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1.
A.J.H. Van Es 《Livestock Production Science》1974,1(1):21-32
It is argued that in view of the many new methods in dairy farming an economic model of the dairy farm should be available to improve advisory work. Some quantitative data concerning the dairy cow needed for such a model are given. They deal with a net energy feeding value of grass, hay, silage, artificially dried grass and concentrates estimated with a feed evaluation system based on results obtained with lactating cows. Also data on the requirements for net energy and for long forage dry matter are given, again obtained with such cows. Finally information is given on voluntary intake of forage dry matter at pasture, from fresh grass fed indoors, from various preserved forages including forage pellets, as influenced by milk yield and condition of the cow and by kind of forage and level of concentrates fed. Special attention has been paid to the precision of the information. These data are used to predict both the maximal and minimal amounts of long forage which can be fed in the stall period without loss of production, and the additional quantities of concentrates needed. For the grazing cow the problem of the adjustment of voluntary intake of grass to milk yield and amount of concentrates fed is studied. It is concluded that the information is sufficient to develop an economic model of a dairy farm. For its development grassland research should supply data on pasture yield in terms of digestible organic matter when the forage is fed to sheep at the maintenance level, and the economists should add data on costs of food and labour. 相似文献
2.
Feeding ionophores to beef cows or replacement heifers fed harvested forages increases weight gain and improves feed efficiency. These responses are influenced by diet quality and body condition of the animal. These compounds may reduce postpartum interval to estrus, but this effect appears to be diminished if nutritional status is poor. Although ionophores do not alter fertility, they decrease age at puberty in the female. These changes in reproductive performance appear to be related to a hormonal response to an increased propionate:acetate ratio in the rumen characteristic of ionophore feeding. Responses to ionophores in milk yield and weight gain improvements in calves of ionophore-fed cows are variable. Length of gestation, incidence of dystocia, calf birth weights and percent calf crop are not altered by ionophore feeding. The potential to improve cow herd production through the use of ionophores depends primarily on forage quality and availability. 相似文献
3.
Development of a model for the prediction of feed intake by dairy cows: 1. Prediction of feed intake
A study was undertaken to develop a model for the prediction of dry matter intake by lactating Holstein Friesian dairy cows. To estimate the model parameters, a calibration dataset was compiled with the data from 32 feeding experiments conducted at 9 different sites. The database contained weekly information on 1507 lactating Holstein Friesian dairy cows regarding their diet composition and feed analysis, together with their individual voluntary feed intake, milk yield (MY), milk composition, parity, days in lactation and days pregnant.Dry matter intake was predicted from feed and animal characteristics. The feed chemical composition and digestibility can be related to feed degradation, bulk volume, intake rate, palatability and other factors influencing feed intake. Therefore, the data of standard feed analysis were used to estimate the satiety value of numerous commonly used feeds and forages. The satiety value is the measure of the extent to which a feed limits intake. The cows' ability to process the intake-limiting satiety value-units is expressed as the feed intake capacity, which is predicted from parity, days in milk and days of pregnancy which are indicators of the size and physiological state of the cow. This study shows that feed intake can be predicted using a limited number of easy-to-measure inputs that are available on commercial farms, yet reasonably biologically sound. Because the model inputs are not related to animal output (milk yield or body weight), future extension of the intake model with models for the prediction of animal performance is possible. 相似文献
4.
Standard feeding means that the amount of feed offered is regulated according to actual requirement, with special reference to energy. Lead feeding indicates liberal supply during early lactation in order to challenge the cows for high peak yield. The lead feeding, in contrast to standard feeding rigidly practised, allows the cow to express its yield potential during the critical period of early lactation. Adjusted standard feeding may, however, be practised in a more flexible way by ad libitum feeding of forages, lead feeding during early lactation and with individual rationing of concentrates throughout.Adjusted standard feeding requires individual recordings of milk yield at intervals and qualitative judgement of the roughage available. Such a system is described and discussed.Adjusted standard feeding, flexibly practised seems most applicable for the small farm situation. By using a computerized system for diet calculation combined with adequate techniques for individual milk recordings and concentrate feeding, the system may be feasible even for larger herds.Adjusted standard feeding, as described, stresses the significance of high forage consumption together with efficient use of concentrates, high efficiency overall, and positive effect on ketosis and infertility. 相似文献
5.
