Effects of Supplementing Cows with Vitamin A on Calf Performance
Project Title
Effects of Maternal Supplementation of Vitamin A During Late Gestation on Intramuscular Fat Deposition in the Offspring
Researchers
Marcio Duarte (University of Guelph) mduarte@uoguelph.ca
Katie Wood (University of Guelph); Ira Mandell (University of Guelph); Mike Steele (University of Guelph); Nick Serão (Iowa State University); Min Du (Washington State University); Mateus Gionbelli (Universidade Federal de Lavras); Fabyano Silva (Universidade Federal de Viçosa)
Scientific Journals
| Status | Project Code |
|---|---|
| Completed August, 2023 | POC.14.20 |
Background
It is well understood that fetal programing through maternal nutrition impacts calf development, growth and even meat quality. Qualities like marbling are extremely desirable in feeder calves but it can be challenging to increase this intramuscular fat without also promoting undesirable subcutaneous fat. Knowing that vitamin A is an essential precursor to grow fat cells for marbling, this team sought to uncover whether supplementing vitamin A during late gestation could improve the meat quality of their calves.
Objectives
- Investigate the effect of maternal vitamin A supplementation during late gestation on intramuscular adipogenesis and marbling deposition in the offspring.
What they Did
This study aimed to investigate the potential impact of vitamin A supplementation of pregnant cows at late gestation on intramuscular fat development on the offspring. The study involved 30 cows at 180 days of gestation, divided into two groups of 15. One group received supplemental vitamin A enriched diet (3X NRC recommendations), while the other group was fed the same diet without additional vitamin A (fed NRC recommended levels). The cows’ performance was closely monitored, including individual feed intake and average daily weight gain. Muscle samples were obtained through biopsies from calves starting at as young as 5 days old. These samples were then used to evaluate the expression of key markers associated with intramuscular fat deposition. Throughout the post-calving period until slaughter, carcass ultrasound imaging of the offsprings’ carcasses was collected to allow continuous assessment of the amount of intramuscular and subcutaneous fat as well as ribeye area development throughout the growth of the calf.
What They Learned
Despite having a lower feed intake compared to the control cows, there was no impact on maternal performance of vitamin A supplemented cows during the last ~100 days of pregnancy. However, this was not the case for their calves. Researchers found improved performance in calves from vitamin A supplemented cows compared to those from supplemented mothers. This improvement was seen as a higher body weight at calving, enhanced formation of fat cells, and increased percent marbling without having any increase in undesirable fat. These advantages to marbling without encouraging undesirable fat compared to calves from non-supplemented calves were observed from calving up until slaughter. However, calves from dams fed a vitamin A enriched diet did have lower tenderness scores compared to control calves.
What This Means
The results clearly show that supplementing vitamin A during late gestation, a point of pregnancy that is important for the formation of fat cells in calves, enhanced marbling in the offspring throughout their life. This could be a promising route for producers who are interested in improving the carcass quality of their calves without needing more days on feed or higher input costs (besides the cost of additional vitamin A) and without burdening the packer with an abundance of subcutaneous fat. However, more research should be done to understand the link between maternal vitamin A supplementation and reduced tenderness.