Serum distribution of iodine after oral administration of ethylenediamine dihydriodide in cattle

Serum concentrations of iodine were determined after cattle were given ethylenediamine dihydriodide (EDDI) orally at dosages ranging from 0.0 (placebo) to 0.77 mg/kg of body weight/day. The serum iodine concentration was correlated with the dosage of EDDI. A rate of 0.11 mg EDDI/kg/day was correlated with serum iodine concentrations (20 to 80 micrograms/dl) previously found to be effective in preventing foot rot in cattle. A linear dose-response curve that was generated could be helpful in predicting dosage of EDDI if the serum iodine concentration is known.     

Clinical infectious bovine rhinotracheitis in cattle fed organic iodine and urea.

The feeding of ethylenediamine dihydriodide (EDDI) at the dose levels of 50 and 500 mg/animal/day and urea at the dose level of 45 g/animal/day did not affect duration of clinical signs, body weight gain, magnitude or duration of fever, serum concentration of glutamic oxalacetic transaminase, packed cell volume, and differential white blood cell counts in feeder cattle experimentally infected with infectious bovine rhinotracheitis (IBR) virus. However, coughing and abundance of nasal discharge were significantly greater in calves fed EDDI before and during primary IBR virus infection. Those calves fed 500 mg of EDDI/day coughed more, had greater nasal discharge, and exhibited greater lacrimation than did those given the smaller dose. These 3 clinical signs were considered to reflect both the expectorant action of EDDI and the pathogenic effects of IBR virus. In all calves, including controls, the coughing, nasal discharge, and lacrimation were most prominent during the period of peak infection (7 to 14 days after the calves were given intranasal inoculation) of the IBR virus. Total serum iodine concentration became maximal (mean of 1,400 ng/ml) in 8 calves after they had been fed the larger dose of EDDI for 2 weeks. This value was maximal (about 300 ng/ml) in another 8 calves after 3 weeks' feeding of the smaller dose (50 mg/day). When EDDI exposure was maintained at the dose level of 50 mg/day for 5 weeks longer, mean serum iodine values remained at about 275 ng/ml, and those of control calves averaged 140 ng/ml.     

高寒地区中国荷斯坦犊牛早期断奶方案对犊牛生长发育、腹泻与培育成本的影响

[目的]研究高寒地区中国荷斯坦犊牛早期断奶方案的推广价值。[方法]选取1周内新生、体重相近的犊牛16头,采用对照的试验方法将16头犊牛随机分为试验组和对照组,每组8头。试验组为早期断奶方案,对照组为常规断奶流程,试验期为90 d。[结果]试验组在60日龄与90日龄的日增重均显著高于对照组（P〈0.05）。试验组90日龄增重显著高于对照组（P〈0.05）。对照组犊牛30日龄内腹泻发病率为100%,重复发病率为75%;试验组30日龄内腹泻发病率为50%,重复发病率为50%。试验组与对照组相比节约成本32.52%。[结论]高寒地区中国荷斯坦犊牛可实行早期断奶方案,且能够提高企业和养殖户的经济效益,具有较好的推广价值。     

断奶应激对奶水牛犊牛血液生理生化指标和免疫功能的影响

为研究断奶应激对奶水牛犊牛的影响,选用5头健康犊牛,分别于断奶前1 d、断奶后1、14和21 d进行采血,测定犊牛的血常规、血清生化指标和免疫指标。结果显示,奶水牛犊牛的白细胞数、淋巴细胞数、红细胞数、单核细胞数、红细胞压积、天冬氨酸转氨酶活性、血糖含量、皮质醇含量、免疫球蛋白G含量在断奶前后无显著变化（P > 0.05）;中性粒细胞数在断奶后21 d显著低于断奶前1 d（P < 0.05）;血清乳酸脱氢酶、丙氨酸转氨酶活性在断奶后显著高于断奶前（P < 0.05）;血清尿素氮含量在断奶后21 d显著高于断奶前1 d（P < 0.05）;血红蛋白含量在断奶21 d显著低于断奶前1 d（P < 0.05）。结果表明断奶应激不仅影响了奶水牛犊牛的生理机能,而且降低了其免疫力和抵抗力。     

