用植物蛋白和赖氨酸代替鱼粉降低鱼饲料中蛋白和磷并减少水质污染的效果(一)

前言水产养殖业对环境的影响取决于水产动物的种类、养殖方法、养殖密度、饲料类型以及养殖场的管理(Wu,1995)。当前水产养殖场排放过多的营养物,特别是氮和磷,这种情况正日益受到关注。事实上,这样的排放会使被排入的水域发生富化作用(Skonberg等,1997),而氮和磷的主要来源是饲料(Cho和Bureau,1997)。因此,制定鱼饲料配方应当让饲料的养分水平刚够满足鱼的营养需求,这是降低养殖场环境污染的有效途径(Talbot和Hole,1994)。制作肉食性鱼饲料通常需要大量鱼粉。鱼粉在大多数商业肉食性鱼饲料中占配方的30%~50%,一直被作为日粮蛋白的主要来…     

The pollution of water by fish feeding

Fish feeding causes water pollution by uneaten feeds, by faeces and by excretions via gills and kidneys. Pellet stability is essential for maximizing the consumed proportion of diets offered. At given water temperatures and feeding to satiation feed intake of trout its negatively correlated to dietary concentration of digestible energy. Increasing DE from 15 to 20 MJ per kg reduces feed conversion ratio from 1.33 to 1.00 and, concurrently, reduces the amount of organic matter voided in faeces from 680 to 230 g per kg weight gain of trout. For minimizing water pollution, trout diets containing 20 MJ DE per kg should not exceed 40% Protein and 0.6% P.     

紫花苜蓿浓缩叶蛋白替代鱼粉对星斑川鲽氮磷排泄的影响

本研究以体重为(83.0±0.20)g星斑川鲽幼鱼为试验对象,研究紫花苜蓿浓缩叶蛋白(APC)替代0%(S0)、10%(S10)、20%(S20)、30%(S30)、40%(S40)、50%(S50)的鱼粉对其氮磷排泄的影响。结果显示:各试验组氮摄入量、氮沉积率均呈先稳定后显著下降的趋势。氮排泄量与氮沉积率变化趋势相反,当鱼粉替代水平>30%时显著上升(P<0.05)。磷摄入量与磷排放量均呈显著下降趋势(P<0.05),磷沉积率呈上升趋势(P<0.05)。与对照组相比,可溶性磷酸盐排泄量随APC替代鱼粉量的增加呈下降趋势(P<0.05)。综合上述试验结果,从保护养殖水体的角度出发,APC替代鱼粉蛋白的比例应控制在30%以内。     

Response of growing-finishing pigs to decreasing floor space allowance and(or) virginiamycin in diet

Five hundred forty crossbred pigs were utilized in four trials (10 replications) at two stations to determine the separate and interacting effects of decreasing floor space allowance with or without the addition of virginiamycin to the diet on performance of growing-finishing pigs. Pigs were allowed .37, .33 or .28 m2/pig during the growing phase (23 to 55 kg) and .74, .66, .56 m2/pig during the finishing phase (55 to 100 kg) and fed either a corn-soybean meal control diet or the control diet plus 11 mg of virginiamycin/kg of diet. Floor space allowances were achieved by varying pen size, so the number of pigs and feeder space per pig were constant for all pens. During the growing phase, daily gain (P less than .01) daily feed intake (P less than .05) and feed conversion ratio (P less than .05) decreased as floor space allowance decreased. During the finishing phase and for the total test period, daily gain (P less than .01) and feed conversion ratio (P less than .05) were reduced but daily feed intake was not affected (P greater than .05) by restricted floor space allowance. The addition of virginiamycin to the diet had no effect on pig performance. The virginiamycin X floor space allowance interaction was not significant, suggesting that pigs fed a diet with or without virginiamycin responded similarly to restricted floor space allowance. The data suggest that the addition of virginiamycin to the diet was ineffective in overcoming the decrease in performance of growing-finishing pigs caused by crowded conditions.     

Effect of pesticide water pollution on some haematological, biochemical and immunological parameters in Tilapia nilotica fish

Nine groups of Tilapia nilotica fish each consisting of 50 fish were used to assess the effect of pesticides on the haematological, biochemical and immunological parameters in fish. Four groups were injected with 0.05 ml of Staphylococcus aureus antigen plus complete Freund's adjuvant, the first group (G1) was exposed to lindane treatment, the second (G2) was exposed to dialdrin, the third (G3) was exposed to diazinon and the forth group (G4) was exposed to malathion. Four other groups were not immunized, but injected with the adjuvant and exposed to the pesticides, the fifth group (G5) was exposed to lindane, the sixth (G6) was exposed to dialdrin, the seventh (G7) was exposed to diazinon and the eighth group (G8) was exposed to malathion. The ninth group (G9) was exposed to water without any pesticide treatment and served as controls. Both vaccinated and non-vaccinated groups were exposed to 1/10 LC50 of the tested pesticides for 30 days. The results revealed that the mean total RBCs, WBCs counts, PCV, Hb, MCV, MCH, MCHC values were lower in vaccinated groups than in the groups exposed to the tested pesticides. The total protein, globulin and serum enzymes ALAT; ASAT values as well as macrophage phagocytic index and antibody titer were lower in vaccinated as compared to the non-vaccinated groups.     

