WO1993000017A1

WO1993000017A1 - Poultry feedstuff

Info

Publication number: WO1993000017A1
Application number: PCT/GB1992/001134
Authority: WO
Inventors: John Michael Forbes; Akram Yalda
Original assignee: The University Of Leeds
Priority date: 1991-06-22
Filing date: 1992-06-22
Publication date: 1993-01-07
Also published as: AU2195192A; EP0599856A1; BR9206189A; JPH07503602A; CA2111956A1; AU655302B2

Abstract

Intensive poultry husbandry feed includes dry feed and between more than 75 to 250 % of water.

Description

POULTRY FEEDSTUFF

This invention relates to feeds for intensive poultry husbandry. The invention also relates to a method of use of the feeds. The invention may be used to feed a variety of birds such as chickens, turkeys, pheasants, quails, geese, guinea fowl and the like, referred to in this specification simply as "poultry".

Intensive poultry husbandry is widely practised both for the rearing of broiler chickens and other birds and also for egg production. Intensive poultry husbandry may be defined by the housing of 500 birds or more in a building or other structure such as an open air compound to which feedstuffs, water and other amenities are provided. The birds may have access to both a building and paddock. Intensively reared poultry are usually fed a dry pelleted feed and provided with a separate water supply.

According to a first aspect of the present invention an intensive poultry husbandry wet feed includes dry feed and between more than 75 to 250% by weight of water.

Percentages and proportions in this specification are by weight unless indicated otherwise.

The feed may further comprise nutrients or other additives as are described below. The dry feed may be pelleted, ground or provided in other convenient forms. Moist feed may be used, the proportion mixed with water being calculated on the dry weight.

Use of the feed in accordance with the present invention has been found to cause poultry to convert food more efficiently or when possible to consume more food and grow at a faster rate without any significant detrimental effect on the carcass composition. The conversion of food to body weight is in most cases more efficient. Surprisingly this effect is not achieved by use of less than 75% of added water. Use of 300% or more has been found to be excessive.

It is believed that the digestibility of the food is enhanced, - this being a surprising result since an increased food intake had been thought to cause a faster rate of passage of digesta with less time for digestion to occur. In preferred embodiments of the invention the feed includes 80% to 250% more preferably 100 to 250% water. Especially preferred embodiments of the invention incorporate 120 to 225% water, more preferably 150 - 200%.

Any conventional dried poultry feed may be employed, for example Dalgety feed. Alternatively raw materials mixed on the farm or locally may be used.

Preferred feeds have medium to high nutrient density as measured by metabolisable energy and protein.

Preferably, the proportion of water added to the dry feed results in a wet feed or wet mash having a pourable, semi liquid porridge-like consistency. This consistency produces a wet feed in which an optimum amount of liquid has been absorbed. If less water is added, the wet feed will be too dry, whereas if more water is added, a layer of water will be formed on the top of the feed. The existence of a layer of water above the bulk of the wet feed deters poultry from feeding.

The dry feed may be provided in the form of pellets, but is preferably in a powdered form.

According to a second aspect of the present invention we provide use of a feed in accordance with the first aspect of this invention for intensive poultry husbandry.

Besides use with adult poultry the feed may be used for intensive husbandry of chicks. The term "chicks" may refer to poultry from hatching to the age of maturity. Chicks of 3 days may be conveniently introduced to the wet feed. Younger chicks for example 12 hours to 24 hours of age may also be reared using the feed although the cages and feeding apparatus should be arranged to prevent the chicks from bathing in the wet feed.

Mortality of chicks is especially high during hot weather when the chicks have been without water during transport from the hatchery. Unless they find the drinkers quickly the chicks can become dehydrated and succumb. By offering wet food, which is found easily and is eaten immediately, further significant economic benefit is obtained by reduction of mortality in the early stages of rearing.

Additional drinking water may be provided although this is not always essential. The necessity of providing additional drinking water is especially dependent on the amount of water provided in the feed within the scope of this invention.

Use of the present invention in preferred conditions affords increased body weight without detracting from the carcass composition. A higher voluntary intake as measured by the dry weight of feedstuff may be induced. Efficiency of feed conversion or utilisation of the foodstuff is improved.

Under many circumstances use of the present invention whilst increasing the efficiency of feed conversion or utilisation of the food, will not result in an increased body weight. In other words, by use of the present invention, birds will under certain circumstances attain their maximum body weight earlier and/or by eating less food than birds which are fed a conventional dry feed.

