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早籼稻谷替代玉米的肉牛饲粮在瘤胃中干物质与粗蛋白降解规律的研究 总被引:2,自引:1,他引:1
采用尼龙袋技术研究用早籼稻谷替代玉米的肉牛饲粮在瘤胃中干物质与粗蛋白降解规律 ,实验处理分4个组 ,分别为早籼稻谷替代饲粮中玉米 0 % ,5 0 % ,75 %和 10 0 %。结果表明 :( 1)各组饲粮在瘤胃中的干物质与粗蛋白的动态降解率分别为 74.5 4% ,71.39% ,6 9.16 % ,6 8.0 7%和 71.74% ,70 .35 % ,6 8.2 1% ,6 9.5 6 % ;( 2 )经单因子方差分析各组饲粮在瘤胃中的干物质与粗蛋白的动态降解率各组间差异不显著 (P >0 .0 5 ) ;( 3)各组饲粮在瘤胃中的干物质 (X)与粗蛋白 (Y)的动态降解率呈线性正相关 (Y =38.5 882 + 0 .44 32X ,r=0 .85 73)。 相似文献
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搜集整理了2018年肉牛饲料添加剂的最新国外研究文献,对脂类、矿物质、维生素、饲用微生物、甘油等饲料添加剂的应用效果进行了总结。脂类添加剂主要研究了椰子油、棕榈油、米糠油、鱼油等对肉牛生产性能、消化性能和胴体特性的影响;矿物质则集中于铜、锌、硒、锰等常规微量元素和矾、伊利石等非常规微量元素对肉牛瘤胃发酵的影响研究;维生素侧重于维生素A和维生素D对肉牛营养吸收的影响;饲用微生物方面主要对酵母和乳酸菌2种饲料添加剂展开了研究;甘油侧重于能量饲料的替代及其饲用安全评价。通过了解国外的饲料添加剂研究进展,为我国肉牛产业的发展提供思路。 相似文献
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以3头带有永久瘤胃瘘管的湖北本地阉黄牛用尼龙法对早籼稻谷替代玉米的肉牛饲粮粗脂肪在瘤胃中的降解特性进行了比较研究。试验处理为早籼稻谷分别替代精料中0%,50%,75%,和100%的玉米4个替代水平的肉牛饲粮。结果表明:随早籼稻谷替代水平的提高粗脂肪胃动态降解率呈下降趋势,分别为76.48%,75.22%,74.48%和66.71%,经单因子方差分析,除100%替代水平组与其它各组间差异显著外(P<0.05),其它各组间差异不显著(P>0.05);动态消化参数各组饲粮间差异不显著(P>0.05);能较好地符合模拟方程P=a+b(1-e^-ct),拟合度高(R^2=0.960-0.998)。 相似文献
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本文综述了饲用微生物制剂的定义和作用机理. 针对目前饲用微生物制剂使用效果不一致的问题分析了其影响因素, 并就饲用微生物应具备的条件, 在使用中的安全问题、功效评价等研究进展, 以及今后的研究发展方向进行了探讨. 相似文献
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饲用微生物制剂的研究进展 总被引:1,自引:0,他引:1
本文综述了饲用微生物制剂的定义和作用机理。针对目前饲用微生物制剂使用效果不一致的问题分析了其影响因素,并就饲用微生物应具备的条件,在使用中的安全问题、功效评价等研究进展,以及今后的研究发展方向进行了探讨。 相似文献
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Thirty-two male Ile de France lambs were divided into four equal groups at age 37 days. Two groups were allowed to graze a natural pasture in France each at a different growth rate (grass high and grass low groups). The other two groups were raised in stalls and fed concentrates to achieve the same growth rates (stall high and stall low groups, respectively) as from the grass groups. The animals were slaughtered when they attained 35 kg and their carcass and meat quality were evaluated. Animals from the two high growth rate groups were slaughtered at an average age of 129 days while those from the low growth rate groups were slaughtered at 163 days. Carcasses from stall-fed lambs were heavier than those from grass-fed lambs as the digestive tract percentage was higher in the grass lambs. Carcasses from stall lambs had better muscular conformation score (P <0.05) and were fattier than those from grass-fed animals. Subcutaneous fat was more yellow and harder in grass-fed lambs (P <0.05). Meat from grass-fed lambs was darker (P <0.05) in colour (lower L*) than meat from stall animals up to 24 h of display. Meat from stall fed animals was more tender and juicier than meat from grass-fed animals (P <0.01), as judged by a trained panel of assessors. Typical lamb flavour was higher in stall-fed lambs (P <0.01). Meat from grass-fed animals had more pronounced liver flavour (P <0.05) and less fatty flavour (P <0.01) than stall-fed lambs. Overall the difference in meat quality between the two different growth rates was minimal. 相似文献
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Restructured beef roasts, made to a standardized formulation, were prepared using the following types of meat that had been stored at - 18 °C for 5 or 10 weeks: grass-fed bull beef pre-rigor injected with a salt/phosphate brine; uninjected grass-fed bull beef; uninjected grain-fed beef; a 50:50 blend of pre-rigor injected grass-fed bull beef and grain-fed beef; and a 50:50 blend of uninjected grass-fed bull beef and grain-fed beef. After frozen storage, pre-rigor injected beef had a higher (p < 0.05) ultimate pH than uninjected beef . Grain-fed beef had the lowest ultimate pH. Roasts made from pre-rigor injected beef were redder (higher Hunter a(?) values) than roasts made with uninjected beef (p < 0.05). Roasts made from grain-fed beef were lighter and looked more cooked (higher L(?) and lower a(?) values respectively) than those made with grass-fed beef. Extending frozen storage to 10 weeks decreased the cook yield (p < 0.05), peak force (p < 0.001) and extensibility (p < 0.05). Consumer panellists preferred (p < 0.05) roasts made from pre-rigor injected beef for tenderness, juiciness and overall acceptability compared with roasts made from uninjected beef. 相似文献
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This study uses experimental economic techniques to explore consumers’ preferences between conventional beef and grass-fed beef, and their willingness to pay for grass-fed beef. Our analysis shows that palatability attributes play a central role in determining consumers’ preferences and WTP. We also find that consumers’ nutrition knowledge, beef consumption behavior, health condition, living alone status and household size have significant impacts on consumers’ WTP for grass-fed beef. 相似文献
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Alice Moscovici Joubran Karina M. Pierce Niamh Garvey Laurence Shalloo Tom F. O'Callaghan 《Journal of dairy science》2021,104(7):7364-7382