泌乳奶牛日粮碳、氮、硫、磷营养素平衡性及粪污减排的研究进展

奶牛养殖业是我国畜牧业的重要支柱之一,养殖规模在未来一段时间内还将有一定幅度地提高,相应地,排泄废弃物也将随之提高,这将对养殖生态环境和农业用地营养素的消纳带来一定的压力。奶牛营养的精准平衡供给是缓解生产规模扩大与环境容纳量有限矛盾的必要措施之一。本文即通过泌乳奶牛生产中日粮碳氮硫磷供给,粪污营养素排放及与耕地承载能力等的研究综述,探讨日粮中碳氮硫磷精准平衡的供给,为奶牛养殖的精准饲养和减排增效提供一些参考资料。     

淡水鱼类饲料原料选择和原料质量控制技术(2)

3淀粉类饲料 鱼类利用淀粉作为能量来源的能力远不如陆生动物，但淀粉类饲料又是最廉价的饲料原料，所以在淡水鱼饲料中依然占有很大的比例。     

Replacement of fish meal protein by surimi by‐product protein in the diet of blue gourami Trichogaster trichopterus fingerlings

Based on the nutrient requirement of Trichogaster trichopterus, a fish meal–based basal diet with 350 g/kg diet crude protein and 16.7 MJ/kg energy was formulated, in which the fish meal protein was replaced by surimi by‐product protein at 0.0 (control), 12.5, 25, 50, 75 and 100% levels. The formulated diets were fed ad libitum to T. trichopterus fingerlings (4.80 ± 0.03 g) in triplicate groups for 45 days in a closed water system. Eighteen fibre‐reinforced plastic tanks with 200 l of water were used for rearing the fish. Weight gain, specific growth rate, feed/gain ratio, protein efficiency ratio, nutrient retention and digestibility (protein and energy) of fish were not affected (p > 0.05) up to 50% fish meal protein replacement level by surimi by‐product protein. While whole‐body protein content of fish was marginally decreased, the lipid content was increased with increase in surumi by‐product incorporation level in the diet. The study results suggest that the fish meal protein, which is scarce and costly nowadays, could be replaced up to 50% by surimi by‐product protein in the diet of blue gourami without hampering the growth and nutrient utilization of fish.     

Effects of different phosphorus sources in the diet on bone composition and stability (breaking strength) in broilers

In two fattening trials (in each 100 broilers kept in four groups with 25 animals) as well as in a balance trial (four groups with four broilers in a group) the effects of inorganic phosphorus sources [monocalcium phosphate (MCP), dicalcium phosphate (dihydrate; DCP) and defluorinated phosphate (DFP)] in broiler diets were examined. The four diets contained up to 9 g calcium and 6 g phosphorus per kg and comparable energy and nutrient contents. Controls were fed a commercial diet with Ca-Na-phosphate as inorganic phosphorus source supplemented by phytase. In both fattening trials body weight gain, feed consumption and feed conversion were proved as well as the calcium and phosphorus levels in serum, the breaking strength of tibia or humerus and the femur mineralization (ash content in the fat free dry matter). Furthermore, in the balance trial the retention of calcium and phosphorus was determined by calculation (intake minus excretion) as well as by analysis of body composition. On a high performance level (that was only slightly influenced by the different treatments), the addition of DFP resulted in significantly reduced phosphorus availability (estimated by analysis of the whole carcass: control/MCP/DCP/DFP: 48.6/46.0/45.7/35.5%). The significantly reduced phosphorus level in serum (1.77 +/- 0.20/1.77 +/- 0.24/1.73 +/- 0.28 1.34 +/- 0.33 mmol/l) indicates the lower phosphorus retention in broilers given DFP. Furthermore, the crude ash content (582 +/- 17.6/580 +/- 18.6/563 +/- 15.2/547 +/- 29.7 g/kg fat free DM) and the breaking strength of bones (in right tibia in trial 2: 232 +/- 82.4/227 +/- 51.5/232 +/- 41.7/196 +/- 655 N) were lowest when given DFP. For diagnostic purposes it is of special interest that the phosphorus levels in the serum reflected markedly the different concentrations of available phosphorus in the diet.