Breeding method of female pig for propagation and feed for female pig for propagation

Abstract

Disclosed are a breeding method of a female pig for propagation characterized by feeding at least one lipid selected from a fatty acid having 12 to 24 carbon atoms which has a melting point falling in a range of −60 to 40° C. and an iodine value falling in a range of 30 to 470 and which has 2 to 6 double bonds in a molecule, a triglyceride containing the above fatty acid and a metal salt of the above fatty acid, and a feed for a female pig for propagation containing the above lipid in a proportion of 0.5 to 10 % by weight in terms of the fatty acid described above. According to the breeding method of a female pig for propagation of the present invention, breeding results can be elevated by further increasing a litter size, allowing the number of delactation to grow large, shortening the days of returning estrus and increasing an annual average delivery frequency.

What is claimed is:  
     
         1 . A feed adapted to be fed to a female pig for propagation characterized by comprising at least one lipid selected from a fatty acid having 12 to 24 carbon atoms which has a melting point falling in a range of −60 to 40° C. and an iodine value falling in a range of 30 to 470 and which has 2 to 6 double bonds in a molecule, a triglyceride containing said fatty acid and at least one selected from a group consisting of a calcium salt and a magnesium salt of said fatty acid in a proportion of 0.5 to 10% by weight in terms of said fatty acid.  
     
     
         2 . The feed as described in  claim 1 , further comprising a base feed to feed the female pig, blended with said at least one lipid.  
     
     
         3 . The feed described in  claim 1 , wherein the fatty acid is at least one selected from linoleic acid, linolenic acid, bishomo-γ-linolenic acid, arachidonic acid and eicosapentaenoic acid.  
     
     
         4 . The feed as described in cliam  1 , wherein said at least one selected from a group consisting of a calcium salt and a magnesium salt of said fatty acid is produced by reacting a fatty acid with a metal oxide or a metal hydroxide by means of an extruder having at least a raw material-feeding zone, a kneading and reacting zone and a cooling zone.  
     
     
         5 . The feed as described in  claim 4 , wherein said at least one selected from a group consisting of a calcium salt and a magnesium salt of said fatty acid is produced by controlling a temperature of of the raw material-feeding zone in the extruder to 20 to 80° C., a temperature of the kneading and reacting zone to 80 to 200° C. and a temperature of the cooling zone to −20 to 5° C.  
     
     
         6 . The feed as described in  claim 1 , produced by blending a base feed with. said at least one selected from a group consisting of a calcium salt and a magnesium salt of said fatty acid obtained by decomposing or refining soybean oil, corn oil, rapeseed oil, sunflower oil, safflower oil, sesame oil, rice oil, beefsteak plant oil, evening primrose oil, borage oil, linseed oil, palm oil or fish oil.  
     
     
         7 . The feed as described in  claim 6 , wherein said at least one selected from a group consisting of a calcium salt and a magnesium salt of said fatty acid is a fatty acid calcium salt or a fatty acid magnesium salt containing at least one selected from linoleic acid, linolenic acid, bishomo-γ-linolenic acid, arachidonic acid and eicosapentaenoic acid in a proportion of 20 to 99% by weight or both of them.