Agro-Techs: 2012

Friday 25 May 2012

WELCOME EVERYONE

This blog was created to assist agricultural science teachers

It contains aids for the teaching of artificial insemination

It was created by Stephen Charles, Ruth Morian and Louise Morris

Please feel free to comment

Thursday 24 May 2012

Possible objectives for a lesson

Students should be able to:

Define artificial insemination.
List the advantages and disadvantages of artificial insemination.
Explain the process of artificial insemination.
Identify the instruments used to carry out the process.

Ways of introducing the topic “Artificial Insemination”:

1. Show students a short video of artificial insemination. This will stimulate the students’ minds and also bring up any misconceptions that they have about the concept.

2. Place students in groups and give each group a collection of photos of artificial insemination. Have them observe the samples carefully and then ask them to give an idea of what they think the lesson is about.

3. Play a sound of several people talking about artificial insemination without actually saying what the topic is. Then invite a few students to guess the topic.

4. Dictate a few sentences that hint at the topic without revealing it. Then ask students to guess the topic.

5. In the case of a field trip, take students to the insemination stall to observe the act of artificial insemination. Then call on a few students to comment on their observations.

6. Write the topic on the board in capital letters. Read out a short sentence related to the topic. Put students in small groups and ask each group to expand the sentence. Later invite each group to read out their sentence.

Two successful methods that I have used to teach the process of artificial insemination

1. Field trips to animal production centres (Beausejour Agricultural Station) where artificial insemination takes place. On the field trip the students will get a chance to observe live demonstrations of artificial insemination. They might even get a chance to participate.

To get advice on how to organize proper field trips visit http://www.campsilos.org/excursions/hc/fieldtrip.htm

2. Computer aided lessons: use videos to help teach the topic.

Show students a complete video of artificial insemination and ask them to take brief notes of the scenes that are of interest or the scenes that are important. After, engage the students in a discussion on the topic. Later ask students to summarize the process of artificial insemination by listing all the steps that should be followed. Invite a few students to present their summaries to the rest of the class. Then clear up all misconceptions the students may have had from viewing the video.

Evaluation

This exam can be used to evaluate students' understanding of artificial insemination.

Section 1: Multiple Choice (10 marks)

Directions: Each question in this section has four suggested answers, lettered (a), (b), (c) and (d). Read each question carefully, decide which choice is best, and SHADE it. There is only one correct answer to each question.

1. What is semen for use in artificial insemination put in?
a. Your hand
b. Syringes
c. Straws
d. Cups

2. What is in the semen tank to preserve the semen?
a. Xenon
b. Liquid nitrogen
c. Salt
d. Hydrogen

3. How soon can a cow be rebred if the semen did not stick?
a. 30 days
b. 10 days
c. 90 days
d. 21 days

4. Which of these is part of an insemination rod?
a. Elastrator
b. Slycobut
c. Pipette
d. Delaval

5. What lubricant is used in artificial insemination?
a. K-Y Jelly
b. Vaseline
c. Saliva
d. Bag Balm

6. Which is an acceptable method to thaw semen?
a. In the air
b. In a microwave
c. On the sidewalk
d. In a warm water bath

7. Semen is stored at a temperature of
a. 96oC
b. -96oC
c. 196oC
d. -196oC

8. Estrus is the time when the female
a. is willing to receive the male
b. has reached sexual maturity
c. is ready to give birth
d. is lactating

9. All of the following are signs of heat in a cow EXCEPT
a. Clear mucus discharge from the vulva
b. Increase in appetite
c. Undue noise making
d. Restlessness

10. A teaser cow is one which is
a. on heat
b. mature
c. hungry
d. sexy

Section 2: Short Answer Questions (10 marks)

Directions: This section consists of ONE numbered question. You should attempt it fully.

1. Farmer John owns a dairy farm with 50 cows and one bull. When the cows are on heat, the farmer collects the semen from the bull and inseminates the cows manually.

a. What type of insemination is he practicing? (1 mark)
_________________________________________________

b. List FIVE advantages of this type of insemination. (5 marks)
1._______________________________________________
2.______________________________________________
3._______________________________________________
4. ______________________________________________
5. ______________________________________________

c. State FOUR problems that may arise from using this type of insemination. (4 marks)
1. ______________________________________________
2. ______________________________________________
3. ______________________________________________
4. ______________________________________________

Section 3: Long Answer Questions (15 marks)

Directions: This section consists of ONE numbered question. You should attempt it fully.

1. Name and discuss the three main segments of Artificial Insemination.

Wednesday 23 May 2012

Signs of heat in cows

This information is for a handout and it should be used together with the video.

1. Riding of other cows can be a sign of heat, but all riders are not necessarily in heat.

2. Roughened hair, or hair rubbed off, on the tailhead may be evidence of others riding, indicating this animal may be in heat.

3. Cows in heat may follow others, stand close and sniff, nuzzle and lick the back or rump of others.

4. Cows in heat or near onset of heat tend to group together.

5. Cows generally are more nervous than usual, and may bawl considerably, pace the fence and generally are more restless. Keen observers, familiar with their animals, often can tell cows in or approaching heat by subtle changes in normal appearance. A drop in milk production sometimes is observed.

6. Another good indicator is stringy, clear (egg white appearance) mucus hanging from the vulva opening or smeared on the tail or buttocks. Clear mucus discharges often can be seen in the gutter or on the ground where a cow had been resting.

