虹鳟鱼饲料中肉骨粉替代鱼粉的研究

研究在饲料中用10%肉骨粉替代10%鱼粉对虹鳟鱼的影响。试验分2个处理组,处理1组和处理2组饲料中鱼粉和肉骨粉的添加量分别为15%、10%和5%、20%,试验共进行11周。试验结果表明,2个处理组虹鳟鱼成活率、增重率、特定生长率、肥满度和饵料系数未产生显著的差异(P>0.05);处理2组单位鱼成本下降0.68元/kg,显著提高了体脂肪含量、肝体比、脏体比(P<0.05),粗灰分含量显著下降(P<0.05),体水分和体蛋白含量也表现出下降的趋势。可见,用10%肉骨粉替代10%鱼粉对虹鳟鱼的生产性能没有影响,但可影响体脂肪含量。     

Comparison between wheat, triticale, rye, soyabean oil and strain of laying bird on the production, and cholesterol and fatty acid contents of eggs.

1. The effects of feeding three types of cereal grain (wheat, triticale or rye) and soyabean oil (0 or 20 g/kg) over a 12-week period on the production, yolk cholesterol and yolk fatty acid concentrations of three strains of laying pullets were studied. 2. Pullets fed on wheat- or triticale-based diets had higher body weight gains, egg productions, egg weights, egg mass and lower yolk cholesterol concentrations than pullets fed on rye-based diets. However, there were no significant differences between the cereals in yolk cholesterol content. 3. There were no significant differences between the three cereals in total food consumption of pullets nor of yolk weight nor yolk concentration of palmitic, stearic and oleic acids. 4. Pullets fed on triticale-based diets had higher yolk linoleic acid concentrations and lower yolk oleic acid: linoleic acid ratios than pullets fed on rye- or wheat-based diets. 5. Soyabean oil supplementation increased egg production, egg mass, yolk linoleic concentration and yolk unsaturated to saturated fatty acid ratio, but reduced yolk oleic acid: linoleic acid ratio. 6. There were differences between strains of pullets in weight gain, food consumption, rate of lay, egg weight and yolk cholesterol, but not in yolk fatty acid concentrations. 7. It was concluded that wheat- or triticale-based diets gave good production of eggs of lower cholesterol content, that soyabean oil supplementation gave eggs with a high unsaturated to saturated fatty acid ratio and that two strains of layers produced eggs with lower yolk cholesterol concentrations than a third strain.     

Double-yolked pheasant eggs provide an insight into the control of albumen secretion in bird eggs

1. The possible role of the presence of the yolk in stimulating secretion of albumen was investigated. 2. Double-yolked and single-yolked pheasant (Phasianus colchinus) eggs were opened to determine the masses of the shell, albumen and yolk(s). 3. In double-yolked eggs, the two yolk masses were not significantly different. Albumen mass was increased above that expected from an egg with a single-yolk of comparable size but below that expected from an egg having a mass of the combined yolks. The mass of shell per unit area reflected the mass of the initial mass of the egg irrespective of the number of yolks. 4. The additional mass of albumen is unrelated to yolk or initial egg mass. It is postulated that in double-yolked eggs the oviduct is mechanically stimulated by the presence of both yolks, which empties the stores of water-soluble albumen proteins in the magnum wall. Such stores are insufficient to provide the same amount of protein for the two yolks.     

奥尼罗非鱼日粮中酶解大豆蛋白部分替代鱼粉的研究

在奥尼罗非鱼（Oreochromis niloticus ♀×O．aureus ♂）日粮中分别添加0、2．5％、5％、7．5％、10％的酶解大豆蛋白．相应等氮替代0、21．89％、43．77％、65。66％、87。54％鱼粉．观察对奥尼罗非鱼生长性能的影响。试验发现,随着替代鱼粉比例的逐渐增加,奥尼罗非鱼的平均日采食量逐渐下降,差异显著（P〈0．05）,相对体重增长率、特定生长率逐渐下降,差异不显著（P〉0．05）,肝体比呈逐渐下降趋势,对肥满度无显著影响（P〉0．05）,存活率呈逐渐上升趋势：蛋白质效率、饲料系数、单位增重成本在添加2．5％大豆蛋白,均出现拐点,蛋白质效率此时达到最高,之后逐渐下降,饲料系数、单位增重成本在此拐点值最低,之后逐渐升高,但差异均不显著（P〉0．05）。     

Revealing genetic relationships between compounds affecting boar taint and reproduction in pigs