The invention has the further advantage of allowing additives such as enzymes and other nutrients, for example vitamins, or medicaments to be added to the feed by simple dissolution in the water. Nutrients can be provided in soluble form avoiding any need for provision of impregnated dried feedstuffs and especially for supplies of different impregnated feedstuffs for different stages of poultry development or in response to variations in day to day requirements.

Indeed a farmer may obtain an independent supply of powdered feed with which the additives may be combined. Pelleting of feed can cause thermal degradation of certain ingredients. Dried additives are easier to store and transport and are more stable than impregnated foodstuffs. Addition of enzymes to the wet feed allows breakdown of the foodstuff to commence before ingestion by the birds. This contrasts with use of dried feeds in which enzymic additives are only activated after ingestion

Thickening agents may be added to the wet feed in order to increase the amount of water which may be added without formation of a supernatant water layer.

Use of feed in accordance with this invention facilitates distribution within an intensive husbandry building or other facility. The necessity for mixing the dried feed and water adjacent or within the building confers a considerable advantage. In conventional intensive facilities mixing apparatus is not necessary. However when a mixer is provided a farmer may elect to mix his own feed from locally available ingredients. This affords a greater flexibility of supply and can result in increased efficiency. Water may be mixed to the dried feed either immediately before use or at a convenient period beforehand, for example 24 hours before use. A single batch of wet feed may be prepared and used during the following 24 hours. Metabolisability of feed has not been found to significantly deteriorate upon soaking.

A further advantage is that the liquid feed may be cooked before use to release nutrients and enhance digestibility, in which case thermally sensitive additives could be introduced after cooking.

The invention is further described by means of examples but not in any limitative sense, with reference to the accompanying drawing which shows a schematic view of apparatus adapted for carrying out the invention.

The apparatus shown in the drawing is used for wet feeding of poultry. Bulk feed hoppers 1 are arranged to allow one or more bulk feeds to be applied to a mixing tank 4 by use of motors 2 which drive an auger 3. The mixing tank 4 is insulated to prevent heat loss. Load cells 5 serve to determine the weight of feed or water within the mixing tank 4. A water tank 6 preferably incorporates heating means (not shown) and is connected to the mixing tank 4 by a pump 7 which serves to meter water supplied from tank 6 through a delivery pipe 8. An auxiliary tank 9 allows storage of water soluble or miscible materials such as amino acids, medicines, minerals or vitamins for addition to the tank 6 or directly to the mixing tank 4 via a bypass pipe 19. A water meter 10 serves to regulate the supply of water to the auxiliary tank 9. Meter 12 serves to control the supply from the main water supply 11 , the water supply to the drinkers 13 being also connected to the main supply 11. A control unit 14 connected to the load cells 5, pump 7, meters 10 and 12 and motor 2 is supplied by a mains electricity supply 18. A motor 16 drives a driving chain, helical screw or other arrangement to distribute wet feed into feed trough 15 which extends through the poultry shed. The wall of the poultry shed is shown at 17.

Alternative apparatus may be employed in accordance with this invention. A stirrer may be provided in the mixing tank 4. The heating means may be omitted.

In use of the apparatus one or more dry feeds may be delivered to the mixing tank 4. Water which may be pre-heated and which may incorporate additives from the auxiliary tank 9 is delivered to the mixing tank 4 from the water tank 6. The mixture of water, dried feed and additives is then delivered by the driving chain or other arrangement through the feed trough 15 to the poultry (not shown). The trough 15 may be arranged in a cyclical manner or otherwise as convenient.

The following examples include trials which were carried out under the same conditions as are employed in large scale poultry husbandry. The results are applicable to rearing of larger numbers of birds under intensive husbandry conditions.

In any row of values those with the same letter do not differ significantly. Different letters indicate statistically significant differences, with a probability of less than 5%. The abbreviation TRT refers to "treatment".

SET A

COMPARATIVE EXAMPLE 1

ADDING 50% WATER TO THE DIET ON VOLUNTARY FOOD INTAKE IN

BROILERS

TRT1 : Birds fed normal dry feed as control (12 birds)

TRT2: Birds fed control + 50%- added water (12 birds)

Age: 4 - 7 Weeks

Results: 7 weeks Food intake (g/bird/d)

Body weight (g)

Abdominal fat weight (g/bird)

Total lipid (g)

Total protein (g)

This experiment showed that there was no significant effect of 50% water on intake or growth.

