Diurnal variation of peripheral plasma levels of testosterone in bulls measured by a rapid radioimmunoassay procedure

A radioimmunoassay technique, using antibodies to testosterone-3-(O-carboxymethyl) oxime-bovine serum albumin, has been applied for the measurement of peripheral plasma levels of testosterone in bulls. The individual as well as the mean 24-hr. pattern of peripheral plasma levels of testosterone in the four bulls investigated showed three distinct peaks. The mean peripheral plasma level of testosterone peaked around 10 p.m., around 6 a.m. and around noon, the mean levels obtained at these times being 6.2, 6.1 and 4.2 ng/ml, respectively. In one bull an additional peak occurred around 2 a.m. (8.2 ng/ml). Significantly lower peripheral plasma levels of testosterone were observed between the peak values.     

种公牛的饲养管理

随着人工授精技术和精液冷冻技术的发展,极大地提高了种公牛的利用率,减少了种公牛的饲养数量,但对种公牛的质量提出了更高要求。优秀的种公牛要具备充沛的精力、健壮的体格、优良性状的稳定遗传,并能够产生大量高品质精液。种公牛的生育能力是由遗传因素和环境因素共同决定的,环境因素主要包括营养、健康状况以及饲养管理。饲养管理的科学性和规范性在优秀种公牛培育中发挥着重要作用。本文综述了种公牛的选择方法、国家有关种畜禽饲养的相关条例以及国内种公牛培育现状,从种公牛营养需求、科学管理等方面,分析种公牛饲养管理的重要影响因素,探讨提高种公牛饲养管理水平的具体措施。     

Effect of improved nutrition during calfhood on serum metabolic hormones, gonadotropins, and testosterone concentrations, and on testicular development in bulls

The objective of the present study was to evaluate the effects of improved nutrition during calfhood on serum metabolic hormones, gonadotropins and testosterone concentrations, and on sexual development in bulls. Bulls received high (n = 17) or control nutrition (n = 16) diets from 10 to 30 week of age and the same control nutrition diet from 31 to 74 week of age. Improved nutrition during calfhood resulted in a more sustained period of elevated LH secretion (pulse frequency and total secretion in 10 h) during the early gonadotropin rise. GnRH-stimulated LH secretion was not affected by diet, indicating that pituitary responsiveness was not altered; therefore, improved nutrition had direct effects on GnRH secretion by the hypothalamus. Insulin and insulin-like growth factor-I (IGF-I) concentrations were greater during calfhood in bulls receiving high nutrition, indicating that these metabolic hormones might be involved in regulating GnRH and LH secretion. Improved nutrition also resulted in increased testosterone secretion that was associated with greater circulating IGF-I concentrations, suggesting a role for this metabolic hormone in regulating Leydig cell number and function. Furthermore, improved nutrition during calfhood resulted in greater testicular weight and sperm production in mature bulls, indicating that increased LH secretion during calfhood, and increased IGF-I and testosterone concentrations during calfhood and peripubertal period were associated with greater testicular cell proliferation and enhanced function.     

Effect of nutrition during calfhood and peripubertal period on serum metabolic hormones, gonadotropins and testosterone concentrations, and on sexual development in bulls

The objective of the present study was to characterize the effects of nutrition on circulating concentrations of metabolic hormones, gonadotropins, and testosterone during sexual development in bulls. Nutrition regulated the hypothalamus-pituitary-testes axis through effects on the GnRH pulse generator in the hypothalamus and through direct effects on the testes. Pituitary function (gonadotropin secretion after GnRH challenge) was not affected by nutrition. However, nutrition affected LH pulse frequency and basal LH concentration during the early gonadotropin rise (10-26 weeks of age). There were close temporal associations between changes in insulin-like growth factor-I (IGF-I) concentrations and changes in LH pulse frequency, suggesting a role for IGF-I in regulating the early gonadotropin rise in bulls. The peripubertal increase in testosterone concentration was delayed in bulls with lesser serum IGF-I concentrations (low nutrition), suggesting a role for IGF-I in regulating Leydig cell function. Serum IGF-I concentrations accounted for 72 and 67% of the variation in scrotal circumference and paired-testes volume, respectively (at any given age), indicating that IGF-I may regulate testicular growth. Bulls with a more sustained elevated LH pulse frequency during the early gonadotropin rise (high nutrition) had greater testicular mass at 70 weeks of age relative to the control group (medium nutrition), despite no differences in metabolic hormone concentrations after 26 weeks of age. Therefore, gonadotropin-independent mechanism regulating testicular growth might be dependent on previous gonadotropin milieu.     

