Hi! I think you should do the milk fat measurement again because 20% is not normal, not even in ewes milk which they have a lot more milk fat content by the end of lactation period. Which method are you using  for determination? Maybe is just a misconception about the scale.

Hi

The fat milk cow level was range 4.7-5.9% The level increase in end milking or animal feed on food of fat rich . but 20% very high . please retest by using Gerber method .

Carmen, this is a reasonable value for milk strippings.  We had the same problem when we wanted to measure progesterone in milk and progesterone is bound up in lipid bundles.  We found we could get a representative sample by taking a spot sample at 90s after the start of milking.

Toby

Hi Carmen, we send out the samples to LIC (Livestock Improvement Corporation) which is an authorized agency for conducting herd test in New Zealand. But i am not sure about the method they use. I even tried inquiring them, they said their machines and methodology were working properly.

Thanks Alaa, but in my research scenario, doing fat measurement by any other method except sending it to LIC is not feasible.

Hi Toby, so do you mean, the high percentage i am getting is reasonable? Can you help me with any references regarding tendency of getting such higher values? Any hormonal changes that support them? In my case, the values are diverse. Some of the cows are within the normal fat range while some are extremely high.

Thank you.

No, the average should be 2-8% but the individual spot samples start at 0.5% and rise through to the 20% you experience.  This is not hormonal I think its physical. The lipids are lighter than the H2O and you are draining the cisterns from the bottom.  The old textbooks from the sixties have some tables but I do not have any to hand.

It depends on lot of factors, like breed, age, stage of lactation, feeding etc. Therefore You question simply lacks a lot of details. However, you may obtain significantly higher values of fat content if milk sample is taken at the very end of milking, since the greatest amount of fat is exceeded at this point.

Toby, did u mean the lighter lipids accumulated at the top of cistern in the initial milking and in the later stripping, they were concentrated?

Grzegorz: All the cows are on pasture; Mostly HF, few Jerseys, in early month of lactation, none are heifers. There aren't much variation except for age, and difference in milk fat were seen within Jerseys and HF too.

I think it is a problem of correct sampling and I agree with the aforementioned answers by Toby Trevor Mottram.

Lipids are lighter and during milking, milk is not homogenous. The correct sampling could be only after milking is over (preferably quarter milking) and sample after mixing the whole yield.

If sampling is based on striping, than it had to be done somewhere in the middle of milking time (and Toby’s suggestion on 90 seconds, sound practical), since at finishing, as lipids are lighter the last strips would be fat enriched. The same phenomenon is recorded with ewes at the last days of milking period, just before drying off, when the quantity of produced milk is reduced and the fat percentage is significantly increased

Well it's pretty obvious that You see differences between HF and Jersey since HF in general is characterized by ~3.8% of fat content in milk whereas Jersey can easily achieve even over 6%. Pasture even promotes this phenomenon since milk yield is not as high as when eg. TMR is used.

I think nobody can give You exact amount of fat You can observe. We can tell You that is quite normal - You can observe this kind of situation (20% of milk fat in sample), upon very specific conditions (even more than 50% of milk fat might be exceeded in very last phase of milking). Taken together, If you really want to obtain representative sample, You have to follow the clues You already got here. Collect milk from whole milking, preferably from each quarter separately, and then collect 10-12.5 mL from each quarter, bulk it and then perform measurement.

And that would be my another question - how do You measure fat content ?

Dear Sulav,

when I worked we had something like this problem, it means 20% of fat is the error but how can find the error by checking this steps;

1. Sampling

2. Keeping

3. Carrying

4. Operator

5. Materials

6. Gadget (calibration)

You can check it these stages.

Good luck

The fat, lactose and protein contents of milk vary according to stage of lactation. Solids-not-fat content is usually highest during the first 2 to 3 weeks, after which it decreases slightly. Fat content is high immediately after calving but soon begins to fall, and continues to do so for 10 to 12 weeks, after which it tends to rise again until the end of the lactation.

Hi Sulav, I know this problem very well and yes the value found in stripping milk is totally possible. I found more than 100g/liter in last fraction of milk in dairy lacaune ewes, that is a big challenge when you have to develop milk meter with proportional sampling throughout milking!!. But be carefull, because this Fat content is highly variable depending of the quality of milking before and percentage of stripping milk. If you have an Oxytocin discharge or not when you strip you can also modify in enormous proportion this fat content. Can you explain what you want to test in this herd in order to help you at the best?

best regards

Hi again, I would like to precise a point (after reading all the answer). The differences between milk fat content at the beginning and end of milking is not at all due to density of milk fat. As I explain to my students, an old experiment in england was done to test milking with animals lied on their back and machine milking emptying gland by the top. And theiy always find low fat at the beginning and high fat content at the end of milking!!! It is a physical problem and also anatomo-physiological explanation. Fat globules have for a part of them, a larger diameter than the small galactophorous ducts. Thus, without mecanical pressure on the aveolus, it is not possible to force these globules to pass in these small ducts. The milk naturally drained between milking is thus filtrated and a part of the fat content is kept in alveolus. During milking or suckling, after Oxytocin discharge, the pressure is suffcient and fat globules arrive in cistern and fat content increase continuously throughout milking. Stripping milk correponds to milk non extracted, may be because of an incomplete milk ejection, may be naturally, because milk flow begins to become too low and cluster are removed before a total exrtaction of the milk . It is accepted as normal to let around 5 to 10 % of milk in udder after milking (without any deleterious impact on further milk secretion). It is normal that if you strip or want to extract residual milk by oxytocin injection, the milk extracted will be very rich in fat but quite normal in lactose and protein. In dairy goats it is a little bit different because, ducts seems to be larger and fat globule smaller, making fat transfert between milking more efficient. addictionnaly, the milk retained in alveolus and ducts represnet only a very small part of the total milk (Till 90% citernal!). But if you extract residual milk with OT, it will be the same than for other species with very high yield of fat percentage. If you want to evaluate the mean milk fat, The only solution is to collect milk individually and mix it before to analyse. To take a sample in the middle of milking is a way to evaluate a mean fat content but for a scientific work it can be criticized because, it is also very variable depending of the moment you sample milk and depending of animal because kinetic of fat evacuation could differ a lot between animals.

regards

I think that fat level is possible. We analysed composition of strippings (last milk) in Holstein cows in our Department's herd in Izmir, Turkey. Mean fat percentage in strippings was over 7% and maximum value we found was 16.25%. Best regards.

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There are however a number of concerns that have been raised with regards the practicality of using larvae in livestock feed.Under EU regulations, in response to the BSE and Foot and Mouth crises, insects are not allowed to form part of livestock feed; with animal product (insects being classed as animals) banned from consumption by livestock entering the food chain.

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