COMPARATIVE EXAMPLE 2

EFFECT OF ADDING 25, 50 AND 75% WATER TO THE DIET ON VOLUNTARY

FOOD INTAKE IN BROILERS

TRT1 : Birds fed control (8 birds)

TRT2: Birds fed control + 25% added water (8 birds)

TRT3: Birds fed control + 50% added water (8 birds)

TRT4: Birds fed control + 75% added water (8 birds)

Age: 4 — 7 weeks

Result: 7 weeks

This experiment showed that wet diets reduced body fat, probably by reducing dry matter intake.

EXAMPLE 3

EFFECT OF ADDING 75% OR 200% WATER TO THE DIET WITH NO DRINKING

WATER ON VOLUNTARY FOOD INTAKE IN BROILERS TRT1 : Birds fed control (12 birds)

TRT2: Birds fed with 75% added water; no drinking water;

(12 birds)

TRT3: Birds fed + 200% added water - drinking water (6 birds)

Age: 3 - 7 weeks

Results: 7 weeks TRT2 was abandoned after 1 week as feed intake was very low and birds gained little weight.

The experiment showed that 200% water added to the feed significantly increased intake and body weight gains without affecting carcass composition; 75% addition of water, without access to drinking water was unsuitable.

EXAMPLE 4

EFFECT OF ADDING 150, 175, 200 OR 225% WATER TO THE DIET ON

VOLUNTARY FOOD INTAKE IN BROILERS

TRT1 : Birds fed control (6 birds)

TRT2: Birds fed control + 150% added water (6 birds)

TRT3: Birds fed control + 175% added water (6 birds)

TRT4: Birds fed control + 200% added water (6 birds)

TRT5: Birds fed control + 225% added water (6 birds)

Age: 4 - 7 weeks

Results: 7 weeks

TRT1 TRT2 TRT3 TRT4 TRT5 eed

an approximately equal extent.

EXAMPLE 5

EFFECT OF ADDING 200% WATER TO THE DIET WITH OR WITHOUT

DRINKING WATER ON VOLUNTARY FOOD INTAKE IN BROILERS

TRT1 : Birds fed control (8 birds)

TRT2: Birds fed control + 200% added water without access to drinking water (8 birds)

TRT3: Birds fed control + 200% added water with access to drinking water (8 birds)

Age: 4 - 7 weeks

Results: 7 weeks

The improvement in intake and growth was seen when the birds have free access to water. However, providing drinking water did not interfere with the growth-stimulating effects of wet feed and is beneficial since there was no risk of the birds' welfare being compromised from lack of water. EXAMPLE 6

200% WATER IN THE DIET FOR FEMALE BROILERS

The possibility that the phenomenon is restricted to males kept under short day lengths was tested by using females under 23 hours lighting per day.

TRT1 : Birds fed control (9 birds)

TRT2: Birds fed control + 200% water - drinking water (9 birds)

Age: 2 - 7 weeks

Results: 7 weeks

Digestibility of DM (%) 65a 73a

The effect of wet feeding was significant with female broilers continuously illuminated and digestibility may have been improved.

EXAMPLE 7

RESTRICTIONS OF WET FEED INTAKE TO THE SAME DRY MATTER INTAKE

AS CONTROL FEMALE BROILERS

TRT1 : Birds fed control (8 birds)

TRT2: Birds fed same weight of DM as that consumed by

TRT1 , but with 200% added water, no drinking water (8 birds)

TRT3: Birds fed control + 200% added water; no drinking water (8 birds)

Age: 4 - 7 weeks

Results: 7 weeks

TRT1 TRT2 TRT3 Food intake (g/bird/d) Body weight (g) Abdominal fat weight (g) Digestibility of DM (%)

This experiment showed that restriction of wet—fed birds to the same DM intake as controls allowed an increase in performance which was intermediate between that which occurs when wet feed or dry feed is offered ad libitum. The effect of wet feeding in this case was therefore to stimulate a higher voluntary feed intake and to improve efficiency of feed utilization

EXAMPLE 8

200% WATER IN THE DIET FOR COCKERELS OF AN EGG-LAYING STRAIN

TRT1 : Birds fed control (6 birds)

TRT2: Birds fed control + 200% added water (6 birds)

Age: 3 — 6 weeks

Results: 6 weeks

Food intake (g/bird/d) Body weight (g)

The effect of wet feeding on weight gain was significant although than on feed intake was not.

