Artifical Breeding - LIC

1. LIC: Artificial breeding - The process from semen collection and quality control to detecting ovulating cows to artificially inseminating the cow.

Advantages for Artifical breeding(AI)

•  increased efficiency of bull usage
• increased potential of genetic selection
• increased safety for animals and farmers
• Decreased costs
• Reduced animal disease transmission

Disadvantages for AI

• more labor intentive
• detection of correct status for conception is responsibility of farmer not bull
• risk of failure in transport and storage
• reduces gene pool in a herd level, nationally 
• un thawing 
• poor AI technician (human error)

Collecting Semen from bulls

Semen is collected from a bull using a teaser animal (usually a steer or another bull) and an artificial vagina.  

Semen should be evaluated grossly for abnormal appearance. The presence of small "clots" or blood can indicate such conditions as seminal vesiculitis.

Parameter	Normal Values
Ejaculate volume	5 ml (range 1-15 ml)
Sperm concentration	1200 million/ml (range 300-2500 million/ml)
Total sperm per ejaculate	Typically 4-5 billion
Progressive motility	Greater than 30%
Morphology	Greater than 70% normal

Semen is then examined under the microscope for concentration, morphology and motility.

Semen is stored in special tubes called straws, 

Which are then stored in liquid nitrogen. (-196 degrees C) This prevents deterioration and biological quality. 

Artificially inseminating a cow

Effects of excess nitrogen on waterways

Nitrogen A chemical element that is the most abundant uncombined element in Earth’s atmosphere and occurs in all organisms. To be used by plants and animals, nitrogen must be fixed from the atmosphere and converted to ammonium (NH4) or nitrites (NO2-) and nitrates (NO3-). 

Nitrate-nitrogen (NO3-N) is an important plant fertiliser but it is highly water soluble so it leaches through soils very easily and reaches waterways. Sources of NO3-N include inorganic fertiliser, septic tanks and leaking sewerage systems.

Nitrate can also enter waterways from the nitrification of the ammonia in animal waste. 

The main ways that nutrients end up in water from diffuse pollution is through leaching and runoff. Nitrogen makes its way to water mainly through leaching which occurs when the plant cover cannot take up all the nitrogen so it moves down past the shallow root zone and through the soil. The nitrogen eventually moves into water, either groundwater storage areas or laterally into streams and then lakes and estuaries. The main form of nitrogen leaching is from cow urine because it occurs in small concentrated patches that the pasture cannot take up.

Nitrogen itself is only harmful to humans at very high concentrations (11.3mg/l)

Nitrate has ecosystem consequences at much lower levels than when it becomes unsafe to drink.  Ecosystem effects can start to occur at levels below 1 mg/l in water.

Nitrogen is toxic to fish at far lower levels than it is toxic to humans.

Too many nutrients (mainly nitrogen and phosphorus) in rivers and lakes cause unwanted plants (weeds and algae) to grow in excessive amounts which form into mats of slimy growth and soupy, green, smelly water.

 Excess nutrients cause growths of algal mats like this from the Oroua River.

So an overabundance of weed growth in water can cause oxygen levels in the water to fluctuate between very high and very low levels from day to night (diurnal fluctuations). 

In contrast, a healthy stream has constant oxygen levels. As streams become more enriched with nutrients, and the algal/plant life blooms, the more the oxygen fluctuates. High fluctuations in oxygen levels can cause high rates of gross primary productivity (GPP), which is bad for biodiversity.

These changes are harmful and eventually lethal for river ecology, making it impossible for fish and insects to live. 

Water Quality

Soil Science

Soil Science - What grows in the Soil?

The Science Learning Hub has a number of great resources online, this is one of them

Observing soil microbes - website how to make one

In this activity students make a soil habitat for microbes to live in, and then they can observe what kinds of microbes grow in the different conditions - aerobic and anaerobic.  This could be set up in class and observed over a long period of time, this a great opportunity for students to see what happens to colonies of microbes over time.  

Soil Habitat

Soil profiles - Tell you what has happened in the past.

Looking a soil profile for an area, enables you to understand the history surrounding the development of the landscape.