A comparative study at two different altitudes with two dietary nutrition levels on rumen fermentation and energy metabolism in Chinese Holstein cows

The object of this study was to investigate the effect of two altitudes (1600 vs. 3600 m) with two nutritional levels [5.88 MJ/kg dry matter (DM) vs. 7.56 MJ/kg DM] on apparent total tract digestibility, rumen fermentation, energy metabolism, milk yield and milk composition in Chinese Holstein cows. Sixteen Chinese Holstein cows in their third lactation with close body weights, days in milk and milk yield were randomly divided into four groups, of which two were directly transferred from Lanzhou (altitude of 1600 m) to Lhasa (altitude of 3600 m). Four treatments (high plateau and high nutrition level, HA‐HN; high plateau and low nutrition level, HA‐LN; low plateau and high nutrition level, LA‐HN; and low plateau and low nutrition level, LA‐LN) were randomly arranged in a 2 × 2 factorial experimental design. Results indicated that the apparent total tract digestibility of a diet’s DM, organic matter, crude protein, neutral detergent fibre and acid detergent fibre and DM intake were not affected by either altitude or nutrition level (p > 0.05). Milk protein percentage was higher for the diet with the high level of nutrition than for the diet with low nutrition level irrespective of altitude (p < 0.05). Percentages of milk fat and milk lactose were not affected by either altitude or nutrition level (p > 0.05). The metabolizable energy used for milk energy output was decreased by high altitude in comparison with that at low altitude (p < 0.05). No differences were observed in the live body weight or body condition score (BCS) of Chinese Holstein cows among all of the four treatments (p > 0.05).     

Influence of varying levels of dietary cation anion difference on ruminal characteristics,nitrogen metabolism and in situ digestion kinetics in buffalo bulls

This study was conducted to examine the influence of varying dietary cation anion difference (DCAD) on nutrient intake, digestibility, ruminal characteristics, blood acid base status and in situ digestion kinetics in Nili Ravi buffalo bulls. Four iso‐nitrogenous and iso‐caloric diets having ?110, +110, +220 and +330 mEq/kg dry matter (DM) DCAD were formulated which were represented by A (anionic), LC (low cationic), MC (medium cationic) and HC (high cationic), respectively. These diets were used in four ruminally cannulated Nili Ravi buffalo bulls in a 4 × 4 Latin Square Design. Improved nutrient intake was recorded at high DCAD levels while digestibility remained unaffected. Ruminal ammonia nitrogen, rumen pH, acetate and acetate : propionate ratio were higher in buffalo bulls fed MC and HC diets than those fed A and LC diets. Blood pH and HCO₃^‐ also tended to increase as DCAD level was increased in the diet. Serum Ca and Cl concentrations were higher in bulls fed A and LC diets whereas serum Mg, P and S remained unaffected. Urine pH increased with increasing DCAD level. Nitrogen intake and blood urea nitrogen concentrations were also higher in bulls fed MC and HC diets. There was a consistent increase in ruminal DM and neutral detergent fiber degradability, rate of disappearance and extent of digestion at high DCAD levels in the diet. However, lag time decreased at high DCAD level. This study indicated that buffalo bulls fed MC and HC diets improved feed intake, ruminal characteristics and digestion kinetics.     