Boar taint is characterized by an unpleasant taste or odor in intact male pigs and is primarily attributed to increased concentrations of androstenone and skatole and to a lesser extent by increased indole. The boar taint compounds skatole and indole are produced by gut bacteria, metabolized in the liver, and stored in the fat tissue. Androstenone, on the other hand, is synthesized in the testis along with testosterone and estrogens, which are known to be important factors affecting fertility. The main goal of this study was to investigate the relationship between genetic factors involved in the primary boar taint compounds in an attempt to discover ways to reduce boar taint without decreasing fertility-related compounds. Heritabilities and genetic correlations between traits were estimated for compounds related to boar taint (androstenone, skatole, indole) and reproduction (testosterone, 17β-estradiol, and estrone sulfate). Heritabilities in the range of 0.47 to 0.67 were detected for androstenone concentrations in both fat and plasma, whereas those for skatole and indole were slightly less (0.27 to 0.41). The genetic correlations between androstenone in plasma and fat were extremely high (0.91 to 0.98) in Duroc and Landrace. In addition, genetic correlations between androstenone (both plasma and fat) and the other sex steroids (estrone sulfate, 17β-estradiol, and testosterone) were very high, in the range of 0.80 to 0.95. Furthermore, a genome-wide association study (GWA) and a combined linkage disequilibrium and linkage analysis (LDLA) were conducted on 1,533 purebred Landrace and 1,027 purebred Duroc to find genome regions involved in genetic control of the boar taint compounds androstenone, skatole, and indole, and sex hormones related to fertility traits. Up to 3,297 informative SNP markers were included for both breeds, including SNP from several boar taint candidate genes. From the GWA study, we found that altogether 27 regions were significant at a genome-wide level (P < 0.05) and an additional 7 regions were significant at a chromosomal level. From the LDLA study, 7 regions were significant on a genome-wide level and an additional 7 regions were significant at a chromosomal level. The most convincing associations were obtained in 6 regions affecting skatole and indole in fat on chromosomes 1, 2, 3, 7, 13, and 14, 1 region on chromosome 6 affecting androstenone in plasma only, and 5 regions on chromosomes 3, 4, 13, and 15 affecting androstenone, testosterone, and estrogens.     

蛋鸡日粮中添加富硒酵母对鸡蛋中硒含量及分布的影响

试验选用产蛋率约为80%的罗曼褐蛋鸡35只,随机分为7组,进行为期30d的饲养试验。A组为对照组,饲以基础日粮,其余6组为试验组,B、C、D组在基础蛋鸡日粮中分别添加0.2mg/kg、0.5mg/kg、1mg/kg硒的亚硒酸钠,E、F、G组在基础蛋鸡日粮中分别添加0.2mg/kg、0.5mg/kg、1mg/kg硒的富硒酵母。试验过程中记录蛋鸡的生产性能,每隔7d从各试验组鸡所产的鸡蛋中任取3枚,测定鸡蛋中硒的含量,并于试验的第14、15天,28、29天从A、C、F组每组各取5枚鸡蛋分别测定蛋黄和蛋清的硒含量。结果显示,日粮中添加硒对蛋鸡生产性能无显著影响,能极显著提高鸡蛋中硒含量,并且硒主要存在蛋黄中,添加富硒酵母组蛋硒含量较亚硒酸钠组提高更为显著。     

鸡蛋媒体的兴起

尽管鸡蛋喷码技术在国内“安全鸡蛋”、“清洁鸡蛋”的提倡者、生产者们手中,作为食品安全溯源的实用技术,已经使用了多年,并由此产生了国内的喷码设备（之前多为进口设备）产业。由此我们可以从整个鸡蛋生产链条上,清晰的见到围绕鸡蛋建立起来的一个个产业：种禽产业、孵化产业、饲料产业、兽药产业、养殖设备、农贸产业等,这些跟鸡蛋相关的产业,在随着我国家禽产业的不断完善而不断成熟、发展。但更让人感慨的是．把鸡蛋作为一种传媒载体的“鸡蛋媒体”．已经成为一个新兴的产业,在国外已经形成多年。最近,有新闻媒体报道,“鸡蛋媒体”已经走进我们身边。     

Melamine residues in eggs of quails fed on diets containing different levels of melamine

1. An experiment was conducted to determine residual melamine concentrations in eggs of quail given diets containing different concentrations of melamine, and to estimate the time at which withdrawing melamine from the diet would result in undetectable concentrations in eggs. A total of 600 Japanese quails (Coturnix coturnix japonica) were randomly divided into 5 treatments, and given melamine at concentrations of 0, 2, 10, 50, and 100?mg/kg diet respectively for 30?d. From d 31 to 41, all quails were given a diet without melamine. Each diet was offered to 4 replicates (cages) of 30 quails each. On d 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, and 41, eggs were collected for the determination of melamine and cyanuric acid levels.

