Influence of multiple amino acid supplementation on the performance of rainbow trout, Oncorhynchus mykiss (Walbaum), fed soya based diets

Using rainbow trout, Oncorhynchus mykiss (Walbaum), of approximately 50 g, a 63 day feeding trial was undertaken to evaluate the efficacy of individual and multiple amino acid supplements in diets where soyabean meal was used as the principle protein source. Iso-nitrogenous diets (45% crude protein) were formulated where the control diet (F) contained fishmeal as the reference protein and a solvent extracted soyabean meal (S) replaced approximately 66% of this protein source. The soyabean containing diets were then supplemented with crystalline amino acids thus; methionine only, dual supplemented with two methionine and lysine levels and finally, a supplement comprising methionine, lysine, tryptophan, threonine, arginine and histidine. The results showed that soyabean meal (SBM) was inferior to the reference protein when SBM was used to replace 66% of the fishmeal and that no significant restoration in growth, feed efficiency and apparent net protein utilization was obtained by either methionine only or dual methionine and lysine supplementation. However, by comparison with the fish fed the unsupplemented, single and dual supplemented diets, multiple amino acid incorporation was associated with significantly improved percentage weight gain, specific growth rate and marginal improvements in apparent net protein utilization. However, performance was not equal to that of the fish fed the fishmeal based control diet. The results are discussed with respect to the level of each of the essential amino acids (EAA) as a proportion of the total EAAs (A/E index) of test diets by reference to the whole body tissue amino acid profile of rainbow trout.     

疾病的演化

许多因素造成了疾病的演化 ,我们会面临什么样的未来呢 ?     

DENTIGEROUS CYST IN THE VENTRAL CONCHAL SINUS OF A HORSE

A 14-year-old Quarter Horse was presented for evaluation of a chronic, intermittent purulent discharge from the left nostril. A radioopaque mass and multiple, air-fluid interfaces in the paranasal sinuses were identified on survey radiographs. The mass was removed and identified as a dentigerous cyst. Substantiated reports of dentigerous cysts in the paranasal sinuses are rare.     

Effect of Weight Gain and Subsequent Weight Loss on Glucose Tolerance and Insulin Response in Healthy Cats

The effects of weight gain and subsequent weight loss on glucose tolerance and insulin response were evaluated in 12 healthy cats. Intravenous glucose tolerance tests (IVGTT) were performed at entry into the study, after a significant gain of body weight induced by feeding palatable commercial cat food ad libitum, after a significant loss of body weight induced by feeding a poorly palatable purified diet to discourage eating and promote fasting, and after recovery from fasting when body weight had returned to pre-study values and cats were eating commercial foods. A complete physical examination with measurement of body weight was performed weekly, a CBC and serum biochemistry panel were evaluated at the time of each IVGTT, and a liver biopsy specimen obtained 2 to 4 days after each IVGTT was evaluated histologically for each cat. Mean serum glucose and insulin concentrations after glucose infusion and total amount of insulin secreted during the second 60 minutes and entire 120 minutes after glucose infusion were significantly (P > .05) increased after weight gain, as compared with baseline. At the end of weight loss, cats had hepatic lipidosis and serum biochemical abnormalities consistent with feline hepatic lipidosis. There was a significant (P > .05) increase in mean serum glucose concentration and t_1/2, and a significant (P > .05) decrease in mean serum insulin concentration and the glucose disappearance coefficient (K) after glucose infusion for measurements obtained after weight loss, compared with those obtained after weight gain and at baseline. Insulin peak response, insulino-genic index, and total amount of insulin secreted during the initial 10 minutes, 20 minutes, and 60 minutes after glucose infusion were decreased markedly (P > .05), compared with measurements obtained after weight gain and at baseline. In addition, the total amount of insulin secreted for 120 minutes after glucose infusion was decreased markedly (P > .05) in measurements obtained after weight loss, compared with those obtained after weight gain. At the end of recovery, all cats were voluntarily consuming food, serum biochemical abnormalities identified after weight loss had resolved, the number and size of lipid vacuoles in hepatocytes had decreased, and results of IVGTT were similar to those obtained at baseline. These findings confirmed the reversibility of obesity-induced insulin resistance in cats, and documented initial deterioration in glucose tolerance and insulin response to glucose infusion when weight loss was caused by severe restriction of caloric intake.     

Evaluation of upper respiratory tract function during strenuous exercise in racehorses

Forty-six racehorses with a history of poor performance underwent endoscopic evaluation of laryngeal and pharyngeal function while exercising on a high-speed treadmill. This evaluation allowed the definitive diagnosis of intermittent or continual upper respiratory tract obstruction as a cause of poor performance, as well as the documentation of the dynamic functional anatomy of the obstruction. Ten of the horses (22%) were determined to have a functional abnormality of the upper respiratory tract. These abnormalities included epiglottic entrapment (1 horse), persistent dorsal displacement of the soft palate during exercise (4 horses), and left laryngeal hemiplegia (5 horses). Thirty-two horses were observed to have signs of left laryngeal hemiparesis (asynchronous arytenoid movement) at rest that did not impair full laryngeal abduction during strenuous exercise.     

世界猪病的发展与演变

1 疾病是生态的和进化的动态过程 任何疾病都是某些相互作用持续进行的结果,这种相互作用在传统上一直被称为“病原-宿主-环境”三者之间的相互作用,这种概念已经相当过时。甚至较新的病因网络观点仍然有其局限性,因为它仅仅考虑到危害因素,而疾病的发展还包括时间和空间上的因素。我们只注意捕捉疾病的个别图像,这种思维方式往往左右了我们对疾病的考虑。动物死亡之后,病理学家看到的只是疾病的“静态照片”;临床专家看到的只是主要时期的