Overcrowding causes severe infertility in maiden heifers
On a farm visit in Co. Derry we had a split call between an outside and home farm where maiden heifers were bred on the two locations. The pregnancy rate on the maiden heifers on the home location was excellent with 95% of a group of 35 heifers in calf for a six week breeding period. On the outside farm, the situation was radically different with approximately 50% of a group of 70 heifers in calf over a six week breeding period. It transpired that the same diets were being fed to both groups of animals so that ruled out diet as a factor. Further investigation revealed that the heifers on the outside farm were densely stocked at approximately 35 square feet per animal and on the home location the stocking rate was closer to 60 square feet per animal. The stocking rate on the outside location also en pinched on feed face available per animal and this type of competition resulted in reproductive abnormalities, embryonic deaths and animals returning to a prepubertal state.