The toxicity of myoporum tetrandrum (Boobialla) and myoporaceous furanoid essential oils for ruminants

Boobialla (Myoporum tetrandrum)leaf contains from 0.25 to 0.5% wet weight of furanoid sesquiterpene essential oils of which the main component is dehydrongaione. The plant was toxic when dosed to calves at equivalent dose rates of oils of from 50 to 134 mg/kg, causing mainly extensive haemorrhagic centrillobular necrosis; and to sheep at equivalent dose rates of oil of from 55 to 66 mg/kg, causing either centrilobular or periportal liver lesions with or without acute pulmonary oedema. An essential oil mixture of similar composition derived from Myoporum deserti produced similar syndromes. In addition, treatment of calves with phenobarbitone or Melaleuca linariifolia essential oils prior to dosing with the Myoporum oils caused periportal hepatic necrosis rather than the centrilobular lesion which occurred usually in this species. The liver lesions found in the experimental calves and sheep respectively, were thus similar to those reported in suspected field cases of Boobialla poisoning in cattle and goats in Western Australia. The liver injury that may be expected in intoxication of livestock by myoporaceous plants containing this type of essential oils can thus be either periportal, midzonal or centrilobular necrosis, depending, probably, on the nutritional regime of the animal immediately prior to consumption of the toxic plant.     

饲料中黄曲霉毒素的危害及脱毒方法

黄曲霉毒素是由黄曲霉菌产生的对人体和畜禽有毒的一类生物毒素,给畜牧养殖业造成了极大的损失。黄曲霉毒素对饲料的污染具有季节性和区域性,南方夏季高温高湿的气候极易发生饲料黄曲霉毒素污染。文章主要从黄曲霉毒素对畜禽的危害、黄曲霉毒素的检测方法及脱毒方法进行概述。     

Comparative study on the aflatoxin B1 degradation ability of rumen fluid from Holstein steers and Korean native goats

The aflatoxin B1 degrading abilities of two different ruminants were compared in this study. One set of experiments evaluated the aflatoxin B1 degradation ability of different rumen fluid donors (steers vs. goats) as well as the rumen fluid filtration method (cheese cloth filtered vs. 0.45 µm Millipore) in a 2 × 2 factorial arrangement. Additional studies examined aflatoxin B1 degradation by collecting rumen fluid at different times (0, 3, 6, 9 and 12 h) after feeding. Cannulated Holstein steers (740 ± 10 kg bw) and Korean native goats (26 ± 3 kg bw) were fed a 60% timothy and 40% commercial diet with free access to water. Rumen fluid from Korean native goats demonstrated higher (p < 0.01) aflatoxin B1 degradability than Holstein steers. However, filtration method had no significant influence on degradability. In addition, aflatoxin degradation did not depend upon rumen fluid collection time after feeding, as no significant differences were observed. Finally, a comparison of two types of diet high in roughage found aflatoxin degradability in goats was higher with timothy hay opposed to rice straw, although individual variation existed. Thus, our findings showed the aflatoxin degradability is comparatively higher in goats compared to steers.     

Toxicity of Different Diets Contaminated with Various Fungi to Rice Moth Larvae (Corcyra Cephalonica St.)

Growth studies of rice moth larvae (Corcyra cephalonica st) have been carried out in groundnut meal and wheat bran contaminated with A. flavus, A. oryzae, P. purpurogenus and P. rubrum. It was observed that the diets contaminated with A. flavus only are toxic to these larvae. Wheat bran contaminated with A. flavus is more toxic than contaminated groundnut meal. The higher toxicity of wheat bran contaminated diet has been discussed. Aflatoxins produced in different substrata are shown to differ when analysed chromatographically. Growth studies of rice moth larvae have also been carried out with aflatoxin and the susceptibility of these larvae has been established.     

