Future outlook for the Irish dairy industry: a study of international competitiveness, influence of international trade reform and requirement for change

European Union (EU) trade liberalisation policies will continue to push EU milk price downwards and necessitate increased efficiency and scale at farm and processing level to maintain profitability. In Ireland pasture-based dairying, based on the efficient conversion of grazed grass into milk can be competitive within the EU. Continued technical innovation increasing animal performance from grazed grass, increasing herd genetic potential and developing labour efficient lower fixed cost systems will be essential. At processing level, increased efficiency in commodity processing, higher margin product development and the evolution of milk payment systems to reflect the true product value of supplies received will be required.     

Nutritional requirements and economics of lowering feed costs

Feed costs are, and will continue to be, the largest single expense for milk production. Gross efficiency of milk production is greater for high-producing cows because a lower proportion of total feed intake is used for maintenance of the cow. High milk production and high feed intake are positively correlated. The challenge for the future is to continue the remarkable progress in milk yield potential and increased feed efficiency realized in the recent past. Some areas of research that show promise for improving our knowledge and ability to feed cows for even greater efficiency include studies of energy metabolism, protein metabolism, voluntary feed intake, ruminal fermentation and fiber requirements, effects of growth hormone on milk production and animal metabolism, mineral nutrition, buffers, and vitamins. Practical studies on treatment and utilization of by-product feeds, manipulation of milk composition through nutrition, and continued development of better computer models for feeding and management decisions will have a significant effect on the efficiency and profitability of the dairy enterprise.     

Marketing premium milk and products for specialist groups

The problems faced by the producers of Channel Islands premium-quality milk in maintaining their market share are considerable. To counteract a fall in liquid milk sales on the doorstep. there have been increased sales in cartons through supermarkets where a separate product identity can be established. New product types with the Gold Top image have been developed and successfully marketed: frozen double cream, UHT semi-skimmed milk and dairy ice creams containing butter fat from Channel Islands milk. An unsalted butter gave keeping quality problems, but it is hoped that improved raw milk quality control will allow the product to be re-introduced.     

Energy Nutrition and Metabolism of the Lactating Dairy Cow

The genetic trend for increasing milk yield in the dairy cow population is impressive evidence of the application of genetic principles in dairy cattle selection. Walton (31) recently predicted that by the year 2000, individual cow records will approach 31,800 kg of milk per year and 1,360 kg of milk fat. Top individual herd averages will be nearly 16,000 kg of milk and 635 kg of milk fat. If these predictions are close, the subject of energy nutrition and metabolism will remain a relevant topic for many years. It will be a continuing challenge to design feeding systems and diet formulations that support this high production. An appropriate question is what high genetic merit for milk production means to a nutritionist or physiologist. To me it means the physical capacity and the physiological drive for cows to eat large volumes of energy-dense feeds, to assume negative energy balance through much of the first trimester of lactation, and to partition most of the feed energy plus energy from body stores into milk energy.I will sketch a broad picture of energy nutrition and metabolism in the lactating cow and identify those areas in knowledge and understanding that constrain dairy scientist from assisting cows of superior genetic merit to produce milk more efficiently. I see five areas for potential improvement in use of energy by lactating cows: a) increased production, b) increased energy consumption, c) increased digestive efficiency, d) increased metabolic efficency, and e) changed energy flow to partition more dietary energy to mik and less to body reserves for a longer period during lactation. I will attempt to relate the symposium speakers’ presentations to some of these areas.     

Research Needs to Supply Milk Protein in the Human Diet

Emergence of government action to define a national policy on food and nutrition implies increased emphasis on programs for food production and marketing. Optimal policy will rely upon information from targeted basic and applied research. Dairy cattle are discussed in the context of their comparative advantage among livestock species for providing high quality protein in the human diet Research needs are suggested to supply economical milk protein by improving biomass efficiency, economic efficiency, milk pricing, and aggregate analyses of systems of dairy production.     