Perennial ryegrass is the primary forage component of ruminant diets in New Zealand. It is persistent and palatable, and immature ryegrass has a high nutritive value (NV). However, seed-head development substantially lowers its feeding value (FV) as fibre concentration increases, the rate and extent of digestibility decreases, and voluntary intake declines. Ryegrass pastures are susceptible to accumulation of endophytic and saprophytic fungi in dead material at the base of the sward, especially when mature and laxly grazed. Feeding forage legumes to ruminants grazing grass-dominant pastures will improve animal performance and lessen the reliance on a single species to meet all nutritional requirements. The FV of forage is a function of intake and NV, measured by chemical analyses and animal feeding trials. Performance of individual animals grazing forages is usually limited by energy intake because structural fibre can slow digestion and clearance from the rumen and because of competition between individuals for available feed. The use of metabolisable energy (ME) content of forage to signify FV can give a reasonable indication of animal performance, but it should be used in conjunction with chemical analyses to improve the accuracy of predictions. The relationship between FV, pasture production, animal performance and profitability is complex. The importance of skilled management to maintain pasture quality and optimise animal performance under inconsistent climatic conditions should not be underestimated. Acceptable animal performance with minimal veterinary intervention requires good nutrition, but the genetic potential of livestock in New Zealand cannot be met solely by grazing pasture, especially when a high utilisation of pasture is required to maintain quality and profitability. Producers are responding to industry demands to reduce the seasonality in supply of milk and meat by changing lambing and calving dates, and extending lactation length in dairy cows. Social changes include adoption of once-daily milking in the dairy industry. Some changes have necessitated increased use of supplements and others can be met by feeding forages with a higher FV than ryegrass, all of which require an improved knowledge of feed quality. This information is available through rapid and inexpensive near infrared spectroscopy (NIRS) analysis, enabling animal nutritional needs to be balanced by appropriate nutrient supply. It is essential that producers continue to improve animal welfare, limit excessive use of fertilisers and meet the demands of overseas consumers. Good nutrition, with an increased use of legumes and other forages to complement ryegrass pastures, will enable these objectives to be achieved. 相似文献
6.
Perennial ryegrass is the primary forage component of ruminant diets in New Zealand. It is persistent and palatable, and immature ryegrass has a high nutritive value (NV). However, seedhead development substantially lowers its feeding value (FV) as fibre concentration increases, the rate and extent of digestibility decreases, and voluntary intake declines. Ryegrass pastures are susceptible to accumulation of endophytic and saprophytic fungi in dead material at the base of the sward, especially when mature and laxly grazed. Feeding forage legumes to ruminants grazing grass-dominant pastures will improve animal performance and lessen the reliance on a single species to meet all nutritional requirements. The FV of forage is a function of intake and NV, measured by chemical analyses and animal feeding trials. Performance of individual animals grazing forages is usually limited by energy intake because structural fibre can slow digestion and clearance from the rumen and because of competition between individuals for available feed. The use of metabolisable energy (ME) content of forage to signify FV can give a reasonable indication of animal performance, but it should be used in conjunction with chemical analyses to improve the accuracy of predictions. The relationship between FV, pasture production, animal performance and profitability is complex. The importance of skilled management to maintain pasture quality and optimise animal performance under inconsistent climatic conditions should not be underestimated. Acceptable animal performance with minimal veterinary intervention requires good nutrition, but the genetic potential of livestock in New Zealand cannot be met solely by grazing pasture, especially when a high utilisation of pasture is required to maintain quality and profitability. Producers are responding to industry demands to reduce the seasonality in supply of milk and meat by changing lambing and calving dates, and extending lactation length in dairy cows. Social changes include adoption of once-daily milking in the dairy industry. Some changes have necessitated increased use of supplements and others can be met by feeding forages with a higher FV than ryegrass, all of which require an improved knowledge of feed quality. This information is available through rapid and inexpensive near infrared spectroscopy (NIRS) analysis, enabling animal nutritional needs to be balanced by appropriate nutrient supply. It is essential that producers continue to improve animal welfare, limit excessive use of fertilisers and meet the demands of overseas consumers. Good nutrition, with an increased use of legumes and other forages to complement ryegrass pastures, will enable these objectives to be achieved. 相似文献
7.
