Improving reproduction with performance minerals

The idea that simply improving the source of trace minerals in a herd nutrition programme can improve conception rates by 20% is jarring for a lot of folks. The knee-jerk reaction is, “How?!”. How can nutrition improve herd reproduction by 20%, especially if a herd is already achieving overall pregnancy rates above 90%? The answer lies in earlier conception and improved calving distribution.

Across four published university studies conducted in four unique geographic regions, research has shown improvements in conception rate of more than 20% by upgrading from inorganic sources of zinc, manganese, copper, and cobalt to Zinpro® Availa® 4 (zinc, manganese, and copper amino acid complexes; cobalt glucoheptonate). But what does a 20% improvement actually look like?

The economics of fertility and profitability

Start with an industry-standard baseline conception rate of 60% and a 65-day breeding season. A 20% improvement results in a 72% conception rate. This means more cows conceived at each cycle, especially the early cycles, resulting in an earlier average calving date. More calves born earlier in the calving season leads to an older average weaning age (approximately four days older) and more calves conceived within the breeding season (2% more calves). Mathematically, the increase in weaning age and pregnancy rate results in a 1% higher total weaning weight for the herd. Read that again. Simply by improving mineral supplementation with Zinpro Availa 4 and no additional labour, a herd can produce 1% more total calf weight headed for market thanks to a 20% improvement in conception rate.

The economics are exciting, and researchers have also been excitedly working to understand what contributes to this 20% conception rate improvement. The majority of overall pregnancy loss occurs during the first 30 to 45 days after conception, and a recent meta-analysis reported 48% pregnancy loss in just the first 28 days after conception (Reese, 2020). Thus, researchers have focused their attention on early pregnancy.

Oocyte development

Starting before conception even occurs, researchers reported that cows fed Zinpro Availa minerals produced a greater quantity of high-quality oocytes and subsequent high-quality embryos than cows fed inorganic minerals (Dantas, 2019). Most notable was the frequency of high-quality oocytes developing into high-quality embryos. Cows fed Zinpro Availa minerals had a 32% embryo development rate versus 14% for cows fed inorganic minerals, demonstrating the importance of dietary trace mineral source in just the first week of pregnancy and embryo development.

Pregnancy retention

Building on the previous research, investigators looked at pregnancy retention through the first two months of pregnancy (Perry, 2021). Replicated across two years, weaned heifers were fed diets including either Zinpro Availa 4 or inorganic minerals throughout development. Following artificial insemination (AI), pregnancy was determined starting at day 17 post-AI. Although early pregnancy rates did not differ, by day 60 there were notable differences in pregnancy rate. From day 17 to day 60, heifers fed Zinpro Availa 4 retained 73% of pregnancies versus 62% for heifers fed inorganic minerals. The research demonstrated the impacts of trace mineral source on pregnancy retention through the crucial early months.

What could 20% mean to you?

A 20% conception rate improvement has a substantial impact on herd profitability. Although seemingly unrealistic at first, recent research helps explain how a 20% improvement is achieved, by improving unfertilised oocyte quality, early embryo quality, and pregnancy retention though the critical first months. Along with considering how a 20% conception rate is plausible, consider how it would impact your herd’s profitability.

All posts

Anri Strauss is a scientific adviser in the ruminant team at Chemuniqué, holding a master’s degree in nutrition from the University of Pretoria. She grew up on a farm and still lives in the Free State, where she and her husband also farm with Boer goats.

2 thoughts on “Improving reproduction with performance minerals

Leave a Reply

Your email address will not be published. Required fields are marked *