Utilisation of dried poultry manure by growing chickens fed on a practical diet

1. Dried poultry manure (DPM) has been tested as a replacement for groundnut cake in poultry diets.

2. Body weight gain, and the efficiency of food conversion were improved when the diet contained 50 g DPM/kg but higher rates of inclusion (100 or 150 g/kg) depressed growth.

3. Birds fed on diets containing 50 g DPM/kg yielded meat of comparable quality to those fed on the control diet whereas those fed on diets containing more DPM yielded meat containing more fat and less water.

4. The percentage moisture in the meat was inversely related to the lipid content.

5. Nitrogen retention was comparable in all groups.     

Replacement of groundnut cake by dried poultry manure in the diets of laying hens

1. The effect on food consumption by pullets when dried poultry manure (DPM) replaced part of dietary groundnut cake depended on the strain of the birds: in two of the three hybrids food consumption was not affected when up to 100 g DPM/kg was fed.

2. Increases in food consumption were accompanied by increases in egg production.

3. The food required per dozen eggs was improved by up to 100 g dietary DPM/kg and variation in the sizes of eggs laid depended on the hybrid.

4. Concentrations of DPM up to 100 g/kg did not affect the water‐soluble nitrogen content of the egg but the crude albumen nitrogen content was depressed at concentrations of 80 g/kg or above.

5. Feeding DPM to laying pullets depressed body weight.     

The effects of dietary calcium concentration on pheasant breeder performance

1. Thirteen pens of breeding pheasants (Phasianus colchicus) were fed ad libitum on diets containing 20, 23 or 27 g calcium/kg.

2. All diets were formulated to contain 10.6 MJ ME/kg.

3. Three pens of birds receiving the diet containing 23 g calcium/kg were also offered grit free choice containing 280 g calcium/kg.

4. There were no effects of treatment on food consumption or reproductive performance.     

Utilisation of leucaena leaf meal by broilers

1. The effect of including Leucaena (Leucaena leucocephala) leaf meal (LLM) in broiler diets was investigated employing LLM at 0, 50, 100, 150 and 200 g/kg diet. Experiments were also conducted to investigate whether reduced food intake of diets containing LLM is responsible for the growth depression.

2. LLM appears to be a good source of protein and calcium.

3. Food intake was not significantly affected (P>0.05) with dietary LLM inclusion up to 200 g/kg.

4. Inclusion of LLM up to 150 g/kg diet did not influence significantly (P>0.05) the performance of broilers in terms of body weight gain and food efficiency. However, inclusion of LLM at 200 g/kg diet had an adverse effect on weight gain and food efficiency, when compared to other dietary treatments. The profitability over food costs was low with the 200 g LLM/kg diet compared to those of other diets.

5. It may be inferred from these experiments that LLM can safely be included in broiler diets up to 150 g/kg.

6. Studies using force‐feeding and restricted feeding techniques indicated that reduced food intake was not responsible for the growth depression in diets containing higher amounts of LLM.     

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.     

The effects on rearing and subsequent laying performance of rearer diets containing two levels of protein and dried poultry manure or urea

1. Six hundred and seventy‐two light‐hybrid pullets aged 6 weeks were allocated to eight experimental treatments and cage‐reared to 18 weeks of age when they were transferred to single‐bird battery cages and fed on a common layer diet.

2. In the 6‐ to 12‐week period four dietary treatments were applied: a diet containing about 160 g crude protein (CP)/kg with or without 50 g dried poultry manure (DPM)/kg (diets 2 and 1 respectively) and a diet containing about 140 g CP/kg with or without 50 g DPM/kg (diets 4 and 3). In the 12‐ to 18‐week period two additional diets were fed: diets 1 and 3 supplemented with 10 g urea/kg (diets 5 and 6 respectively). Diets containing DPM were formulated to utilise the CP, energy, calcium and 50% of the phosphorus content of DPM.

3. Pullets fed on diets 1, 2 and 5 (high‐protein) were significantly heavier at 18 weeks than those fed on diets 3, 4 and 6 (low‐protein). In the laying period total estimated egg weight, food intake and conversion were significantly greater, and the age at first egg was significantly less (2.4 d).

4. Dietary DPM had no significant effect on the 18‐week body weight but food consumption was significantly less and conversion was significantly improved. There were no significant effects on subsequent laying performance. Dietary urea caused no significant effects on rearing or laying performance.     

Comparison of nutritive values of groundnut oil cake and Niger oil cake for laying pullets

1. The nutritive value of Niger oil cake (Guizotia abyssinica, Cass.) as a protein supplement for layers’ diets has been assessed.

2. Replacing groundnut oil cake (GNC) by Niger oil cake (NC) on an isonitrogenous basis, did not affect egg production, egg weight or the amount of food required per dozen eggs.