Lactose: Use,measurement, and expression of results

Lactose has different uses in the dairy, food, and pharmaceutical industries. Being aware of the different forms of lactose and their concentrations can be very helpful in managing dairy product quality, properties, and manufacturing efficiency. Correct measurement and reporting of lactose concentration in milk and other dairy products will be of increased importance in the future as more value-added uses of lactose are developed and as milk lactose data are used in farm management decision making. Lactose should be reported as anhydrous lactose because lactose data will be used to make increasingly important decisions in dairy processing, dairy product labeling, and milk production in the future. Lactose also plays an important role in milk synthesis within a cow. Milk production factors and dairy cattle breed selection influence the amount of high value fat and protein produced per unit of lactose. If the off-farm value of lactose remains low, more attention may be focused on using ultrafiltration to process milk and leave 50 to 60% of the lactose and water from milk at the farm to recover the energy value of the lactose as feed and reduce the hauling cost of the high value components of milk to a dairy product manufacturing factory. Many methods exist to determine lactose concentration, but the most important methods are enzymatic assays, HPLC, and mid-infrared analysis. New, value-added uses for lactose need to be developed. Consistent and accurate methods of lactose measurement and consistent expression of lactose results will support this development process. Starting in January 2017, the USDA Federal Milk Market Laboratories began reporting lactose content of milk as anhydrous lactose and discontinued the reporting of lactose by difference.     

Limitations for Dairy Production in Developing Countries

Animal products (fish, eggs, meat, and milk) provide nearly 53 million Mt of edible protein and more than 1 billion Meal of energy per year. This is equivalent to 53% of the protein and 26% of the energy from cereal grains. The 550 million Mt of milk provides 53% of all animal protein. Present production is equivalent to .36 liters per capita, but consumption is high in developed countries, .5 to .8 liters per day but less than .2 liters in developing countries. From 1969 to 1978 world milk supplies increased 1.4% peryr, but human population grew 2.1%. Comparing rates of increase in cattle numbers (1.1%) and in milk (1.4%) indicates milk per animal has changed little. Land for agricultural cropping increased 1.1% per year 1969 to 1978. Expansion of cropping into traditional grazing areas and rise in fossil fuel prices has tended to reduce availability of milk in urban centers of developing countries. Elasticity of demand for milk in developing countries is high, but general market growth is slow because of limits in income growth by the majority of the population.Many developing countries are giving greater emphasis to milk supplies and are seeking bank loans to support development of infrastructure for dairying both on and off farms. Growth in milk must come largely from small farms which will require identification of constraints and development of appropriate technology. On subsistence farms there is a high dependence on animals to provide goods and services of nonfood nature which also will require consideration in developing milk supplies. Potential for growth of milk supplies in developing countries is high and affords an excellent opportunity for dairy scientists in the United States to assist in training and research.     

Influence of raw milk quality on fluid milk shelf life

Pasteurized fluid milk shelf life is influenced by raw milk quality. The microbial count and somatic cell count (SCC) determine the load of heat-resistant enzymes in milk. Generally, high levels of psychrotrophic bacteria in raw milk are required to contribute sufficient quantities of heat-stable proteases and lipases to cause breakdown of protein and fat after pasteurization. Sanitation, refrigeration, and the addition of CO2 to milk are used to control both total and psychrotrophic bacteria count. It is not uncommon for total bacterial counts of raw milk to be < 10,000 cfu/mL. In the past, fluid milk processors have not focused much attention on milk SCC. Increased SCC is correlated with increased amounts of heat-stable protease (plasmin) and lipase (lipoprotein lipase) in milk. When starting with raw milk that has a low bacterial count, and in the absence of microbial growth in pasteurized milk, enzymes associated with high SCC will cause protein and fat degradation during refrigerated storage, and produce off-flavors. As the ability to kill, remove, or control microbial growth in pasteurized refrigerated milk continues to improve, the original milk SCC will be the factor limiting the time of refrigerated storage before development of an off-flavor in milk. Most healthy cows in a dairy herd have a milk SCC < 50,000 cell/mL. Bulk tank SCC > 200,000 cell/mL are usually due to the contribution of high SCC milk from a small number of cows in the herd. Technology to identify these cows and keep their milk out of the bulk tank could substantially increase the value of the remaining milk for use in fluid milk processing. To achieve a 60- to 90-d shelf life of refrigerated fluid milk, fluid processors and dairy farmers need to work together to structure economic incentives that allow farmers to produce milk with the SCC needed for extended refrigerated shelf life.     