Effect of a quadrivalent vaccine against respiratory virus on the incidence of respiratory disease in weaned beef calves

We investigated the effect of vaccination of male beef calves (mean age+/-S.D.: 158+/-31 days) against bovine herpes virus (BHV-1 or IBR virus), bovine respiratory syncitial virus (BRSV), bovine viral diarrhea (BVD) virus and para-influenza (PI(3)) virus on the incidence of respiratory disease during the first forty days after weaning and entering a feed-lot in Portugal. In May 2003, Mertolenga, Preta and mixed-breed calves from 10 different beef herds, were systematically assigned (by order of entrance in a chute) to two treatment groups, before moving to a common feed-lot. One hundred and twenty five male calves were vaccinated with a quadrivalent vaccine (Rispoval 4) and revaccinated after 21-27 days while 148 herdmates were injected with saline (0.9% NaCl) on the same occasions. The incidence and severity of clinical cases of "bovine respiratory disease" (BRD) were evaluated every day during the first 40 days after entering the feed-lot. Morbidity (3% vs. 14%) and mortality (0% vs. 4%) due to BRD were significantly lower in the vaccinated group. Ten days after revaccination, the calves were treated with an antimicrobial - ending the study - after an outbreak of BRD caused a high incidence of disease in the non-vaccinated group. In conclusion, our results showed that Rispoval 4, a quadrivalent vaccine against respiratory viruses, under field conditions, reduces morbidity and mortality due to BRD in beef calves after weaning.     

Effect of Weaning Stress on Blood Physiology and Biochemistry Indexes and Immune Function in Dairy Buffalo Calves

To study the effect of weaning stress on dairy buffalo calves,5 healthy calves were chosen and weaned,and the blood samples were collected at 1 day before weaning,and 1,14 and 21 days after weaning to analysis blood physiology and biochemistry indexes and immune function.The results showed that the count of white blood cell,lymphocyte,erythrocyte,monocytes and hematocrit,aspartate aminotransferase activity,blood glucose,cortisol and immunoglobulin G contents of dairy buffalo calves were no significant difference between before and after weaning treatments (P > 0.05).The count of neutrophils at 21 d after weaning were significantly lower than that of 1 d before weaning of dairy buffalo calves (P < 0.05).However,lactate dehydrogenase and alanine aminotransferase activity in weaned treatments were significantly higher than those of animals in the treatment before weaning (P < 0.05).The serum urea nitrogen of dairy buffalo calves at 21 d after weaning was significantly higher than that of 1 d before weaning (P < 0.05) and hemoglobin content at 21 d after weaning was significantly lower than that at 1 day before weaning (P < 0.05).It indicated that the physiological and immunity function of dairy buffalo calves were challenged under weaning stress.     

初乳饲喂次数对娟姗犊牛生产性能的影响

为研究探讨初乳饲喂次数对娟姗犊牛生产性能的影响,试验选取初生重接近的健康娟姗犊牛20 头,随机分为4 组,分别为对照组、试验I组、II组和III组,每组5 头犊牛,试验期为60 天。4 组犊牛出生当日饲喂两次初乳,首次初乳量按照体重的10.0%进行灌服,第2次初乳于出生后6~8 h按照体重的5.0%进行饲喂。4 组犊牛出生当日在产房饲养,2日龄时均转为室外犊牛岛单栏饲养。2日龄后,对照组每天上午06:00和下午16:00时各饲喂常乳1次,2~6日龄每次饲喂1.50 L,7~20日龄每次饲喂1.80 L,21~35日龄每次饲喂2.50 L,36~60日龄每次饲喂3.00 L,自7日龄开始犊牛自由采食颗粒料。试验Ⅰ组、Ⅱ组、Ⅲ组分别继续饲喂初乳至犊牛2日龄、4日龄、6日龄后再饲喂常乳,饲喂时间和饲喂量与对照组一致。结果表明:(1)在饲喂初乳后48 h、72 h、96 h,试验组与对照组犊牛血清免疫球蛋白g(IgG)均差异显著(p<0.05),120 h、144 h、168 h,试验Ⅰ组与对照组比较,犊牛血清IgG含量差异不显著(p>0.05),试验Ⅱ组、Ⅲ组血清IgG含量与对照组相比,差异极显著(p<0.01)。(2)随着初乳饲喂次数的增加,可有效降低犊牛20日龄内腹泻发生率,试验Ⅰ组、Ⅱ组、Ⅲ组较对照组比较犊牛腹泻发生率分别降低9.5%、22.5%、36.5%,治疗犊牛腹泻总成本较对照组分别下降12.0 元、43.2 元、76.8 元,3 组试验组犊牛成活率为100.0%。(3)初乳饲喂次数的增加,使0~60日龄娟姗犊牛平均日增重(ADG)升高,试验组与对照组相比较,日增重均差异极显著(p<0.01),分别增加16.7 g、33.3 g、80.0 g。试验Ⅱ组、Ⅲ组较试验Ⅰ组ADG差异也极显著(p<0.01)。综合考虑,建议娟姗犊牛饲喂初乳至6日龄,可降低犊牛腹泻发生率、减少治疗费用,提高犊牛成活率及ADG。     

