Agricultural producers are under constant pressure to minimize the impact their management practices have on the environment. Although most environmental concerns related to animal agriculture have focused on water quality during the past two decades, air quality issues have become an increasing concern. Odors have been the main air quality concern related to agricultural animal production. However, ammonia emissions from livestock and poultry operations have recently received significant attention. New air quality standards that cover ammonia emissions in the United States were adopted in 1997. These regulations will have a significant impact on the future of animal production operations. The purpose of this publication is to provide an overview of ammonia production associated with animal agriculture and to explain why it is receiving greater attention from those concerned with environmental quality.

All milking equipment, lines, and utensil surfaces that come into contact with milk or dirt or manure must be thoroughly cleaned and sanitized before the next milking. Bulk milk tanks also must be cleaned after each milk pickup. and sanitized before the next milking. The purpose of cleaning is to remove milk soils, organic and mineral solids that form on equipment surfaces after the milk is removed. The purpose of sanitizing is to kill residual microorganisms present on these surfaces immediately prior to milking. Inadequate or improper cleaning or sanitizing or both allows bacteria to remain on equipment surfaces and to grow and multiply. This results in elevated bacteria counts in milk

Many dairy producers practice some crossbreeding, and the numbers increase every year. Motivating factors include a desire to improve fertility, survival, milk components, and calving ease. Some producers want cows smaller than mature Holsteins. Several large, long-term dairy crossbreeding experiments have been conducted in the United States in the past. Cows involved in previous projects were not the result of intensive selection programs for type and production that produced today’s purebred populations.

The Merit indexes are dairy sire selection tools published by USDA that combine genetic evaluations for production, health, fitness, and fertility traits. The indexes are designed to improve the lifetime economic performance of future dairy cows. Periodic revisions include new traits and adjusted economic weights. This document describes the indexes as revised for August 2006. Future changes are inevitable, thus the title “2006 Version.” 

The future of the dairy herd is dependent on the production of superior heifers to replace culled lactating animals. Therefore, it is imperative that the health status of the replacement animal is optimized to present a healthy first calf heifer to the lactating herd. Studies have consistently demonstrated the detrimental effects of pneumonia in calves on age at first calving and on milk production once these animals enter lactation. Calves with respiratory infections were twice as likely to leave the herd and age at first calving was delayed by 6 months when compared with calves that did not experience respiratory disease or pneumonia. In another study, calves treated for scours were three times more likely to calve at 30 months of age or greater.

Questions about dewormers are some of the most frequent that producers have. I will try to address the most common questions producers ask as well as my list of the most important questions. The answers are a combination of current research and my interpretation of that research. In some cases the answers are my educated opinion based on our current understanding of worms and dewormers.

Ethanol is produced when starch in corn grain is fermented. Most other constituents in the grain remain unchanged. The end product of the corn is distiller’s grains or DDGS (distiller’s grains with solubles). The DDGS retain the original fatty acids, protein, and phosphorus. In addition, variability in the grain nutrient content used in the fermentation process and the actual process itself results in a feed with variable nutrient content. Distiller’s grains can be fed either in the wet (less than 25 percent dry matter) or dry (greater than 85 percent dry matter) form. Wet DDGS are difficult to store and must be fed within a few days of production. The wet DDGS can be the most cost-effective, however, if used close to where they are produced.

Raising dairy replacement heifers is expensive. In fact, if the dairy is divided into different enterprises (eg. labor, feed cost for lactating cows, facilities, etc.), rearing replacements is the second largest cost, behind feed cost for lactating cows. The percentage will vary from farm to farm, but approximately 9% to 20% of the expenses incurred will involve rearing and developing heifers. Therefore, heifers should represent a sound investment, as their impact on future herd profitability is enormous.

Well managed dairy herds with low somatic cell counts (SCC below 200-300,000) often may experience problems with onsets of clinical mastitis. Approximately 40-45% of the mastitis cases in low SCC herds are caused by environmental pathogens which can be difficult to detect because of their short duration. Cows in low SCC herds are most susceptible to environmental streptococci and coliform infections after drying off and just prior to calving but which appear in early lactation.

You cannot just “get” bed bugs. They have to be brought into your home. So what is your first clue that you have brought bed bugs home (say after a trip, or after purchasing a piece of used furniture that you bought at a garage sale)? Most people become suspicious of a bed bug infestation when they find unexplained bites on their bodies.

Animal agriculture is facing the significant issue of managing excreted nutrients, and researchers are designing programs to address the issue. The intense management of animals in the poultry, swine, and dairy industries can contribute to environmental pollution. Although there are more beef than dairy cattle in Virginia, beef cattle are typically maintained on pasture and dispersed over a greater area. Feed management in dairy cows to reduce nutrient consumption has been identified as being very effective in reducing output of potentially polluting nutrients such as nitrogen and phosphorus.

