Factors Affecting Susceptibility to Mastitis
This section deals with :
� Determinants of Mastitis
� Timing of Infection and Stage of Lactation
� Nutrition and Mastitis
Determinants of Mastitis
Whether or not IMI occurs depends on the interaction of host, agent, and environmental factors.
HOST FACTORS include: the presence/absence of natural resistance to mastitis, the state of defense mechanisms (are they present and are they functional), the stage of lactation, and whether there are stress factors.
AGENT FACTORS include: the number of organisms in the gland, the pathogenicity of the organisms (they must penetrate the gland, then adhere to the tissue, and then reproduce), the presence of other virulence factors, and the state of the host defenses for resistance to infection.
ENVIRONMENTAL FACTORS include: the design and function of the milking machine, the milking environment, the milking hygiene practices, the type of housing and bedding, and the weather.
Timing of Infection and Stage of Lactation
Most environmental IMI occur during the periods of active involution after drying off, the period just prior to calving, and during early lactation, however, new IMI can occur at any time.
Active involution – At the beginning of the dry period the cow is no longer milked. The mammary gland undergoes a period of active involution Several situations which occur within the first two weeks after a cow is dried off predispose the mammary gland to mastitis:
� The gland continues to secrete milk with maximum fluid accumulation occurring 2 to 3 days after milk removal is stopped. Pressure in the gland can cause the streak canal to widen and the teat sphincter to dilate, allowing bacteria into the gland.
� Bacteria inside the gland are no longer regularly removed from the gland by the milking process.
� Teat dipping ceases.
� Phagocytes are involved in removal of secretory cell products (fat, casein), and are not particularly efficient at removing bacteria in the gland.
� Increasing amounts of immunoglobulins and lactoferrin (decreasing citrate : LF ratio) in the gland improve defense, but cannot override the problems noted above.
� Dry cow treatment of all quarters with antibiotics at the time of drying off reduces streptococcal and staphylococcal (but not coliform) IMI during active involution.
� Reducing the period of active involution by infusing colchicine (disrupts milk secretion mechanisms) decreases IMI during the active involution phase.
Peripartum Period – Several defense mechanisms are compromised during the period just prior to and after parturition (coinciding with colostrum formation) which predispose the gland to mastitis.
� Fluid volume in the gland increases resulting in increasing intramammary pressure and dilation of the streak canal and sometimes leakage of colostrum.
� Citrate concentration rises and lactoferrin is low.
� Phagocytic cells are not efficient at engulfing and killing bacteria in colostrum contained in the gland at this time.
� High immunoglobulin concentrations in the gland at this time are not effective in preventing new IMI. IgG1, the major immunoglobulin isotype in cow colostrum, is not normally an effective opsonin in the mammary gland.
� Antibiotic concentration from dry cow antibiotic therapy is too low to combat infection.
� Teat dipping during this period is not particularly effective in mastitis prevention.
Early lactation – Cows in early lactation are metabolically stressed. This stress can compromise the cow’s disease resistance and result in clinical outbreaks of subclinical infections (eg. IMI acquired during the dry period or at calving time). In addition, mastitis is sometimes associated with high concentrate feeding which accompanies early lactation.
Nutrition and Mastitis
Deficiencies of the following vitamins and minerals have been shown to be related to increased incidence of clinical or sub-clinical mastitis, increased severity of infection, or elevated somatic cell counts:
o Selenium – deficient in soils of the Midwest and northeast. Protects mammary tissue from oxidative damage and augments phagocytic function.
o Vitamin E. Protects mammary tissue from oxidative damage and augments phagocytic function.
o Less well documented in their relationship to mastitis are: B-Carotene (high in fresh forage, low in stored feed), Vitamin A, Zinc, Copper, Cobalt, and some others.