Diagnosis of copper deficiency and effects of supplementation in beef cows.

The effects of feeding supplementary dietary copper to a herd of 400 beef cows, were studied over a two year period. In the first year of the trial, the calves showed clinical signs of copper deficiency. There was improved growth following subcutaneous injection of copper ethylenediamine tetraacetate, and the treated calves had a 2.8% increase in adjusted weaning weights. In the second year of the trial pregnant cows were fed a basal ration of bromegrass silage, barley and minerals over the winter feeding period. The feed was supplemented with copper so that half received 5.5 mg/kg of copper on a dry matter basis and half 40 mg/kg. Calving occurred in the spring and half the calves were treated with injectable copper at birth and again at 12 weeks of age. There was no evidence of copper deficiency in the calves and there was no effect of high level copper supplementation on calf birth weight, or neutrophil candidacidal activity. Susceptibility to diarrhea varied in a complex fashion; morbidity was lowest in calves born to dams fed supplementary copper and highest in calves born to supplemented dams and injected with copper at birth. The cows and calves grazed the same copper deficient pasture over the summer. The average daily gain for calves born to supplemented cows was 0.999 +/- 0.010 kg/day (x +/- SEM) which was significantly greater than the 0.972 +/- 0.009 kg/day for calves from nonsupplemented dams (p = 0.044). The benefit of copper supplementation on 200 day weaning weight was estimated at 4.8 kg. Evidence of copper deficiency was seen when a herd test showed mean serum levels below 9 mumol/L and liver values below 0.09 mmol/kg wet matter.     

不同断奶模式对犊牦牛生长发育、血清生化指标及抗氧化能力的影响

【目的】 本研究通过比较不同断奶模式对犊牦牛生长发育、血清生化指标及抗氧化能力的影响,以期探索科学的犊牦牛早期培育模式。【方法】 选取体重相近、健康的新生犊牦牛24头,随机分为3个处理组,每组8头,公母各半。对照组（GF）犊牦牛出生后在天然牧场内随母放牧哺乳;早期断奶组（EW）犊牦牛随母放牧哺乳至15日龄时隔离母犊,逐渐过渡为饲喂代乳粉,提供开食料及天然牧草自由采食,至犊牦牛固体饲料采食量达到0.5 kg/d时停喂代乳粉,90日龄后停喂开食料转入天然牧场放牧饲养;早期断奶＋益生菌组（EWP）断奶过程同EW组,并在代乳粉、开食料中添加复合益生菌（乳酸杆菌、芽孢杆菌、酵母菌,≥9.98×10¹¹ CFU/g）。分别于犊牦牛30、60、90、150日龄时测定体重及体尺指标,于30、60、90日龄晨饲前采集犊牦牛颈静脉血,测定血清中生化指标、激素、免疫球蛋白水平及抗氧化能力指标。【结果】 30日龄时,EW、EWP组犊牦牛体重、体尺,血清葡萄糖（GLU）、甘油三酯（TG）、胆固醇（CHO）,生长激素（GH）、胰岛素样生长因子1（IGF-1）,以及免疫球蛋白A （IgA）、免疫球蛋白G （IgG）水平均显著低于GF组（P<0.05）,EW组皮质醇水平显著高于GF组（P<0.05）;60~150日龄各组犊牦牛体重、体尺均无显著差异（P>0.05）;60日龄时,EW、EWP组犊牦牛血清IGF-1以及谷胱甘肽过氧化物酶（GSH）含量均显著高于GF组（P<0.05）;90日龄时EW、EWP组犊牦牛血清GLU、尿素氮（BUN）、IGF-1、甲状腺素（T₄）及IgA水平均显著高于GF组（P<0.05）,且EWP组血清TG、GH含量及过氧化氢酶（CAT）活性均显著高于GF组（P<0.05）。【结论】 与随母放牧哺乳模式相比,两种早期断奶方式在断奶初期（30日龄）对犊牦牛均产生了一定负面影响,但在断奶后补饲代乳粉与开食料有利于改善犊牦牛后期的生长发育、营养代谢、机体免疫与抗氧化能力,且补充益生菌能够缓解犊牦牛的早期断奶应激,并对犊牦牛生长发育及抗氧化能力的提升有进一步促进作用。     