The two possible pathways contaminating milk and milk products with mycotoxins are either the secretory or post-secretory route. The latter is of only little importance due to cooling conditions in production and storage. A secretory contamination can only occur with such mycotoxins, which undergo no complete degradation through their passage into the milk. From the mycotoxins, present in cow's feed; virtually only aflatoxin B1 yields a milkborne metabolite, the aflatoxin M1. The carry over rate is low (2 +/- 1%), but can be enhanced by polyhalogenated biphenyls, also present in the forage. Under normal conditions, however, this enhancement will not be measurable due to low equimolar concentrations of both reactants. The aflatoxin M1 content in herd's bulk milk depends exclusively on the content of the precursor aflatoxin B1 in the ration of the cow and is with less than 10 ng/kg fairly low at present in the Federal Republic of Germany. A careful supervision of the imported feed ingredients for mixed feed, however, will ensure to keep those batches out of dairy cow feeding which exceed a certain level of aflatoxin. The legal threshold is 10 micrograms/kg, being even too high to ensure a milk containing less than 10 ng/kg under high energy feeding conditions. The discussed thresholds for aflatoxin M1 in milk are 50 and 10 ng/kg resp., the latter value is scheduled for milk used in infant nutrition. To keep this low concentration the intake of aflatoxin B1 must be less than 2 micrograms/kg of the daily ration. 相似文献
8.
本试验应用EM发酵玉米秸秆和青贮玉米秸秆饲喂奶牛,以观察两种方法处理的玉米秸秆对奶牛生产性能及经济效益的影响效果。结果表明,用EM发酵的玉米秸秆饲喂奶牛较青贮玉米秸秆饲喂奶牛,每天每头奶牛采食量提高1.03%,平均产奶量提高2.02%,经济效益提高0.13元;EM原液发酵的玉米秸秆和青贮玉米秸秆1∶1混合饲喂奶牛,每天每头奶牛采食量、平均产奶量、经济效益分别比饲喂青贮玉米秸秆的奶牛提高2.85%、2.99%和1.15元。 相似文献
9.
复合草颗粒生产及饲喂奶牛试验 总被引：3，自引：0，他引：3
通过刈割-干燥-粉碎-配制-制粒程序将紫花苜蓿(Medicago sativa)鲜草加工成理想的高附加值商品--复合草颗粒,同时采用随机编号、分组试验法,替代2.5、2.0 kg精饲料饲喂奶牛,测定替代量与产奶量、草料消耗成本之间的关系.结果表明,复合草颗粒是一种体积小,便于运输、贮藏,使用方便,适口性好,营养价值高的... 相似文献
10.
The main feeding factors leading to optimum milk production in dairy goats are studied in this paper. Because of its high milk yield, the goat consumes large quantities of dry matter. Accordingly, the intake of energy seems to be the most important dietary factor influencing milk production.The amount of concentrates offered must be determined according to the type and the quality of forages. For obtaining maximum production the energy density of the diet must approximate 0.80 F.U./kg D.M.The annual feeding programme of the dairy goat must be adapted to its behaviour and must take into account its physiological status. Before and after parturition, feeding of good quality forages favourably affects the onset of lactation. The supply of concentrates before parturition should not exceed about 8 g D.M./kg L.W. After parturition, the increase in the concentrate intake of the goats should not be too rapid. In the middle of lactation and especially at the end of lactation, maintenance of milk production at a high level requires a slightly higher supply of concentrates than that necessary to meet the requirements for energy. 相似文献
11.