不同热处理工艺对牛乳中热敏感成分的影响

热处理是保证乳制品质量稳定和卫生安全的重要手段之一,牛乳在热处理过程中会发生美拉德反应、乳糖异构化和蛋白质变性等多种化学变化,且反应程度与热处理强度密切相关。文中以纯鲜生乳为材料,经巴氏、超巴氏和超高温瞬时杀菌(UHT)等热处理后,分析检测牛乳中主要热敏感成分的变化。结果表明:随着热处理强度的提高,牛乳中的糠氨酸含量呈指数关系增加,纤溶酶活则逐渐下降;热处理强度不同导致乳清蛋白各组分的变性程度也不同,其中β-LgB和BSA对热最敏感,β-LgA其次,α-La的耐热性最强;热处理温度越高,时间越长,牛乳中VB1和VB6的损失率也就越高。根据牛乳中热敏感成分含量或活性在热处理过程中的的变化规律,可以将糠氨酸、α-乳白蛋白和纤溶酶活等作为牛奶受热程度的指示物,从而更好的指导实际生产和维护消费者权益。     

Milk Pricing with “B” Conversion–Uneven Class Use

A major problem facing the dairy industry is the continued and consistent conversion of manufacturing grade milk to grade A, and the disproportionate effect of this on Class I utilization and, hence, on farm milk blend prices in the parts of the country where most of the grade B is located. Potential supplies of grade A milk are so concentrated and likely to convert to grade A in such substantial quantities that the problem is serious–far more so than in the past. New broader based pooling and pricing procedures which will stabilize interorder blend price relationships and at the same time preserve orderly marketing and deter uneconomic milk movements are needed. The likely economic results of such programs including standby pool, regional pools, national pools, flat Class I pricing and increased Class II prices are analyzed in this paper.     

紫外线对牛乳杀菌效果的研究

研究紫外线在牛乳杀菌中,照射时间、照射距离、牛乳厚度以及温度四个因素与杀菌率之间的关系。通过正交实验得出各因素的最佳工艺组合参数,发现照射时间和牛乳厚度影响杀菌率最为显著;紫外线照射可使牛乳中维生素Ｄ增加。     

Agriculture and dairying in the south-west of England

Within a region that is mainly agricultural, livestock production dominates and milk production accounts for nearly half the total annual value of output of £ 100 million. Over the past decade milk production has risen at a faster rate than nationally, due mainly to increased numbers of cows. There has been a marked degree of concentration in the structure of production. Here, Dorset stands out with one-third of the herds and almost two-thirds of the cows in units of 100 cows or more. Increased output has meant that profits have increased in real terms with efficiency gains in fixed costs.
Future prospects offer little hope of increased milk support prices in the EC, and the success of our milk producers will depend on expanding their share of the UK market and the extent to which fixed costs can be contained or even reduced.     

Milk production

This paper outlines some of the factors likely to influence the development of the United Kingdom dairy industry over the next decade. It considers the role of non-European Community countries in European milk supply and utilization, the impact of changing agricultural policies and the strategies available to dairy farmers to respond to the challenges that lie ahead. It is concluded that while Eastern European countries may have long term importance as sources of low cost milk production the influences of changing agricultural policy and marketing frameworks within the EC will have a more immediate and more significant impact on UK dairy farmers. It is envisaged that medium term developments in the UK will include an increased variety in the linkages between producers and retailers and producers and manufacturers; some resurgence in farm-based manufacturing; increased emphasis on milk compositional quality and manufacturing characteristics; continued pressure to reduce unit costs of farm production; and a movement towards lower input, less intensive systems of production.     

Reproductive loss in high-producing dairy cattle: where will it end?