Experimentally induced foot rot in feedlot cattle fed rations containing organic iodine (ethylenediamine dihydriodide) and urea.

Foot rot was experimentally induced in feedlot cattle with a mixed inoculum of Fusobacterium necrophorum (Sphaerophorus necrophus) and Bacteroides melaninogenicus. Both bacteria were isolated from the lesions. Isolates of F necrophorum from 2 of the lesions were serologically compared, using a passive hemagglutination test with the strain used to induce the lesions. These isolates were serologically similar but not identical, indicating antigenic change had occurred during animal passage. The addition of ethylenediamine dihydriodide or urea to the rations did not affect the frequency of experimentally induced foot rot.     

Effects of limited concentrate feeding on growth and blood and serum variables, and on nutrient digestibility and gene expression of hepatic gluconeogenic enzymes in dairy calves

This study elucidated the effects of limited concentrate feeding on growth, nutrient digestibility, blood profile and gene expression of gluconeogenic enzymes in the liver of dairy calves. The study utilized 36 German Holstein dairy calves (5-7 days of age) divided into two groups of 18 calves each for 150 days. Control group calves received 2 kg/(calf × day) of concentrate, whereas calves in the restricted group received only 1 kg/(calf × day). Good quality forage (mixture of maize and grass silages) was available for ad libitum consumption to both groups. The intake of milk replacer before weaning, and of concentrate were recorded daily per calf; however, the consumption of forages was quantified as daily average of the group. Body weights (BW) were recorded at start and on days 35, 70, 112 and 150. Blood and serum samples and spot urinary and faecal samples were also collected at similar time points. On days 70 and 150, liver biopsies were collected from seven animals in each group. The BW was not different between the groups at all times. Total BW gain in the control group was 124 kg as opposed to 111 kg in restricted group that led to average BW gain of 827 g/day and 739 g/day in respective groups, and the differences were significant (p = 0.018). As planned, the control group had higher concentrate and lower forage intake than the restricted group. The blood haemoglobin, haematocrit and serum variables (glucose, total protein, albumin and urea) were within the normal range in both groups, but serum glucose was higher (p < 0.05) in control than in restricted group at 70 days. There was no difference between groups in organic matter (OM) digestibility which declined (p < 0.001) with increasing age in both groups. Microbial crude protein (MCP) synthesis estimated from urinary allantoin excretion increased (p < 0.001) in both groups with increasing age but was not different between groups. The mRNA expressions for the gluconeogenic enzymes, cytosolic and mitochondrial phosphoenol pyruvate carboxykinase (EC 4.1.1.32) and pyruvate carboxylase (EC 6.4.1.1) measured by quantitative real-time PCR in liver biopsies showed no differences between groups. Overall, restricting concentrate moderately reduced the growth intensity without affecting the normal serum and blood indices, and MCP synthesis and OM digestibility showed no differences between groups, indicating that both concentrate feeding schemes can be successfully applied.     