Paulo Salgado Vu Q. Thang Tran V. Thu Nguyen X. Trach Vu C. Cuong Philippe Lecomte Didier Richard 《Tropical animal health and production》2013,45(2):561-568
In North Vietnam, during winter, alternative forage resources are needed to balance the feed ration of dairy cows. The objective of this study was to investigate the effect of oat forage as a component of traditional winter roughage diets on feed intake, milk production and feeding cost in dairy cows. The study was conducted on-farm using 24 mid-lactation Holstein–Friesian cows. The feeding experiment consisted of two successive periods and two dietary treatments per period. Traditional basal diets included fresh tropical grasses, maize silage and hay. The oat forage had no effect on the dry matter intake of the basal diet, but the total crude protein intake was higher in cows fed with oat diets than in those fed with control diets. The yield of butterfat-corrected milk (FCM) was not significantly different between diets during period 1, but there was a trend (P?=?0.078) of higher FCM yields in cows fed with the oat diet compared to those with control diet during period 2 (17.3 vs. 16.3 kg/day). The decline rate in milk yield was significantly higher (P?<?0.001) in cows fed with control diets than in those fed with oat diets in both experimental periods. The total feeding cost of cows fed with oat diets was on average 12 % lower than those fed with control diets (P?<?0.01). So, the oat forage is an important winter resource for cows in North Vietnam allowing higher milk yield whilst reducing feeding cost, compared to traditional roughage diets. 相似文献
12.
Effects of feeding fatty acid calcium and the interaction of forage quality on production performance and biochemical indexes in early lactation cow 
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下载免费PDF全文 Z. Y. Hu Z. Y. Yin X. Y. Lin Z. G. Yan Z. H. Wang 《Journal of animal physiology and animal nutrition》2015,99(5):899-904
Multiparous early lactation Holstein cows (n = 16) were used in a randomized complete block design to determine the effects of feeding fatty acid calcium and the interaction of forage quality on production performance and biochemical indexes in early lactation cow. Treatments were as follows: (i) feeding low‐quality forage without supplying fatty acid calcium (Diet A), (ii) feeding low‐quality forage with supplying 400 g fatty acid calcium (Diet B), (iii) feeding high‐quality forage without supplying fatty acid calcium (Diet C) and (iv) feeding high‐quality forage with supplying 400 g fatty acid calcium. This experiment consisted 30 days. The milk and blood samples were collected in the last day of the trail. Intakes were recorded in the last 2 days of the trail. Supplementation of fatty acid calcium decreased significantly dry matter intake (DMI) (p < 0.01). Addition fatty acid calcium decreased milk protein percentage (p < 0.01) and milk SNF percentage (p < 0.01), but increased MUN (p < 0.05). Supplemented fatty acid decreased concentration of blood BHBA (p < 0.05), but increased TG, NEFA, glucagon, GLP‐1, CCK, leptin, ApoA‐IV, serotonin and MSH concentration in blood, the CCK concentration and feed intake showed a significant negative correlation (p < 0.05). 相似文献
13.
