Requirement of the hen for sulphur‐containing amino acids

1. The sulphur amino acid requirements of White Leghorn‐type laying hens were determined in two 52‐week experiments using diets based on maize and soyabean meal providing from 5.0 to 6.5 g sulphur amino acids/kg, 12.35 MJ ME/kg and 8.6 to 8.8 g lysine/kg. There were six replicates of 15 individually‐caged hens each per treatment.

2. A requirement of approximately 775 to 800 mg sulphur amino acids /hen d, of which about 390 to 440 mg was methionine, was found for a maximum of 80 to 83 eggs/100 hen d. There were indications that the requirement for maximum egg production was less than that for maximum efficiency of food utilisation.

3. Diets containing 138 g protein/kg supplemented with methionine and lysine supported production and food utilisation as effectively as a diet containing 167 g protein/kg.     

Dietary factors affecting the utilisation of protein by laying hens and their effects on the concentrations of certain nitrogenous constituents in the excreta

New techniques involving extraction with organic solvents and lithium carbonate solution have been used to fractionate nitrogenous components of the excreta from laying hens fed diets in which the supplementary protein was groundnut meal, poor‐quality fish meal or good‐quality fish meal. The effect of adding methionine or lysine or both to the groundnut diet was also studied.

The proportion of ingested nitrogen excreted as uric acid or urate was significantly higher when the dietary protein supplement was groundnut meal than when it was good‐quality fish meal or groundnut meal supplemented with both lysine and methionine. Nitrogen retention, egg production and the apparent digestibility of nitrogen were higher on diets containing good‐quality fish meal than on diets containing groundnut meal alone. Intermediate effects were obtained when feeding diets supplemented with poor‐quality fish meal of groundnut meal containing either lysine or methionine. The implications of these findings are discussed. The main differences in protein utilisation associated with variations in dietary protein quality were reflected in the proportions of ingested nitrogen excreted as urates and as protein. Other nitrogenous components of excreta examined showed little variation with dietary protein quality. Benefits derived from the addition of methionine and lysine to the groundnut diet were obtained mainly by a more efficient use of absorbed amino acids.     

Hydrolysed feather protein as a source of amino acids for laying hens

1. The value of hydrolysed feather protein (HFM), included at 70 g/kg in a wheat‐based diet, as an amino acid source for laying hens was determined.

2. Egg production was reduced in hens fed on diets containing HFM owing to a deficiency in lysine, methionine and tryptophan.

3. Supplementation of the diet containing HFM with 3'0 g lysine (as L‐lysine HC1), 0.7g DL‐methionine and 0.5g L‐tryptophan per kilogram, resulted in a daily egg mass output similar to that achieved with a conventional layers’ diet.     

The nutritive value of field beans (Vicia faba L.) for laying hens 1

In experiments carried out in three successive years an assessment has been made of the feeding value of field beans (Vicia faba L.) as a protein supplement in laying rations. When 15% beans were fed in a cereal‐based diet without methionine fortification, egg production was depressed significantly below that attainable with a diet containing fish meal as a protein supplement. When 0.1 % DL‐methionine was added to the diet, production was raised significantly to a level which in most cases was not significantly different from that supported by the fish meal diet. Whether or not methionine was added to the diets, the inclusion of bean meal at levels of 25 to 33% gave rise to lower egg production than did a level of 15%. Culling losses during the experiments tended to be higher on the bean diets.

It is concluded that field beans supplemented with methionine can be a useful source of dietary protein for laying hens but the rate of inclusion should not exceed 15% until more is known of factors which cause lowered production at higher levels.     

Sulphur amino acid requirement of laying hens and the effects of excess dietary methionine on laying performance

1. Individually‐caged laying hens were fed on maize‐soya bean meal diets containing 11.50 or 12.35 MJ ME/kg with sulphur amino acid (SAA) contents varying from 5.0 to 7.0 g/kg in period 1 (0 to 20 weeks); from 5.0 to 8.0 g/kg in period 2 (21 to 36 weeks) and from 5.0 to 10.0 g/kg in period 3 (37 to 52 weeks).

2. A SAA requirement of about 750 mg/hen d, of which about 425 mg was methionine, was found to be adequate for birds producing on average 51 g egg mass per hen d over 52 weeks. The SAA requirement was found to be higher for maximum efficiency of food utilisation than for maximum egg yield.

3. A diet containing 140 g protein/kg adequately supplemented with methionine and lysine, could sustain laying performance almost identical to that achieved on a diet containing 167 g protein/kg.

