Sounds like you were given Critical Care (or maybe Science Recovery).
I find those to be a very expensive way of getting syringe food, and have used Excel pellets blitzed in a blender and mixed with water until at a consistency to syringe. I tend to weigh out 30g of pellets, then after blitzing them add various extras depending on the reason for syringe feeding. A pinch of Avipro if they're on antibiotics (as well as plenty of Avipro water seperately), a drop or two of Abidec if they're very low and been not eating properly for more than a day or so, etc.
Alternately, Nutripowder from Galens Garden is very good pre-powdered food. I'd certainly prefer it over Crit Care personally, and it still works out a little cheaper.
I think when it comes to syringe feeding there's no hard and fast rule as to what to give, as the reasons for syringing can vary so much. But overall I'm happy with Excel pellts mashed up (or maybe Science Recovery, never used it as a mash) or Nutripowder. Excel is £5 for 2kg, so considerably cheaper than sachets of Crit Care!
Piggies tend to be able to manage OK with missing incisors for a little while, they can pick up hay and gum it onto their back teeth to chew. However, I do agree it's better to be safe than sorry, so syringing is a very good idea. Different piggies can require a different technique to get him to take it, some will stand there and suck the syringe dry, others need to be towel wrapped to hold them still for it. I aim for 0.3ml at most a push out the syringe and wait for them to chew and swallow, and 10 - 15ml a feed with feeds every 4 hours or so. But if he really refuses you don't want to force too hard as it may be he's simply full and you don't want to increase the risk of digestive upsets. Also if he struggles with the water bottle look at getting at least 30ml water (mixed with probiotic if required) into him daily too as you don't want him getting dehydrated.
To finish, I can't stress strongly enough how potentially dangerous syringe feeding is. There is always a danger the timing can go wrong, and then you have a choking piggie, penumonia, or worse. I managed to get it wrong when feeding a 35ish gramme baby, and how he survived I will never know. Adults should be easier, but you can never afford to be complacent, and never try to get one last feed in if *you* are too tired to be sure you're capable. Missing a feed for a couple of hours is safer than pushing plastic nozzles full of food into a piggies mouth when you're exhausted.