Post by mal on Dec 16, 2010 9:21:44 GMT
16/12/10 07:24hrs
Good morning, that's milking all finished and the rest are off cleaning up.
It's my job to prepare for the vet visit this morning. We have picked all the cows out that need to see the vet. Paddy (our vet) has phoned to say he is running late owing to a difficult calving this morning, so that gives me a bit more time to sort myself out.
We have 20 cows for Paddy to look at this morning, a combination of PD (Pregnancy Diagnosis), blind bullings and a few which i think have cysts on their ovaries
Not too much of a challenge for Paddy this morning.
Pregnancy Diagnosis
These cows will be treated to an ultra sound scan internally to determine if they are in calf and if so how far along they are.
Typically we will PD 28 days after an AI service if the cow has shown no signs of bulling and we are attaining our target of 45% in calf at first service.
Cystic Cows
We are suffering with a good number of cows turning cystic after service. The reasons for this are many but if i had to chose my "favourites" they'd be
Lack of energy, brought about by a lack of maize in the diet coupled with poor quality silage
Stress, brought about by the demands we put on the cows as part of our system and historical issues with Dry periods not being as long as they should be.
There are changes being made to the buildings soon to help reduce stress.
Cysts develop on the ovaries and don't realy cause any harm to the cows, and are easily treated. A PRID (Progesterone Releasing Intravaginal Device) is inserted into the cows vagina,
When the PRID is inserted into the vagina, progesterone is slowly released over the 7 day treatment period. The removal of the PRID results in the rapid decline of plasma progesterone and the onset of oestrus in animals responding to treatment.
PRIDs wil also be used to brings cows on Bulling (These cows are terms anestrus) again this is due to the release of progesterone and on removal of the PRID the cow generally shows signs of bulling within 2-3 days
I have attached an image of a PRID and the gun with which it is inserted to give some idea as to what Paddy will be on upon with the cows this morning.
Blind Bullers
These are cows which are showing no signs of heat or where signs have been missed. Paddy will examine the cow internally to establish where in the reproductive cycle the cow is.
Depending on his findings we will either leave the cow to come bulling naturally or should a Corpus Luteum be present we will give an injection of Estrumate to bring the cow on we generally see results within 5 days.
Reproductive cycle of a cow
If we take day 0 as the start of the heat. This is the period of the heat cycle in which the cow will stand to mounted either by a bull or more likely by another cow. As you saw in the diagram of bulling signs yesdy.
Most textbooks will tell you that heat lasts for approximately 18 hours in the cow. However, using Heatime we can see that cows are in heat for only 6 to 8 hours.
During heat, there is a structure on the ovary known as the
follicle. The follicle is a fluid filled blister-like structure which contains the egg. The follicle also produces the hormone estrogen and it is this hormone that is responsible among other things for the bulling signs that indicate heat, Another function
of estrogen is to trigger the release of gonadotropin releasing hormone (GnRH) from within the brain.
GnRH is responsible for causing the release of another important hormone from within the brain – luteinising hormone (LH). LH is the hormone that will act on the ovary to cause the follicle to ovulate (to release the egg from the ovary). The egg is released into the oviduct about 32 hours after the onset of heat.
Fertilisation will take place in the oviduct if sperm are present. The fertilized egg (embryo) will remain in the oviduct for 3 to 4 days before entering the uterus.
Following ovulation, LH will also cause the remnants of the follicle to develop into the corpus luteum (CL). The CL is an extremely important structure on the ovary. As the CL grows it begins to secrete the hormone progesterone between 4 and 5 days after heat and reaches maximum size and progesterone output at 9 to 10 days after heat. Progesterone is essential for pregnancy. It prevents the cow from coming into heat and ovulating as well as prepare the uterus for pregnancy
If the cow does not become pregnant, the uterus will release the hormone prostaglandin (PG) on day 16 to 18 of the heat cycle. PG will cause regression (death) of the CL, resulting in a rapid decline in progesterone. However, if there is a successful pregnancy, the embryo will block the release of PG so that the CL continues to produce progesterone
The decrease in progesterone allows for an increase in GnRH. As well as stimulating the release of follicle stimulating hormone (FSH). FSH acts on the ovary to stimulate rapid growth of another follicle. The follicle will secrete estrogen to cause the next heat and ovulation.
This cycle is repeated until the cow gets pregnant. The reproductive cycle is assumed to be 21 days, but really it can be anything between 18 and 24 days as i mentioned yesdy.
Oi wake up i'll be asking questions at the end.