Nutritional strategies for managing the heat-stressed dairy cow 总被引：1，自引：0，他引：1
West JW 《Journal of animal science》1999,77(Z2):21-35
Heat stress results from the animal's inability to dissipate sufficient heat to maintain homeothermy. Environmental factors, including ambient temperature, radiant energy, relative humidity, and metabolic heat associated with maintenance and productive processes, contribute to heat stress. The focus of this article is to identify environmental and metabolic factors that contribute to excessive heat load, describe how disruption of homeothermy alters physiologic systems of the cow, and discuss nutritional modifications that help to maintain homeostasis or prevent nutrient deficiencies that result from heat stress. Changes in diet are needed during hot weather to maintain nutrient intake, increase dietary nutrient density, or to reestablish homeostasis. Formulation for adequate nutrient intake is challenging because of the competition between nutrient density and other needs for the cow, including energy density and adequate dietary fiber. Lower DMI during hot weather reduces nutrients available for absorption, and absorbed nutrients are used less efficiently. An excess of degradable dietary protein is undesirable because of energy costs to metabolize and excrete excess N as urea. Optimizing ruminally undegraded protein improves milk yield in hot climates. Mineral losses via sweating (primarily K) and changes in blood acid-base chemistry resulting from hyperventilation reduce blood bicarbonate and blood buffering capacity and increase urinary excretion of electrolytes. Theoretical heat production favors feed ingredients with a lower heat increment, such as concentrates and fats, whereas forages have a greater heat increment. Improved dietary energy density and the lower heat increment associated with the inclusion of dietary fat must be coupled with limitations to fat feeding to avoid ruminal and metabolic disorders. Numerous nutritional modifications are used for hot weather feeding; however, many need further investigation to achieve specific recommendations. 相似文献
14.
J.A. Bines 《Livestock Production Science》1976,3(2):115-128
The physiological state of the animal will influence the amount of energy it can utilize and this, in turn, will tend to affect its demand for food. Particularly when the energy concentration of the ration is not high, any effect of the physiological state on abdominal capacity will affect intake, e.g. young, fat or pregnant animals will have a reduced capacity compared to older, thin or non-pregnant animals, respectively. In general, intake of energy will increase with increasing concentration of digestible energy in the ration, but it becomes constant once the animal is able to meet its total requirement. When the energy concentration of the ration is not limiting, an increased output of energy will, in general, be matched by an increased intake. The response may not be immediate however, so that after parturition for example, peak food intake frequently occurs after peak milk yield. Correlations between intake and milk yield are generally low, whereas there is usually a marked relationship between body weight and intake in the lactating cow. Simple equations linking intake to body weight and milk yield are usually quite accurate in the general situation, but rarely of value to predict intake of an individual. More complex equations, though more accurate, are difficult to apply in the practical situation.The relationship between lactation and food intake is examined in some detail. It is concluded that efficiency of utilization of food energy for milk production could be improved by minimizing cyclic variations in liveweight of the cow during lactation. To permit this, methods are currently being examined for manipulating diet composition to enable the cow to consume enough food in early lactation to meet the requirement for milk production. If these methods are successful, it will be possible to feed the cow for constant liveweight by feeding to appetite at all times and altering the composition of the diet to match the energy demand of the cow. Allowance should be made for growth and pregnancy, but fatness should be avoided. 相似文献
15.
为研究不同饲草对反刍动物甲烷(CH4)排放量的影响,利用虚拟仪器技术设计的体外发酵产气自动记录系统,结合气相色谱仪,测定了奶牛业常用饲草体外发酵72 h后的发酵指标。结果表明:发酵72 h后,供试饲草的CH4产量介于56.85～74.63 mL.g-1DMloss,最高的为玉米(Zea mays L.)秸秆,最低的为苜蓿(Medicagosativa L.)干草Ⅰ。体外发酵程度由高到低依次为青贮玉米、苜蓿干草Ⅰ、苜蓿干草Ⅱ、羊草(Leymus chinensis T.)干草、苜蓿茎秆、玉米秸秆。各饲草的产气动态均呈指数函数变化,趋势相似,在0～24 h内累计产气量迅速增加,24～36 h内增长速率渐缓,36 h以后速率趋于平缓。各饲草的CH4产量与其中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)含量成显著正相关(P<0.05),与其粗蛋白(CP)含量成极显著负相关(P<0.01);通过逐步回归分析,建立常规养分含量与CH4产量的回归模型:PCH4=60.02-0.91×CP+0.44×ADF(R2=0.96)。综上表明,饲草的CH4产量与其品质有关,优质饲草体外发酵程度高,CH4产量低,从而提高饲料利用率、减少温室效应,而劣质饲草则相反。 相似文献
16.