4. In diets with 140 g protein/kg the addition of 0.5 to 3.5 g dl‐methionine/kg diet in excess of the requirement did not affect egg production adversely, but food conversion efficiency was decreased.     

Effect of feeding clinoptilolite (zeolite) on the performance of three strains of laying hens

1. One hundred and twenty 16‐week‐old single combed pullets of three strains were fed on a diet containing 135 g protein/kg with or without 50 g clinoptilolite/kg in a trial with 20 hens per treatment. Sterile river sand replaced clinoptilolite in the control diet in order to keep the diets isoenergetic. The hens were individually caged in a naturally ventilated laying house and fed one of the two diets for ten 28‐d periods.

2. Significant dietary effects of feeding clinoptilolite were observed with number of eggs laid per hen, shell thickness, efficiency of food utilisation and droppings moisture content. No significant dietary effects between treatments were observed with body weight, age at first egg, egg weight, Haugh units, food intake/hen and rate of amino acid absorption of radioactive lysine and methionine into the bloodstream. Significant differences between strains were observed with regard to all parameters except food intake/hen. There were no significant strain × clinoptilolite interactions.     

Effect of soybean meal substitution by different concentrations of sunflower meal on egg quality traits of white and coloured dwarf dam lines

1. The effect of soybean meal substitution by different concentrations of sunflower meal on egg quality traits of white and coloured dwarf dam lines was investigated.

2. A total of 144 dwarf hens (38 weeks of age) from the same hatch were randomly divided into 12 groups of 12 birds (4 dietary treatments × 3 replicates).

3. A 2 × 4 factorial design was used to study the effect of 2 lines (Factor A) and substitution of soybean meal (SBM) with 4 concentrations (0, 10, 15 and 20%) of sunflower meal (SFM) [Factor B] on egg quality traits of dwarf dam line hens.

4. All the diets were designed to be isocaloric (11?3 MJ ME/kg) and isonitrogenous (180 g/kg crude protein) The duration of the experiment was 12 weeks.

5. Analysis of variance indicated a highly significant line effect. There were non-significant effects of substitution of soybean meal with different concentrations of sunflower meal on egg quality traits except for Haugh unit.

6. White plumaged dwarf broiler breeder dam line produced significantly fewer, but larger, eggs than coloured dwarf dam line hens.     

Studies on the effect of lysine and methionine supplementation of a high‐protein maize‐soyabean diet and of a low‐protein barley‐white fish meal diet on the performance of caged layers

Selected literature relating to the amino acid supplementation of layers’ diets is reviewed and the results of two experiments are presented.

In the first experiment a basal soyabean meal diet (14.3 per cent crude protein) was supplemented with L‐lysine and DL‐methionine, singly and together. Supplementation of the basal soyabean diet with the amino acids caused no significant effects on egg production, mean and total egg weight or food conversion efficiency. None of the soyabean diets proved as satisfactory for egg production or food conversion efficiency as a fish meal control diet (16.9 per cent crude protein).

In the second experiment the effect of adding 0.1 per cent each of L‐lysine and DL‐methionine or 0.2 per cent each of l‐lysine and DL‐methionine to a low fish meal diet (2.5 per cent fish meal) was examined. The addition of 0.2 per cent of each amino acid caused an increase in egg production.

Mean egg weight was improved by the addition of amino acids at both levels although this effect was not statistically significant. Comparison of the low fish meal diets with a fishmeal control diet (10 per cent fishmeal) showed that at the 0.2 per cent addition of amino acids, egg production, total egg weight and food conversion efficiency were better than on the 10 per cent fish meal control diet.

Two breeds, light and medium hybrids were used in both experiments.

The results are discussed with reference to their practical significance.     

Comparison of laying rations with and without animal protein at the Canadian Random Sample Egg Production Test

For a number of years, the laying ration fed to the hens at the Canadian Random Sample Egg Production Test has contained foodstuffs of animal origin to the extent of 3 per cent meat meal, 2 per cent fish meal, 1 per cent dried whey and 2 per cent tallow. Recently, over a period of 2 years, this ration was compared with a modification in which all of the animal products except tallow were removed. The proportions of the remaining ingredients in the modified diet were adjusted to keep protein, energy, calcium and phosphorus levels comparable in the two rations.

In the first test year, the modified diet was slightly superior to the control diet in terms of egg numbers, egg weight and egg quality. In the second year, there were no significant differences in these traits between diets. Although 17 strains were tested in the first year, and 14 in the second, no significant strain × ration interactions occurred in any performance trait.