Detection and Diagnosis of Mastitis
The ideal means of dealing with mastitis is to prevent it from happening. However, even under the best prevention and control programs, mastitis will occur. Remember that mastitis is an inflammation of the mammary gland. Detection of mastitis is generally based upon some manifestation of the inflammation (changes in the udder or in the milk). However, treatment of mastitis works best if there is some information on the particular bacterium causing the problem. So, detection of the inflammation and diagnosis of the specific cause of the inflammation are important.

Detection of the Inflammation : Detection of the inflammation is based upon the response of the animal to the infection. From the sections in Mastitis Lesson A you learned that several significant changes occur in the tissue and in the milk in response to infection. These include infiltration of leukocytes (referred to as somatic cells) and increased vascular permeability, resulting in alterations in the chemistry of the milk resulting from hydrolysis of milk proteins by hydrolytic enzymes and oxidative substances released from phagocytes, alterations in milk pH and ionic solutes, and ingestion of milk components by phagocytes.
Approaches to Detection of Mastitis
Visualization and palpation of the udder : In clinical mastitis, the udder may turn hard, red, and hot to the touch. Palpation of the udder may be painful to the cow. These symptoms arise from the changes in vascularity and blood flow of the gland when inflammed.
Detection of Somatic Cells : Several methods for detection of mastitis are available for detecting somatic cells in milk, including the California Mastitis Test (CMT; a cow-side test), the Wisconsin Mastitis Test (WMT; on-farm test), Microscopic Somatic Cell Count (usually requires a laboratory), and Electronic Somatic Cell Counting (requires sophisticated equipment). The CMT and WMT detect formation of a gel when DNA in somatic cells react with a detergent. The reaction occurs on a paddle (CMT) and is graded subjectively (neg, trace, 1,2,3), or in a tube (WMT) and is measured in millimeters. CMT or WMT results can be used as rough estimates of the number of somatic cells in milk and to identify subclinically infected mammary glands.
Somatic cell counts can be run on milk from the bulk tank (this indicates herd mastitis status) or from individual cows (detects a specific cow with possible mastitis). Somatic cell counts of less than 100,000 to 200,000 cells/ml of milk are not indicative of mastitis. As cell counts increase so does the chance that a bacterial infection is present. A bulk tank somatic cell count exceeding 750,000 cells/ml will result in loss of Grade A milk status (the producer cannot continue selling the milk until the problem is fixed).
N-acetyl-�-D-glucosaminidase (NAGase) : NAGase is a lysosomal enzyme which increases in milk when mastitis is present. Some NAGase comes from the leukocytes infiltrating the tissue, but most of it comes from the epithelial cells in response to the presence of the leukocytes. So, the activity of NAGase in milk is highly correlated with the concentration of leukocytes (the somatic cell count). Assays for NAGase are enzyme assays and often use fluorescent substrates. The amount of fluorescence generated in these assays is correlated with the somatic cell count and with the degree of inflammation.
Electrical Conductivity : Electrical conductivity of milk increases during mastitis due to increases in Na+ and Cl- and decreases in K+ and lactose. Changes in conductivity can be detected by hand-held or in-milkline instrumentation.
Detection of Antibodies in Milk : An ELISA test has been developed to detect antibodies to Staphylococcus aureus in milk. Antibodies to S. aureus may be present in milk long after an infection is gone, or if it is a new infection the antibodies may be slow in increasing in concentration, these may result in false positives and false negatives in individual cases. Consequently, this method has limitations on detecting S. aureus as the cause of acute mastitis, but may be useful in situations of chronic mastitis and whole herd screening.
Identification of the Pathogen Causing Mastitis
Collecting sterile milk samples for bacteriological culture is the only way to definitively diagnose infectious mastitis and identify the causative organism. Proper technique in collecting the sterile milk sample is essential! Separate samples usually are collected from each quarter. Remove dirt and water from the teats and udder; wash and dry hands; strip out the foremilk; disinfect the teat ends with alcohol and/or teat dip (do the teats on the side away from you first); remove the cap from the sterile sample tube taking care to prevent contamination inside the tube; collect sample with tube at 45 degree angle to teat (collect the near teats first); replace the cap on the tube and dip the teats.
Proper sample handling : Refrigerate or keep the sterile milk samples on ice (if plating will occur in less than 24 hours) or freeze the samples (if storing for greater than 24 hours).
Plating the sample : Plating the samples requires special bacteriological medium, conditions of a laboratory and personnel with good technique in microbiology. Agitate the milk sample to mix. Plate 0.01 ml milk per each quarter of Blood agar plate using a loop or pipette. For suspected coliforms, plate 0.1 ml milk for each half of a Blood agar plate or plate on MacConkey agar. Incubate at 37 C for 48 hours.
Pathogens vs Contaminants : How do you tell if growth on the plate is a pathogen or a contaminant? These criteria assume you are using good technique in collecting the sterile sample and in plating the samples. Greater than or equal to 5 identical colonies from 0.01 ml milk (pure culture) = significant. Greater than or equal to 5 identical colonies from 0.01 ml milk (mixed culture) = significant, but questionable. Less than 5 identical colonies from 0.01 ml milk = a contaminant.
Intrepretation : Streptococcus agalactiae and Staphylococcus aureus are usually significant (representing a causative agent) in any number. Bacillus is usually a contaminant when present in any number.
Antibiotic Sensitivity Tests : are often used to determine what antibiotics may affect the bacterium isolated from the udder. However, these take time and additional microbiological techniques. These tests use either disc diffusion or minimal inhibitory concentration assays. The in vitro results may not necessarily reflect the in vivo sensitivity of the bacterium.
Control of Mastitis
Mastitis Control
Awareness of the economic losses associated with mastitis is resulting in a desire for mastitis control programs. Control programs are focused on detection of mastitis (by the above methods), identification of the causative agent(s) and prevention of transmission by removing the source of the agent (milk contaminated fomites, bedding, persistently infected cows, etc.). Knowledge of mammary anatomy and physiology, mammary defense mechanisms, microbial habitats, microbial virulence factors, milking machine function, and antibiotics/germicides is important in achieving effective mastitis control.

