LinnieGirl is correct in what she has stated. That said, I use an observational method instead. Both work, I find people just have different styles that feel right to them. Both have the same result at the end if you do them right. I don't weigh babies until fledging unless I have a specific concern. I can feel the meat around the keel and between their legs to see if they have enough weight on them. I don't measure the amount of food I give them as it varies so much baby to baby, feed to feed. I feed them formula until the crop is full, not bulging like LinnieGirl said. I feed with a pipette, as it gives me great "feel" of the food flowing into the baby. I don't talk on the phone, or allow any other distractions as I have that pipette bulb in the babies mouth. Anyone I ever knew that aspirated a baby did so when turning their head to talk to someone, answered the phone or some other thing to pull their attention from what they were doing. It is very difficult to aspirate a baby in actuality. Like humans, when swallowing... the airway closes. Slow and steady wins the race. If you are in a rush, you can squeeze too fast, or if the rubber gasket on a syringe is dirty, or old and dry and sticky, food can rush out too fast. That is why I don't use them. I don't trust myself to not push down too fast accidently. You watch them eating, swallowing and the crop filling as you feed them.
Improper brooders that don't hold steady and appropriate temps, formula that is too hot and burns a crop, or formula too thick or thin are much more common issues. Linnies are easy to feed as long as they are not pulled extremely late. That said, I find them fun and easy to feed at most ages. If you are starting out, I would focus on the purchase of a high quality brooder, and get your pair primed for breeding, I wouldn't worry about these feed amounts and times to feed so much early on because that changes based on when you decide to pull them to handfeed. Linnies can be tricky parents, and if you choose to intervene to save a young one.... all bets are off. We can offer more specific advice when we know the age of the babies you are dealing with. Having a brooder on hand as well as handfeeding supplies can really make a difference if you need to step in. A word of caution (easy for me to give since I just raised 2 from the first 48 hours of life after swearing 5 years ago I never would do it again) peeking in that box makes it really hard to leave a baby in trouble. Early hatches that need round the clock care can be really hard on your sanity, physical health and personal relationships. It seems after 5 years of swearing I would never do it again, my memory fades and I get sucked in again. Here is a picture of one of them on day 4 - it seems like they grow so slow you don't even notice it happening for the first week.
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If you are trying to determine if you can fit handfeeding in with work/home responsibilities.... at the proper age of pulling (I like no earlier than 2 weeks... when they start to color in, better) plan on 5x-6x a day. I do 7am, 10am, noon, 3pm, 7pm, 10-11pm. I feed a little closer together in the mornings as it seems they burn through the food faster after the overnight. I find feeding more frequently yields babies that grow well, never beg, don't get stress markings in their feathering, and wean on schedule. You can see the crop when it is empty, I only like them going dry overnight. If your schedule doesn't allow this due to work.... if you did the first two feeds before you left, came back at lunch, fed the moment you walked in after work, then after dinner, and before bed.... you would be just fine. Incubator or early pulls need feeds round the clock.
Hope this info helps... I am up past my bedtime, let me know if something wasn't clear in my tired mind.