Grazing pasture is the basis for dairy production systems in regions with temperate climates, such as in Ireland, New Zealand, parts of Australia, the United States, and Europe. Milk and dairy products from cows on pasture-based farms predominantly consuming fresh grazed grass (typically classified as “grass-fed” milk) have been previously shown to possess a different nutrient profile, with potential nutritional benefits, compared with conventional milk derived from total mixed ration. Moreover, pasture-based production systems are considered more environmentally and animal welfare friendly by consumers. As such, there is significant potential for market capitalization on grass-fed dairy products. As competition in this space increases, the regulations of what constitutes as grass-fed vary between different regions of the world. With this in mind, there is a need for clear and independently accredited grass-fed standards, defining the grass-fed criteria for labeling of products as such, subsequently increasing the clarity and confidence for the consumer. This review outlines the numerous effects of pasture production systems on dairy product composition, nutritional profile, and sustainability, and highlights potential future methods for authentication. 相似文献
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《Journal of dairy science》2021,104(12):12394-12402
The prevalence of “grass-fed” labeled food products on the market has increased in recent years, often commanding a premium price. To date, the majority of methods used for the authentication of grass-fed source products are driven by auditing and inspection of farm records. As such, the ability to verify grass-fed source claims to ensure consumer confidence will be important in the future. Mid-infrared (MIR) spectroscopy is widely used in the dairy industry as a rapid method for the routine monitoring of individual herd milk composition and quality. Further harnessing the data from individual spectra offers a promising and readily implementable strategy to authenticate the milk source at both farm and processor levels. Herein, a comprehensive comparison of the robustness, specificity, and accuracy of 11 machine-learning statistical analysis methods were tested for the discrimination of grass-fed versus non-grass-fed milks based on the MIR spectra of 4,320 milk samples collected from cows on pasture or indoor total mixed ration–based feeding systems over a 3-yr period. Linear discriminant analysis and partial least squares discriminant analysis (PLS-DA) were demonstrated to offer the greatest level of accuracy for the prediction of cow diet from MIR spectra. Parsimonious strategies for the selection of the most discriminating wavelengths within the spectra are also highlighted. 相似文献
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The objective of this study was to examine the effect of wintering pregnant, nonlactating dairy cows outdoors on either kale or grass, fed in 1 [11 kg dry matter (DM) of kale or grass + 3 kg DM of baled barley straw offered in the morning] or 2 allocations (5.5 kg DM of kale or grass grazed + 1.5 kg DM of barley straw offered morning and afternoon) per day. The body condition score (BCS) gain over the 47-d winter feeding period was higher for grass-fed (0.5 BCS units) than kale-fed cows (0.3 BCS units), but was unaffected by feeding frequency. Forage DM utilization was higher for kale-fed (97%) than grass-fed cows (76%), leading to higher estimated dry matter intake (DMI) in kale-fed (10.7 kg of DM/cow per day) than grass-fed cows (7.7 kg of DM/cow per day). Forage DM utilization and estimated DMI were not affected by feeding frequency. Prehension bite rate was greater for grass-fed (37.3 bites/min) than kale-fed cows (7.6 bites/min), but more mastication bites were required for kale-fed cows. Cumulative DMI after 2, 3, and 6 h was greater in cows allocated forage once than twice a day and for kale than grass after 3 and 6 h. Mean eating time was greater for cows offered forage once (477 min) than twice (414 min) per day. In conclusion, increasing feeding frequency from once to twice per day decreased the intake rate within the first 6 h after allocation, but did not affect total daily DMI, DM utilization or BCS gain. Thus, moving cows more frequently would not have any significant advantage. It may increase labor requirements, thereby creating a more challenging wintering management than feeding once per day. 相似文献
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The effect of country of origin (local, Switzerland, Argentina, Uruguay), finishing diet (grass, grass plus concentrate, concentrate), and price (low, medium, high) on consumer's beef choice and segmentation was evaluated in Spain, France and United Kingdom. Sensory acceptability of Uruguayan beef from different production systems was also evaluated and contrasted with consumers' beef choices. Origin was the most important characteristic for the choice of beef with preference for meat produced locally. The second most important factor was animal feed followed by price with preference for beef from grass-fed animals and lowest price. The least preferred product was beef from Uruguay, concentrate-fed animals and highest price. Sensory data showed higher acceptability scores for Uruguayan beef from grass-fed animals with or without concentrate supplementation than animals fed concentrate only. Consumer segments with distinct preferences were identified. Foreign country promotion seems to be fundamental for marketing beef in Europe, as well as the development of different marketing strategies to satisfy each consumer segment. 相似文献
