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991.
黑皮冬瓜品质综合评价方法的探讨   总被引:2,自引:0,他引:2  
以24个不同来源、不同类型的黑皮冬瓜为试材,采用数据归一化法进行黑皮冬瓜品质综合评价体系研究。通过对可溶性固形物含量、总酸度、肉质致密性、含水量等营养品质性状以及皮色、瓜形等商品品质性状进行分析,结果表明:肉质致密性以及糖酸比等性状是衡量黑皮冬瓜品质优劣的主要指标,结合当前生产和消费的评价标准,制定了一套综合评价黑皮冬瓜品质的方法。  相似文献   
992.
The conjugated linoleic acid (CLA) content of grazing sheep and goat milk fat, throughout their lactation period, was examined. Six sheep and six goat representative farms were selected at random and milk samples were taken at monthly intervals for fatty acids profile determination. Sheep and goat nutrition was based on natural grazing and on supplementary feeding during the winter months. From April onwards, grazing native pastures was the only source of feed for sheep and goats. The University farm whose sheep are kept indoors all year round without any grazing, was also used as reference. Fifteen individual milk samples were also taken in April from a sheep and goat farm respectively, in order to see the variability of CLA inside the farm. The results showed that: a. the CLA content of grazing sheep and goat milk fat increased significantly in April–May (early growth stage of grass) and then declined while that of indoors kept sheep was more or less constant during the same period, b. the isomers cis-9, trans-11 and trans-10, cis-12 of CLA were found in grazing sheep milk fat, while in indoors kept sheep and goats' milk fat only the cis-9, trans-11 isomer was found, c. the CLA content of sheep milk fat was much higher than that of goats, d. a negative correlation between sheep milk fat and CLA content was found and e. there was considerable variation in milk fat CLA content between sheep and goat farms and inside the farms.  相似文献   
993.
The effect of rolled canola seeds (RCS, 0% or 20% of the dry matter (DM) of the concentrate) combined with percentage of concentrate (45% (L) vs. 65% (H) of the diet DM) on rumen fermentation characteristics, production parameters and fatty acid (FA) profile of milk fat was studied in 20 entire goats and 12 goats fitted with ruminal and duodenal cannula. Goats were fed TMR ad libitum for 15 weeks with the final 12 weeks as the test period. Individual milk samples were taken in weeks 5 and 11 to determine the FA profile of milk fat. Feeding the H diets increased NEL intake, raw milk yield and yield of fat, protein and lactose. Feeding RCS increased fat corrected milk, milk fat content and fat yield. Combination of RCS and high percentage of concentrate increased fat corrected milk and fat yield. Milk protein content was not affected by dietary factors. Feeding the H diets increased the proportion of short-chain FA (C4:0–C8:0), each isomer of trans-C18:1 and c9,t11-C18:2 in milk at the expense of medium-chain FA with 11 to 17 C units. Feeding RCS decreased the proportion of medium-chain FA with 10 to 17 C units in milk and it increased that of C18:0, all isomers of trans-C18:1, c9-C18:1 and c9,t11-C18:2. Goats fed the H diets, and those fed the RCS had lower c9-C18:1/C18:0 and c9,t11-C18:2/t11-C18:1 ratios. Combination of RCS and high percentage of concentrate produced the highest proportion of all isomers of trans-C18:1 and c9,t11-C18:2 in milk, with the highest variability among the four diets for these FA. This was possibly related to between-goats differences in ruminal fermentation and to individual difference in desaturase activity in the mammary gland. It is concluded that feeding a high-concentrate diet combined with rolled canola seeds had a synergistic effect on the milk production and fat yield without alteration in milk protein content in dairy goats. This combination also resulted in changes in FA profile that may differently affect the nutritional value of goat milk for human health.  相似文献   
994.