Combined subcutaneous administration of ivermectin and nitroxynil in sheep: Age/body weight related changes to the kinetic disposition of both compounds

The effect of age/body weight in the plasma disposition kinetics of ivermectin (IVM) and nitroxynil (NTX) after their co-administration as a combined formulation to sheep was studied. Sixteen (16) male sheep were allocated into two experimental groups (n = 8 each): (a) high body weight (high bw) (18-20 months old), and (b) low body weight (low bw) (6-8 months old). Animals in both groups were subcutaneously (sc) treated with IVM (200 μg/kg) and NTX (10 mg/kg) using a commercially available combined formulation (Nitromectin^®, Lab. Ovejero, Spain). Blood samples were taken by jugular venopuncture before (time 0), at 2, 4, 8, 12 h and at 1, 2, 3, 5, 7, 10, 15, 20, 25, 35, 40, 50 and 60 days after administration. Recovered plasma was analysed to quantify IVM and NTX by HPLC. Higher IVM plasma concentrations were measured until 20 days post-administration in “low bw” compared to “high bw” animals, where IVM was recovered up to 35 days post-treatment. The IVM absorption process greatly differed between experimental groups. A significantly higher (p < 0.01) C_max (36.7 ± 7.52 ng/ml) value was obtained at a delayed (p < 0.05) T_max (48.0 ± 0.0 h) in light compared to heavy (C_max: 8.0 ± 0.80 ng/ml; at 34.0 h) body weight sheep. IVM elimination half-life and mean residence time were significantly shorter in light compared to heavy (older) sheep. NTX mean plasma concentrations were lower in “low bw” compared to those measured in “high bw” sheep, with elimination phases declining up to 60 d post-administration in both experimental groups. The NTX AUC value in “low bw” (1188.5 ± 122.6 μg day/ml) was significantly lower (p < 0.05) than that obtained in the “high bw” (oldest) animals (1735.0 ± 155.8 μg day/ml). Shorter NTX elimination half-life and mean residence time (p < 0.01) were obtained in the youngest (“low bw”) compared to the oldest (high bw) sheep. The work reported here assessed for the first time the disposition of IVM and NTX after their combinated injection to sheep, demonstrating that animal body weight/development greatly affects the kinetic behaviour of both anthelmintic drugs.     

Assessment of the accuracy of testicular dysfunction detection in male donkey (Equus asinus) with the aid of colour-spectral Doppler in relation to plasma testosterone and serum nitric oxide levels

This study aimed to determine the usefulness of colour and pulsed Doppler modes for the accurate diagnosis of donkeys suffering from subfertility to determine whether testicular vascularity assessment could be an indicator for sperm functionality. The study sample was composed of 10 male donkeys with normospermia (control group) and 10 donkeys with hypospermia. Animals underwent scrotal circumference measurement, testicular Doppler examination, seminal evaluation, blood sampling and hormonal assay. Semen volume and concentration were significantly (p ≤ .05) lower in the subfertile group (30.25 ± 1.22 ml and 89.44 ± 2.55 × 10⁶/ml) as compared with the control group (82.76 ± 1.65 ml and 452.78 ± 1.25 × 10⁶/ml), and total sperm/ejaculation was significantly (p ≤ .05) higher in the normal donkeys (28.30 ± 2.32 × 10⁹/total ejaculated) as compared with the subfertile group. Intratesticular coloured area showed a marked decline in the hypospermic males. There was no significant difference between the two groups in testosterone level, although the normal group showed an increase in nitric oxide metabolites. Both Doppler indices of the three branches of the testicular artery were elevated significantly (p ≤ .05) in abnormal donkeys, whereas Doppler peak systolic and end-diastolic velocities were increased in the normal group. Male donkeys with subfertility demonstrated lower arterial vascularity parameters in the form of intratesticular coloured area and blood flow rate; therefore, the most optimal parameters for differentiating subfertile hypospermic from normospermic donkeys were found to be the two Doppler indices, velocities parameters, testicular blood flow rate and nitric oxide levels.     

