VFAs can influence reproduction in the following ways:
– They impact ovulation – VFAs, especially propionic acid, are thought to have a significant impact on follicular development and ovulation.
– They impact reproductive hormones – VFAs can influence the production and availability of reproductive hormones including GnRH (gonadotrophin- releasing hormone) and LH (luteinising hormone). These hormones are crucial for ovulation (synthetic forms are utilised in common artificial insemination programs)
– They have been attributed to uterine health. Buytric acid has been found to play a role in maintaining uterine pH. Uterine health is essential for successful implantation and maintenance of pregnancy.
Meanwhile, glucose, as a primary source of energy in cows, is imperative for reproductive performance. Diet, body condition and metabolic status can impact glucose levels. Extensive periods of low glucose (brought upon by Negative Energy Balance) can delay ovulation or the onset of oestrus, thus reducing fertility.
Glucose also helps a cow’s immune cell function and her overall health. When a cow is sick, a significant proportion of energy is directed to the immune system to restore her health. Therefore, low levels of glucose over time can also result in a vulnerable immune system, making the cow more susceptible to disease and lower reproductive performance. Glucose is a precursor of lactose, the key sugar in milk. To maintain optimal milk production, a consistent level of glucose needs to be maintained.
A cow’s Body Condition Score (BCS) is a key indicator when it comes to the impacts of glucose levels and NEB. Optimal glucose metabolism aids in maintaining ideal BCS as glucose directly impacts fat synthesis and mobilisation. Optimal BCS is often correlated with reproductive success.
Recent results from Terragen’s Big Cow Project, conducted with The University of Queensland, Harrisville, 2023, found cows whose feed was supplemented with MYLO® maintained better body condition after calving and had higher glucose levels than control cows. It was also found that cows fed MYLO® presented for artificial insemination 9.6 days earlier than control groups indicating improved reproductive performance.