Replacement of fish oil in plant‐based diets for Pacific white shrimp,Litopenaeus vannamei,by stearine fish oil and palm oil

Stearine fish oil (SFO) and palm oil (PO) have emerged as promising alternatives for the replacement of fish oil (FO) in aquafeeds. This study evaluated the replacement of FO with alternative oils in practical diets for Litopenaeus vannamei. In a clear brackish water study (14.1 g/L) utilizing shrimp (0.29 ± 0.02 g, initial weight), FO was replaced by SFO at inclusion ratios of 100:0, 75:25, 50:50, 25:75, and 0:100 (FO:SFO) and PO as 90% of FO. After 55 days, no significant differences (p < 0.05) in final weight, growth, or survival of shrimp were observed. A second trial (8 weeks) in low‐salinity water (2.1 g/L) with shrimp (0.92 ± 0.02 g, initial weight) evaluated diets with 100% FO, 100% SFO, 90% PO, 90% soybean oil (SO), or 90% flaxseed oil (FXO) as a replacement for FO and four commercially produced diets with 2% of FO, SO, PO, or FXO. One treatment received half rations of the commercial FO diet, and one treatment was based entirely on natural productivity. Results show that the fatty acid profiles of the tail muscle conformed to the lipids of the feed, and highly unsaturated fatty acids (HUFAs) were preserved. Following 8 weeks of culture, there were no significant differences in production performance.     

Seasonal growth and diet of juvenile chinook salmon (Oncorhynchus tshawytscha) in demonstration channels and the main channel of the Waitaki River, New Zealand, 1982–1983

Abstract– Juvenile chinook salmon in the Waitaki River, New Zealand and demonstration channels, living at about 16°C, increased in length by 0.32 mm day⁻¹ between 4 November and 4 March. They gained weight quickly, accumulated large visceral fat deposits and had high conditions factors. At 1600 h, stomachs averaged half full. The number of prey tended to decline as the fish grew and consumed larger items. Initially the diet was based mainly on chironomid larvae, but by December it included a diversity of prey in more equal proportions. These included Deleatidium in the Waitaki; amphipods in the demonstration channels; various trichopterans, hemipterans, elmid beetles, zooplankton. terrestrial dipterans and a variety of other prey. There were significant differences between sites in numbers of prey consumed and these probably reflected differences in the benthos. Diets in the Waitaki differ from those in the Rakaia River and the food of juvenile salmon appears closely linked to the availability of a diverse range of possible prey.     

Effects of fat supplementation on plasma glucose,insulin and fatty acid analysis in ponies maintained on a forage‐based diet

The objective of this study was to observe how fat incorporated into an equine forage‐based diet through supplementation altered levels of plasma glucose, insulin and fatty acids. Five Shetland/Hackney cross pony mares were fed alfalfa pellet diets top dressed with commercially available vegetable oil (blend of soya bean, canola and corn oils) at 0%, 5%, 10% or 15% of diet. Ponies were randomly assigned one of four diets to start, with a 14‐day adjustment period between transitioning to another one of the four diets. Ponies were gradually adapted to the new diet within the 14‐day period before a five‐day trial period. Each pony received all four diets by the end of the study. Each trial was a five‐day period with a three‐day sample collection. Blood samples for each collection week were taken 0, 30, 60, 90, 120, 150, 180, 210, 240 and 270 min and at 5, 6, 7, 8, 9 and 10 hr post‐feeding. Excess fat did not impact plasma glucose (p > .1), nor did it affect blood plasma insulin concentration. While there was no time alteration found for plasma fatty acid concentration (p > .1), C14:0 increased when ponies were fed 0% fat and C18:2 decreased when ponies were fed 0% fat. Plasma fatty acids (% of total FA) were higher in C18:0, C18:1, C18:2 and C20:1 in the added fat diets (p < .1). These findings suggest the amounts reported in this study of fat supplementation on a forage‐based diet did influence the fatty acid analysis within the pony, but did not negatively impact blood glucose and insulin concentrations.     