Paddy will probably be here for about two hours this morning.
Good morning, that's milking all finished and the rest are off cleaning up.
It's my job to prepare for the vet visit this morning. We have picked all the cows out that need to see the vet. Paddy (our vet) has phoned to say he is running late owing to a difficult calving this morning, so that gives me a bit more time to sort myself out.
We have 20 cows for Paddy to look at this morning, a combination of PD (Pregnancy Diagnosis), blind bullings and a few which i think have cysts on their ovaries
Not too much of a challenge for Paddy this morning.
Pregnancy Diagnosis
These cows will be treated to an ultra sound scan internally to determine if they are in calf and if so how far along they are.
Typically we will PD 28 days after an AI service if the cow has shown no signs of bulling and we are attaining our target of 45% in calf at first service.
Cystic Cows
We are suffering with a good number of cows turning cystic after service. The reasons for this are many but if i had to chose my "favourites" they'd be
Lack of energy, brought about by a lack of maize in the diet coupled with poor quality silage
Stress, brought about by the demands we put on the cows as part of our system and historical issues with Dry periods not being as long as they should be.
There are changes being made to the buildings soon to help reduce stress.
Cysts develop on the ovaries and don't realy cause any harm to the cows, and are easily treated. A PRID (Progesterone Releasing Intravaginal Device) is inserted into the cows vagina,
When the PRID is inserted into the vagina, progesterone is slowly released over the 7 day treatment period. The removal of the PRID results in the rapid decline of plasma progesterone and the onset of oestrus in animals responding to treatment.
PRIDs wil also be used to brings cows on Bulling (These cows are terms anestrus) again this is due to the release of progesterone and on removal of the PRID the cow generally shows signs of bulling within 2-3 days
I have attached an image of a PRID and the gun with which it is inserted to give some idea as to what Paddy will be on upon with the cows this morning.
Blind Bullers
These are cows which are showing no signs of heat or where signs have been missed. Paddy will examine the cow internally to establish where in the reproductive cycle the cow is.
Depending on his findings we will either leave the cow to come bulling naturally or should a Corpus Luteum be present we will give an injection of Estrumate to bring the cow on we generally see results within 5 days.
Reproductive cycle of a cow
If we take day 0 as the start of the heat. This is the period of the heat cycle in which the cow will stand to mounted either by a bull or more likely by another cow. As you saw in the diagram of bulling signs yesdy.
Most textbooks will tell you that heat lasts for approximately 18 hours in the cow. However, using Heatime we can see that cows are in heat for only 6 to 8 hours.
During heat, there is a structure on the ovary known as the
follicle. The follicle is a fluid filled blister-like structure which contains the egg. The follicle also produces the hormone estrogen and it is this hormone that is responsible among other things for the bulling signs that indicate heat, Another function
of estrogen is to trigger the release of gonadotropin releasing hormone (GnRH) from within the brain.
GnRH is responsible for causing the release of another important hormone from within the brain – luteinising hormone (LH). LH is the hormone that will act on the ovary to cause the follicle to ovulate (to release the egg from the ovary). The egg is released into the oviduct about 32 hours after the onset of heat.
Fertilisation will take place in the oviduct if sperm are present. The fertilized egg (embryo) will remain in the oviduct for 3 to 4 days before entering the uterus.
Following ovulation, LH will also cause the remnants of the follicle to develop into the corpus luteum (CL). The CL is an extremely important structure on the ovary. As the CL grows it begins to secrete the hormone progesterone between 4 and 5 days after heat and reaches maximum size and progesterone output at 9 to 10 days after heat. Progesterone is essential for pregnancy. It prevents the cow from coming into heat and ovulating as well as prepare the uterus for pregnancy
If the cow does not become pregnant, the uterus will release the hormone prostaglandin (PG) on day 16 to 18 of the heat cycle. PG will cause regression (death) of the CL, resulting in a rapid decline in progesterone. However, if there is a successful pregnancy, the embryo will block the release of PG so that the CL continues to produce progesterone
The decrease in progesterone allows for an increase in GnRH. As well as stimulating the release of follicle stimulating hormone (FSH). FSH acts on the ovary to stimulate rapid growth of another follicle. The follicle will secrete estrogen to cause the next heat and ovulation.
This cycle is repeated until the cow gets pregnant. The reproductive cycle is assumed to be 21 days, but really it can be anything between 18 and 24 days as i mentioned yesdy.
Oi wake up i'll be asking questions at the end.
Paddy will probably be here for about two hours this morning.