Scrotal circumference, bodyweight and serum testosterone concentration of Red Sokoto weaner bucks as influenced by dry season crop-residue supplementation

The effect of dry season supplementation with crop‐residue‐based rations on bodyweight, scrotal circumference and serum testosterone concentrations in Red Sokoto weaner bucks at 5, 6 and 7 months of age was investigated in the present study. There were 7 treatment groups which were fed a positive control ration (conventional concentrate) fed at 1 and 2% of the bucks’ bodyweights (Rations 1A and 2A), two crop‐residue‐based test rations each fed at 1 and 2% of bodyweight (1B, 2B, 1C and 2C), and a negative control that was unsupplemented (Ration D). All treatment groups had ad libitum access to natural pastures and Digitaria smutsii hay as a basal diet. Bodyweight and scrotal circumference of the bucks significantly increased (P < 0.05) with age from 5.9 kg to 10.2 kg, and 4.40 cm to 6.95 cm, at 5 and 7 months of age, respectively. Bucks on Ration D (unsupplemented group) had the lowest bodyweight and scrotal circumference. Bucks on Ration 2A showed a significant increase in basal testosterone concentration from 0.32 ng/mL at 5 months of age to 0.65 ng/mL at 7 months of age. Peak testosterone concentration also increased from 1.0 ng/mL at 5 months to 2.8 ng/mL at 7 months of age. Bucks on test Ration 2C had higher bodyweights (6.75, 8.00 and 10.00 kg at 5, 6 and 7 months of age, respectively) than bucks on the other test Ration B (6.20, 7.20 and 8.50 kg, respectively). There were no significant differences between the two test rations with regard to scrotal circumferences of the bucks at all ages. However, at 7 months of age, bucks on test Ration 2C had significantly higher peak testosterone concentration (1.80 ng/mL) than their counterparts on test Ration 2B (1.30 ng/mL). The secretory patterns of testosterone were episodic and pulsatile in nature. It was concluded that crop‐residue supplementation in prepubertal Red Sokoto bucks has a significant influence on their bodyweight, scrotal circumference and testosterone production. Test Ration C was a cheap, affordable and better crop‐residue‐based ration for optimal reproductive performance than test Ration B.     

L-精氨酸对热处理MLTC-1细胞氧化、凋亡及睾酮合成相关基因表达的影响

试验旨在研究热处理对睾丸间质细胞的影响及L-精氨酸对热处理睾丸间质细胞抗氧化、抗凋亡及睾酮合成相关基因表达的影响.试验选用小鼠睾丸间质瘤细胞系(MLTC-1)细胞,将细胞分为4组,分别为对照组(C)、热处理组(HT)、5 μg/mL L-精氨酸+热处理组(5H)和10μg/mL L-精氨酸+热处理组(10H),处理结束...     

营养水平对荷斯坦肥育牛胴体品质及肉品质量的影响

将24头去势荷斯坦公牛随机分成3组,进行为期180 d的肥育试验.Ⅰ组饲喂低营养日粮,Ⅱ组和Ⅲ组分别饲喂中、高营养日粮.结果显示:试验Ⅱ组、Ⅲ组与Ⅰ组比较,宰前活重、胴体重、屠宰率、净肉重、胴体出肉率及内骨比均显著提高(P＜0.05);Ⅱ、Ⅲ组之间胴体出肉率和肉骨比差异显著(P＜0.05).胴体品质:Ⅱ组和Ⅲ组的背膘厚、胴体脂肪、肠系膜脂肪、眼肌面积和大理石花纹均优于Ⅰ组(P＜0.05);Ⅱ和Ⅲ组的背膘厚、胴体脂肪、肠系膜脂肪三项指标显著差异(P＜0.05).常规化学成分:各组间干物质、粗脂肪和粗蛋白显著差异(P＜0.05);各组的钙、磷差异不显著(P＞0.05).牛肉质量:Ⅱ组、Ⅲ组的滴水损失、pH值和剪切力值均优于Ⅰ组(P＜0.05);Ⅱ和Ⅲ组之间差异不显著(P＞0.05).结果表明,日粮营养水平对荷斯坦肥育牛的胴体品质及肉品质量具有显著影响.     