The effects of creep feed composition and form and nursery diet complexity on small intestinal morphology and jejunal mucosa-specific enzyme activities after weaning in pigs

Fifty-six litters from first-parity sows standardized to 12 piglets were used to determine the effects of creep feed composition and form and the provision of low- or high-complexity nursery diets on the evolution of small intestinal histomorphology and jejunal mucosa-specific enzyme activities postweaning. At 5 d of age, litters (initial bodyweight [BW] 2.31 ± 0.61 kg) were assigned to one of four creep feeding regimens (n = 14): 1) commercial creep feed (COM), 2) liquid milk replacer (LMR), 3) pelleted milk replacer (PMR), or 4) no creep feed (NO). At weaning (21 d of age), six pigs per litter were provided a HIGH- (contained highly digestible animal proteins) or LOW- (contained corn and soybean meal as main protein sources) complexity nursery diet (n = 7). At 21, 28, and 59 d of age, two pigs per pen (one castrated male and one female) were euthanized, and ileal and jejunal segments for histomorphological measurements and jejunal mucosal scrapings were collected to determine specific mucosa enzyme activities. At weaning, pigs provided COM had a greater ileal absorptive capacity (M) than LMR or NO, which were not different (14.1 vs. 10.4 and 10.5 ± 0.9 μm²; P < 0.05); PMR was intermediate. On days 28 and 59, M was not different among pigs regardless of creep feed treatments. Pigs fed LOW had reduced jejunal villus height (VH; P < 0.001) and M (P < 0.001) on day 28 vs. day 21. The VH and M were not different for pigs fed HIGH or LOW by the end of the nursery period. For all dietary treatments except COM-HIGH and COM-LOW, jejunal mucosal maltase-specific activity was not different between days 21 and 28 of age but greater on day 59 (P < 0.05). For pigs that received COM-HIGH, maltase-specific activity was not different between days 21 and 28 but greater on day 59 than day 28 (P < 0.05). For pigs that received COM-LOW, maltase-specific activity was not different between days 21, 28, and 59. Regardless of creep or nursery treatment, sucrase-specific activity was the greatest on day 59, followed by days 21 and 28 (P < 0.001), and lactase-specific activity was greater on day 21 than on days 28 and 59 (P < 0.001), which were not different. Therefore, pigs that provided LOW diet had greater villus atrophy and reduced M during the first week after weaning vs. pigs that provided HIGH, regardless of creep feeding regimen, but were able to recover by the end of the nursery period.     

昆虫人工卵制卵机的研究

本文报道一种结构比较简单的昆虫人工卵制卵机,设计原理与同类其它制卵机不同。用本机制卵,成卵率平均为86％,卵粒外径约564微米,卵壳厚度约17微米。每小时可制人工卵2公斤。用切片石蜡为卵外壳、蛋白质水解物等为内含物制成的人工卵,饲养中华草蛉和大草蛉,成茧率可达97％,与用米蛾卵饲养的结果无明显差异。     

温度和食物种类对红褐斑腿蝗取食、生长及肠道消化酶活性的影响

在实验室不同温度(10、25、35℃)下,比较茶叶和小麦苗对红褐斑腿蝗Catantops pinguis取食利用能力的影响及其与蝗虫肠道消化酶活性之间的关系。结果表明,温度对蝗虫的日均取食量、相对生长率影响极显著,均表现为35℃>25℃>10℃,对日均绝对增重(干重)的影响趋势与此相同,但各处理温度间差异不显著,对消化酶活性影响显著,总体表现为高温时活性大于低温,但不同的水解酶表现各不相同。食物种类对近似消化力影响不大,但对小麦苗的取食量极显著高于对茶叶的取食量;三个处理温度下日均绝对增重均以小麦苗为食时高于以茶叶为食,但差异不显著,以小麦苗为食时相对生长率极显著高于以茶叶为食,显示食物对相对生长率影响显著;取食小麦苗时肠道消化酶活力极显著高于以茶叶为食,只有类胰凝乳蛋白酶活力差异不显著。     