3. The percentage retention of nitrogen from diets containing 30% GNC or 30% NC was similar.

4. The ME value of NC used was 3025 kcal/kg.

5. It is concluded that NC can replace GNC in layers’ diets.     

The nutritional value of low lathyrogenic Lathyrus (Lathyrus sativus) for growing chicks

1. The feeding value of new low β‐N‐oxalyl‐amino‐L‐alanine (BOAA) lines of Lathyrus sativus (lathyrus) and the benefits of dehulling the seed or of pre‐adapting chicks to lathyrus‐based diets were examined in several experiments.

2. Chicks fed on diets containing 400 g/kg of the low (1.3 g BOAA/kg seed) and medium (2.2 g BOAA/kg seed) BOAA lines did not differ (P>0.05) in weight gain (WG) or in apparent fat and protein digestibilities compared to birds fed on a wheat‐based diet.

3. Consumption of 600 g low BOAA lathyrus/kg diet caused a slight, but significant (P< 0.05), decrease in WG. Food efficiency decreased as the amount of dietary lathyrus was increased, suggesting that lathyrus may contain an antinutritive factor(s) other than BOAA.

4. Removal of the hull (70 g hull/kg seed) from the seed did not affect chick performance (P> 0.05).

5. Pre‐adapting chicks for 7 d to diets containing up to 600 g medium line lathyrus/kg diet did not reduce the detrimental effects of the lathyrus.

6. Although dehulling and pre‐adaptation of chicks to lathyrus were not beneficial, the low and medium lines of lathyrus tested show potential for use in chick diets up to at least 400 g lathyrus/kg diet.     

Rapeseed meals in broiler diets: Effect on performance and sensory evaluation of carcasses

1. The effect of including rapeseed meal (RSM) in lieu of soyabean meal in broiler diets was determined.

2. Live‐weight gains, from 8 to 63 d, were depressed when the diet contained 150 g RSM/kg and there was a highly significant negative correlation between weight gain and inclusion rate of RSM over this period.

3. The efficiency of food utilisation was worse when the diet included 150 g solvent RSM/kg than when it contained no RSM: food efficiency was consistently poorer whenever RSM was included in the diet but the difference was significant only when the diet contained 10 g tallow/kg.

4. Carcasses from birds fed on diets containing 10 g tallow/kg had a better appearance than those from birds on diets containing 30 g tallow/kg, while the flavour of meat from birds fed on a diet containing 150 g solvent RSM/kg treatment was adversely affected. However, up to 100 g solvent RSM/kg may be included in broiler diets without affecting appearance, taste, texture or acceptability of the meat.

5. Inclusion of 50 g or more, solvent RSM/kg reduced growth rate and worsened food efficiency.     

Diets for growing pullets containing unusual ingredients and varying concentrations of cereals,including no cereals

1. Growing pullets (Shaver 288) were fed on diets containing about 150 or 100 g protein/kg and 800, 600, 300 or 0 g of a mixture of equal parts of wheat and barley, from 12 to 20 weeks of age.

2. Varying mixtures of dried poultry manure, dried grass, dried potato meal, poultry offal meal and tallow were substituted for the cereal portion, so that calculated metabolisable energy values and methionine and lysine concentrations were constant within each protein series.

3. Within the 150 g protein/kg series, body weight at 20 weeks of age was similar for diets containing 800, 600 and 300 g/kg cereal whereas with the cereal‐free diet body weight was depressed by 10%; with the latter diet sexual maturity was also delayed by nearly 4 d though subsequent egg production was unimpaired.

4. Within the 100 g protein/kg series, body weight at 20 weeks of age and subsequent egg production, calculated either to a fixed age or for a given time spent laying, were depressed by diets containing 300 or 0 g cereal/kg, compared with diets containing 800 or 600 g/kg.

5. Dietary concentrations of dried poultry manure up to 250 g/kg had no effect on mortality.     

Hydrolysed feather protein as a source of amino acids for broilers

1. The inclusion of 25 g hydrolysed feather meal (HFM) in each kilogram of diet (floor experiment) and 60 g/kg (cage experiment) did not depress performance.

2. Chemical tests indicated 72.5% of the total lysine in HFM was available.

3. Total lysine concentration of 11.3 g/kg diet maximised performance during the period 0 to 34 d.

4. Reduction in dietary methionine content during the period 0 to 34 d from 4.2 g/kg to 3.2 g/kg did not depress performance on diets containing 60 g HFM/kg.

5. The results indicate that at least 57% by weight of the total sulphur amino acid requirement of broilers can be provided by cystine.     