These trials provided no evidence that the laying hen responds to unknown factors contained in animal products. There was also no evidence that the removal of animal products adversely affected protein quality, although dietary protein levels may not have been low enough to reveal such a change.     

Comparison of a 19.7%‐protein wheat (triticum aestivum L), three 13.5%‐protein wheats,and corn (zea mays) in broiler diets with different protein and lysine contents

An experiment using broiler chicks up to 3 weeks of age was conducted to examine the use of corn (Zea mays), Glenlea, Pitic 62, 13.5%‐protein Neepawa and 19.7%‐protein Neepawa wheats (Triticum aestivum L) as ingredients in broiler diets. Two dietary protein contents (calculated as 18.5 and 23.0%) with and without supplementary lysine (0.3%) were used in the diets containing each of the five grains. The desired dietary protein contents were obtained by varying the proportions of the grains and soybean meal.

Grain, dietary protein and added dietary lysine significantly affected body weights and efficiencies of food conversion.

Significant first‐order interactions between grain x protein, grain x lysine and protein x lysine were found for both body weights and efficiencies of food conversion and resulted mainly from responses obtained with the 19.7%‐protein Neepawa wheat supplemented with lysine when compared with the responses obtained to the other grains. When substituted into the higher‐protein diet, supplemented with lysine, the 19.7%‐protein Neepawa wheat supported a similar performance in chicks to other grains fed under similar conditions.     

The nutritional value of algae for poultry. Dried chlorella in layer diets

1. The nutritional value of a sample of algae meal, mainly Chlorella, was assessed in an experiment with laying hens. The algae meal was that described by Lipstein and Hurwitz (1980).

2. Diets formulated by linear programming contained up to 120 g algae meal/kg with supplementary DL‐methionine.

3. There were no significant effects of dietary algae meal on egg output, food conversion or egg‐shell quality. Thus algae meal at the concentrations tested can be a useful substitute for soyabean meal in diets for laying hens.

4. High concentrations of dietary algae meal caused a deep yellow yolk colour of acceptable appearance.     

The necessity of supplementing laying hen diets with linoleic acid

Results from four experiments with laying hens have been re‐examined using the means of individual 28‐d periods during egg production to investigate the influence of the developing ovary and linoleate storage during growth on the linoleic acid requirement of the laying hen.

Apart from a possible beneficial effect during the first few weeks of production, little increase in egg weight occurs when birds are fed on conventional rearing diets and then fed on laying diets containing linoleic acid in excess of requirement.

After depletion of linoleate reserves, dietary supplementation with linoleic acid significantly increases egg weight at any age.

The necessity of supplementing diets for laying hens with linoleic acid is discussed.     

Comparisons of sorghum grain (milo) and maize as the principal cereal grain source in poultry rations. 3. The supplementation of milo layer diets with fish meal and acidulated soapstock

Two trials were performed in order to determine the effect of all‐vegetable milo diets on layer performance, and in an attempt to pinpoint possible deficiencies in milo grain. The diets were supplemented with acidulated soya soapstock, fish meal and/or methionine.

Under the conditions of this study, the only consistent and significant effect due to the source of cereal grains was the reduction of egg size due to milo. Fish meal supplementation of milo diets almost, or completely, equalised egg weights, and some beneficial effects were also obtained from added methionine and soapstock.

The linoleic acid content of maize is decidedly higher than that of milo, a difference which is reflected in the fatty acid composition of the respective diets, and which causes corresponding changes in the fatty acid pattern of the yolk lipids of eggs produced by hens fed these diets. Soya soapstock added to milo diets tended to equalise the yolk fatty acid pattern obtained with milo and maize diets.

It is suggested that in milo‐soya diets methionine is the first limiting factor, and that linoleic acid is the next limiting factor in increasing egg size, after the first requirement has been met.     

Behavioural adaptation of laying hens to dilution of diets under mash and pellet form

1. Two laying diets, control (A) and a low‐energy (B) diet diluted by adding 450 g/kg wheat bran, were fed to semi‐heavy hens in three different forms: mash, small pellets and large pellets. The behavioural adaptations and the production characteristics for these six regimens were studied on 72 individually caged hens, between 19 and 29 weeks of age, subjected to a lighting pattern of 14 h light/24 h.

2. Diet B, as mash, showed a lower apparent physical density than the others. The hardness and durability of the pelleted diets were similar.