2. Throughout the 41?d experimental period, inclusion levels of melamine in the diets of quails had no significant effect on daily feed intake, egg production percentage, and feed efficiency. No detectable amount of cyanuric acid was found in all eggs. When the diets contained melamine at 2?mg/kg, the amounts of melamine in eggs were below the detection limit. During the entire 30?d exposure, the maximum melamine concentrations in eggs were 0·162, 0·998 and 1·784?mg/kg for the 10, 50 and 100?mg/kg treatment groups, respectively, which demonstrated a linear dose-response relationship.

3. Upon feeding a diet without melamine, the melamine concentration in eggs decreased rapidly. The time taken for the amounts of melamine to decline below the detection limit were 1, 5, and 5?d for quails fed on the diets containing melamine at 10, 50, and 100?mg/kg respectively.

4. Melamine is not metabolised into cyanuric acid in quails, and a positive relationship exists between the concentrations in feed and in eggs.     

Influence of bird strain on competitive exclusion of Campylobacter jejuni in young chicks

1. Newly hatched chicks of either layer or broiler strain were treated orally at regular intervals with either homologous or heterologous gut-flora preparations from young donor birds, in an attempt to prevent subsequent colonisation with Campylobacter jejuni by 'competitive exclusion' (CE). 2. Donors of 3 to 10 d of age were chosen to correspond with the period in which intensively reared poultry are least likely to become colonised with Campylobacter. 3. In two separate trials, material from donor layer hens (ISA Brown) protected male chicks of the same strain against a low (195 to 360 cfu/bird) Campylobacter challenge, but the same kind of material was ineffective when administered to chicks of a broiler strain (JA957). 4. Two further trials involved treatment preparations from young broilers, which failed to prevent Campylobacter colonisation of broiler chicks, even when colonisation occurred relatively slowly from a challenge of 90 to 94 cfu/bird. 5. It was concluded that any CE effect observed was strongly dependent on bird strain.     

东方蜜蜂和西方蜜蜂交哺行为的研究

选择东方蜜蜂和西方蜜蜂各 5个群势基本相等的实验蜂群 ,分别从每个实验群里提出 1张具有卵、小幼虫、大幼虫和蛹的子脾 ,放入对应的不同蜂种的蜂群里进行蜜蜂交哺行为研究。结果发现 :东方蜜蜂群拒绝哺育西方蜜蜂的卵和幼虫 ,在 2 4h内西方蜜蜂的幼虫基本被全部清理出房 ;5d后 ,所有没有被哺育而死亡的卵被清理出房 ;有大约 18 5 3%的封盖蛹出房 ,被蜂群接受。而西方蜜蜂群可以哺育少量东方蜜蜂的卵 ,有 7 90 %的卵可以孵化为小幼虫 ,但这些小幼虫连同其他卵和幼虫因不再被哺育而死亡 ,在随后的 6d内被工蜂全部清理出房 ;有大约 8 0 1%的封盖蛹出房。在东方蜜蜂蜂群里介绍的西方蜜蜂的王台幼虫 ,或者在西方蜜蜂蜂群里介绍的东方蜜蜂的王台幼虫 ,12h内均全部被清理出房。     

Effects of replacing fishmeal with black soldier fly larval meal in the diets of grower-finishing guinea fowls reared under tropical conditions

The study was conducted with the view to determine the impact of replacing fishmeal with black soldier fly larval meal (BSFLM) on growing guinea fowls. BSFLM replaced fishmeal (3% in the control diet) in the ratios of 0, 20, 40, 60, 80, and 100% to produce six dietary treatments, which were iso-caloric and iso-nitrogenous. Two hundred and forty-eight-week old guinea fowls with mean live weight of 273.2?±?10.9 g were tagged, weighted, and randomly assigned to 24 (6?×?4) floor pens; each pen was treated as a replicate. Feed and water were provided ad libitum during the entire period, which lasted 10 weeks. Feed consumption differed among the treatment groups (P?=?0.0072) with the 100% fishmeal diets recording the lowest. Daily gain was significantly (P?=?0.009) higher for birds fed high BSFLM diets compared to the control (100% fishmeal diet). The inclusion of BSFLM in the diets elicited positive linear effect on weight gains of the guinea fowls (R²?=?0.91) with increasing concentration resulting in higher live weight gains. The feed conversion ratio (FCR) also differed between treatments (P?<?0.05) but similar for the 100% fishmeal (control) and 100% BSFLM diets. Organ and haematopoitic integrity were equally assured regardless of levels of the protein sources fed to the birds. Generally, meats from birds fed 60 to 100% BSFLM and from hens were more acceptable. A study to evaluate the economics of utilising BSFLM in guinea fowl production is recommended.     

Transfer of 125I to eggs in hens fed on diets containing rapeseed meal.

1. Transfer of 125I into the egg in hens fed on diets containing rapeseed meal and a source of myrosinase, to liberate the antithyroid compounds from the glucosinolates, was studied. 2. It was found that less 125I was transferred if the diet contained a myrosinase source and rapeseed meal.     