EXAMPLE 9

OFFERING A CHOICE BETWEEN DRY FOOD AND 200% ADDED WATER IN

COCKERELS OF AN EGG-LAYING STRAIN

TRT1 : Birds fed a choice of control and 200% water with access to drinking water (5 birds)

TRT2: Birds fed a choice of control and 200% added water without access to drinking water (5 birds)

Age: 4 — 6 weeks

Results: 6 weeks Wet food intake (gDM/bird/d) Dry food intake (gDM/bird/d) Total food intake (g/bird/d) Body weight (g)

When given access to drinking water the birds greatly preferred to eat dry food but in the absence of drinking water they ate wet food to give the same DM intake and grew at the same rate.

EXAMPLE 10

300% WATER IN THE DIET FOR MALE BROILERS

TRT1 : Birds fed control (6 birds)

TRT2: Birds fed control + 300% water without drinking water (6 birds)

The experiment was stopped after 2 days because the birds refused to eat even though they became very hungry. There was a layer of water on top of the food which prevented the birds realising that there was food beneath.

This experiment showed that 300% is too much water to add to the feed.

SET B

Eighteen pens were used in the experimental broiler house, avoiding those at the ends of the building. Initially 100 day-old birds were placed in each (50 male, 50 female) and fed the standard starter feed ad libitum. Free access to drinking water was given throughout. The experiment started 11 days from arrival when the total weight of the birds in each pen was recorded. Ten males and 10 females, which had been kept in other pens, were weighed individually, wing-tagged for individual identification, and added to each pen to give a total of 120 birds. The groups and the 20 individuals within each group were weighed again on days 26, 34 and 41. Deaths were recorded daily.

Feeding Three feeds with the same formulation (Table 1 ) were prepared. One was pelleted and fed dry in the conventional way to six pens; the second was also pelleted and mixed with twice its weight of water in accordance with the invention left overnight and then fed to a further six pens. The third was left unpelleted and mixed with twice its weight of water also in accordance with the invention the day before being offered to the remaining six pens.

Table 1. Formulation and composition of the feeds (source:

Dalσetv Agriculture)

MAIN INGREDIENTS: g/kg

Fine Wheat 701

Hi-Protein Soya 74

Full-Fat Soya 100

Chilean Fish Meal 40

Meat Meal 40

Fat 30

Vitamins, Minerals and Additives 15

Table 2. Composition of the feeds (source: Dalσetv

Agriculture)

ANALYSIS: g/kg

Oil 77

Protein 209

Crude Fibre 27

Ash 48

Moisture 98

Within a few days it became clear that neither of the wet feeds were absorbing all of the added water, leaving a layer of supernatant water making it difficult for the birds to eat. The amounts of water added were therefore reduced from 200% to 160% and 120% for the pelleted and unpelleted wet feeds, respectively. The amounts of feed added to the troughs in each pen were increased daily so as to leave only small remainders. Slaughter

On day 41 , 5 tagged males and 5 tagged females from each of two pens per treatment were killed, plucked and eviscerated. On day 42 another third of the pens were killed and the remainder on day 43. The carcasses were weighed and chilled to be minced a few days later. The digestive tracts were weighed full and empty; the abdominal fat pad was weighed. The minced samples were sent to Leeds to be analysed for fat, protein, ash and dry matter.

Statistical analysis

Data were analysed for the effect of treatment by analysis of variance. Results

Live weight§

Mean live weights for all the birds on each treatment are given in Table 3. By day 34 both wet-fed groups were significantly heavier than those on dry feed but at the end of the experiment only those given wet mash having a porridge like consistency were significantly heavier than controls.

The mean weights of those 20 birds per pen which were weighed individually were similar to the groups presented above, but the differences did not attain statistical significance.

Feed intake

Mean feed intakes are given in Table 4. Table 4. Voluntary feed intake (kg air—dry feed per bird per day; means of six pens).

Overall conversion ratios were 1.79, 1.69 and 1.66 (sed, 0.02) for dry pellets, wet pellets and wet mash, respectively. The improvement given by both wet feed treatments was significant compared to the dry feed.

Slaughter data

Table 5 shows that there was no effect of treatment on carcass weight or abdominal fat. Intestine weight, both full and empty tended to be less after wet feeding while the weight of contents (full - empty) tended to be less for dry feeding.

No obvious differences attributable to dietary treatment were apparent.

SET C 50 birds were kept in groups supplied with Dalgety starter feed until day 15 when 36 were caged individually and 12 birds (6 male, 6 female) offered each of the three dietary treatments. Free access to drinking water was given throughout. Each bird was weighed individually on days 19, 25, 29, 36, 43 and 47.