In this study, we investigated the effect of ascorbic acid (AA) administration on goat excitability due to transportation. Ten goats administered AA (p.o.) at 100 mg/kg of body weight before transportation served as the experimental group, and seven goats administered only 10ml/kg of sterile water (p.o.) served as controls. Excitability scores were recorded for each goat; when weighed, before, immediately after, and 3 h after 8 h of transportation. A score of one to four was allocated to each goat; higher scores represent greater excitability. Immediately after transportation, excitability scores decreased significantly, especially those of control goats (p < 0.001). At 3 h post-transportation, the excitability scores of animals in the experimental group were not significantly (p>0.05) different from their pre-transportation normal values, whereas those of control goats were significantly lower (p < 0.01). The correlation i.e. the relationship between excitability score values and percent excitability (percentage of goat with particular excitability score) for different excitability score group 3 h post-transportation was positive and highly significant (p < 0.001), in both experimental and control goats. Our results indicate that road transportation induces considerable stress (depression) in goats as evidenced by a lower excitability score post-transportation. Moreover, the administration of AA pre-transportation facilitated the transition from a state of depression to excitation. In conclusion, AA administration to animals prior to transportation may ameliorate the depression often encountered after road transportation.  相似文献   
995.
A study was conducted with male chicks of a commercial broiler strain to evaluate the effects of different dosage levels of a commercial α-galactosidase enzyme. Diets were formulated based on corn and soybean meal to meet the nutrient standards of top poultry companies. The positive control diet was formulated with no adjustment in the ME content of the soybean meal associated with enzyme supplementation. The negative control diet was formulated assuming a 10% improvement in the ME of the soybean meal. The negative control diet was supplemented with 0, 1.5, 3.0, 4.5, or 6.0 g of enzyme per kilogram of soybean meal to provide for 0, 45, 90, 135, or 180 galactosidase units (GALU)/kg of soybean meal. Each of the test diets was fed in mash form to 8 replicate pens of 30 birds. Body weight, feed efficiency, mortality, and calorie conversion were determined at 14, 35, and 42 d of age. Body weight, feed efficiency, and mortality were not significantly (P < 0.05) affected by dietary treatment. Birds fed the negative control with no enzyme supplement were numerically reduced in body weight or feed efficiency as compared with the control diet; however, addition of the enzyme was without benefit. When unadjusted energy values were analyzed, birds fed the negative control diet were more efficient in calorie conversion, but this finding was unrelated to enzyme addition, suggesting that diet composition was responsible for the differences in calorie utilization. When adjusted energy values were compared, birds fed the negative control tended to have higher (less efficient) calorie conversion than those fed the positive control with little or no indication of improvement from the addition of the α-galactosidase enzyme. Results of this study show no benefit from the addition of the enzyme used in this trial.  相似文献   
996.
In recent years, policies encouraging the production of ethanol have stimulated an enormous increase in the production of distillers dried grains with solubles (DDGS). The form of the ingredient that is becoming increasingly available differs from that of previous decades in that it is derived almost entirely from corn and is dried under less severe conditions. Seventeen DDGS samples were obtained from 6 different plants in the midwestern United States from 2002 to 2004. Each sample was analyzed for TMEn, and 8 representative samples were analyzed for total and digestible amino acids (AA) by the precision-fed rooster assay using conventional or cecectomized Single Comb White Leghorn roosters, respectively. Color [lightness (L*), redness (a*), and yellowness (b*)] of each DDGS sample was measured with a Minolta Chroma Meter CR-300. The TMEn ranged from 2,490 to 3,190 kcal/kg (86% DM basis) and had a mean of 2,820 kcal/kg. Variation was noted among samples, presumably reflecting differences in the original corn composition, fermentation, and disposition of solubles. Considerable differences were observed among the true AA digestibilities of the DDGS samples. Most samples were golden in color, and true AA digestibility values were relatively consistent among these samples. The average total concentration and digestibility coefficients of several most limiting AA for the 8 DDGS samples were as follows: Lys, 0.71% (70); Met, 0.54% (87); cystine, 0.56% (74); Thr, 0.96% (75), Val, 1.33% (80), Ile, 0.97% (83); and Arg, 1.09% (84). Correlations were found among digestible Lys, Thr, Arg, His, and Trp and the yellowness (b*) and lightness (L*) of the DDGS samples. In general, DDGS samples that were more yellow and lighter in color had higher total and digestible AA levels. The variation in TMEn and AA digestibility observed among samples strongly indicated that confirmatory analyses should be conducted prior to using samples from a new supplier.  相似文献   
997.