马黄曲霉毒素中毒性流产的诊断研究

陕西眉县土岭马场突发性马流产,主要病理变化为皮下,粘膜及内脏出血,肝脏和肾脏变性坏死。真菌检验:该场各种饲草、饲料及畜体内外环境中黄曲霉出现率为100％,污染率为8.3～100％。黄曲霉毒素B_1测定:1.流产马驹胃肠内容物、马厩暴皿培养及混合饲料中,产生黄曲霉毒素B_1菌株检出率为96.3％;2.混合饲料中黄曲霉毒素B_1含量为250ppb;3.流产马驹肝脏中黄曲霉毒素B_1残留量达60ppb。生物活性测定证实,自饲料与畜体分离的黄曲霉均具有较强烈的病原性与致死性。     

The effect of the preparation Kurasan (ethoxyquin) on the toxigenic properties of the mold Aspergillus flavus

The effects of Kurasan antioxidant (min. 78% ethoxyquin) were studied on toxin formation of the fungus Aspergillus flavus (strain AF 1982/M1). Aflatoxins mostly of type B1, G1, M1 are produced by the mentioned fungal strain. The strain was cultivated for seven days at high relative humidity on a substrate mostly of cereals (Karlovarské suchary--Carlsbad rusks). Application of 25 mg Kurasan per 1 kg substrate reduced type G1 aflatoxin formation by 90%. The total production of aflatoxins decreased expressively (by 50-60% after addition of 100-200 mg Kurasan per 1 kg substrate). It was only at high amounts of Kurasan that B1 and M1 aflatoxin formation was inhibited and it was correlated. Positive effects of Kurasan antioxidant applied to feed mixtures were demonstrated--aflatoxin formation by toxicogenic fungi is inhibited.     

Major biological consequences of aflatoxicosis in animal production.

Aflatoxins, a family of closely related, biologically active mycotoxins, have been known as a prominent cause of animal disease for 30 yr. The toxins occur naturally on several key animal feeds, including corn, cottonseed, and peanuts. Occurrence of aflatoxin on some field crops tends to spike in years when drought and insect damage facilitate invasion by the causative organisms, Aspergillus flavus and A. parasiticus, which abound in the crop's environment. Acute aflatoxicosis causes a distinct overt clinical disease marked by hepatitis, icterus, hemorrhage, and death. More chronic aflatoxin poisoning produces very protean signs that may not be clinically obvious; reduced rate of gain in young animals is a sensitive clinical register of chronic aflatoxicosis. The immune system is also sensitive to aflatoxin, and suppression of cell-mediated immune responsiveness, reduced phagocytosis, and depressed complement and interferon production are produced. Acquired immunity from vaccination programs may be substantially suppressed in some disease models. In such cases the signs of disease observed are those of the infectious process rather than those of the aflatoxin that predisposed the animal to infection. Mixtures of aflatoxin with other mycotoxins can result in greatly augmented biological responses in terms of rate of gain, lethality, and immune reactivity. Because of its great biological activity, its wide-spread potential presence in areas where critical feed crops are grown, and its propensity to spike in problem years, aflatoxin promises to be a continuing problem in animal production.     

Aflatoxin in a Swedish grain sample

So far aflatoxin has not been detected in crops grown in Sweden but only in imported feedstuffs or in feed mixtures containing imported products. During the survey for other mycotoxins in Swedish crops a compound was detected in oats which, by further analysis, was identified as aflatoxin B1. Quantitative evaluation showed concentrations as high as 2.6 ppm. The fungal population in this highly contaminated sample consisted almost entirely of Aspergillus flavus.     

Progression of aflatoxicosis in growing barrows

The progression of aflatoxicosis was evaluated in growing crossbred barrows given 0, 1, 2, 3, or 4 mg of aflatoxin (AF)/kg of feed for 28 days (6 to 10 weeks of age). On day 28, pigs were euthanatized and necropsied, and tissues were removed for histologic examination. Body weight gains were decreased in barrows fed 2 mg of AF/kg after 7 days and in barrows fed 1 mg of AF/Kg after 14 days. By 28 days, all barrows fed AF had decreased body weights and weight gains. Compared with decreased in all barrows fed AF. Neither liver weights nor bone ash values were altered, although liver lipid values were increased in barrows fed AF. Serum aspartate transaminase, gamma-glutamyl transferase, and alkaline phosphatase activities were increased in barrows fed AF, whereas creatine kinase activity was decreased. Aflatoxin diets resulted in decreases in serum concentrations of urea nitrogen, phosphorus, cholesterol, albumin, and total protein. Histologic alterations in liver included interlobular fibrosis, periportal lipidosis, bile duct hyperplasia, and periportal lymphocytic infiltration. Lymphocytes in the thymus were depleted, and numbers of granulocytic cells in the bone marrow were reduced. The frequency and severity of lesions increased with increased doses of AF.     

