The goal of dairy farmer Mark Sluis is efficient utilisation of his own grassland. His breeding strategy also plays a significant role. By selecting breeding bulls with a high score for longevity, he aims to increase the lifetime production of his herd. This approach reduces the amount of feed he needs to raise young stock.
Mark Sluis effortlessly sums up some figures from the Recycling Indicator – an administrative tool for mineral use – for 2019. ‘Last year, 85% of the protein for our cows was sourced from our own meadows and we fed 24 kilos of concentrates per 100 kilos of milk with average production of 10,000 kilos of milk with 4.30% fat and 3.48% protein’, the dairy farmer from the Hem in North Holland explains. ‘I think the importance of the KPI ‘” percentage of protein produced on the farmer’s own land” will grow in the years ahead. And, of course, producing a lot of protein on your own land and making good use of it makes very sound financial sense for our income.’
Own protein production
Sluis and his wife Linda run a dairy farm with 170 dairy cows and 85 heads of young stock on 110 hectares, of which 15 hectares are rented to grow flower bulbs. The land surrounding the farmhouse and barn covers 48 hectares. ‘Our farm lends itself well to grazing and helps us to effectively utilise the protein in the grass. Last year, the cows had meadow access for an average of 5.7 hours on 196 days’, he continues. In addition to high grassland production and a balanced ration, according to Sluis, cows with a high lifetime milk output also contribute to a high utilisation percentage of protein from his own land. He explains this by saying ‘Older cows are more efficient at converting feed into milk than younger cows, so the lower the replacement rate, the few young stock I need to rear.’
Protein percentage and longevity
According to him, breeding can make a significant contribution to increasing lifetime production and therefore a higher percentage of protein from his own meadows. ‘We select bulls based on breeding values for protein percentage and longevity. Bulls with a high score for longevity generally also score well for health and conformation, otherwise their daughters would never have long productive lives’, the farmer argues. He uses SireMatch to make the best mating matches and to prevent inbreeding. ‘In addition, I have exclusively used breeding bulls for twenty years. Not because I don’t see the benefits of using genomic breeding values – we genotype all the calves and we take part in HerdOptimzer – but a bull’s breeding value for longevity only has true merit if it is based on the performance of large numbers of daughters’, he explains.
The current names on the insemination list are Nilson, Malcolm, Solero, Lucifer and Rocky. The latter bull is a particular favourite of Sluis. ‘We also use the Brown Swiss bull Cadence’, he adds.
‘Bulls with a high score for longevity generally also score well for health and conformation’
Breeding for grazing
CRV has developed a grazing index to help farmers wanting to breed cows that are efficient converters of grass into milk. This grazing index ranks bulls based on traits that make their progeny more suitable or less suitable for grazing systems. Bulls with a high grazing index score well for persistency, fertility, locomotion, chest width and body condition. Bulls that produce daughters with a smaller stature have an added advantage. These qualities have formed the fundament of breeding strategies in New Zealand for years. The most interesting bulls offered by CRV in New Zealand are also available for dairy farmers in the Netherlands and Flanders. In addition, the CRV CrossFit concept offers help with breeding cows suitable for grazing systems.