Subclinical endometritis in Norwegian Red Cattle - prevalence, predisposition and effect on reproductive outcome
The aim of this study is to investigate the field prevalence of subclinical endometritis (SE) in Norwegian Red Cattle (NR) in Nord-Trøndelag at time of artificial insemination, and to evaluate its impact on the reproductive success. The study also aims to investigate if there is any genetic predisposition for development of SE in NR individuals.
The techniques to evaluate SE includes cytology from a tape that is inserted into the uterine lumen. The total percent of polymorphonuclear cells (PMN) at a microscopic cell count defines the indvidual as negative or positive. The individual status will be compared to reproductive outcome, genetic information, and history of disease.
The data collection will be performed in field, starting in the fall 2017 in Nord-Trøndelag. Two thousand dairy cattle will be included in the study, a sample size calculated using ausvet’s epitools. The technicians who will perform the sampling are chosen based on their experience, and their time as employed for Geno. This helps to assure an adequate handling and sampling of the animals. Animals showing any signs of clinical disease or un-normal vaginal discharge will be excluded from the study.
A cytology sample will be collected from the endometrium of each individual. This collection is performed at the same time as the insemination, using a cytotape that is located within the insemination tube. Only one penetration of the cervix is needed in total.
Milk samples will be taken from all animals at time of insemination, and day 21 and 42 of pregnancy.
The first two milk samples will be analyzed for progesterone – this Controls heat status and pregnancy control. A more reliable pregnancy diagnosis will be set at day 42 through a PAG test on milk.
All animals will also be genetically tested. This will be done by collection of a tissue sample, using the ordinary sampling technique developed by Geno and approved by Mattilsynet. The farmer performs the testing himself, using a pre-ordered biopsy needle that at the same time inserts an ear tag.
The animals will live the ordinary life of a dairy cattle, and the testing will be performed during insemination using the same technique which is used for normal insemination. The experience for the animal will likely not be any different than what they feel at an ordinary insemination. The sampling of tissue will give rise to a short and mild pain, comparable to what the animal feels when it is given an intramuscular injection. Signs of inadequate response to the samplings will be reported to the researchers. In conclusion, we assess this trial to be minimally invasive and in concordance with the three R’s.
The practical part of the study will be ended when the animals have been confirmed pregnant or non pregnant through the PAG test from milk on day 42 after insemination.
Results from this study has a great potential to impact advice on reproductive management in NR. This helps to reduce inaccurate medical treatment and thereby it contributes to a better animal welfare.
The techniques to evaluate SE includes cytology from a tape that is inserted into the uterine lumen. The total percent of polymorphonuclear cells (PMN) at a microscopic cell count defines the indvidual as negative or positive. The individual status will be compared to reproductive outcome, genetic information, and history of disease.
The data collection will be performed in field, starting in the fall 2017 in Nord-Trøndelag. Two thousand dairy cattle will be included in the study, a sample size calculated using ausvet’s epitools. The technicians who will perform the sampling are chosen based on their experience, and their time as employed for Geno. This helps to assure an adequate handling and sampling of the animals. Animals showing any signs of clinical disease or un-normal vaginal discharge will be excluded from the study.
A cytology sample will be collected from the endometrium of each individual. This collection is performed at the same time as the insemination, using a cytotape that is located within the insemination tube. Only one penetration of the cervix is needed in total.
Milk samples will be taken from all animals at time of insemination, and day 21 and 42 of pregnancy.
The first two milk samples will be analyzed for progesterone – this Controls heat status and pregnancy control. A more reliable pregnancy diagnosis will be set at day 42 through a PAG test on milk.
All animals will also be genetically tested. This will be done by collection of a tissue sample, using the ordinary sampling technique developed by Geno and approved by Mattilsynet. The farmer performs the testing himself, using a pre-ordered biopsy needle that at the same time inserts an ear tag.
The animals will live the ordinary life of a dairy cattle, and the testing will be performed during insemination using the same technique which is used for normal insemination. The experience for the animal will likely not be any different than what they feel at an ordinary insemination. The sampling of tissue will give rise to a short and mild pain, comparable to what the animal feels when it is given an intramuscular injection. Signs of inadequate response to the samplings will be reported to the researchers. In conclusion, we assess this trial to be minimally invasive and in concordance with the three R’s.
The practical part of the study will be ended when the animals have been confirmed pregnant or non pregnant through the PAG test from milk on day 42 after insemination.
Results from this study has a great potential to impact advice on reproductive management in NR. This helps to reduce inaccurate medical treatment and thereby it contributes to a better animal welfare.