In the August 2009 edition of The Ranger, I wrote a detailed article (ARE YOU FED UP?) on what to do if you think that there has been a problem with the feed. It gave details of how to take a feed sample; what analyses may be worth requesting and why those particular analyses may be helpful. Feed compounders do a fantastic job in formulating and delivering good quality feeds but they are not totally infallible. Mistakes can occasionally happen. In addition, even when there has not been a mistake in the mill, it is still possible for you to offer your hens a feed that is nutritionally unbalanced. This is because the only practicable way of getting the feed from the lorry to the feed bins on your farm is for it to be blown into the bins. This can cause a problem – separation.
FEED SEPARATION
I have come across cases recently where the feed sample that was analysed was highly unlikely to be representative of the whole delivery. Instead of a composite sample of the feed being taken over a number of days, it was taken on one occasion only, i.e. as the feed was falling into the feed hoppers in the house. It is clear from the analyses that at that particular moment, the feed that was falling into the hopper was likely to have been from the heavier and finer fractions of the feed. When being blown into the feed bins they tend to go to the sides of the bins. The lighter and coarser fractions of the feed tend to funnel down in the centre of the bins and then what has been clinging to the sides of the bins slides down with a ’whoosh’. A sample taken at that time would probably give an analysis that looks like the tables on the following pages: (’As Received’ basis).
Examples 2 and 3 are more helpful than Example 1. What can we glean from the analyses?
1. CALCIUM & ASH
In all of the samples, the calcium concentration was higher than wanted and this was correlated with the high Ash concentrations. In practice, some of the limestone granules (or flour) had presumably separated from the rest of the feed ingredients. Limestone is an unpalatable ingredient and it has to be included into a layers feed at about 8 - 9% of the total ingredients, so as to achieve the approx 4.1% of calcium that the hens require. Certainly the range of calcium concentrations in these examples implies that the feed may have been unpalatable. Intakes of calcium, which are higher than necessary, can lead to ’calcium splashing’ on the shells (i.e. deposits of calcium on an otherwise perfect shell). This is often seen when the pullets first come into lay but it should be infrequently thereafter
2. MANGANESE / MINERAL VITAMIN MIX Manganese is analysed because it gives some help in deciding whether the feed contains the mineral/vitamin mix that is usually added separately into the feed at the mill. In Examples 1 and 3, it appears that it too had separated when being blown into the bins, even though it had probably been included at the correct levels in the mill. As the manganese was at a high concentration in Examples 1 and 3, it is possible that other minerals and vitamins may also have been at a higher level than necessary. For the metabolism of the hens to be working as smoothly as possible, the mineral intake must be balanced. An excess of some minerals could disrupt the metabolism within the hens’ cells. Likewise, hens need vitamins to be at the correct ratio to one another. If they are not, antagonisms between some of the vitamins may occur within the gut of the hens. For example, an excess of Vitamin A can ’kill off’ Vitamin E within the gut and this can lead to the degradation of muscles.
3. SODIUM (from Salt and/or Sodium Bicarbonate)
It is worrying that the sodium concentration in the feed can be as high as it was in Examples 1 and 3. At this concentration, on free range farms (where the daily feed intake can be high), a sodium concentration of 0.26 – 0.27% could verge on being toxic. Certainly the feed would be unpalatable and when toxic, the hens would realise this and eat less. This would be stressful and cause production and egg size problems. The metabolism of the hens would be adversely affected. The hens would have to drink more, so as to help with the excretion of an overdose of sodium.
Their droppings would probably be wetter than usual.
4. METABOLISABLE ENERGY
Hens are good at adjusting their feed intake to ingest the energy that they require. Where, as in Examples 2 and 3, the ME is low; the hens would try to increase their feed intake, so as to try to ingest sufficient energy from the feed. However with these samples that would be difficult, because of the high Sodium, Calcium and Ash contents. It seems likely that one of the explanations for the ME being low in these samples is that the calcium was high. The limestone that would be the predominant source of the calcium would be extremely low in energy. In addition, some energy can come from protein and especially in Example 2, the protein was lower than anticipated.
It can be seen therefore that whereas the feed compounder has probably made a good job of formulating and mixing the feed, it can sometimes still reach the hens in an unpalatable and potentially toxic form. How can this be avoided?
Blowing the feed into the bulk bins is potentially the most likely cause of the problems in these examples. The snag is that layers feed in meal form contains a wide range of ingredients. Some are heavy e.g. limestone: some are light e.g. Wheatfeed; some have a larger particle size e.g. ground cereals. Blowing this mixture into feed bins therefore has to be a compromise between the grist, the velocity and amount of air that are needed. In practice, on most lorries, the speed of the blower on the lorries when blowing a layers meal should be approx. 1100 – 1200 revolutions/minute. When the blower is at this speed, the rate of discharge of the feed into your hoppers is likely to be about 2½ minutes for each tonne of meal.
So are you now asking yourself whether you should be feeding crumbs or pellets? If you are and are not producing organic eggs, the answer is a definite no. Don’t do it! Use a layers meal. The risks of the hens getting a full crop when fed pellets or crumbs and then becoming bored are too great. Separation of the feed is potentially a lesser problem than the risk of bored hens cannibalising. The choice of ingredients for a non-organic free range feed, when correctly ground at the mill, should not result in a meal that is unpalatable.
The lorry drivers will have been told how fast the discharge rate should be. However one can imagine that on a day when they have been stuck in a traffic jam, and the wife has requisitioned her husband to baby sit, it would be a very human reaction to increase the velocity a bit! If that happened, the degree to which the feed separates as it is being blown would increase.
For example, you may have a feed delivery of 24 tonnes? How long is the driver taking to discharge it into your feed bins? If it is less than about an hour, it is possible that an unacceptable degree of separation will have occurred. Unfortunately, there will always be some separation of a layers meal and great care should be taken to avoid an increase in the degree of separation.
The aim is to avoid a ’boom or bust’ sort of situation, i.e. where on some ’boom’ days the hens would be getting high energy feed from the cereals and it would be very palatable. (However, the calcium intake that is necessary for tomorrow’s eggshell would be low and the energy would be less than needed. The hens would have to deplete the store of calcium in their Medullary Bones so as to top up what is necessary for a successful shell quality).
This could then be followed by ’bust’ days of unpalatable feed with a low energy feed and too much calcium and that excess would have to be excreted. Humans are lucky, because we are usually able to be flexible about what we eat, because of freedom of choice. Hens have to "take it or leave it". What is in the feed trough is all that is on offer and if it is not of an optimal quality, stress may ensue, with detrimental effects on production and health becoming possible.
Do you have two feed bins? This is a very sensible thing to do. It avoids a new delivery of feed being put on top of the remainder of the previous delivery. Therefore in the event of some separation of each load, the risks of days when the feed quality looks like that of the Examples are reduced. It is desirable that each bin has been emptied before the next delivery of feed into it.
" A little of what you fancy does you good". That applies to hens too. Make sure that your management of the feed lets the hens have what they fancy on a consistent and daily basis.