It was the one of the best seller for her book, and the story is pretty thoughtful on how people coming to a decision not made by themselves. Pretty much similar to our lives in the modern. We have to make choices, and some choices we made might not satisfactorily, but we have to live on with it. I pretty much enjoy her story. And I believe that one of her story is made into movie called “Interview with the vampire”. You should check it out.

The one thing to remember if you are waiting to get a book published is that you are going to need time – and a lot of it. Even Harry Potter (yes, the infamous Harry), went through a few years of rejections and the need to find the right publisher. So, if you are going for the publishing route with a particular company, remember that patience is your key.

When you start to approach publishing options, you will need a Bible. This is the Writers Market for the current year. Sometimes, the last year will also be available and will have enough information that is updated. This will give you a list of all of the publishing companies, their address and their requirements. By using this book, you can automatically submit your manuscript into the hands of those who are looking for a story like yours. This will eliminate some of the players on the field and give you a direct line.

Your next step is to submit like crazy. You don’t want to put all of your eggs in one basket in the hopes that they will say yes. Get your query letter together and send it to at least 10 publishers. This way, you will be able to find the best deals when they come along. Once again, expect to wait for the letters to come in, and in the mean time, keep submitting. Eventually, something will fall together. And, if not, keep your rejection letters as memorabilia in a shoe box. They can be motivational, even if you know you have a best seller on your hand.

Eventually, you will find a publisher. The trick is to remember who is on the other side. Typically, they can only put out a certain amount of money a year, meaning a couple of books, and they need to have something they know is the right fit. If you keep their looking glasses on, the rejection letters don’t seem so personal, and you can come to terms with it just taking a matter of time before you find someone who knows that your name is put into print.

Just like baseball, you have to swing and run a lot before you hit a home run. If you keep playing the game, eventually, you will find a publisher who is ready to say ‘yes’ to your book.

Participants must enter through the Sobol website, where up to 50,000 manuscripts will be accepted, online only and when applying an $85 fee is required.