Neuroleptic treatment of red deer calves at weaning

AIMS: To determine whether neuroleptic drugs could be useful in reducing weaning stress in red deer, two groups of 30 calves were studied following separation from their dams for weaning at 3-4 months of age. METHODS: Within each group, on the day of separation (Day 0), 15 calves were given 0.2 mg/kg haloperidol (a short-acting neuroleptic) and 1 mg/kg perphenazine enanthate (a long-acting neuroleptic) by intramuscular injection (the treated calves) and 15 calves were given a 3 ml intramuscular injection of saline (the control calves). The calves were weighed on Days 0, 14 and 28 and the behaviour of eight individuals (four treated and four control calves) within each group was observed for 2 hours on Days 0, 1, 2, 3, 7, 8, 14 and 15. RESULTS: No significant effect of the treatment on weight gain to Days 14 or 28 was observed (mean increases for treated and control calves to Day 14 were 3.4 kg and 3.5 kg, respectively (s.e.d. 0.26 kg), and 6.0 kg for both treatments to Day 28 (s.e.d. 0.36)). Behavioural variables (standing, grazing, moving, fenceline pacing, proximity to other deer and proximity to the fenceline) did not differ significantly between treatments, but in one group sitting in sternal recumbency was lower in treated calves compared with control calves (p < 0.05). Disturbed behaviour declined over the observation days with fenceline pacing, being within 2 m of a fence, and being within 1 m of another deer decreasing, and sitting and grazing both increasing (p < 0.01). CONCLUSIONS AND CLINICAL RELEVANCE: It was concluded that we could not provide evidence from the present study that treatment with haloperidol and perphenazine enanthate at these dose rates was beneficial in reducing weaning stress in red deer calves.     

纳豆枯草芽孢杆菌对犊牛断奶前后瘤胃发酵和酶活的影响

本试验旨在研究纳豆枯草芽孢杆菌在犊牛瘤胃中可能的作用机理。选取24头7日龄左右中国荷斯坦奶牛公犊牛,分为试验1、2组及对照组。试验1、2组犊牛直接饲喂N1型和Na型纳豆枯草芽孢杆菌菌液,对照组不饲喂菌液,当各组犊牛开食料采食量达到规定要求时断奶。断奶时每组随机选取4头犊牛屠宰,剩余12头犊牛继续饲喂,8周后屠宰。结果表明：①在断奶时及断奶后8周,试验1组犊牛瘤胃pH显著低于对照组和试验2组（P<0.05）;②断奶时及断奶后8周两处理组犊牛瘤胃总挥发性脂肪酸显著低于对照组（P<0.05）;断奶早期3组犊牛瘤胃食糜中乙酸的摩尔百分比差异不显著,而断奶后8周试验1组犊牛瘤胃中乙酸的摩尔百分比较对照组低（P<0.05）;与对照组相比,断奶时试验组犊牛瘤胃中丙酸的摩尔百分比显著降低（P<0.05）,而断奶后8周各组间无显著差异;③断奶早期试验2组犊牛瘤胃中氨氮浓度显著低于对照组（P<0.05）,试验1组氨氮浓度较对照组略低,但无显著差异;断奶后8周两处理组犊牛瘤胃中氨氮浓度显著低于对照组（P<0.05）;④整个试验期对照组犊牛瘤胃中性蛋白酶活性显著高于两试验组（P<0.05）,而外切葡聚糖酶活性显著低于两试验组（P<0.05）,各组犊牛瘤胃中β-葡萄糖苷酶和内切葡聚糖酶活性无显著差异。本试验说明在犊牛生长的不同时期,不同类型纳豆枯草芽孢杆菌的饲喂效果不尽相同。日粮中添加纳豆枯草芽孢杆菌有利于瘤胃的发育,从而促进犊牛生长。     

饲料营养对母牛繁殖率影响效果研究

通过对妊娠后期（后１４２ｄ）母牛、带犊哺乳母牛的不同阶段饲料营养配合试验,探讨母牛的饲养技术方案。选择条件大致相同的妊娠后期母牛３６头,随机分为试验１、２组和对照组各１２头。试验１组和试验２组根据妊娠月份及粗饲料种类不同,粗饲料日喂量各有所调整,对照组牛则采用当地的传统饲养方式。试验结果,试验１组母牛产仔成活１１头,哺乳期平均１１７ｄ,断奶成活１０头,繁殖成活率８３．３％,母牛产后开始发情时间平均     

Effect of parenteral administration of glutamine on autophagy of liver cell and immune responses in weaned calves