Replacement value of blue‐green alga (spirulina platensis) for fishmeal and a vitamin‐mineral premix for broiler chicks

1. The effect of sun‐dried Spirulina platensis in poultry diets was studied in a 12‐week feeding trial by replacing either fishmeal (FM) or groundnut cake (GC) in a commercial diet with algae at isonitrogenous concentrations of 140 g/kg and 170 g/kg respectively. Additional vitamins/ minerals were omitted from the algal diets because Spirulina is rich in them.

2. Efficiency of food utilisation, protein efficiency ratio and dressing percentage indicated that substitution of FM or GC by alga did not affect the performance of broilers.

3. None of the diets affected the weights, compositions and histopathology of the various organs of the chicks.

4. Meat quality remained unchanged except for a more intense colour in the case of birds fed on the alga‐containing diets.     

Voluntary food restriction by laying hens mediated through dietary self‐selection

1. Individually caged Single Comb White Leghorn hens simultaneously received two diets which allowed selection of certain nutrients: these “ split‐diets “, essentially provided concentrated sources of either protein and energy (191 g crude protein, 12.82 MJ ME and 4.7 g Ca/kg diet), or calcium (107 g CP, 7.28 MJ ME and 131 g Ca/kg).

2. During four, 28‐d periods of lay, birds offered these split‐diets consumed some 7% less food in total than did control birds receiving a conventional diet ad libitum.

3. Calculation of nutrient intakes showed that birds on the split‐diets consumed significantly less protein, energy and calcium than the control birds.

4. Giving split‐diets also resulted in superior shell quality; treatment differences were also noted in the timing of oviposition.

5. It is suggested that the voluntary reduction in food intake noted for birds offered split‐diets is associated with an appetite for calcium.     

The response of egg weight to the inclusion of different amounts of vegetable oil and linoleic acid in the diet of laying hens

1. Four diets containing different amounts of vegetable oil and linoleic acid were fed to White Leghorn hens throughout a full laying year.

2. Egg weight was poor with the low fat basal diet but increased in relation to the amounts of maize oil (4 and 30 g/kg) included in the diet.

3. With a diet containing 30 g olive oil/kg, egg weight was similar to that obtained with the diet containing the same amount of maize oil.

4. Rearing the birds on diets containing low or moderate amounts of linoleic acid did not affect the response to fatty acid content of the layer's diet.

5. It is concluded that the requirement of the laying hen for linoleic add is not higher than 9 g/kg but that egg weight does respond to higher dietary amounts of readily absorbable fatty acids.     

Performance of laying hens fed on low sulphur amino acids diets supplemented with choline and methionine

1. Two experiments were carried out to examine the possibility of replacing a part of the methionine content with choline in a layers’ diet.

2. In the first a low methionine diet with 2.6 g methionine/kg was supplemented with 0.3, 0.6, 0.9 and 1.2 g DL‐methionine/kg. Choline at 1.12 g/kg was added to the diets, which contained 5.4, 6.0 and 6.6 g TSAA.

3. In the second diets with 3.02, 3.80, 4.53, 5.30, 6.04 and 6.51 g TSAA/kg were used and 0.94 g choline/kg was added to these diets.

4. Supplemental methionine increased egg production but not egg weight in the first experiment. When the low TSAA diet was supplemented with choline, egg output increased slightly but not significantly.

5. When supplemental methionine was added to the low protein and TSAA diets in experiment 2 it increased egg production and egg weight. Added choline did not increase egg production or egg weight, even with the diet very low in protein and TSAA. Body weight gain, food intake and feed conversion efficiency of food utilisation were improved by supplemental methionine but not choline.     

Effect of dietary levels of rapeseed meal and polyethylene glycol on the performance of male broiler chickens

1. In a 5 × 2 factorial experiment, the performance of male broiler chickens given starter (1 to 21 d) and finisher (21 to 42 d) diets containing five concentrations (0, 74.5, 149.0, 223.5 and 298.0 g/kg) of rapeseed meal (RSM) and two concentrations (0 and 15 g/kg) of polyethylene glycol (PEG) was measured.

2. Bodyweight gain and food intake decreased (P<0.01) with increasing dietary RSM both in the starter and finisher phases.

3. The relative weights of thyroid glands, liver, heart and the ratio of water to food intake increased (P<0.01) while the dressing percentage, abdominal fat‐pad weight and the feather condition score decreased (P<0.01) with increasing dietary RSM.

4. The mortality rate was increased (P<0.05) on diets containing 149 g/kg or more of RSM. The main causes of deaths and culling on the high RSM diets were enlarged livers and hearts, liver haemorrhage and leg disorders.

5. The inclusion of 15 g/kg PEG in the starter diets increased (P<0.01) bodyweight gains and food intake. It also increased (P<0.05) water consumption between 37–39 d, faecal moisture content at 40 d and the haemoglobin content in blood.

