Influence of dietary vitamin E and oxidised sunflower oil on the storage stability of cooked chicken muscle

1. The effects of oxidised dietary sunflower oil and dietary α‐tocopheryl acetate supplementation on α‐tocopherol concentrations in broiler muscle and on the storage stability of refrigerated, cooked, minced muscle were determined. Broiler chicks were fed on diets containing fresh sunflower oil and 30 (FS30) or 200 (FS200) mg α‐tocopheryl acetate/kg, or oxidised sunflower oil and 0 (OS0), 30 (OS30) or 200 (OS200) mg α‐tocopheryl acetate/kg.

2. Inclusion of oxidised sunflower oil significantly reduced dietary and hence, muscle α‐tocopherol concentrations.

3. Oxidised oil increased oxidation in raw and cooked muscle, and reduced the oxidative stability of muscle during refrigerated and frozen storage.

4. Supplementation with α‐tocopheryl acetate improved the stability of muscle, with stability increasing as muscle α‐tocopherol concentrations increased, when fresh or oxidised oil was fed. Supplementation with 200 mg α‐tocopheryl acetate/kg offset the effects of oxidised oil in breast, but not in thigh.

5. The results show that the prooxidising effects of oxidised oils in muscle foods can be overcome, but α‐tocopherol content needs to be adequately adjusted to compensate for increased oxidative stress. Supplementation with 200 to 400 mg α‐tocopheryl acetate/kg may be necessary to achieve an optimum muscle α‐tocopherol concentration.     

Effect of hesperidin dietary supplementation on hen performance,egg quality and yolk oxidative stability

1. The purpose of this study was to evaluate the effects of dietary supplementation with hesperidin (one or 3 g/kg of feed) for 31 d on the performance, egg quality and yolk oxidative stability of brown and white laying hens (26-wk old).

2. Supplementation with hesperidin did not affect egg production, egg weight and egg quality traits.

3. No hesperidin effect on yolk and plasma cholesterol was observed. A strain effect was found with lower total and per g yolk cholesterol of brown hens in comparison to the white ones.

4. Oxidative stability of egg yolk, expressed as ng MDA/g yolk, was significantly improved in the hesperidin groups even from the first week of supplementation. At the same time, a significant improvement in the oxidative stability of egg yolk due to the incorporation of hesperidin in hens’ diet was observed after 30 and 90 d of storage at 20°C and 4°C, respectively.

5. No hesperidin by strain interaction was detected for any of the traits measured.

6. In conclusion, incorporation of hesperidin to laying hens’ feed did not affect productive and egg qualitative traits. On the other hand, dietary hesperidin supplementation significantly improved oxidative stability of both fresh and stored eggs. Antioxidant properties of hesperidin seem to make it a promising natural agent for improving the shelf life of eggs.     

Improved early performance of turkey poults given an Aloe ferox leaf extract with bentonite

1. AT-402 (20 g/kg), a proprietary blend of Aloe ferox leaf extract and calcium bentonite, had no adverse effect on poult body weights at 3 weeks of age.

2. Lower body weights and lower feed consumption were observed in 4-week-old poults given 10 and 20 g/kg of AT-402 compared to poults given 0 or 5 g/kg.

3. Floor-reared poults, given either 5 or 10 g/kg AT-402 to 4 weeks of age, were significantly heavier than controls (0 g/kg AT-402), and feed conversion ratios for AT-402 given poults were improved.

4. Xylose uptake in 5 g/kg AT-402-fed poults was significantly greater than in poults given AT-402 at 0 and 10 g/kg, reflecting increased body weights of 5 g/kg AT-402-fed poults.

5. Delayed access by poults to the AT-402 until 10 d of age also improved 4-week body weights, suggesting that the AT-402 might improve performance as soon as it is given.

6. AT-402 at 5 g/kg was most efficacious as demonstrated by improved body weights and feed conversions.     

A fishy taint in eggs: Interaction between fishmeal diets and strain of bird

1. Field cases of fishy or crabby taint in eggs have been reported, similar to those caused by feeding rapeseed meal (RSM), even though no RSM was fed. The cause was investigated using Babcock B380 and Warren SSL hens.

2. The taint was due to the inclusion of either 25 or 70 g Icelandic capelin fishmeal/kg of the diet.

3. Babcock hens produced significantly more (17%) tainted eggs than Warrens (1.2%).

4. Tainted eggs were significantly reduced to a very low proportion (1.3%) by the third day of feeding a fishmeal‐free diet.

5. The taint was due to the presence of up to 17 mg/trimethylamine kg in affected eggs.     

Relationship between monensin and sulphur amino acid requirements IN broiler chickens

1. Diets containing 80, 100, 125, 150, 175 or 200 mg monensin/kg were fed to broiler chickens from 0 to 28 d in cages that prevented access to excreta.

2. Growth was depressed with 125 mg monensin or more/kg and food intake tended to decrease. Feathering was adversely affected with 175 mg or more/kg.

3. In a similar experiment, diets containing 8.8, 9.1, 9.4, 9.7 or 10.1 g total sulphur amino acids (SAA)/kg were supplemented with 125 or 80 mg monensin/kg and compared with a diet containing 8.8 g SAA and 33 mg robenidine/kg.

4. With 125 mg monensin/kg, body‐weight gain was significantly less than that of birds receiving robenidine if dietary SAA content was 9.4 g or less/kg. With 9.7 g SAA or more/kg, gain in birds receiving monensin was similar to that of birds receiving robenidine.