With the price of milk and the cost of milk production where they have been the past few years, tight control over dairy management decisions will make a significant impact upon farm returns. One decision which will improve profitability is to cull problem cows. A dairy farm's goals should include: (1) Maintaining profitable levels of milk production based upon sound feeding, breeding, and management programs; and (2) An effective herd health program to reduce losses from mastitis and other cow disorders. On most dairy farms, annual culling rates exceed 30-35% of the herd. According to December 1998 DHI summary for Virginia, 36% of all cows enrolled in Virginia's DHI program were culled. 

A herd whose bulk tank somatic cell count exceeds 200,000 or DHI SCC score is above 2.5-3.0, or a herd where more than 3 cows per 100 cows show clinical mastitis over a month's time has a costly mastitis problem because of significant lost milk production and reduced economic returns. Herds with elevated SCC may not have many cows that are clinical, but subclinical mastitis infections may cause permanent destruction of milk secretory cells with permanently lower milk producing ability. In other herds, short duration environmental infections may not have great impact upon SCC, but these cows also have depressed milk yields, and considerable milk may be discarded because of antibiotic treatments. Consequently, dairy herds are losing money through greater culling, increased labor intensity, and greater risk of shipping milk that may be contaminated with antibiotic residues.

The mating of related individuals is called inbreeding. New dairy animals created by AI or natural service inherit a random sampling of the genetic makeup of each parent. If the parents are related, some of the genes transmitted to offspring by each parent will be copies of the same genes found in the common ancestor(s) which caused the parents to be related. As the genetic relationship between parents increases, the likelihood that pairs of genes in offspring are copies of a single gene in an ancestor generations back increases. Such genes are said to be "identical by descent."

When feeding lactating dairy cows it is best to limit amounts of certain feeds. Reasons can be problems with palatability, high oil or fat content, and imbalances of certain nutrients. Knowing these restrictions can prevent problems from occurring. Also, combinations of some of these feeds can be a problem if the maximums are used with no regard to type and amount of nutrients that are provided. This is where your nutritionist can be an asset in identifying optimal relationships with consideration for cost of the ration. Here is a list of some feeds used in Virginia and suggested maximums. Remember that these are maximum amounts and not necessarily optimum amounts.

Several factors can dramatically reduce replacement-rearing cost and increase potential profits for the producer: (1) maximizing immunity from colostrum to minimize mortality and sickness, (2) formulating rations for specific weight gains during strategic periods of development and avoiding over-fattening prior to puberty because it impairs mammary development, (3) formulating rations for an average daily gain of 1.8 lb. for Holstein heifers, (4) using AI sires ranking in the top 20% for (PTA$) to optimize genetic improvement, (5) monitoring age, body weight, wither height, body condition score as well as peak milk and ME milk yield of first lactation heifers to evaluate management at first calving, and (5) controlling the size of the replacement herd by calving heifers at 24 months and raising no more than needed.

The presence of drug or antibiotic residues in milk and meat is illegal. Milk supplies containing detectable concentrations are not acceptable. Unless drug residues are avoided to protect milk's reputation as a healthy, safe food, the market becomes jeopardized. Consumers want to be confident that their food supply is free of contamination by herbicides, pesticides, drugs, or antibiotics. Approximately 5-10 percent of the population is hypersensitive to penicillin or other antibiotics and suffers allergic reactions (skin rashes, hives, asthma, anaphylactic shock) at concentrations as low as 1 ppb penicillin. There is concern that small amounts of certain antimicrobial agents may significantly shift the resistance patterns in the microbial population in the human intestinal tract.

Nitrogen (N) and phosphorus (P) are the two nutrients that cause the most concern with respect to environmental pollution from animal manure. Generally, higher concentrations of N and P in the ration result in their greater excretion in urine (N) and feces (N and P). Overfeeding these nutrients can be a significant problem, particularly if nutrient levels accumulate in the soil and contaminate water sources through leaching or surface runoff. Nitrogen can also volatilize as ammonia and pose a potential environmental problem with air emission standards, which are currently under review. 

Preventing drug contamination of milk and meat is the responsibility of every farm. Drug residues can be avoided by a well planned drug use program. There is no way that a milk plant can use contaminated milk. The sale of contaminated milk or meat will cause the responsible party to be subjected to severe penalties, including suspension of permits and monetary loss. Milk with drugs can adulterate a whole truckload or holding tank of milk.

According to the National Mastitis Council, using FDA-approved intramammary antibiotics at drying off can decrease the number of existing mastitis infections and prevent new infections during the early weeks of the dry period. Dry cow therapy has the following advantages over lactation therapy: a) The cure rate is higher than that achieved by treatment during lactation, b) A much higher dose of antibiotic can be used safely, c) Retention time of the antibiotic in the udder is longer, d) The incidence of new infections during the dry period is reduced, 

Dairy producers have selected for higher milk production for many years. Genetic improvement causes an average Holstein cow born in 2003 to produce over 7,000 pounds more milk in one lactation than her ancestor born in 1960 produced. Type traits, particularly udders and feet and legs, have also improved because of intensive selection. However, the health and fertility of dairy cows cannot be included among these success stories. Genetic trend was responsible for half of a 9-point decline in pregnancy rate in Holsteins between 1960 and its low point in 1995. Dairy-cattle breeders responded by developing national genetic evaluation programs for a number of fitness traits in recent years. 