Feeding

The same three feeds were used as described in Set B above. Each cage was provided with one container of feed and one of water. From days 15 to 19 the water addition to both pellet and mash wet feeds was 200% but this was then reduced to 160% and 120%. Feed intake was recorded daily.

Slaughter

All birds were killed, plucked and eviscerated on day 47. The carcasses were weighed and frozen to be minced two weeks later. The digestive tract was weighed full and empty; the abdominal fat pad was weighed. The minced samples were analysed for fat, protein, ash and dry matter. Results

Live weight

Mean live weights for all the birds on each treatment are given in Table 6. Although the birds on the wet feeds tended to grow faster in the middle of the experiment, by the end the weights were very similar and at no stage were there significant effects of treatment.

Table 6. Live weights at various stages of the experiment. Age (days) Dry pellets Wet pellets Wet mash sed

19 522a

25 861a

29 1120a

36 1591a

43 2243a

47 2521a

Feed intake

Mean daily feed intakes during each period are given in Table 7. Although the wet feeds tended to be eaten in reduced quantities, compared to the dry, this was only significant from days 37-43.

Table 7. Mean feed intakes over several stages of the experiment. Age (days)

19-25

26-29

30-36

37-43

44-87 Total over days 19-47

Overall conversion ratios were 2.15, 1.98 and 2.03 (sed, 0.092) for dry pellets, wet pellets and wet mash, respectively, the differences not being significantly different.

Slaughter data

Table 8 shows weights taken at slaughter. There- were tendencies for heavier carcasses and less abdominal fat in the wet mash treatment, but these were not significant. Intestinal weights, both full and empty were significantly reduced by wet pellets while weight of digesta was slightly reduced by the wet feeds.

Table 8. Weights of carcasses, abdominal fat and full and empty intestines.

Weight (g) Dry pellets Wet pellets carcass 1755a 1773a abdominal fat 47.3a 40.3a intestine 176.7a 148.3b full intestine 133.6a 113.1b

empty

Carcass analysis

No obvious differences in carcass composition due to dietary treatment were apparent.

SET D FEEDING WET DIET TO BROILER CHICKENS FROM HATCHING Methods Ninety day old male broiler chicks were divided into 15 groups (6 chicks each) and allocated to 5 treatments (TRT1 , TRT2, TRT3, TRT4, TRT5) , replicated three times. TRT1 birds were fed dry feed (Dalgety broiler starter) throughout; TRT2 was provided with wet food (2kg water/kg feed) immediately after arrival but proceeded to climb into the feeders and cake their down with wet feed so dry feed was offered; when the switch to wet feed was made at 3 days there were no problems. The other three treatments were switched from dry to wet feeds at 7, 11 and 15 days, respectively, and the experiment finished when the birds were 19 days of age. Wet food was prepared 2 or 3 times a day and given to the birds without soaking. The feed absorbed all the water immediately, so there was no water separation from the diet at any time.

Results

The results are shown in Table 9. It will be seen that there was an increase in weight gain during the three days after starting wet feeding and that this advantage was maintained for the rest of the experiment. At 19 days the birds which had been on wet feed since 3 days and 7 days were significantly heavier than controls, the 3-day birds being 15% heavier than those fed on dry feed and the gain from 3 days was greater by 17.5%.

Feed intake (expressed as air-dry feed) was not significantly affected by treatment but tended to be higher with the wet feeds, particularly at the end of the experiment. Feed efficiency was improved in almost every case once wet feeding had been introduced, but in no case was this statistically significant, because each mean is based on only three observations in view of the group feeding used in the experiment. Over the whole period of the experiment the improvement was 13%, comparing dry-fed controls with those on wet feed from 3 days of age. The other groups were intermediate in efficiency. Expressed as weight of feed per unit of weight gain the value for dry feeding is 1.52 while that for wet feeding from 3 days is 1.34.

Carcass weight was significantly increased by feeding wet diets, the increase for chicks on wet feed from 3 days being 20% greater than dry—fed controls. The significant increase in body weight and carcass weight was not reflected in abdominal fat which was similar for all treatments at 19 days of age.