The dairy industry in the United States has changed dramatically in the last decade. Milk production per cow has increased steadily because of a combination of improved management, better nutrition, and intense genetic selection. Dairy farms are larger, and nearly 30% of the dairy cows in the United States are on farms with 500 or more cows. The shift toward more productive cows and larger herds is associated with a decrease in reproductive efficiency. Cows with the greatest milk production have the highest incidence of infertility, but epidemiological studies suggest that, in addition to milk production, other factors are probably decreasing reproductive efficiency in our dairy herds. The reproductive physiology of dairy cows has changed over the past 50 yr, and physiological adaptations to high milk production may explain part of the reproductive decline. Critical areas for new research include control of the estrous cycle, metabolic effects of lactation on reproduction, mechanisms linking disease to reproduction, and early embryonic mortality. Solving reproductive loss in dairy cows will not be easy because only a small number of research groups study reproduction in postpartum dairy cows. Therefore, the present research base will need to be expanded. For this to occur, research funding must be increased above its current level and a renewed emphasis must be placed on solving the emerging crisis of infertility in dairy cows.     

Ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry MSE-based untargeted milk metabolomics in dairy cows with subclinical or clinical mastitis

In this study, a novel metabolomics technique based on ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry in the MS^E mode was used to investigate the milk metabolomics of healthy, subclinical, and clinical mastitis cows, which were classified based on somatic cell count and presentation of clinical symptoms. Meanwhile, univariate and multivariate statistical analyses were performed to identify the significant differences across the 3 groups. Compared with healthy milk samples, less glucose, d-glycerol-1-phosphate, 4-hydroxyphenyllactate, l-carnitine, sn-glycero-3-phosphocholine, citrate, and hippurate were detected in the clinical mastitic milk samples, whereas less d-glycerol-1-phosphate, benzoic acid, l-carnitine, and cis-aconitate were found in the subclinical mastitic milk samples. Meanwhile, the milk concentration of arginine and Leu-Leu increased in both the clinical and subclinical mastitis groups. Besides, less 4-hydroxyphenyllactate, cis-aconitate, lactose, and oxoglutarate were detected in the clinical than the subclinical mastitic milk samples, whereas the abundance of some oligopeptides (Leu-Ala, Phe-Pro-Ile, Asn-Arg-Ala-Ile, and Val-Phe-Val-Tyr) increased by over 7.95-fold. Our results suggest that significant variations exist across healthy and mastitis cows. The current metabolomics approach will help in better understanding the pathobiology of mastitis, although clinical validation will be required before field application.     

Effect of varying protein and energy densities in complete rations fed to cows in first lactation

Sixty-three Holstein cows in first lactation were allotted randomly at 28 days postpartum to receive one of nine rations in a 3 X 3 factorial design. Rations had crude protein 12, 15, or 18% in each of three energy densities from ratios of forage:concentrate of 75:25, 55:45, and 35:65. Corn silage and hay crop silage were combined in a ratio of 2:1 (dry basis) in each case, and diets were offered for ad libitum intake as complete feeds for an 11-wk experimental period plus 2 wk for a digestion trial. In regression analysis as energy density increased, feed intake, milk yield, milk protein, and lactose yields increased linearly, urea nitrogen in blood plasma decreased linearly, and milk fat percent and yield decreased curvilinearly. As dietary protein increased, feed intake, fat-corrected milk, milk fat yield, and plasma urea nitrogen increased linearly, and yields of milk, solids-corrected milk, milk protein, and lactose increased curvilinearly. Actual milk yield adjusted for dry matter intake increased with greater energy density but not with higher protein concentration. Increases of energy and protein each resulted in linear increases of digestibility of dry matter, crude protein, and energy of diets. There were no interactions of energy X protein for these measurements. Cows in first lactation will increase milk production in response to increasing protein over a range of energy densities when feed intake is increased.     

Milk composition,but not cheese properties,are impaired the day after transhumance to alpine pastures

Short-term effects of transhumance to high altitude were investigated in Valdostana bovine milk and Fontina cheeses. The study included samples taken at each milking on days 1, 2 and 5 after transhumance compared with 5 days before; individual cow milk was collected and bulk milk was manufactured to cheese. Somatic cell count and milk fat content increased the day immediately after transhumance. In bulk milk, transhumance effects were less pronounced. Except for sour taste, no clear trend for impaired composition or sensory properties was observed in the cheeses produced on the day after transhumance and ripened for 115 days. Milking time and, with that, manufacturing time influenced milk and cheese quality, leading to higher fat and more melting cheeses in the evening. These results allow better characterisation of the changes during this transition and will help farmers to tackle the difficulties in producing cheese during this period.     