The objectives of this study were to determine the effects of an increased jugular supply of L‐Gln on post‐weaning growth, immune responses, intestinal morphology and autophagy of weaned calves. At 35 days of age, 24 Holstein calves (initial 50 ± 1.5 kg; 35 ± 2 day of age) were randomly allocated to four treatments, and each treatment included five male and one female calves. Holstein calves were assigned to treatments of (i) i.v. infusion of 2 l of 0.85% NaCl, Control group [C]; (ii) i.v. infusion of 8 g/day of L‐Gln mixed with 2 l of 0.85% NaCl solution [L]; (iii) i.v. infusion of 16 g/day of L‐Gln mixed with 2 l of 0.85% NaCl solution [M]; and (iv) i.v. infusion of 32 g/day of L‐Gln mixed with 2 l of 0.85% NaCl [H]; The infusion was 2 h/day for each of 14 consecutive days starting on day 1 after weaning. Feed and water were freely available to all calves. All calves were killed on the 14th day post‐weaning for measurements of autophagy of liver cell and intestinal morphology. Gln has no effect on dry matter intake (DMI) and average daily gain (ADG). Gln infusion increased quadratically the abundance of CD4+, monocyte and the ratio of CD4+/CD8+. The urea N, Gln and Glucose in plasma increased linearly with increasing Gln loads. Gln infusion increased quadratically villus height and crypt depth of intestine. The autophagy level of liver cell was improved with the Gln infusion dose increased.     

Effect of supplementation of calf starter with fennel powder on performance,weaning age and fermentation characteristics in Holstein dairy calves

The objective of this experiment was to investigate the effects on performance, weaning age and rumen fermentation characteristics in Holstein calves when fennel powder was added to their starter diets. Thirty Holstein calves with a mean birth weight 40 kg (SD = 0.5) were allocated randomly to one of the following experimental diets: (i) control (starter diet without fennel powder), (ii) starter diet containing 0.4% of fennel powder and (iii) starter diet containing 0.8% of fennel powder (DM basis). The effect of treatments on mean dry matter intake was significant (p < 0.05) in the post‐weaning and total experimental periods. Average daily weight gain before (0.38, 0.49 and 0.47 kg/day) and after (0.6, 1.01 and 0.83 kg/day) weaning and during the entire study (0.45, 0.7 and 0.58 kg/day) was influenced by diets of 1, 2 and 3, respectively (p < 0.05). Maximum daily weight gain and the best feed conversion ratio were achieved with 0.4% fennel powder. Mean weaning age of the calves supplemented with fennel powder was lower (p < 0.05) than that of the control group. Ruminal fluid pH in calves offered starter containing 0.8% fennel powder was lower (p < 0.05) compared to calves fed the other diets. Ammonia nitrogen content increased (p < 0.05) in the third week of feeding fennel powder. The mean concentration of total short‐chain fatty acids (SCFA) and propionate molar percentage in the ruminal fluid of the calves fed with the fennel powder were higher (p < 0.05) at 6 weeks and 2 weeks after weaning than control group; however, acetate‐to‐propionate molar ratio was lower (p < 0.05). The results showed that adding 0.4% fennel powder to the starter increased the propionate molar percentage in the rumen and improved the calf performance, allowing the calves to be weaned at an earlier age.     

Utilisation of iodine from different sources in pigs.

Balance experiments have demonstrated that growing pigs fed a ration consisting of wheat, barley, extracted soya meal, dicalciumphosphate, and iodine-free feeding salt utilised 48.8% of the received iodine. The tested supplementary iodine sources included potassium iodide (KI), ethylenediamine dihydroiodide (EDDI), iodine humate (HUI) prepared from iodine acid (HIO3), and the product P containing 0.004% iodine in an oil base (P). The amount of the supplemented iodine was in all cases 1 mg per 1 kg feed. The utilisation of iodine from the supplements reached 93.6, 92.6, 90.7, and 67.9% for KI, EDDI, P, and HUI, respectively. The values were significantly higher compared with controls (P < 0.01). Compared with KI and EDDI, the utilisation of iodine from HUI was significantly lower (P < 0.01). The lower availability of iodine from HUI was probably due to the high binding capacity of humate. The amount of urinary iodine excreted by control pigs receiving in the non-supplemented ration 147.5 micrograms iodine per day, was 40.3 micrograms per day (27.3%). In the pigs receiving in the supplemented ration 1647.5 micrograms iodine per day, the amount of urinary iodine reached 734.9 to 805.0 micrograms per day (44.6 to 48.9%). The corresponding values of faecal excretion were 75.6 micrograms iodine per day (51.2%) for the control pigs and 106.2 to 121.1 micrograms iodine per day (6.45 to 7.35%) for the pigs fed the supplemented rations. A high amount of 528.6 micrograms iodine per day (32.1%) was excreted in the faeces by pigs of the group HUI.     