TRT1 TRT2 ED Dry from 3d Body weight (g/bird)

3 days 77* 78*

7 days 167^b 181*

11 days 293^b 323*

15 days 457^b 510^a

19 days 637^c 736¹

Food intake (g DM/bird/d)

7 days 27* 28*

11 days 43¹ 43*

15 days 64* 64*

19 days 78* 86*

Total food intake (g DM/bird)

3-19 848* 884* 889* 862* 884* 6.9 days

Feed efficiency (g gain/g feed)

7 days 0.800* 0.09

11 days 0.754* 0.05

15 days 0.623* 0.05

19 days 0.644* 0.08

3-19

0.677* 0.03 days

Carcass weight (g/bird)

19 days 422^b 508* 492* 489' 483* 20.3

Abdominal fat (g/bird)

19 days 5.0* 5.7* 5.7* 5.1* 5.5* 1.4

Means in the same row at the same age with different letters are significantly different (p<0.05) .TRT3 = birds fed wet food

(2000g/kg) added water from 7-19 days. SET E

Period of Soaking

Materials and Methods

Thirty two, 25-day old Mayfield male broiler chicks were divided into 4 groups (8 chicks each) with the same mean body weight. They were kept in individual cages, eight on each of the following treatments, until 40 days of age: DRY was fed Dalgety grower food in the air-dry form, SOAK0, SOAK12 and SOAK24 were fed the same grower diet with the addition of 1600 g water/ kg of air dried food. For SOAK0 the food was mixed with the water and offered immediately after mixing, for S0AK12 the food was mixed and kept for 12 hours before feeding, while for SOAK24 the food was mixed and kept for 24 hours before feeding.

Food intake was measured daily while body weight was recorded at 25, 30, 37 and 40 days of age. Excreta were collected for a four-day period for the estimation of DM digestibility. All the birds were killed at 40 days of age or the measurement of carcass and abdominal fat weight.

Results

The results are shown in Table 10. After five days of the experiment the increase in body weight for the chick in SOAK0 and SOAK12 were significantly greater than those in DRY. SOAK0 gained 204 gm more than DRY in this period. However, at 40 days of age all the chicks fed wet food were significantly heavier than those fed air dry food. Total body weight gain was increased dramatically for those in SOAK0 (43%), while those on S0AK12 and SOAK24 were increased by 18 and 22% respectively. The increase in body weight for the chicks fed wet food was proportionately greater than the increase in food intake ie improved food conversion efficiency.

Total food intake for SOAK0 was increased significantly from those in DRY and SOAK24 by 18.7 and 12%. Carcass weight was increased in parallel with body weight, but there was no difference in the deposition of abdominal fat. Table 10. Effect of length of soaking time of feed on the performance of male broiler chicks.

Body weight (g)

25 days

30 days

37 days

40 days

Total gain (g)

25-40 days 1114^C 1595* 1314^b 1358^b 80.6

Food intake (g/bird/d)

25 days 104* 107* 103* 104* 4.2

30 days 117^b 149* 146* 130* 8.9

37 days 148^c 175* 161 157* 5.3

40 days 147^c 190* 169^b 156^b 7.9

Total food intake (g/bird/d)

25-40 days 2268^c 2661* 2513^Λ 2378^bc 83.0

Carcass weight (g)

40 days 1438^b 1815* 1598*¹⁵ Λ691'^b 74.7

Abdominal fat weight (g)

40 days 28.7* 28.9* 25.0* 27.0* 3.8

Food efficiency (g gain/g food)

25-40 days 0.49* 0.60* 0.52' 0.57^b 0.02

Food conversion (g food/g gain)

25-40 days 2.00* 1.67^b 1.69* 1.74^b 0.1

Digestibility 67.7^b 71.4* 66.4^b 68.6^th 2.1

Means in the same row at the same age with different letters are significantly different (p<0.05).

SED = standard error of difference between means

The experiments of sets B and C described above showed reductions in feed intake and little difference in body weight gain, carcass weight or carcass composition. Efficiency of conversion in Set B was significantly improved from 1.79 with dry feed to 1.69 with the wet pellets and 1.66 with the wet mash. Although in Set C the conversion ratios were not significantly affected by treatment they improved to a similar extent to those in Set B and it is not believed that there were real differences in the effects of giving wet feeds between the two sets.

For the first few days intake of wet feed was low and growth retarded. Once the rate of addition of water had been reduced to give the same sort of "porridge" consistency as previously used these problems disappeared. It is well known that compensatory growth occurs after a period of restricted feeding and it must be considered that the improved efficiency during the remainder of the experiment was due to that phenomenon. However, the period of restriction was only of a few days duration and did not, in Set B, grossly reduce intake. Even by day 26 there was no suggestion of differences in body weight (Table 2). In Set C the birds were reallocated to treatments when the water content of the wet feeds was reduced so that any tendency for compensatory growth was spread evenly across all treatments. The improvement in efficiency observed in the wet feed treatments was not due to compensatory growth.