Correlation between shell colour and ultrastructure in pheasant eggs

1. The histochemistry and ultrastructure of pheasant eggs were compared on the basis of blue or brown shell colour. 2. Differences in lectin histochemistry of the outer shell membrane calcification surface indicate a biochemical disruption of the calcification sites in blue eggs. 3. Significant differences were observed in all aspects of eggshell ultrastructure with blue eggs having thinner shells with structural defects. 4. Poor hatchability of blue eggs may reflect high rates of weight loss associated with a defective eggshell.     

The effects of dietary fat and bird age on the weights of eggs and egg components in the laying hen

1. A low-fat diet or an isoenergetic and isonitrogenous high-fat diet containing 55 g maize oil/kg were fed to laying hens at different stages during the laying year in two experiments. 2. Feeding the high-fat diet to young hens resulted in a rapid increase of 2.5 g in egg weight, made up of increases in both yolk and albumen weights. 3. Switching the diets at 50 weeks caused changes in egg weight that were accounted for entirely by changes in egg albumen weight. 4. Feeding the high-fat diet from 46 weeks in a second experiment increased egg and egg albumen weights by 1.26 and 1.34 g respectively. 5. The increase in egg weight with age was associated with a greater increase in the proportion of yolk, at the expense of albumen, compared to egg weight increases related to dietary fat. 6. It is concluded that dietary fatty acids increase egg weight by a mechanism different from that causing age-related increases in weight and that the mechanism involves a stimulation of oviduct protein synthesis.     

维生素B_2对蛋鸡产蛋性能和鸡蛋中维生素B_2含量影响

本研究将48只300日龄的蛋鸡随机分成3组,每组4个重复,分别在日粮中添加7.2、10.8mg/kg和14.4mg/kg的维生素B2(80%)。结果表明:添加10.8mg/kg和14.4mg/kg维生素B2组产蛋率有所下降,蛋重有增加趋势,但差异均不显著(P0.05);日采食量无显著变化;添加10.8mg/kg和14.4mg/kg试验组比7.2mg/kg组显著提高了鸡蛋中维生素B2的含量(P0.05)。     

Incidence of boar taint in Swedish Landrace and Yorkshire boars

Boar taint in 500 Swedish Landrace and Yorkshire boar carcasses was tested by smelling fat samples heated on the tip of a soldering iron at 150°C. About 40% of the boars were scored as non-tainted; in another 40%, the judges were unsure whether taint was present or not. Boar taint was judged present in only 20% of the boars.The effects of weight and sex on boar taint were studied in approx. 275 boars, barrows and gilts slaughtered at 70, 90, 110 and 130 kg live weight. The number of boars scored as tainted increased with weight, but weight did not affect the level of taint in all boars. When the taste of boar meat and fat was compared to castrates, no differences were found in 80% of comparisons at 70 or 90 kg.The effect of weight on boar taint was studied in 69 boars reared on ad libitum or restricted feed. Biopsies were taken, by a needle biopsy technique, at 70, 90 and 100 kg live weight. The incidence of boar taint did not increase from 70 to 100 kg when boars were on restricted feed, but the weight effect was significant and linear at the ad libitum feeding level. The cause was probably an interaction between physiological development, age and weight of the boars.     

Glycerol use in dairy diets: A systemic review

There is an increasing interest in the production of biodiesel as bio-renewable fuel source, with numerous biofuel byproducts becoming available. The annual productions of biodiesel and crude glycerol were 34.5 and 3.8 billion liters, respectively, in 2016 and that of biodiesel is expected to reach 41 billion liters in 2019. Glycerol is a sugar alcohol without a color or odor, but with a sweet taste and high solubility index in water. Experiments support the use of glycerol at low levels ranging from 5% to 8% of the diet dry matter as a transition cow therapy. Administration of glycerol increases serum glucose and decreases ketone bodies. Glycerol is very rapidly fermented in the rumen to propionate and butyrate, at the expense of acetate, resulting in a decreased milk fat. Because glycerol is highly fermented in the rumen, it requires an adaptation period at the beginning of feeding. Administration of glycerol in the diet of lactating animals was paralleled with a decreased or an unaffected feed intake in most experiments. Improved ruminal environment to enhance nutrient digestibility was observed in many experiments; however, others observed reduced digestion of dietary fiber with feeding glycerol. Enhanced, lowered, or unaffected milk production and composition were observed with the administration of glycerol in lactating animal diets; however, in most cases, glycerol decreased milk fat content. The inconsistencies between results of experiments are due to the level and the purity of glycerol, diets, production stage of the animals, and other factors. Therefore, further research should be conducted to establish the efficacy of different levels, purity and administration periods of glycerol, and production stage of dairy animals fed glycerol-based or supplemented diets.