Effects of concentrate supplementation on carcass and meat quality attributes of feedlot finished Small East African goats

Effects of concentrate supplementation on carcass and meat quality of feedlot finished Small East African (SEA) goats were assessed using 23 animals (14.5 months old and 20.1 kg body weight). Goats were subjected to four levels of concentrate supplementation: ad libitum concentrate allowance (T100), 66% of ad libitum concentrate allowance (T66), 33% of ad libitum allowance (T33) and no concentrate (T0). All goats were slaughtered after 90 days of experimental period. The ad libitum concentrate intake attained by the goats was about 370 g DM/d. All concentrate-supplemented goats had similar (P > 0.05) total dry matter intake. T100 goats had 31 g and 14 g higher (P < 0.05) daily body weight gain than T33 and T66 goats, respectively. T100 and T66 goats were comparable in final live weight and empty body weight but both were heavier (P < 0.05) than that of T33 and T0 goats. Hot and cold carcass weights for both T100 and T66 goats were 3 kg heavier (P < 0.05) than that of T0 goats. Concentrate-supplemented goats had similar (P > 0.05) EUROP scores for carcass fatness. T100 and T66 goats had 6.5 and 3 units higher (P < 0.05) scores for conformation than T0 and T33 goats, respectively. Dressing percentage increased with levels of concentrate supplementation in a curvilinear fashion, with highest values in T66 goats. At 6 h post-mortem, muscle pH for concentrate-supplemented animals was significantly lower compared with T0 goats. Carcass fat content was 9% higher (P < 0.05) in concentrate-supplemented goats than in their contemporaries. No differences in cooking loss or shear force were observed among treatments, while these variables were affected by the type of muscle. It is concluded that feedlot finishing of SEA had limited effects on meat quality. Finishing SEA goats at 66% of their ad libitum concentrate intake, however, significantly improved weight gains and carcass fatness. Cost–benefit analyses are recommended before embarking on a large scale feedlot finishing of SEA goats.     

The effect of high doses of aflatoxin on the pig]

In two experiments, 18 pigs were given feed contaminated with aflatoxin which had been prepared by the extraction of the cultures of toxinogenic strains of the fungus Aspergillus flavus. After the ingestion of aflatoxin (AFB1) at a dose of 5.4 to 10.5 mg per kg of live weight, the pigs showed symptoms of peracute aflatoxicosis and died within 12--20 hours. After ingestion of AFB1 at a dose of 1.4 or 3.1 mg per kg live weight, the pigs suffered from acute aflatoxicosis and died within 3 to 26 days from the administration of the contaminated feed. In the cases of these experimental aflatoxicoses, clinical symptoms, haematological and biochemical changes in the blood and the patho-anatomical and histological findings in the swine organism were described.     

Prevalence and distribution of caseous lymphadenitis in feral goats

A total of 2,920 feral goats from pastoral areas of Western Australia were examined and the prevalence of caseous lymphadenitis was estimated to be 7.8 +/- 0.9% in goats presented for slaughter. Head, body and visceral lesions were present in 49.3%, 46.7% and 12.3% of affected goats, respectively. A comparison with previously reported data from sheep has been made and significant differences are discussed. Lung lesions were relatively uncommon in goats, whereas the distribution of carcase lesions was similar between the species. Multiple lesions appear to be less common in goats than in sheep.     

Polioencephalomalacia in goats

Of six goats with polioencephalomalacia, three responded to thiamin therapy, whereas three died 2 to 7 days after onset of signs. The goats were 2 months to 2 1/2 years old. They were affected during the winter or early spring, and concentrate feeding was a prominent part of the history. Transketolase activity values were obtained from two affected goats and from nine controls. The affected goats had lower transketolase activity than any of the controls.     