3. Hens fed the mash diet B could not completely adjust their food intake to compensate for the dilution and showed reduced egg output and body weight gain compared to the other groups.

4. Video observation of each hen for 14 consecutive hours showed that mash‐fed hens ate for longer periods than pellet‐fed hens during the first 11 h (proportion of time spent eating: 41.3% mash B, 32.5% mash A and 20% to 25% for all the pelleted diets). These differences were less pronounced during the last 3 h of the photoperiod.

5. Trough‐oriented stereotypies were noted in 14 out of 22 mash‐fed hens and in 12 out of 47 pellet‐fed hens. Dilution of the diet did not appear to exacerbate stereotyped behaviours under the conditions of the study.

6. This experiment demonstrates that the feeding behaviour of laying hens is affected by the physical characteristics of the diet and that this may lower their productivity.

7. Low‐energy pelleted diets might be used to feed hens efficiently in tropical countries where cereal by‐products are abundant.     

Effect of enzyme preparation containing xylanase and beta-glucanase on performance of laying hens fed wheat/barley- or maize/soybean meal-based diets

1. A commercial enzyme preparation (Quatrazyme HP) containing xylanase and beta-glucanase was examined in two laying hen experiments with wheat/barley- or maize-based diets. The activities of other enzymes were measured also. Starch, cell wall contents and effects of Quatrazyme HP on in vitro viscosity of wheat, barley, maize and soybean meal were determined. 2. In the first experiment, 90 ISA Brown laying hens at 28 weeks of age were given a wheat/barley basal diet with or without 20mg of Quatrazyme HP, which provided 560 and 2,800 IU of xylanase and beta-glucanase/kg diet. In the second experiment, 66 ISA Brown laying hens at 45 weeks of age were given a maize/soybean meal basal diet with or without 20 mg of Quatrazyme HP/kg diet for 9 weeks. Egg production, egg weight, egg mass, feed conversion ratio and change in body weight were recorded as response criteria. 3. There was a significant improvement in feed conversion ratio with enzyme supplementation. Birds given an enzyme-supplemented diet gained 86 g while those fed on the unsupplemented diet lost 103 g of their body weight by the end of the experiment. 4. The enzyme preparation did not affect either egg production, egg weight or egg mass of birds fed on the maize/soybean meal diet. However, a significant improvement in feed conversion ratio was detected. Birds on either the supplemented or unsupplemented diet exhibited an increase in their body weight at the end of the experiment. 5. Addition of xylanase and beta-glucanase decreased in vitro viscosity of wheat, barley, maize and soybean meal. This effect was greater for wheat and barley than for maize and soybean meal. 6. It was concluded that the beneficial effect of using an enzyme preparation containing xylanase and beta-glucanase is not limited to wheat/barley-based diets but also occurs with maize/soybean meal-based diets.     

Comparison of wheats of high or conventional protein content with added lysine in diets for layers

1. High‐protein wheats (196 or 210 g/kg) were compared with conventional wheat (163 or 162 g/kg) in layers’ diets in three experiments.

2. In diets of 160 g protein/kg without added lysine, high‐protein wheats caused lower rates of production and egg size than conventional wheats in White Leghorns. Lysine supplementation of the former diets eliminated these differences.

3. The improvements in egg production and egg weight were significant with 1 g additional lysine/kg and egg production tended to improve further with 2 g additional lysine/kg, as did egg weight with all subsequent additions, but not significantly so.

4. With diets containing high‐protein wheats supplemented with lysine, high egg production and egg weight could be obtained without a protein supplement (e.g. soyabean meal).

5. In broiler‐breeders egg production was lower and food conversion poorer with high‐protein wheat despite added lysine.     

Arginine--lysine interrelationships in the nutrition of broiler breeder pullets during the developmental period

Pullets were fed on diets containing various concentrations of lysine and arginine from 7 to 18 or 20 weeks. Thereafter a conventional layers' diet was fed and egg productivity measured—in the first two experiments for ten, and the third for six 28‐d periods. Pullets were also fed on a standard growers' type diet on a “skip‐a‐day” or on a 20% restriction basis in the third study.