The results of Sets B and C are different from those of previous experiments which showed increased weight gains, carcass weights and feed intakes, still with improved efficiency. An explanation may be the poor quality of the feed previously used which had a dry matter (DM) digestibility of only 65%, improved to 73% by being fed in the wet form. Growth was limited by diet quality; when the latter was improved by wetting, growth was faster. With the Dalgety feed used in Sets B and C diet quality was not thought to limit growth even when fed dry; the birds were growing at their maximum potential rate so that the improvement in nutritive value presumed to be given by wetting resulted in reduced feed intake, not increased growth. The net result in all cases is improved efficiency. It is well established that broilers performed extremely well in Set B, where many birds were kept in one pen,,whereas it is well known that the individual caging used in Set C reduces growth below maximum. The performance of the birds in Set C was inferior to that in Set B and this poor growth rate was not improved by wetting the feed. This result suggested that diet quality was not the limiting factor.

Using the results from Set B, to achieve almost exactly the same carcass weights the wetting of pellets saved 206g of air-dry feed per bird while the wet mash saved 292g, compared with the same pelleted feed fed dry in the conventional manner. There is also a further saving due to avoidance of the need to pellet the feed and the possibility that a small reduction could be made in the protein content of the formulation as there will be no denaturation during pelleting.

The above experiments were carried out on three types of dry feed,one of Bradshaws Feed and two of Dalgety's. It is to be understood that the optimum amount of water which should be added to a dry feed depends on the brand of dry feed being used, and also on the batch of that particular dry feed. Every batch of dry feed produced by a manufacturer, will vary in its constituents. This means that the optimum amount of water to be added will also vary.

In general, as mentioned above the correct consistency for a wet feed according to the invention will be one of a wet mash or "porridge" consistency. If too much water is added to the dry feed, a layer of water will be formed above the dry feed. This is to be avoided, as the birds feeding from the feed are put off by having to dip their beaks into a layer of water.

The wet feed according to the invention may be used raw, or alternatively, the wet feed may be cooked before being given to the poultry. This improves the digestibility of the feed.

The use of the letters 'a' or 'b' after numbers in a row of a table signifies whether a number in a row differs significantly from the other numbers in that row.

A number differing from the other numbers in a row could appear with, for example, the letter 'a' after it, whilst the other two numbers would have a 'b' after them.

The abbreviation 'sed' represents standard error deviation.

Conversion ratio is defined as the ratio of the weight of food eaten by a bird, to the weight of the bird. Efficiency is defined as the reciprocal of the conversion ratio.

SET F

The following example illustrates application of the invention on a larger scale.

19,000 day-old Cobb chicks were housed in two sheds (9,500 chicks each). Each shed was divided into two equal parts containing 4750 chicks. All the chicks were fed Dalgety starter until 8 days of age. From day 8 chicks in the far end of both sheds were fed Dalgety grower pellets and the near end were fed tthe same grower diet mixed with 1800 g water/kg air dry food. Body weight was measured at 2, 8, 17, 23, 30, 38 and 45 days of age by weighing 100 chicks individually from each end of both sheds. At slaughter 12 samples from each group were taken for the determination of abdominal liver and gut weight.

The following results were obtained.

Wet Feed Total food intake (kg/bird) 4.55 Total average weight gain (kg/bird 2.29 Average food conversion ratio 1.99

There was a significantly greater gain in body weight for wet fed birds in both sheds. This shows that the invention can be used for large scale rearing of poultry. Birds and feeds as used above wre used to measure digestability which for the dry food was 64.9% while for food soaked up to 1 hour it was 70.2% and for food soaked for up to 8 hours it ws 70.6%. This is further evidence of a major effect of wet feeding on the availability of nutrients from the food.