Staphylococcus aureus (S. aureus) mastitis is extremely difficult to control by treatment alone. To date, successful control is gained only through prevention of new infections and culling of infected animals. S. aureus organisms colonize teat ends and/or teat lesions. Spread of infection can occur through milkers’ hands, washcloths, teat cup liners, and flies. During milking, irregular vacuum fluctuations can force bacteria up into the teat canal, leading to the potential for new infection. If not culled, infected cows must be segregated from the milking herd and milked last, or milked with separate milking units. A backflush system may help reduce bacterial numbers within the liners, but rinsing units by hand is certainly not recommended.

Nitrogen (N) and phosphorus (P) are the two nutrients that cause the most concern with respect to environmental pollution from animal manure. Generally, higher concentrations of N and P in the ration result in their greater excretion in urine (N) and feces (N and P). Overfeeding these nutrients can be a significant problem, particularly if nutrient levels accumulate in the soil and contaminate water sources through leaching or surface runoff. Nitrogen can also volatilize as ammonia and pose a potential environmental problem with air emission standards, which are currently under review. 

You cannot just “get” bed bugs. They have to be brought into your home. So what is your first clue that you have brought bed bugs home (say after a trip, or after purchasing a piece of used furniture that you bought at a garage sale)? Most people become suspicious of a bed bug infestation when they find unexplained bites on their bodies.

You cannot just “get” bed bugs. They have to be brought into your home. So what is your first clue that you have brought bed bugs home (say after a trip, or after purchasing a piece of used furniture that you bought at a garage sale)? Most people become suspicious of a bed bug infestation when they find unexplained bites on their bodies.

Samples of bulk tank milk are collected regularly and milk quality tests are performed by milk coops, plants, or Virginia Department of Agriculture and Consumer Services. Some milk coops offer bulk tank profiles which involve several tests related to milk quality. The various tests are briefly described below, as well as a list of goals for high quality milk and conditions which adversely affect test results. Hopefully, an explanation of the use of these tests will help Virginia dairy farmers produce high quality milk, which has been defined by the Extension Milk Quality Leadership Council as milk with:

Forage quality has typically been determined by measuring the dry matter, crude protein, fiber, and estimated energy content. Forage testing labs are now able to estimate the actual digestibility of feeds by using newly available tests.

In order to have an accurate forage test for ration formulation, it is important to have a representative sample. The method of sampling varies with forage type. Silages (corn or hay crop) can be sampled either at harvest or at feed out. There is a slight reduction in dry matter and increase in fi ber during storage, but it is possible to use the analysis of the fresh material to indicate the quality after ensiling. If sampling fresh material at harvest, it is best to take three to four handfuls from every third load or more and place them in a container with all samples from the same field. Keep it covered to prevent drying. After mixing the composite, a sub-sample can be taken for analysis (only a pint or 100 grams is needed).

The Merit indexes are dairy sire selection tools published by USDA that combine genetic evaluations for production, health, fitness, and fertility traits. The indexes are designed to improve the lifetime economic performance of future dairy cows. Periodic revisions include new traits and adjusted economic weights. This document describes the indexes as revised for August 2006. Future changes are inevitable, thus the title “2006 Version.” 

The goal for any dairy farm should be to deliver a high quality product that has consumer appeal. The objective of any heards milk management program should include: (1) maximise yield secreted by the mamary gland, (b) milk cows out in a short peroid of time, (c) prevent damage to teats, teat ends, and the udder, and (d) have no adverse effect on chemical composition of milk. It must be recognized that factors other than milking equipment, such as milking practices, can influence milking performance and quality.

Culling decisions affect the profitability of the dairy herd. Feed resources and management skills used to maintain unproductive cows would generate more income if applied to productive cows. DHI records contain important information to help guide culling decisions. This guideline describes three systems for rating cows for production traits. Producers recognize that information about production must be combined with reproductive and health status, age, and other factors to make profitable culling decisions. Suggestions for combining information to make good culling decisions are offered.

Concepts surrounding the word "Heritability" (frequently represented by the symbol h²) are among the most important that a breeder of dairy cattle should understand. Heritability applies to a single trait measured on animals in a specific population at a given point in time. Estimates of heritability for a trait can differ between breeds of dairy cattle and may change slowly over time. Heritability is estimated from performance records on animals and pedigree information used to establish genetic relationships between those animals. Heritability helps explain the degree to which genes control expression of a trait. Heritability is used to calculate genetic evaluations, to predict response to selection, and to help producers decide if it is more efficient to improve traits through management or through selection. This guideline highlights definitions and uses of heritability and lists estimates of heritability for several important traits in dairy cattle breeding.