奶牛养殖业中黄曲霉素污染和预防控制

奶牛摄入含有较高黄曲霉菌及毒素的饲料,奶牛代谢功能受到损害,抑制免疫机能,使得乳房炎增加,产奶量下降及奶牛体质下降。黄曲霉毒素B1在奶牛体内转换为黄曲霉毒素M1,并分布在牛奶中,人食用含有超标黄曲霉毒素Ml的牛奶后,能使人发生肝炎、肝癌[1]。作者从事奶牛科学养殖技术服务工作,为了预防和控制奶牛场黄曲霉毒素的危害,提供有关黄曲霉素危害、预防控制措施,有一定的利用性。     

Evaluation of pathological changes in broilers during chronic aflatoxin (50 and 100 ppb) and clinoptilolite exposure

This study was conducted to evaluate the pathological changes in broilers fed a diet containing low-levels of aflatoxin (AF) and clinoptilolite (CLI) until 42 days of age. A total of 576 one-day-old Ross-308 type broiler chicks were treated with varying levels of AF and CLI (15 g kg(-1)). The gross and histopathological changes in the liver, kidneys, spleen, thymus and bursa of Fabricius were investigated and relative organ weights were calculated. Compared to controls, significant changes (P<0.05), such as slight to moderate hydropic degeneration and/or fatty change (8 cases of 10), bile-duct hyperplasia (7 of 10) and periportal fibrosis (5 of 10), were found in chicks fed 100 ppb AF-containing diet. No gross-pathological changes were observed in any treatments. The addition of CLI to the 100 ppb AF-containing diet significantly decreased the number of affected broilers and/or the severity of lesions (hydropic degeneration and bile-duct hyperplasia) in the livers (P<0.05). The addition of CLI to the AF-free diet did not produce any significant lesions compared with the controls.     

Caprine aflatoxicosis: experimental disease and clinical pathologic changes

Groups of 8 male crossbreed domestic goats were given 3 dosage levels of aflatoxin B1 [(AFB1) mg/kg of body weight/day] orally: 0.1 for 34 days; 0.2 for 18 days; or 0.4 for 10 days. Clinical condition, feed consumption, and selected blood values were determined. Clinical signs of toxicosis included decreased feed consumption, slight-to-moderate loss of body weight, mucopurulent nasal discharge, dyspnea, coughing, lethargy, icterus, diarrhea (4 goats), and subnormal body temperature 24 to 48 hours before death. Clinicopathologic changes included increases in total RBC count, PCV, hemoglobin concentration, serum bilirubin concentration, and serum activities of aspartate aminotransferase, isocitric dehydrogenase, and ornithine carbamyl transferase. Goats given the 2 smaller dosage levels of AFB1 had slight increases of serum total protein (TP) concentration compared with control goats, but goats given the larger dosage levels of AFB1 initially had a slight decrease in TP. Aflatoxin had little effect on total WBC count. Serum alanine aminotransferase (ALT) activities in goats given the 2 larger dosage levels of AFB1 were similar to those of control goats, but goats given the smallest dosage level of AFB1 had increased serum ALT activities. Aflatoxin did not produce consistent dose-related changes in serum alkaline phosphatase activities. Seemingly, goats are susceptible to aflatoxin. Onset of clinical signs was dose-related. Onset and magnitude of increases in PCV, hemoglobin concentration, serum bilirubin concentration, and activities of serum aspartate aminotransferase, ornithine carbamyl transferase, and isocitric dehydrogenase were dose-related. Changes in TP and activities of serum ALT and alkaline phosphatase were neither dose-related nor were they potentially useful indicators of toxicosis.     

Effects of level of concentrate supplementation on growth performance of Arsi-Bale and Boer?×?Arsi-Bale male goats consuming low-quality grass hay