Provision of beta‐glucan prebiotics (cellooligosaccharides and kraft pulp) to calves from pre‐ to post‐weaning period on pasture

We conducted two feeding experiments to evaluate the effects of supplementation with either cellooligosaccharide or kraft pulp on growth performance in grazing beef calves (Japanese Black) from 4 weeks pre‐weaning to 12 to 16 weeks post‐weaning. In Experiment 1 (20‐week duration), nine calves (2.9‐month‐old females) were assigned to either a control group (CON) or an experimental group (CEL) fed cellooligosaccharide at a rate of 10 g/day mixed with concentrate. Average daily weight gain tended to be greater in CEL than in CON, especially after 1 month of weaning. In Experiment 2 (16‐week duration), 10 calves (2.0‐month‐old females) were assigned to either a control group or an experimental group (KRA) fed kraft pulp at a rate of 10% replacement of total digestible nutrients with concentrate. The proportion of fibrolytic bacteria increased and that of methanogenic Archaea decreased in the rumen microbial community composition of KRA calves in Experiment 2, whereas the decrease in Fibrobacter and Archaea was observed in CEL calves at first 4 weeks in Experiment 1. We conclude that beta‐glucan prebiotic supplementation to grazing calves at pre‐weaning would affect rumen microbial composition and modified rumen fermentation characteristics, leading to a better rumen environment via different means.     

黄芪多糖、银黄联用对新生犊牛免疫力及发病的影响

选取健康新生荷斯坦母犊80 头,随机分为试验组和对照组(40 头/组),试验组给予黄芪多糖5 g、银黄3 g,连用7 天,对照组不给药。第7天时测定免疫指标并观察3 周内母犊腹泻、肺炎发病情况。结果表明,相比于对照组,试验组犊牛血清白细胞介素2(IL-2)浓度提高8.4％、肿瘤坏死因子(TNF-α)浓度降低13.7%;T细胞淋巴亚群分布改善,CD4/CD8值提高6.6%;试验组犊牛血清总蛋白(TP)、IgG浓度较对照组分别提高0.28 g/dL和0.24 mg/mL。犊牛疾病低风险牧场,用药7 天内试验组犊牛腹泻发生率显著降低15.0%(P<0.05);犊牛疾病高发牧场,8~21 天试验组犊牛发病率显著降低35.0%(P<0.05),肺炎发病率显著降低30.0%(P<0.05)。说明黄芪多糖、银黄联用可有效提高新生犊牛免疫力,降低腹泻及肺炎发生率。     

The effect of age at weaning on the health status of bull calves in a feedlot

Incidence of morbidity and mortality in a feedlot were compared among 381 bull calves weaned one month apart (October 3 and November 1). The calves were 156 and 192 days old at weaning in the earlier and later weaned groups, respectively. Following an adjustment period, the calves were fed a mixed finishing diet containing 90% concentrate ad lib for 140 days in a feedlot. The rate of morbidity did not differ significantly between the two weaning groups. Sick calves in the earlier weaned group had a longer treatment period than those in the later weaned group (3.2 vs 1.4 days, p<0.05). Infections of the respiratory tract were the major cause of sickness and most of the respiratory infections occurred in the early stages of the feedlot period. The frequency of respiratory infections was higher among the earlier weaned calves compared with that in the later weaned group (p<0.01) indicating a higher susceptibility to these infections when calves were weaned at younger ages. Bloat was the second most common health problem among the bulls; however, its incidence did not differ between the two groups (p>0.05). The rate of mortality did not differ significantly between the two groups.