日粮营养水平和添加莫能菌素对肉牛生产性能的影响

通过饲养试验来研究不同营养水平和是否添加莫能菌素对宁夏地区西门塔尔杂交阉牛增重效果和经济效益的影响。结果表明,与对照组相比,高精粗比(67:33)组和添加200 mg/(头.d)莫能菌素组的平均日增重提高65.18%和37.5%(P<0.05);料肉比降低33.29%和20.58%,显著提高经济效益。     

Effects of immunocastration performed at two live weights on the growth physiology,temperament and testicular development of feral beef bulls

The aim of this study was to examine the effect of administering an anti‐gonadotropin‐releasing hormone vaccine (Improvac^®, developed for pigs) on the performance, temperament, testicular development, and hormone and metabolite profiles of feral bulls (Bos taurus) vaccinated at two different live weights (LW). In all, 16 Serrana de Teruel animals were involved in this 2 x 2 factorial design using the factors LW (LIGHT vs. HEAVY) and vaccine treatment (control, C vs. vaccinated, VA). All animals received the same diet (ad libitum concentrate plus straw) over a 164‐day fattening period. Temperament was assessed using chute and flight speed tests. Testicular diameter and subcutaneous fat thickness were recorded. Testosterone, IGF‐1, urea, NEFA, and creatinine profiles were analyzed. Bull weight gain was reduced in VA compared to C animals, regardless of the initial LW. The vaccine did not affect the temperament tests, subcutaneous fat thickness or NEFA and creatinine concentrations and had minor effects on linear body measures. The vaccine inhibited testicular growth, reduced plasma testosterone to residual levels, and increased urea concentrations. LIGHT‐C animals exhibited increased mean plasma IGF‐1 concentrations compared to LIGHT‐VA animals. In conclusion, vaccination reduced bull growth and sexual development irrespective of LW at immunization.     

伊犁绢蒿体内可塑性营养物质动态变化及分配特征的研究(简报)

2006年3-11月,在新疆阿什里乡对新疆蒿类荒漠草地建群种伊犁绢蒿可溶性碳水化合物、蔗糖、淀粉和粗蛋白进行动态监测。结果表明,伊犁绢蒿中粗蛋白和蔗糖含量居前2位,淀粉含量低,还原糖仅在茎中存在。5月4日-11月14日,可溶性碳水化合物、蔗糖含量呈"升高-降低-再升高-再降低"特征,叶片粗蛋白和淀粉均呈"单峰"曲线,最高为234.05和3.55 mg/g;根粗蛋白基本不变,为67.26 mg/g,茎中呈下降趋势。可塑性营养物质均在10月17日前完成根内贮存。不同生长阶段伊犁绢蒿营养物质在根、茎、叶上分配差异较大。     

Influence of different dietary zinc levels on cashmere growth,plasma testosterone level and zinc status in male Liaoning Cashmere goats

The experiment was conducted to investigate the influence of different levels of zinc (Zn) on cashmere growth, plasma testosterone and Zn profile in male Cashmere goats. Twenty‐eight male Liaoning Cashmere goats, 3 years old and body weight at 56.2 ± 2.45 kg, were assigned to four groups. The animals were fed a basal diet containing of 45.9 mg Zn/kg dry matter (DM) basis and supplemented with 0, 20, 40 or 80 mg Zn (reagent grade ZnSO₄·7H₂O) per kg DM for 90 days. There was no significant effect on growth and diameter of cashmere fibre for Zn supplemented in diets. However, the length and growth rate of wool were improved (p < 0.05) with dietary Zn. The length and growth rate of wool were higher (p < 0.05) for the groups supplemented with 40 or 80 mg Zn/kg DM compared with that of 20 mg Zn/kg DM treatment group. Plasma testosterone concentration was increased for Zn supplemented in diets, and the testosterone concentration was higher (p < 0.05) in goats fed on the diet supplemented with 40 or 80 mg Zn/kg DM compared with those fed on basal diet. Plasma Zn concentrations increased (p < 0.05) with increasing dietary Zn and supplemented with 40 and 80 mg Zn/kg DM groups improved plasma Zn concentration (p < 0.05) more than 20 mg Zn/kg DM group. Fibre Zn content was higher (p < 0.05) in groups supplemented with 40 or 80 mg Zn/kg DM compared with control group, but no difference between Zn‐supplemented groups (p > 0.05). The activity of plasma alkaline phosphatase was increased (p < 0.05) due to dietary Zn supplementation; however, no difference was found between supplemented treatment groups (p > 0.05). In conclusion, Zn content (45.9 mg Zn/kg DM) in control diet was insufficient for optimal wool growth performance, and we recommended the level of dietary Zn for such goats is 86 mg/kg DM during the breeding season and cashmere fibre growing period.     