目的：为探索在奶牛日粮中添加饲料甜菜对其泌乳量的影响,提高奶牛养殖的经济效益。方法：2011年9月20日至11月20日,选择健康黑白花奶牛6头,随机分为试验组（饲料甜菜组）和对照组（普通饲料组）,进行饲料甜菜对奶牛产奶量的影响试验。结果：试验组比对照组头均日产奶量增加2 kg,产奶量提高7.9%,差异极显著（P〈0.01）;试验组比对照组粗饲料采食量增加14%,饲料成本增加504元,差异极显著（P〈0.01）;试验组比对照组头日均收入高6.8元,增加纯收入1 124元,经济效益提高13.2%,差异极显著（P〈0.01）。结论：饲料甜菜饲喂奶牛,牛奶产量和质量明显提高,经济效益提高,在实践中应大力推广。 相似文献
17.
张家口市塞北管理区种草养畜的成本收益分析 总被引：4，自引：2，他引：2
为给华北农牧交错带典型区域张家口市塞北管理区的农、牧业结构调整提供决策支持,在实地调研基础上,对当地种草养畜进行成本收益分析.结果表明:饲草、饲料作物的成本纯收益率为45.2%~125.1%,依次是青贮玉米>青稞>禾本科牧草≥豆科牧草;青贮玉米和多年生牧草的生产成本分别为其购入价格的44.4%~59.1%和48.6%~68.9%;投入不足是限制青贮玉米生产效益提高的主要因子;"全年舍饲"模式下,产奶量4550~6300 kg/头的中、高产奶牛的养殖纯收益为-86.5~1544.2元/头,成本纯收益率为-1.1%~15.5%,盈亏临界产奶量为4588.1~4789.8 kg/头;"舍饲+暖季放牧"模式下,种草养畜(中、高产奶牛)的纯收益为1453.6~3435.2元/头,51.0%以上的纯收益来源于饲草种植,成本纯收益率为22.7%~42.5%,盈亏临界产奶量为2850.0~3182.8 kg/头. 相似文献
18.
19.
随着生活水平的提高和食品消费结构的变化,对动物蛋白的需求迅速增长。然而,由于缺乏优质粗饲料,畜牧业的发展受到了很大的限制。饲用全株小麦产量高、营养品质好,已成为一种优质的饲料来源,因此,围绕饲用小麦的相关研究意义重大。梳理近年来国内外关于饲用小麦生产和利用的现状及发展趋势,重点概述的内容有:1)品种选育:种质创制技术、逆境分子育种和常规饲用小麦品种筛选;2)栽培管理:常规田间管理、放牧利用管理和粮饲兼用管理;3)青贮加工的影响因素:栽培管理、生育期、添加剂和其他因素;4)家畜的饲喂效果:采食量、消化率、畜产品产量和品质等。此外,总结了饲用小麦各研究领域中所存在的问题和不足。同时,对新形势下饲用小麦的研究趋势和研究重点进行了展望,以期对我国饲用小麦的生产和推广利用提供指导与参考。目前,饲用小麦的发展背景主要是粮食过剩、饲草供需矛盾和动物生产性能等问题,它在产量和营养方面表现优异,尤其在冬季饲料缺乏时,小麦具备更大的生长优势,无论是放牧还是青贮利用都较方便,这也缓解了目前的饲料危机,为畜牧业的安全发展提供了保障。但是,粮用小麦品种一般为矮秆,其全株产量受限,为更好地发挥小麦的饲用价值,培育饲用专用品种势在必行。 相似文献