Growth and age at sexual maturation were directly related to the lysine content of the diet and to a lesser extent to the arginine content. Pullets fed on diets with the lower concentrations of lysine and arginine required less food during the growing period and matured later than those fed on a complete diet ad libitum. They also laid more eggs and required less food to produce a dozen eggs. Higher egg production was obtained in the third experiment with low concentrations of lysine and arginine than with the “skip‐a‐day” or the restricted feeding programmes. Pullets fed on the normal grower diet ad libitum produced the smallest eggs in the first and third experiments with no difference in egg size in the second experiment. Pullets maintained on the “skip‐a‐day” or the restricted feeding programme also had a larger egg size than the control group fed on the same diet on an ad libitum basis.

An ingredient effect was observed in the third experiment. Of two diets containing identical calculated values of lysine and arginine, the one containing distillers' dried grains with solubles was superior to the one with soybean meal as regards weight at 20 weeks of age, amount of food consumed during the period 6 to 18 weeks of age and percentage egg production. It is possible that the soybean meal contained a better balance of amino acids than did distillers' dried grains with solubles which resulted in a significant increase in body weight at 20 weeks of age and a subsequent lower level of egg production. These data indicate that it would be best to use ingredients with an imbalance of amino acids in the protein as sources of lysine and arginine in pullet grower diets.

There were no differences in the mortality of the birds during the laying period which could be related to dietary treatment during the pullet growing period.     

Intestinal supply of amino acids in sheep fed alkaline hydrogen peroxide-treated wheat straw-based diets supplemented with soybean meal or combinations of corn gluten meal and blood meal

The intestinal supply of amino acids (AA) in sheep fed alkaline hydrogen peroxide-treated wheat straw (AHPWS)-based diets supplemented with soybean meal (SBM) or corn grain plus combinations of corn gluten meal (CGM) and blood meal (BM) was measured in a 5 X 5 latin square. Sheep (avg wt 45 kg) with ruminal, duodenal and ileal cannulas were fed diets containing 65% AHPWS supplemented with the following protein sources: soybean meal (SBM), corn gluten meal (CGM), blood meal (BM), 2/3 CGM:1/3 BM and 1/3 CGM:2/3 BM. Total nitrogen (N) flow at the duodenum was not affected (P greater than .05) by protein source. Flows of bacterial N and AA increased (P less than .05) and flows of nonbacterial N and AA decreased (P less than .05) when wethers were fed SBM vs corn plus other protein sources. When diets contained SBM, quantities of total AA at the duodenum were lower (P less than .05) and the profile of AA supplied to the intestine was altered substantially. Total flows of AA at the duodenum and total quantities of AA disappearing from the small intestine were similar (P greater than .05) for all diets containing BM and CGM, but flows and disappearance of valine, histidine, lysine and arginine increased linearly (P less than .05), whereas flows and disappearance of leucine, isoleucine and methionine decreased linearly (P less than .05) as BM replaced CGM in the diets. Results suggest that quantities of individual AA flowing to the duodenum and disappearing from the intestine of wethers fed AHPWS-based diets can be altered by source of dietary protein. Furthermore, feeding protein sources resistant to ruminal degradation in combination may improve the profile of AA supplied to the intestine.     

Sweet white Lupinus Albus (cv buttercup) as a feedstuff for layers

1. An experiment was conducted with laying hens to determine to what extent sweet white lupins (Lupinus albus, cv Buttercup) could be used as a protein source in their diets.

2. Twenty five individually caged 20 week‐old Hisex laying hens were used per treatment. The hens were housed in a convection house for the duration of the study which lasted 52 weeks. Two diets were formulated, one containing 300 g sweet lupins/kg and the other containing sunflower oil cake and fish meal as protein sources. These diets were blended to obtain seven diets with lupin inclusion rates of 0, 50, 100, 150, 200, 250 and 300 g/k.

3. Results indicated that up to 300 g lupins/kg diet can be fed to Hisex laying hens without a significant effect on egg production, egg mass, efficiency of food utilisation, egg shell thickness, Haugh units or yolk colour. Food intake was however, significantly (P<0.05) positively correlated with lupin inclusion rates.     

The hen's egg: Genetics of taints in eggs from hens fed on rapeseed meal

1. Fishy taints in eggs from hens fed on rapeseed meal, which have been reported to occur in brown‐shelled eggs of some hens with Rhode Island Red ancestry, occur also in white‐shelled eggs of some hens of a strain of Brown Leghorns.

2. Genetic tests have demonstrated that tainting in these circumstances is conditional on the presence in the hen, in the heterozygous or homozygous state, of an autosomal semi‐dominant mutant gene that has variable expression, depending on environmental factors (including the rate of ingestion of rapeseed meal).

3. No simple test for the presence of this gene, applicable to either sex, can be anticipated at present.