Mastitis

This is an interactive workshop day hosted by Dairy NZ, LIC, AgResearch and University of Waikato where Year 13 students that enjoy Science to experience what a careers could be available in the Agricultural sector.
DairyNZ really need
The day consists of students experiencing 4 different interactive workshops with each of the hosts.

This year the morning workshops consisted of:

Normal cow udder

Mastitis is the inflammation of the mammary gland and udder tissue,  It is a bacterial infection that has entered through the teat canal of the udder.  

Mastitis can affect only quarter of the udder because each quarter compartment is completely separate from the others.  

Symptoms of mastitis are: inflammation (swelling) the milk appears watery, has clots in it, flakes or pus, other symptoms can include lost of appetite, increase in body temperature, reduction in mobility.

Somatic cell counts are also taken often to help detect any clinical mastitis, this is where there is no signs or symptoms yet, however is detected because the somatic cell count is raised, this shows that there is a infection that the body is fighting.  Somatic cells are mostly leukocytes (white blood cells)

Inflamed udder - Mastitis

The SCC is quantified as the number of cells per ml of milk. In general terms:

• An individual cow SCC of 100,000 or less indicates an 'uninfected' cow, where there are no significant production losses due to subclinical mastitis.
• A threshold SCC of 200,000 would determine whether a cow is infected with mastitis. Cows with a result of greater than 200,000 are highly likely to be infected on at least one quarter.

Normal udder

inflammation of udder tissue

Normal udder

inflammation of udder tissue

• Cows infected with significant pathogens have an SCC of 300,000 or greater.

There are two sources of infection, contagious and environmental. 

Contagious bacteria are the bacteria that live on the cow's udder transferred during and after milking

The main bacteria are Escherichia coli (E. coli), Streptococcus uberis and Staphylococcus aureus, 

E.Coli

Staph aureus bacteria

There are different nutrient agar used for the different bacteria, this is used to confirm what type of bacteria are responsible for the infection.

Plating 

Harvesting Maize - Quality Control

Finding our way through the maize crop... I didn't manage to get lost.

Maize                                              Sweetcorn

 Is the maize ready to harvest???  Maize is like corn, however has a lot starch and therefore does not taste as sweet as sweet corn.  Also maize is harvested when the cob is a lot drier than sweet corn.Also the kernels on maize are a bright yellow and a lighter yellow on sweet corn.  

                     milk line test

To tell whether the maize is ready to harvest and the dry matter is between 30-38%.  The milk line technique is used.  This is where on one kernel a sharp object (ball point pen tip) is pushed in and  run the length of the kernel and note when the pen goes from solid starch to milk (liquid) starch.  It should do this 2/3 of the way down the kernel if it ready for harvest.  

 The lovely Dee, weighing the amount of maize produced off a certain area, this is then used to calculate the yeild off the paddock.

The team harvesting maize for quality purpose, measurements eg. height, weight, and dry matter.

Blood Testing

Blood testing 

 

There are a lot of things that can be tested through an animal's blood.  Blood is usually collected through the tail vein, however if it can not be drawn from here it can be taken from the jugular vein in the neck of the animal.
Once the blood is taken off the animal it is stored on ice, then it is returned to the lab to be processed which could involve it being spun in a centrifuge to separate the plasma from the red and white blood cells.

Gen cuts and Rising Plate Meter

 Jen Cuts

Also known as a low cut harvester.  This little machine enables you to cut crops to various crops and harvest it and weigh it and work out the amount of dry matter in a block.


Rising Plate meter

This is a farm management tool that farmers use to quantify pasture cover on a farm.  It is one of the tools that is used to help allocate pasture to stock.  If you do it pre and post grazing measurements this ensures that the pasture has been grazed enough and or the stock are getting enough food. Basically the plate meter measures the compressed height of the grass and using an equation (which has been calibrated) converts the grass height into kg DM (kilograms dry matter)

If you are interested in more about the Rising Plate meter go to the following website where it explains it. www.dairynz.co.nz/media/253639/1-15_Using_the_Rising_Plate_Meter.pdf