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.