6. There were no interactions between the dietary concentrations of RSM and PEG on growth and other variables measured.     

Effects of nutrient concentration and dietary presentation on performance of dwarf hens

1. Diets containing 170 or 190 g protein/kg and 10.9 or 11.7 MJ ME/kg in all combinations were offered to dwarf hens in two dietary presentations: a complete mash or a form in which part of the protein and calcium contents were presented as soyabean meal pellets and limestone grit respectively.

2. Egg production and egg mass output were higher with the 190 g protein/kg diets.

3. Lower‐energy diets gave better egg production, while higher‐energy diets containing 190 g protein/kg improved food conversion efficiency.

4. Separation of protein and calcium constituents tended to give better egg production, food conversion efficiency, shell thickness and egg mass output.     

The performance of male ducklings given starter diets with different concentrations of energy and protein

1. Male ducklings were fed for 14, 21 or 28 d on diets containing 180, 200, 220 or 240 g of protein and 10.88 or 12.55 MJ of metabolisable energy (ME) per kg, followed by a common finisher diet until 56 d of age.

2. Birds given starter diets with 220 or 240 g of protein per kg were significantly heavier at 14 d than those given diets with 180 or 200 g protein per kg.

3. There was no significant benefit in feeding diets with protein levels greater than 180 g/kg for more than 14 d.

4. Diets with only 10.88 MJ of ME per kg produced significantly lighter birds at 28 and 56 d of age and significantly reduced food conversion efficiency up to 14 d.     

Effect of feed supplementation with Satureja khuzistanica essential oil on performance and physiological parameters of broilers fed on wheat- or maize-based diets

1. The aim of this study was to evaluate various levels of Satureja khuzistanica essential oil (SKEO) on performance and physiological parameters of broilers fed on wheat- or maize-based diets.

2. Treatments consisted of two cereals (maize- or wheat-based diets) and three levels of SKEO)0, 250 and 500 mg/kg).

3. Feed intake (FI) and body weight gain (BWG) decreased in broilers fed on the wheat-based diets compared to the control diet. Dietary supplementation of 500 mg/kg SKEO increased FI and BWG. Dietary SKEO supplementation was effective in improving FI and BWG only in wheat-based diets and was effective in improving feed conversion ratio (FCR) in both diets.

4. Dietary supplementation of 500 mg/kg SKEO caused a significant decrease in plasma cholesterol and triglycerides. Also, plasma low-density lipoprotein concentration was decreased in broilers fed on 250 and 500 mg/kg of SKEO. Plasma cholesterol levels in birds fed on the wheat-based diets were lower than in those fed on maize-based diets.

5. Dietary supplementation of 500 mg/kg SKEO increased caecal population of Lactobacillus and reduced total bacterial and Escherichia coli count. Caecal population of Lactobacillus decreased in broilers fed on the wheat-based diets.

6. Digesta viscosity was increased in broilers fed on the wheat-based diets and decreased in broilers fed on 500 mg/kg SKEO compared to the control diet. Dietary SKEO supplementation was effective in reducing digesta viscosity values only in wheat-based diets.

7. Villus height of the duodenum and jejunum decreased in broilers fed on the wheat-based diets. Dietary supplementation of 500 mg/kg SKEO increased villus height and villus height-to-crypt depth ratios and decreased crypt depth of the duodenum compared to the control diet.

8. It can be concluded that dietary SKEO supplementation was effective in improving FI, BWG and FCR values in wheat-based diets.     

Utilisation of squilla meal (a novel animal protein source) by Broilers

1. The nutritive value of squilla meal, which contained 339 g crude protein, 18.6 g ether extract, 72.8 g calcium, 17.2 g phosphorus and 7.13 MJ of apparent metabolisable energy/kg, was examined in 5 experiments with broilers.

2. Squilla meal contained less lysine (3.45 vs 6.74 g/16g nitrogen) and methionine (1.02 vs 1.86/16 g nitrogen) dian fish meal, had a lower protein digestibility coefficient (0.66 vs 0.72) and a lower gross protein value (68% vs 74%).

3. By gradually replacing the fish meal with squilla meal in isocaloric, isonitrogenous broiler diets it was shown that there was a linear decrease in broiler weight gain; efficiencies of food utilisation were also lower at all squilla meal substitution rates. Inclusion of squilla meal in the diets increased intestinal lengths.

4. Addition of a proteolytic enzyme to the diets containing squilla meal restored broiler weight gain and efficiency of food utilisation to that of birds fed on the control diet.

5. Diets containing autoclaved squilla meal resulted in reduced weight gain although efficiency of food utilisation was not affected.