@Dave
I was less concerned about the multiple antigens than by the temperatures. I understand that sometimes you have to handle cattle at times when all is not ideal... and I've killed a couple with heatstroke over the years, so I'm less inclined to feel like I 'have to do it now', regardless - but I didn't have an appointment for all my cows to go to slaughter on a given day.
But... the scientific evidence is strong that response to vaccination is markedly impacted - in a negative way - by heat stress when you get past that 85/70 setpoint (daytime temps above 85, with nighttime temps not dropping below 70). You may have 'vaccinated' those calves, but you may not have 'immunized' them.
I'm not sure why y'all are doing Nasalgen-3 and Bovishield Gold at the same time.
I can certainly see Nasalgen-3 or Inforce-3 to provide fast local mucosal immunity and prime the immune system - with a subsequent Bovishield booster 3 weeks or so later to move systemic immunity to a higher level.