不同饲料颗粒大小对肉牛瘤胃发酵性能的影响

本试验旨在研究不同粒径颗粒饲料在自由采食和限饲条件下对肉牛瘤胃发酵性能的影响。试验日粮分为粉料、直径为3 mm的颗粒料和直径为8 mm的颗粒料,饲喂方式分为自由采食和限饲。采用2×3因子设计试验,选择3月龄的肉牛12头,试验前9周分别用3种料饲喂(自由采食),之后6周进行限饲。自由采食在前4 h较后4 h显著提高了粗料摄入量(P <0.05)。P8组较粉料和P3组显著降低了自由采食8 h的粗料摄入量(P <0.05)。限饲条件下,粉料和P3组早上采食粗饲料较下午高(P <0.05)。P8组较粉料和P3组显著降低了早上粗料摄入量(P <0.05)。采食后两个阶段瘤胃pH都显著降低(P <0.05);无论是自由采食还是限饲P3组较其他组均显著降低了瘤胃氨气含量(P <0.05);进食4 h后,P3组较粉料和P8组显著提高了瘤胃乳酸含量(P <0.05)。进食后,两个阶段均显著提高了瘤胃挥发性脂肪酸含量(P <0.05)。自由采食条件下,粉料和P3组较P8组显著降低了采食4和8 h后瘤胃乙酸含量(P <0.05)。3 mm直径颗粒可以提高瘤胃发酵速度,降低瘤胃pH,较粉料有增加酸中毒的风险。颗粒直径提高至8 mm,无论自由采食还是限饲都不影响干物质摄入量,可以降低瘤胃发酵速度。     

黑麦日粮中添加不同酶制剂对肉仔鸡生产性能及肠道食糜粘度的影响

本文用１８０只肉仔鸡,进行饲养试验,研究黑麦日粮添加４种不同酶制剂,ＮＱ、ＲＭ１、ＲＭ２和ＲＭ３,对肉仔鸡的生产性能以及肠道食糜及泄殖腔粪样粘度的影响。酶制剂ＮＱ和ＲＭ１含有高的木聚糖酶活（７７００ＩＵ／ｇ,３４５０ＩＵ／ｇ）能极显著改进（Ｐ＜０．０１）增重（８．４％,１６．０％）和饲料转化率（１５．４％,１４．４％）,ＲＭ２,含有相对低的木聚糖酶（６０ＩＵ／ｇ）和相对高的阿拉伯呋喃糖苷酶活（５．３ＩＵ／ｇ）,产生类似的效果（Ｐ＜０．０１）：增重提高１０．５％,饲料转化率提高１１．８％,然而ＲＭ３,由于含木聚糖酶活较低（５ＩＵ／ｇ）和较高的蛋白酶活（８０ＩＵ／ｇ）,则对增重无效,但亦可改善饲料转化率（６．４％,Ｐ＜０．０５）。上述酶制剂在降低肠道食糜和泄殖腔粪样粘度方面与增重和饲料转化率有相同的趋势。一般说来,日粮中添加的酶量与食糜相应的粘度成倒数关系。这些结果证明：具有较高木聚糖酶活的酶制剂能明显降低肠道食糜和泄殖腔粪样的粘度,从而改善饲喂黑麦日粮肉仔鸡的生产性能。     

日粮脂肪酸来源对动物产品中不饱和脂肪酸影响的研究进展

主要就动物日粮脂肪酸来源对肉、蛋和奶中不饱和脂肪酸含量的影响作一简要综述。     

日粮蛋白水平对黄羽鹌鹑产蛋性能和血清生化指标的影响

本试验旨在研究日粮粗蛋白质水平对黄羽鹌鹑产蛋性能和血液生化指标的影响。以粗蛋白质水平分别为:17.75%、19.95%、21.85%、24.08%的日粮作为4个处理(处理1、2、3、4),选用35日龄蛋用黄羽鹌鹑120只随机分为4组,每组3个重复,每个重复10只。试验预试期15 d,正试期30 d,试验结果表明:不同蛋白质水平的处理,平均蛋重差异不显著(P>0.05);处理2的平均产蛋率显著高于其他处理(P<0.05);料蛋比显著低于其他处理组(P<0.05);处理1的干物质采食量显著高于处理3和处理4(P<0.05);谷丙转氨酶处理1(17.75%)显著低于处理3(21.85%)(P<0.05)。谷草转氨酶各处理差异不显著(P>0.05);处理3(21.85%)的血清总蛋白显著高于处理1(17.75%)(P<0.05),其他处理血清总蛋白差异不显著(P>0.05);血清尿氮和磷各组差异不显著(P>0.05),血清尿氮处理2(19.95%)最高,磷处理1(17.75%)最高。结果表明,日粮粗蛋白质水平对黄羽鹌鹑产蛋性能和部分血清生化指标有显著影响。