7. The vulva lips will look moist and slightly swollen. A somewhat smoother surface is shown rather than the normal dry, finely wrinkled vulva lips of a non-estrus cow. Further, the hairs of a cow in heat tend to be wet and matted and smeared by tail and rubbing activity.

Different definitions of artificial insemination that can be used by teachers

1. Artificial insemination is the process of collecting sperm cells from a male animal and manually depositing them into the reproductive track of a female

2. Artificial insemination is the introduction of semen into the vagina or uterus by mechanical or instrumental means rather than by sexual intercourse.

3. Artificial insemination is the implanting of live spermatozoa into the genital tract of the female animal.

4. Artificial insemination is the instillation of sperm-bearing semen in the vagina, cervix, or endocervical canal to fertilize an egg.

5. Artificial insemination is the deliberate introduction of semen into a female for the purpose of fertilization, by means other than ejaculation directly into the vagina or oviduct.

6. Artificial insemination is a technique involving the artificial injection of sperm-containing semen from a male animal into a female to cause pregnancy.

7. Artificial insemination is a process by which spermatozoa are collected from male animals and deposited in female genitalia by instruments rather than by natural service.

Advantages and disadvantages of artificial insemination

This is some information that can be given to students in the form of a hand out.

Advantages:

· There is no need of maintenance of breeding bull for a herd; hence the cost of maintenance of breeding bull is saved.

· It prevents the spread of certain diseases and sterility due to genital diseases example contagious abortion and vibriosis.

· By regular examination of semen after collection and frequent checking on fertility make early detection of inferior males and better breeding efficiency is ensured.

· The progeny testing can be done at an early age.

· The semen of a desired sire can be used even after the death of that particular sire.

· The semen collected can be taken to the urban areas or rural areas for insemination.

· It makes possible the mating of animals with great differences in size without injury to either of the animals.

· It is helpful to inseminate the animals that refuse to accept the male at the time of oestrum.

· It helps in maintaining the accurate breeding and calving records.

· Semen can be used on tens of thousands of females a year instead of the actual bull being only able to cover 30 females in a breeding season.

· Job is less dangerous because there is not a potentially dangerous bull to handle after every breeding season

· The rate of genetic development and production gain can be increased, by using semen from males of high genetic merit for superior females.

· It enables breeding between animals in different geographic locations.

· Artificial Insemination can be used in conservation of rare breeds or endangered species.

Disadvantages:

·Requires well-trained operators and special equipment.

· Requires more time than natural services.

· Improper cleaning of instruments and insanitary conditions may lead to lower fertility.

· If the bull is not properly tested, the spreading of genital diseases will be increased.

· There is only a 60 to 70% conception rate for artificial insemination than with using a fertile herd bull

· The operator needs to have adequate knowledge of heat periods of female stock and know what to look for to see if any stock is in heat and then judge the time to artificially inseminate them. There may be added stress involved when females have to be restrained

· Artificial insemination isn't a job that can be learned by trail and error; it has to be taught first by a trained professional before it can be carried out in the field.

· Semen has to be stored properly otherwise it will become no longer viable; improper handling will also render it in viable.

· There has been a decline in fertility in dairy cattle and horses associated with an increase in Artificial Insemination

· The focus on certain individuals may result in loss of genetic variation.

The process of Artificial Insemination

Here is some information that can be given to students after they have viewed the videos

There are different segments of this process. Some of the major parts are:

A. Semen Collection: artificial insemination requires that semen be collected from the male. Semen may be collected via manual stimulation, or use of an artificial vagina. The technique used depends on the species from which the semen is being collected. Semen collection is generally improved if time is given for the male to become stimulated. After the semen is collected from the male, it is evaluated, slowly cooled and frozen at a temperature of –320°F (–196°C). Liquid nitrogen is used to obtain these extreme temperatures. Properly frozen and stored semen can remain viable and be used 30 to 40 years later.

B. Detecting Estrus: in order to insure high conception rates, the artificial insemination technician must be able to detect when the female is in estrus or heat. Estrus signs vary between species. The best indication of estrus for most species is standing heat. Standing heat is the stage of estrus when a female stands when mounted by another animal. Many animals display extra mucus and redness in the vulva.

C. Insemination:

1. Pre-warm AI gun and make sure thaw bath is 95°F.

2. Check the breeding records to match the cow with semen she will be inseminated with.

3. Move one straw of semen from the liquid nitrogen tank to the thaw bath as quickly as possible.

4. Wipe all water from the straw; check the bull name on the straw.

5. Clip the crimped end either with scissors or a cito-cutter.

6. Place straw in a pre-warmed AI gun and place a sterile sheath over the gun & straw.

7. Initiate the insemination process by rectally palpating the cervix through the rectum and prepare it to receive the insemination gun.

8. Use a clean paper towel to wipe away any fecal material or mud from the external genitalia of the cow.

9. Place the AI gun into the vagina at a slight angle with the tip of the AI gun pointing upward to avoid the opening of the urethra.

10. Traverse the cervix with the AI gun and deposit the semen right at the tip of the cervical/uterine junction. Administer the semen for eight to 10 seconds with the insemination rod in the uterus. Stop the flow of semen from the unit and slowly remove the rod. Once the rod is clear of the vaginal cavity, clean the surrounding skin to prevent bacterial invasion.