌对喹诺酮类药物、阿莫西林、土霉素及氨苄青霉素等耐药率较高,而对头孢菌素类和氨基糖苷类药物耐药率则较低。