PREFERRED FEEDS (A) FEED COMPOSITION

Good biological results from the invention can be obtained if the poultry dry feed is one of medium to high nutrient density as described in terms of its energy (as measured by Metabolizable Energy(ME) in MJ/kg) and protein (Crude Protein %). a) Nutrient Content

For the different classes of poultry, the major nutrient composition in minimum terms, given such medium to high nutrient density dry feed requirements of preferred feeds is described below:—

Ma or Nutrient Composition

0.7 0.11 0.7 0.11 0.65 0.11 0.65 0.11

Good results may be obtained in use of this invention if the Modulus of Fineness of any meals and/or mash dry feeds lies between the value of 3 and 6. The Modulus Fineness is a measure of the particle size distribution of the dry feed derived through a sieve test as follows:-

MODULUS OF FINENESS ht on Sieve (%) W1 W1 + W2

W1 + W2 + W3

W1 + W2 + W3 + W4

W1 + W2 + W3 + W4 + W5

W1 + W2 + W3 + W4 + W5 + W6

Modulus of Fineness = 6W1 + 5W2 + 4W3 + 3W4 + 2W5 + 1W6

100

With pelleted feeds, good results are obtained for products manufactured in a press with a die of 0.50 mm to 4.00 mm bore. Such pelleted feeds may either be mixed with water in their original form or after due processing in a standard crumbed or ground physical state.

1. Where Crude Protein (%) as (a) below.

2. ME(MJ)/kg) = 0.1551 x % Crude Protein(a) + 0.3431 x % oil(b) + 0.1669 x % Starch(c) + 0.1301 x % total Sugar (expressed as sucrose) (d). (a) determined by method 4 of the methods of analysis specified in Schedule 2 of the United Kingdom Feeding Stuffs (Sampling and Analysis) Regulations 1982 (S I 1982/1144, amended by S I 1984/52 and 1985/1119).

(b) Determined by procedure B of method 3 of methods of analysis specified in Schedule 2 of the United Kingdom Feeding Stuffs (Sampling and Analysis) Regulations 1982. (The relevant amending statutory instrument is S I 1985/1119).

NB It is preferred that the pre-extraction of oil prior to acid hydrolysis is always carried out on compound feed.

(c) Determined by method 30a (Polarimetric Method) of the methods of analysis specified in Schedule 2 of the United Kingdom Feeding Stuffs (Sampling and Analysis) Regulations 1982.

(d) Determined by method 10a of the methods of analysis specified in Schedule 2 of the United Kingdom Feeding Stuffs (Sampling and Analysis) Regulations 1982. b) Raw Material Content

The raw materials which can be used to provide medium and high nutrient density dry feeds best suited to the invention can be selected from:

A combination of cereals, cereal by-products, food industry by—products, vegetable proteins, other plant proteins, marine proteins, animal proteins, minerals, vitamins, animal fats, vegetable fats, other plant fats and synthetic amino acids.

Bacteriocides and mould inhibitors as well as other preservatives, licensed colorant and antibiotic or chemical growth promoters and medicinal products may be added to the dry feed.

The invention allows raw materials and/or micro ingredients and/or medicinal and non-medicinal additives routinely added to poultry diets, and which are water soluble or can be rendered so through processing, to be excluded from the dry feed and be added through the water phase.

Claims

1. An intensive poultry husbandry wet feed including dry feed and between more than 75% to 250% by weight of water.

2. Intensive poultry husbandry feed as claimed in Claim 1 including 80 to 250% water.

3. Intensive poultry husbandry feed as claimed in Claim 2 including 100 to 250% water.

4. Intensive poultry husbandry feed as claimed in Claim 3 including 125 to 225% water.

5. Intensive poultry husbandry feed as claimed in Claim 4 including 150 to 200% water.

6. Intensive poultry husbandry feed as claimed in any preceding claim including additives or other nutrients dissolved in the water.

7. Intensive poultry husbandry feed as claimed in any preceding claim incorporating a thickening agent.

8. Intensive poultry husbandry feed as claimed in any preceding claim wherein the mixed dry feed and water has been cooked.

9. Use of a wet feed in accordance with any preceding claim for intensive poultry husbandry.

10. Use of a wet feed in accordance with claim 9, for intensive chick husbandry.

11. Use of a wet feed as claimed in claim 9 or 10 wherein additives or other nutrients are dissolved in the water prior to mixing with the dry feed.

12. Intensive poultry husbandry apparatus including: a mixing vessel; a store for storage of dried feed; a supply of water; means for mixing predetermined amounts of dried feed and water in said mixing vessel; and distribution means arranged to deliver the mixture of dried feed and water to the poultry.

13. Apparatus as claimed in claim 12 further including a supply of additives and means adapted to deliver a predetermined quantity of the additives to the mixing vessel.

14. Apparatus as claimed in claims 12 or 13 including means for heating the supply of water.