BREEDING ▶▶▶


Using genetics for better colostrum


The Elevate genomic test, developed by Semex in cooperation with the University of Guelph, provides standard genomic results plus exclusive female immune response results that will identify an animal as a low, average or high immune responder.


BY BRENDA LEE, SEMEX


Females with High Immune Response (Figure 1) have inher- ently superior immunity, reducing disease occurrence, deliv- ering better response to commercial vaccines and producing higher quality colostrum. When bred to Immunity+ sires, producers naturally improve their herd’s health.


Higher quality colostrum Dr Bonnie Mallard and her University of Guelph research team developed the HIR technology that powers Semex’s Immuni- ty+® lineup (launched in 2012) as well as the Elevate® genetic test. Dr Mallard, her team and immunogenetics project leader Dr Lauri Wagter-Lesperance, continues to research the benefits of having calves consume the colostrum of high responding females. Their findings indicate that HIR cows also have higher quality colostrum with more antibodies compared to average and low responding cows for the first six weeks after calving.


Figure 1 - Higher quality colostrum. Through first 6 weeks of lactation


High Ave Low


Dr Wagter-Lesperance says the best time to give colostrum is immediately after birth in order to absorb antibodies and cells into a calf’s bloodstream. She adds that the next best window for colostrum feeding is within the first six hours af- ter birth. After 24 hours, gut closure occurs, and the window of protection is no longer available to the calf. While experts recommend four litres of colostrum per feeding, not all new- born calves can consume this much in a single feeding. That’s why the colostrum of HIR cows is so important — it provides the calf with a higher concentration of antibodies per unit of volume consumed, explains Dr Wagter-Lesperance. “Our research shows that calves getting the colostrum from high responding dams have more antibodies in their blood,” adds Dr Wagter-Lesperance. “The correlation is very significant.” So what does all this mean for dairy producers? Dr Wagter-Les- perance and the Guelph team believe the research indicates: • Calves from HIR dams benefit from the best possible start as their dams offer a higher concentration of antibodies, cells and other factors in their colostrum.


• Colostrum from HIR dams can be given fresh (rich in antibod- ies, cells and other factors), or frozen (rich in antibodies, cells and other factors) to calves from low and average immune response dams giving all calves the best possible start.


•


If a herd has been exposed to a particular pathogen, HIR dams provide colostrum that is rich in antibodies and im- mune cells providing protection against organisms causing disease in their environment.


wk 0 wk 2 wk 3 wk 4 wk 6


Immunity + Daughters have higher quality colostrum High immune cows have significantly more total immunoglobulin and betalactoglobulin in colostrum


The collaboration between Semex and University of Guelph continues to help optimise milk production by reducing the time and money producers spend on treating sick animals with antibiotics or other therapeutics.


▶DAIRY GLOBAL | Volume 7, No. 1, 2020 13


The best time to give colostrum is immediately after birth in or- der to absorb antibodies and cells into a calf’s bloodstream.


PHOTO: SEMEX


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28