GB2312845A

GB2312845A - Treatment of ruminants

Info

Publication number: GB2312845A
Application number: GB9709388A
Authority: GB
Inventors: Reginald Goodwin-Jones
Original assignee: TRACE ELEMENT SERV Ltd
Current assignee: TRACE ELEMENT SERV Ltd
Priority date: 1996-05-11
Filing date: 1997-05-09
Publication date: 1997-11-12
Also published as: GB9609892D0; GB9709388D0

Abstract

A method of treatment of fertile female ruminants, which comprises monitoring the ratio of newborn males:newborn females in the offspring of a herd or flock of fertile female ruminants in a first season; selectively administering to fertile females when the ratio of newborn males to females is greater than 1:1, in the period between four weeks and twelve weeks prior to conception by at least some of the fertile females, a formulation containing a selenium salt, in an amount such as to decrease the ratio of newborn males:newborn females in a subsequent season.

Description

Treatment of Ruminants The present invention is concerned with the treatment of ruminants.

Farmers of cattle and sheep are frequently troubled by the fact their flocks have a preponderance of male offspring, rather than the generally more economically valuable female offspring. We have found that the ratio of female:male offspring can be radically altered by administration of selenium to the dam/female prior to conception.

According to the present invention, therefore, there is provided a method of treatment of fertile female ruminants, which comprises monitoring the ratio of newborn males:newborn females in the offspring of a herd or flock of said fertile female ruminants in a first season; selectively administering to said fertile females in said flock, when the ratio of newborn males to newborn females is greater than 1:1, in the period between four weeks and twelve weeks prior to conception by at least some of said fertile females, a formulation containing a selenium salt, in an amount such as to decrease the ratio of newborn males:newborn females in a subsequent season.

The present invention further provides a method of treatment of fertile female ruminants, which method comprises monitoring the amount of selenium in the blood of fertile females in a herd or flock thereof, and administering a formulation containing a selenium salt to said fertile females when the amount of selenium in blood is less than 40i.u./gram Hb Glutathione peroxidase (GSII-Px), said administration being in the period between four weeks and twelve weeks prior to conception, and being such as to ensure that the amount of selenium in said blood is not more than 150i.u./gram Hb (GSII-Px).

It is preferred to co-administer the selenium salt with a copper salt; this enhances the effect of selenium and alleviates the chance of selenium toxicity.

The administration of selenium to the dam/female prior to conception is believed to alter the bias of access by X chromosome bearing sperm to the egg cell relative to access by Y chromosome bearing sperm. The selenium salt and copper salts may be given to the animal orally in the form of an aqueous solution. The selenium salt typically sodium selenate may be given in an amount of 12 to 20mg of selenium per day, for cattle, and for sheep from 3 to 5mg per day. Copper may be given in an amount from 100 to 150mg per day for cattle, and 5 to 12mg per day for sheep.

The selenium and copper salts may be given to cattle or sheep in the aqueous solution form either as a drench, or preferably as a dressing on the forage of such animals. This may be either silage, hay, straw, or other plant material.

It is preferred to administer the selenium and copper salts when the balance of the other essential elements in the diet of the animals is correct. These other elements are cobalt, iodine, and zinc. Cobalt intake from the diet should be between 10 to 15mg per day for cattle and 2 to 4mg for sheep. Zinc intake should be from 350 to 450mg per day for cattle and 80 to 120mg for sheep. Iodine intake should be from 12 to 20mg for cattle and 3 to 5mg for sheep.

The selenium salt and the copper salt may be administered to a pasture on which the ruminants graze; the salts preferably administered by a method and in amounts substantially as described in our prior patent GB 2220652. Similarly cobalt and zinc may be administered to a grazed pasture as in our prior patent GB 2266241.

The selenium salt may be sodium selenate and/or selenite, or other aqueous-soluble selenate or selenite (that is a selenite or selenate which is soluble in an aqueous medium). The copper may be applied as aqueous-soluble salt, such as copper sulphate, or it may be applied in the form of the oxide, or as the metal itself. The selenium and copper may be co-administered to pasture or forage in the form of an aqueous spray, or, alternatively, they may be mixed with a suitable fertilizer (such as NPK fertilizer) for administration to pasture. When the selenium and copper are mixed with a fertilizer, they may be mixed with individual prills of the latter; alternatively, they may be admixed with the fertilizer, generally by the farmer, just prior to application to the pasture.

Claims

Claims:

1. . A method oftreatment of fertile female ruminants, which comprises monitoring the ratio of newbom males:newbom females in the offspring of a herd or flock of said fertile female ruminants in a first season; selectively administering to said fertile females in said flock, when the ratio of newborn males to newborn females is greater than 1:1, in the period between four weeks and twelve weeks prior to conception by at least some of said fertile females, a formulation containing a selenium salt, in an amount such as to decrease the ratio of newborn males:newborn females in a subsequent season.

2. A method of treatment of fertile ruminants, which comprises monitoring the amount of selenium in the blood of fertile females in a herd or flock, and administering a formulation containing a selenium salt to said females when the amount of selenium in the blood thereof is less than 40i.uJgram Hb Glutathione peroxidase (GSII-Px), said administration being in the period between four weeks and twelve weeks prior to conception, and being such as to ensure that the amount of selenium in said blood is not more than 150i.u./gram Hb (GSll-Px).

3. A method according to claim 1 or 2, wherein the selenium salt is co-administered with a copper salt.

4. A method according to claim 3, wherein said ruminants are cattle or sheep and said selenium and copper salts are administered to cattle or sheep in aqueous solution as a dressing on the forage of said cattle or sheep.

5. A method according to claim 3 or 4, wherein said ruminants are cattle and said selenium and copper salts are administered to a respective one of said cattle when the cobalt intake is between 10 to 15mg per day, zinc intake is between 350 to 450mg per day and iodine intake is between 12 and 20mg.

6. A method according to any of claims 1 to 5, wherein 12 to 20mg of a selenium salt are administered to said one cattle per day.

7. A method according to any of claims 1 to 6, wherein 100 to 150mg of copper are administered to said one cattle per day.

8. A method according to claim 3 or 4, wherein said ruminants are sheep and said selenium and copper salts are administered to a respective one of said sheep when the cobalt intake is between 2 to 4mg per day, zinc intake is between 80 to 120mg per day and iodine intake is between 3 to 5mg per day.

9. A method according to any of claims 1 to 4 or 8, wherein 3 to 5mg of a selenium salt are administered to said one sheep per day.

10. A method according to any of claims 1 to 4, 8 or 9, wherein 5 to lOmg of copper are administered to said one sheep per day.

11. A method according to any of claims 1 to 10, wherein said selenium salt administered is in the form of a selenate or selenite dissolved in an aqueous medium.