SusAn 53 SusSheP Sustainable Sheep Production

The project involved three main issues: 1. How can we increase the ewe longevity? 2. How does the sheep's production level affect the carbon footprint and work effort? 3. Why is there a difference between sheep breeds in fertility and how easy it is to get them pregnant by insemination? The project was managed from Ireland, and researchers from the UK, France and Norway also participated. The main cause of involuntary culling of ewes is mastitis in Norway and Ireland. In the research flocks in Scotland, with the breed Scottish Blackface, the main cause is the wear of teeth (due to rough grazing). Unfortunately, no correlation has been found between information recorded early in the animal's life and longevity, defined as age at last lambing. We have found that the heritability for age at last lambing is low (8.8 %). Two Norwegian sheep farmers recorded their labour input on selected days throughout the year to compare breeds with differences in numbers of lambs. The carbon footprint of the flocks was calculated through a series of information entered into a carbon calculator in Scotland. Two farms in Ireland with breeds that differed in prolificacy were also compared. Although high prolific breeds increased labour input on farms, especially at lambing time, this increase was compensated for by higher economic margins, without a change in terms of kg CO2e/kg meat produced. Artificial insemination is a breeding tool in order to utilize the best rams so that they have more offspring and that they become available throughout the country. In addition, regarding contagious diseases, this is a safe way to get new breeding material around. Abroad, it is common with hormone treatments of the ewes before they are inseminated by laparoscopy through a simple surgical procedure. In Norway, a technique called "shot in the dark" is used, where the semen is deposited deep in vagina when the ewe comes into natural heat. The insemination can be done by the farmer himself after attending an insemination course. In the project, we were looking for differences in cervical anatomy and cervical mucus between breeds with different success rates after mating both in natural and synchronized estrous. Differences in the length of the cervix between ewe breeds was evident but this was more related to the mature body size of the ewe and not related to pregnancy rates following cervical artificial insemination with frozen-thawed semen.There was no relationship between the ewe breed pregnancy rates and the amount or viscosity of cervical mucus collected around the time of ovulation. O-linked glycans were correlated with mucus viscosity and thus likely to affect sperm progression. High fertility ewe breeds (NWS and Fur) had higher percentage of neutral O-glycans (without sialic acid). Sialic acid content of cervical mucus appears to be an important modulator of sperm transport. Key genes involved in sialic acid and O-glycan biosynthesis showed differences in gene expression between high and low fertility ewe breeds. Low fertility breeds have a heightened immune response as evident by a more diverse cervical microbiome as well as the upregulation of key inflammatory genes in cervical tissue. This work has identified a number of biomarkers which appear to be key to sperm transport across the cervix. SusSheP has further generated a large databank of samples for future analysis / projects.

Prosjektdeltakere har knyttet verdifullt samarbeid. Prosjektet har inkludert mange fagområder som har økt kompetansen hos deltakerne. Prosjektet har kreert materiale som kan analyseres videre, samarbeidet vil derfor fortsette og det er å forvente at prosjektets deltagere også vil samarbeide i framtidige prosjekter. Det er kommet fram verdifulle resultater som kan implementeres i avlsarbeidet og er formidlet til brukere, f.eks: Arvegraden for alder ved siste lamming er lav. Produsenter registrerte arbeidsinnsatsen gjennom året for å sammenlikne raser med forskjell i lammetall. Karbonavtrykket for besetningene ble beregnet. Selv om høyere lammetall øker arbeidsinnsatsen, særlig i lamminga, ble økningen kompensert ved at den økonomiske marginen økte. Kg CO2-ekvivalenter per kg kjøtt var omtrent likt. Det er funnet en rekke biomarkører som synes viktige for spermietransporten gjennom livmorhalsen. Denne kunnskapen kan brukes videre i avl og mulig sædbehandling.

The overall aim of SusSheP is to increase the sustainability and profitability of European Sheep Production by addressing key industry focused problems. Sheep are unproductive (but carbon productive) until they produce their first lamb crop, normally at 2 years of age and, on average, ewes only produce 4 crops of lambs in their lifetime. Despite its importance both from an economic and environmental perspective ewe longevity is not included in sheep breeding indexes across Europe. SusSheP will establish the genetic factors controlling ewe longevity, under different Sheep Production Systems (SPSs) and assess if early life predictors (eg reared as single, twin etc) can be used to predict longevity. Further, SusSheP will identify the most carbon and labour efficient SPSs under different management systems in order to enable the development of strategies to reduce the labour input and carbon hoof print per kg of output. The breeding of more efficient sheep has been hampered internationally by the lack of sheep artificial insemination, as the only effective method for use with frozen-thawed semen is a laparoscopic procedure, whereby, semen is injected directly into the uterus but this requires veterinary expertise, is welfare unfriendly and sociable unacceptable. The only exception to this is in Norway, in which vaginal deposition of frozen-thawed semen yields good pregnancy rates. Research in Ireland has demonstrated this is due to the breed of the ewe used in Norway,whereby sperm can transverse the cervix in greater numbers than in other breeds, leading to higher pregnancy rates. SusSheP will interrogate the differences across breeds in cervical physiology and its secretions (genes, proteins and glycans) with a view of developing amore sociably acceptable AI method. Finally, through the participation of strategically chosen SMEs, SusSheP will maximise knowledge transfer to industry, farmers and the scientific communities.