硒钴在“土-草-饲-畜链”(SPFAC)传导中对草畜产品营养的调控

经过2006-2008年在黄河滩区2年生苜蓿草地上的田间试验,研究当Na₂SeO₃·5H₂O的用量在570～765 g/hm²和CoSO₄·7H₂O用量在762～1 548 g/hm²的单施和混合基施情况下,硒钴通过“土-草-饲-畜链”(SPAFC)对草畜产品营养的调控。结果表明,1)苜蓿对硒具有很强的吸收率和很高的从无机硒到有机硒的转化率,硒钴配施能增强苜蓿对肥料中硒的吸收和转化能力,提高硒的有效性和安全性。2)硒钴配量分别在765和762 g/hm²情况下,对提高牧草营养价值有显著效果,干草中粗蛋白和粗脂肪含量得到显著提高,粗纤维和无氮浸出物成分变化不显著;而其他单施和配施肥料则提高了牧草的粗纤维含量,降低了粗脂肪含量,对其他成分影响不显著。3)硒肥能显著提高青干草中Cu、Fe、Mn、Zn 4种元素的含量(P＜0.05),钴与硒配施能显著增强牧草对微量元素的吸收。4)在动物日粮中添加5%的富硒和富硒钴苜蓿草粉,能显著地提高动物产品中硒的含量,其硒的含量与土壤中硒量以及牧草中硒的含量3者之间呈显著的正相关性。     

Non-invasive assessment of growth, gender and time of day related changes of respiratory pattern in healthy cats by use of barometric whole body plethysmography

The objective of this study was to establish a reference base for respiratory variables (respiratory rate [R(R)], inspiratory and expiratory time [T(i) and T(e)], peak inspiratory and expiratory pseudoflow [PIF and PEF], tidal volume [V(T)], minute ventilation [V(E)] and enhanced pause [Penh]) of healthy cats by use of barometric whole body plethysmography (BWBP). Eighteen healthy European cats (10 male, 8 female) were studied from the age of 3 to 13 months in order to assess growth- and gender-related changes of BWBP variables. Chest radiographs and bronchoalveolar lavage cytology were performed to confirm pulmonary health status. Diurnal changes were investigated every 2 h over a period of 24 h when the cats were adult. V(T), V(E), PIF and PEF significantly increased during somatic growth and were higher in males than in females, whereas R(R), T(i), T(e), T(e)/T(i) ratio, PEF/PIF ratio and Penh remained unchanged and were not affected by gender. When measured over 24 h, Penh, T(e) and T(i) were significantly increased in the early morning hours (04:00 h), whereas R(R), PIF and PEF were decreased at that time. This study provides reference values of BWBP variables for healthy male and female cats and indicates when circadian changes might be observed.     