Effects of feeding frequency on ruminal parameters, plasma insulin, milk yield, and milk composition in Holstein cows

Two experiments were conducted to determine the effects of frequency of feeding on ruminal fermentation, blood parameters, milk yield, and milk composition in cows fed a 60% pelleted concentrate and 40% chopped alfalfa hay (DM basis) diet. In Experiment 1, four ruminally cannulated cows were fed concentrates in 12 equal portions at 2-h intervals or in two equal portions at 0500 and 1500 h in a crossover design. In Experiment 2, treatments were as in Experiment 1 plus an additional treatment consisting of a total mixed diet fed at 2-h intervals in a 3 x 3 Latin square design. All treatment periods were 2 wk. In Experiment 1, increased frequency of concentrate feeding tended to result in elevated ruminal pH and increased acetate to propionate ratio. Plasma insulin concentration tended to be higher (1.54 vs. 1.04 ng/ml) and milk fat percentage increased from 2.21 to 2.60% for 2 and 12 times daily feeding, respectively. In Experiment 2, frequency of feeding concentrate or total mixed diet did not affect ruminal and blood parameters or milk yield. In both experiments, milk protein and lactose concentrations were not influenced by feeding frequency. Results suggest that where intake is kept constant, increased feeding frequency will not influence milk yield but could result in elevated milk fat percent in animals fed fat-depressing diets.     

A 100-Year Review: Cheese production and quality

In the beginning, cheese making in the United States was all art, but embracing science and technology was necessary to make progress in producing a higher quality cheese. Traditional cheese making could not keep up with the demand for cheese, and the development of the factory system was necessary. Cheese quality suffered because of poor-quality milk, but 3 major innovations changed that: refrigeration, commercial starters, and the use of pasteurized milk for cheese making. Although by all accounts cold storage improved cheese quality, it was the improvement of milk quality, pasteurization of milk, and the use of reliable cultures for fermentation that had the biggest effect. Together with use of purified commercial cultures, pasteurization enabled cheese production to be conducted on a fixed time schedule. Fundamental research on the genetics of starter bacteria greatly increased the reliability of fermentation, which in turn made automation feasible. Demand for functionality, machinability, application in baking, and more emphasis on nutritional aspects (low fat and low sodium) of cheese took us back to the fundamental principles of cheese making and resulted in renewed vigor for scientific investigations into the chemical, microbiological, and enzymatic changes that occur during cheese making and ripening. As milk production increased, cheese factories needed to become more efficient. Membrane concentration and separation of milk offered a solution and greatly enhanced plant capacity. Full implementation of membrane processing and use of its full potential have yet to be achieved. Implementation of new technologies, the science of cheese making, and the development of further advances will require highly trained personnel at both the academic and industrial levels. This will be a great challenge to address and overcome.     

Effects of exogenous oxytocin on production and milking variables of cows

Five doses of oxytocin (.5, 1.0, 1.5, 2.0, 3.0 IU) were injected through the subcutaneous abdominal vein (milk vein) of 15 Holstein Friesian cows 1 min before machine attachment. After teat cup removal, cows were given 10 IU of oxytocin via the milk vein for measurement of residual milk 1. An additional 10 IU of oxytocin was given 15 min later for estimating residual milk 2. Total milk yield was slightly higher for cows receiving 2.0 and 3.0 IU oxytocin. Milk fat yield was highest for cows receiving 2.0 and 3.0 IU oxytocin. Percent milk protein was less for cows receiving higher doses. Administration of 2.0 or 3.0 IU oxytocin significantly reduced total residual milk yield as compared with other doses. Fat percent in total residual milk was not affected by administration of oxytocin. Machine-on time, peak flow rate, and average milk flow rate did not differ with oxytocin treatment. A dose of either 2.0 or 3.0 IU oxytocin given via the milk vein will lead to slightly higher milk yields but will not affect milk flow dynamics as compared with lower doses. Moreover, milk fat yield is increased and total residual milk yield is decreased with either 2.0 or 3.0 IU oxytocin, suggesting that these doses result in more efficient extraction of milk. Administering more than 3.0 IU of oxytocin intravenously to promote milk ejection should be of no advantage.