Random House, of course, was the country’s largest publisher last year, with U.S. sales of about $1.33 billion, roughly flat with 2003. HarperCollins and Penguin usually run neck and neck for the country’s second largest publisher. In 2004, HC, with a big assist from Zondervan and The Purpose-Driven Life, edged ahead of Penguin. HC had North American sales of approximately $965 million last year, with North America accounting for about 73% of HC’s worldwide sales. Penguin, which received a boost of $40 million from its Penguin Press, Gotham and Razorbill imprints in 2004, had estimated sales in the U.S. of $900 million last year.

To compare: 63,000 small publishers (‘everyone else,’ I’m guessing) generated revenue of $14 billion.

[Source: Publishers Weekly, via KeepMedia]

Because I’m more than a little obsessed with all things wordy, I can’t resist reading books about grammar and usage. I came across a fun one yesterday that even those who aren’t word nerds will enjoy: Grammar Snobs are Great Big Meanies by June Casagrande (Penguin, 224 pages, $14).

Casagrande, author of the “A Word, Please” column that appears in several community sections of the Los Angeles Times, offers a guide to usage that’s mostly based on doing what feels (or at least sounds) right. She’s not big on rules, and she is big on cheesy mnemonic devices to help you remember the rules you do need to know.

She hopes that people can learn to strike a balance between being clueless about grammar and being a “grammar snob,” someone who delights in his or her knowledge of grammar and will use that knowledge to humiliate others who do not know as much.

If you haven’t had the pain of running into a grammar snob, Casagrande elaborates:

Unlike normal people who get giddy about things like love, sex, money, free beer, and classic REO Speedwagon, these guys have the hots for things like punctuation marks and syntax rules and the excavation of lost words that were lost for a reason.

Like a lot of ‘happy’ drunks, these people can turn on you in an instant, transforming from Jekyll-like, playful nerds into bloodthristy grammar Hydes.

Some grammar snobs, Casagrande points out, give truth to the adage that a little knowledge is a dangerous thing. They think they know the rules, so they think they have license to correct what they see as gaffes in other people’s writing and speaking.

But the truth is, these people often don’t know the rules any better than the average person. Or they know rules that are no longer considered rules, like the “rules” against splitting infinitives, ending sentences with prepositions or starting them with conjunctions, all of which this book trashes, once and for all (we hope).

Casagrande also tackles more ticklish subjects like use of the subjunctive (was vs. were), saying “literally” when you mean “figuratively,” how to punctuate and why, and why rock stars can’t spell and what to do about it.

This entertaining and funny book is also educational if you don’t already know the basics of grammar and usage or are always getting rules confused. If you’re a grammar geek already, you might not learn much from this little book, but you should take it as a warning never to become one of the grammar snobs Casagrande takes to task, even if you think you really do know it all.

It’s been a few weeks since I sent out my first queries to literary agents. So far, no bites — just a few rejections.

Luckily, I’m immune to rejections. (I’ve been a freelance writer for a few years, so I’m used to them.) Also, I’m thankful they’ve all been good non-form-letter rejections — each responded to specific things I’d said in my query, which is encouraging.

If I don’t have any luck with anyone from this group, I have another batch of queries ready to go out in May…

In the meanwhile, here are a few more sites offering advice on how to get an agent:

• Literary agents: a four-part series from Writing.org
• Words of Wisdom to Snatch a Literary Agent from FreelanceWriting.com
• Literary Agents – Answers and Advice from TaraKHarper.com

That in itself takes a lot of time because it can be sometimes over a year before you are accepted or rejected and then it’s on to the next one. You have to remember it’s not like a demo tape you listen to and toss in the trash. These are words that has to be read, a story that has to be finished for them to get the big picture.

If they get hundreds and thousands of these then it will take time, a lot of time before  yours is even read.

• Illustration Web
• RABZ Illustration (Fantasy Illustration)
• Dragon Pencil
• Author House