Residual effect after salmon oil supplementation on semen quality and serum levels of testosterone in dogs

The objective of present study was to evaluate the effects of oral supplementation of salmon oil on seminal parameters and testosterone serum levels in dogs, following also the residual effects for 60 days after treatment. Nine healthy male dogs with proven fertility, weighing between 10 and 36 kg, ageing from 2 to 11 years, of different breeds, fed diets supplemented with salmon oil at the manufacturer's recommended dosage. The parameters measured were sperm volume, motility, vigour, normal morphology and concentration, live/dead ratio, membrane viability by means of HOST test and serum testosterone levels. Evaluations occurred at baseline (D0), after 90 days of supplementation (D90) and at the end of the experiment, 60 days after supplementation cessation (D150). Results (mean ± SD) obtained at time D0, D90 and D150 were as follows: motility of 76.66% ± 13.7, 92.77 ± 4.41 and 93.0 ± 7.90 (p = .001); normal spermatozoa of 69.11% ± 24.90, 90.00% ± 5.15 and 80.66 ± 16.04 (p = .05); live/dead (%) from 64.44 ± 22.86 to 85.33 ± 8.41 (p = .001); and spermatozoa (%) with integral membrane in the membrane integrity (HOST) test ranging from 76.44 ± 20.74 to 91.22 ± 4.68 (p = .05). Serum levels of testosterone (ng/ml) increased from 5.50 ± 1.13 to 8.84 ± 1.13 at D90 (p = .003) and decreased after 2 months (D150) to 5.13 ± 1.13. In conclusion, a 90‐day supplementation with salmon oil had a positive influence on semen quality and serum testosterone levels. The supplementation of omegas 3 and 6 at the ratio of 10:1 for 90 days determined an increase in concentration and motility of the sperm, and these effects were maintained for 60 days, with the only exception of testosterone levels.     

Age and season related dynamics of vitamin E levels in the serum of young cattle from birth to the age of 22 months]

The dynamics of serum vitamin E levels in heifers was followed for 22 months. We found that calves were born with a very low, almost nil, content of this vitamin (on an average 0.029 mg%) as a result of the limited diaplacental transfer from the mother to the fetus. In the following period of extrauterine life and growing up of the young cattle conspicuous age dynamics was recorded which is, however, linked or affected by the seasons. Colostral nutrition which is reflected in the increasing serum concentration of vitamin E has an important role. After the change from winter feeding rations to summer feed, consisting mainly of grazing, a marked increase in the serum concentration of vitamin E with an apex was observed, i.e. with the maximum mean value in November. In relation to the age of animals the highest concentration of vitamin E in the blood serum of heifers was recorded, expressed as mean values toward the end of our observations (0.736 mg%), i.e. in the period of sexual maturity; it equalled the concentration of vitamin E determined in cows.     

Investigation of carryover effect of prior fibre consumption on growth,serum and tissue metabolic markers in Ossabaw pigs fed a high‐fat diet

Carryover effect of prior fibre consumption on metabolic markers was investigated. Treatments were arranged in 2 × 2 factorial with 2 fibre sources, 4% inulin or cellulose (Solka‐Floc®) and fat levels (5 or 15%) for the low‐fat diet (LFD) and high‐fat diet (HFD) respectively. Pigs were fed the two fibre diets for the first 56d (nursery phase), and thereafter fed either the LFD or HFD containing no added fibre source from d56 to 140 (growing phase). Pigs on the HFD were heavier (p = .05) than those on LF (64.61 vs. 68.38 kg), regardless of prior fibre type consumed. Pigs that were fed cellulose during the nursery and later fed the HFD had the highest ADG (p < .05). Feeding the HFD resulted in higher back fat (BF) (13.41 and 18.18 ± 0.12 mm for LFD and HFD, respectively; p < .01). The HFD resulted in higher (p < .01) insulin (0.014 and 0.016 ± 0.001 mg/L for LF and HF respectively) and glucose (100.89 and 125.03 ± 4.39 mg/dl for LF and HF respectively) concentrations in the serum. Inulin increased (p ≤ .02) jejunal expression of SREBP‐1c and CL‐4, but reduced (p < .05) TNFɑ and IL‐6 expression in the ileum. Alpha‐diversity was significantly different (p < .05) between the inulin and cellulose fed pigs at the end of the nursery and finishing phases. Therefore, inulin feeding before a HFD may lead to reduction in ADG and inflammatory markers in the small intestine of pigs, and thus prevent future metabolic disorders.