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M. Font i Furnols C. RealiniF. Montossi C. SañudoM.M. Campo M.A. OliverG.R. Nute L. Guerrero 《Food quality and preference》2011,22(5):443-451
Food selection and consumption can be affected by different intrinsic and extrinsic cues. In this study, the effect of three extrinsic cues (country of origin, price and feeding system) on consumer’s purchasing decisions making process for lamb meat in three European countries: Spain, France and United Kingdom was investigated, as well as the relative importance of each cue. Four countries were considered for evaluating the effect of the country of origin (local, Argentina, Switzerland and Uruguay), three feeding systems (grain-fed, grass-fed and grain + grass-fed) and different price levels (low, medium and high), which were simultaneously compared. Fifteen profiles combining the different levels for each of the factors considered where those obtained by means of an orthogonal design. These profiles were evaluated by 100, 99 and 92 consumers in Spain, France and United Kingdom, respectively. Moreover, consumers sensory evaluated lamb from four different feeding systems, grain-fed, grass-fed and two mixtures of grain and grass-fed. Conjoint analysis was carried out both for evaluating clusters of consumers in each country and for considering an overall evaluation of all the countries at the same time. In general, the origin of the meat was the most important factor in determining consumer’s purchasing decisions making process, the local one being the most preferred. Uruguayan origin was the least preferred, which indicates that Uruguayan public and private sectors would need to enhance their country and meat image as well as support market promotion and penetration strategies in the European market. For some consumers the feeding system was the most important factor for choosing any particular meat amongst others, being grass-fed animal the most preferred. These results are not in agreement with the consumer’s acceptability studies of lamb meat when taste the meat from different feeding systems in a blind condition (without information), showing a disconfirmation. Lamb meat price has a minor role in determining consumer’s purchasing decisions. However, one segment of consumers, composed mainly by men, considered that the price is the most important factor. These findings showed the importance of studying consumer preferences and their segmentation for developing market promotions, which should have a holistic approach including extrinsic factors in the evaluation of consumer’s purchasing decisions making process. 相似文献
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KENNETH R. DAVEY 《Journal of texture studies》1985,16(2):143-150
The influence of some factors on the hardness of subcutaneous fat on sides of chilled beef as measured by the average force resisting movement of a cutting pin (Ff) was investigated. Values of Ff determined at a fat temperature of 10°C on grass-fed animals denied water 24 h preslaughter were not significantly influenced by moisture content (5-11%) or fat depth (2-27 mm). There was a quadratic relationship (P<0.001) between the age of animals at slaughter (31-141 months) and Ff, and a linear one (P<0.001) between saturated fatty acid content (35-50%) and Ff. Values of Ffat a fat temperature of 5°C were not significantly related to moisture content (1-22%) but there was a linear relationship (P<0.01) with fat depth (5-13 mm). This had a common slope for the three feeding patterns: (1) grass-fed animals denied water 24 h preslaughter; (2) grass-fed animals given access to water 24 h preslaughter, and; (3) lot-fed animals given access to water 24 h preslaughter. 相似文献
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Ten panelists were selected from the local community to develop a meat lexicon composed of 18 terms that describe flavor attributes found in red meats. This flavor lexicon was used to compare the flavor profile of meat from beef cattle finished on grass or grain. Steaks from grass-fed animals were significantly (P < 0.05) higher in barny, bitter, gamey, and grassy flavor, and lower in juicy and umami notes. Gamey, barny, bitter and grassy were some of the attributes inversely correlated to the degree of liking of the meat and therefore can be classified as “negative” attributes. Brothy, umami, roast beef, juicy, browned, fatty and salty are some of the attributes positively correlated to the degree of liking of beef and therefore can be identified as attributes that drive consumers’ acceptance. Steaks from grass-fed cattle were rated by consumers as slightly liked (6.08 on a 9-point scale), while steaks from grain-fed animals were rated as moderately liked (7.05 on a 9-point scale). 相似文献