Eighteen Arsi-Bale (local) and 18 Boer?×?Arsi-Bale (crossbred) male goats, initially approximately 10 months of age, were used in a 12-week experiment to investigate potential interactions between genotype and nutritional plane in growth performance, carcass and skin characteristics, and mass of non-carcass components. Grass hay (6.7% crude protein and 71.9% neutral detergent fiber) was consumed ad libitum supplemented with 150, 300, or 450 g/day (dry matter; low, moderate, and high, respectively) of a concentrate mixture (50% wheat bran, 49% noug seed cake, and 1% salt). Initial body weight was 20.7 and 14.0 kg for crossbred and local goats, respectively (SE = 0.36). Hay dry matter intake was greater (P < 0.05) for crossbred vs. local goats (461 and 429 g/day) and similar among concentrate levels (438, 444, and 451 g/day for high, moderate, and low, respectively; SE = 4.7). Average daily gain was greater (P < 0.05) for crossbred than for local goats (36.6 and 20.8 g) and differed (P < 0.05) among each level of concentrate (43.7, 29.6, and 12.8 g for high, moderate, and low, respectively). Dressing percentage was similar between genotypes (41.1% and 41.1% live body weight for crossbred and local goats, respectively; SE = 0.59) and greater (P < 0.05) for high vs. low (43.5% vs. 38.7% live body weight). Carcass weight differed (P < 0.05) between genotypes (9.23 and 6.23 kg for crossbred and local goats, respectively) and high and low (8.80 and 6.66 kg, respectively). Carcass concentrations of physically dissectible lean and fat were similar between genotypes and high and low concentrate levels. There were few differences between genotypes or concentrate levels in other carcass characteristics such as color and skin properties. Relative to empty body weight, the mass of most non-carcass tissues and organs did not differ between genotypes. However, the low concentrate-level mass of omental-mesenteric fat was greater (P < 0.05) for local vs. crossbred goats (1.06% vs. 0.54% empty body weight, respectively). In conclusion, growth performance and carcass weight advantages from crossing Boer and Arsi-Bale goats were similar with a low-quality basal grass hay diet regardless of level of supplemental concentrate.     

不同补饲水平对陕北白绒山羊产绒性能的影响

通过研究不同补饲水平对陕北白绒山羊绒的生长和产绒量的影响,探索陕北白绒山羊在冬春季节枯草期放牧时的补饲方案。试验抽取横山县某羊场同年龄段体重相近健康的陕北白绒山羊成年母羊120只,随机分为四组,每组30只。对照组,每天补饲0.2kg玉米;三个试验组分别每天补饲配合精料0.2、0.3、0.4kg。结果表明,在自然放牧条件下,陕北白绒山羊在冬春枯草季节通过补饲可延长绒毛的快速生长期至12月份,而1月至抓绒前绒毛生长缓慢。试验期内0.2kg组、0.3kg组、0.4kg组绒长的增长量分别较对照组增加了66.45%,67.10%,72.36%,产绒量分别提高了26.75%、29.62%、22.48%,三个试验组绒长度及产绒量均显著高于对照组（P〈0.05）,各试验组之间差异不显著（P〉0.05）。研究表明,成年母羊在冬春季节归牧后,补饲0.2kg配合精料可显著提高绒毛的长度和产绒量,但进一步增加配合精料的补给量,效果并不明显。     

Effect of concentrate supplementation levels on growth and slaughter characteristics of SEA and SEA × Norwegian goats under on-farm conditions

A 2?×?3 factorial experiment was carried out to evaluate the effect of goat genotypes and different concentrate levels on growth and slaughter characteristics of Small East African × Norwegian crossbred (SEA × N) and Small East African (SEA) goats. The three concentrate levels were T0 (no access to concentrate), T66 (66 % access to ad libitum concentrate allowance) and T100 (100 % access to ad libitum concentrate allowance). Twenty-four castrated goats of each genotype (18 months old with an average weight of 16.7?±?0.54 kg) were randomly allotted into T0, T66 and T100 treatments. Daily feed intake and fortnight body weight measurements were recorded for the whole 84-day experimental period, after which the animals were slaughtered. Feed intake of T100 animals was 536 g/day, which was 183 g/day higher than that of the T66 group. Supplemented goats (T66 and T100) had significantly (P?<?0.05) higher daily gain and body condition score, and better feed conversion efficiency and dressing percentage than T0 goats. The SEA goats had higher (P?<?0.05) hot carcass weight (8.2 vs. 7.9 kg) and showed better (P?<?0.05) dressing percentage than SEA × N animals. Among supplemented goats, the cost of a 1-kg gain under T66 was Tshs 213/= cheaper than T100 (US$1?≈?Tshs 1,500). It is concluded that goats should be grazed and supplemented with 353 g concentrate/day for satisfactory fattening performance and higher economic return on investment.     

糊化淀粉尿素对山羊饲喂效果的研究

糊化淀粉尿素对山羊饲喂效果的研究@顾炳龙@王福泉...