水杨酸与蔬菜作物抗性关系的研究进展   总被引:4,自引:0,他引:4  
水杨酸在植物的抗病性方面发挥着重要的作用,近年来的研究表明,水杨酸在植物抗冷、热、盐、干旱、臭氧、重金属等环境胁迫方面有明显的作用。对近年来有关水杨酸在蔬菜抗逆境胁迫方面的研究进展进行综述,并提出一些研究思路。  相似文献   
998.
酚类物质与蝴蝶兰褐变关系初探   总被引:1,自引:0,他引:1  
 利用高效液相色谱法对3个褐化程度不同的蝴蝶兰品种A1 (大白花红心) 、B3 (迷你型白花黄心) 和R4 (深红花红心) 进行了9种酚酸定性定量分析, 并研究了以叶片为外植体的初代培养过程中总酚含量的动态变化。结果表明: 绿原酸、邻苯二酚、儿茶酚、咖啡酸及没食子酸、对羟基苯甲酸、香豆酸可能与蝴蝶兰褐变相关, 苯甲酸对蝴蝶兰褐变影响很小; 在褐变过程中, 总酚含量越高, 褐变程度越严重。  相似文献   
999.
 以3年生盆栽红富士(Malus domestica Borkh. ) /湖北海棠〔Malus hupehensis (Pamp) Rehd. 〕为试材, 研究了脱落酸、水杨酸和草酸预处理对叶片脯氨酸的诱导作用, 结果表明, 预处理第2天, 自然干旱效果还不明显时, 水杨酸预处理就使叶片脯氨酸含量提高了7.87%; 自然干旱、脱落酸、水杨酸和草酸预处理至第9天, 叶片脯氨酸含量较对照分别提高了96.30%、110.67%、135.12%和115.96%; 预处理9 d后停止供水至第5天时, 叶片瞬时水分利用效率分别提高了286.77%、75.76%、79.04%和100.44% ,脯氨酸含量也明显提高; 停止供水至第10天时, 脯氨酸含量分别提高了5.33%、262.76%、92.32%和0。综合比较显示, 自然干旱、脱落酸、水杨酸和草酸预处理都可以通过提高叶片脯氨酸含量和水分利用效率而增强苹果的抗旱性, 其中脱落酸的效果最好, 其次是水杨酸, 草酸效果持续时间比较短。  相似文献   
1000.
An experiment was conducted to determine true and apparent ileal amino‐acid digestibility of a native cultivar of wheat (Mahdavi), autoclaved wheat (120°C for 30 min) and spaghetti by‐products available in Iran. One hundred 21‐day‐old broiler chickens were fed a standard corn–soybean meal starter diet from day 0 to 28 post hatch. At 28 days 80 chicks were distributed according to possessing very nearly the same average bodyweight to 20 wire cages. The experimental units were allocated at random to five dietary treatments with four replicates per treatment. The basal diet contained corn and soybean meal as the major ingredients. Three test diets were formulated containing wheat, autoclaved wheat and spaghetti by‐products as the sole source of dietary protein and each test diet was combined with a basal diet 50:50 on a weight basis to form three assay diets. The apparent and true digestibility of amino acid in the test ingredients were estimated from those in the assay diets basal/test diet mixtures, using the difference method. The apparent and true amino‐acid digestibility of the test ingredients were significantly different (P < 0.01). Autoclaving of wheat increase its amino‐acid digestibility (P < 0.01). Among the test ingredients, the average ileal amino‐acid digestibility of spaghetti by‐products was higher than wheat and autoclaved wheat but it was lower than values for the basal diet (P < 0.01).  相似文献   
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