5. Monensin at 125 mg/kg therefore appears to increase the SAA requirement.     

Effect of dietary inclusion of ascorbic acid and palm oil on the performance of laying hens in a hot tropical environment

1. Two experiments were conducted to evaluate the effects of including ascorbic acid (AA), palm oil or a combination of both in the diets of laying hens during the hot months in a tropical environment.

2. The inclusion of AA improved egg production, food intake and efficiency of utilisation, and decreased the cost of food per kg egg. The addition of 400 mg AA/kg diet gave the most efficient performance.

3. Palm oil inclusion reduced the effect of heat stress and increased egg production, egg weight, food intake and efficiency of utilisation.

4. When 200 mg AA and 50 g palm oil/kg were used, additive responses were obtained with further improvements in egg production, food cost and efficiency.

5. Ascorbic acid and palm oil when fed alone or in combination reduced the incidence of cracked eggs.

6. Thus, 400 mg ascorbic acid/kg of diet, 50 g palm oil or 200 mg AA plus 50 g palm oil/kg diet ameliorated the effects of heat stress in laying hens.     

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.     

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.     

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.     

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 influence of certain dietary fillers on the true metabolisable energy of diets for Turkeys

1. An experiment was conducted with Large White turkey poults (0 to 3 weeks of age) to study the influence of dietary fillers on the true metabolisable energy (TME) of the diet.

2. When 25 g sand/kg was substituted for the components of a basal diet, growth was not affected and the TME value of the diet was apparently higher than that of the basal diet, but not significantly so.

3. The substitution of 50 g filler/kg (25 g sand plus 25 g grit/kg) resulted in a higher TME value than the substitution of either 25 g sand/kg or 25 g grit/kg, significantly so in the latter case.

4. Substituting 25 g cellulose/kg resulted in a decrease in TME value, but not significantly so.     

Transfer of dietary sulphamonomethoxine and sulphadimethoxine into various tissues of laying hens

1. Sulphamonomethoxine (SMM) or sulphadimethoxine (SDM) were fed to laying hens at a dietary concentration of 400 mg/kg. Concentrations (mg/kg) of SMM and SDM in the blood, kidney, liver, ovary, muscle and adipose tissue, collected at 4, 8, 16 and 24 h after the start of feeding, were determined by HPLC

2. The relationships between the sulphonamide concentrations (mg/kg) in the tissues and times (h) after the start of the feeding were analysed statistically.

3. Dietary SMM and SDM were transferred throughout the whole body, and concentrations in all tissues became constant 8 h after the start of feeding.

4. Among the 6 tissues examined the constant values (mg/kg) of both SMM and SDM were highest in the kidney and were lowest in adipose tissue.

5. With the exception of adipose tissue, the values of SDM in the tissues were statistically greater than those of SMM.     

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.     

Effects of degree of fatness in broilers on other carcass characteristics: Relationship between fatness and the stability of meat and adipose tissue1

1. Three trials were carried out to compare the effects of different degrees of fatness in broilers and of dietary a‐tocopherol (AT) concentrations on the stability of meat and adipose tissue at 5 to 9 weeks of age.

2. In spite of higher concentrations of AT in carcass fat, the meat and abdominal fat of lean broilers were less stable than those of obese birds, apparently due to an increase in the unsaturation of their carcass fat.

3. Dietary AT improved significantly the stability of meat and adipose tissue, irrespective of the degree of fatness. However, the difference in the stability of these tissues between obese and lean broilers remained apparent even with 60 mg AT/kg of the diet.

4. A linear relationship was observed between dietary AT and the stability of adipose tissue, whereas the relationship between AT intake and meat stability was logarithmic.     

Effect of replacing dietary vitamin E by sage on performance and meatiness of spent hens,and the oxidative stability of sausages produced from their meat

1. A total of 3960 hens (half ISA Warren and half Dekalb White) were housed in 18 compartments with 220 hens each. The effect of replacing dietary vitamin E by sage on productivity, meat yield and oxidative stability of sausages was studied.

2. One third of all animals received either a vitamin E deficient diet (negative control) or diets supplemented with 30 mg/kg α-tocopherylacetate (positive control) or 25 g sage leaves/kg. At slaughter, meat yield was assessed and sausages were produced (n = 12 per treatment).

3. The omission of vitamin E did not impair the oxidative stability of the raw sausage material or the spiced sausages in comparison to the positive control. Sage supplementation improved oxidative stability after 7 m of frozen storage, but not after 1, 4 and 10 m. Spice addition during meat processing had an antioxidant effect regardless of dietary treatment. Diet supplementation of any type did not affect laying performance and sausage meat yield.

4. Feeding antioxidants to spent hens seemed to be not as efficient as in growing chickens, while seasoning with spices during sausage production proved to be a feasible way to delay lipid oxidation.     

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.     

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.     

Influence of dietary calcium and phosphorus on metabolism and production in laying hens

1. The effects of different dietary concentrations of calcium (24 to 56.9 g/kg) and phosphorus (4.5 to 14.2 g/kg) on production and some aspects of metabolism were studied in laying hens.

2. Treatments did not affect egg numbers, food consumption, conversion efficiency of food to egg, bodyweight gain or mortality.

3. Increasing dietary calcium (Ca) significantly increased plasma Ca and inorganic phosphorus (P), breaking strength at the radius and egg specific gravity and significantly decreased plasma alkaline phosphatase and egg weight.

4. Increasing dietary phosphorus increased plasma P and decreased egg specific gravity significantly.

5. Plasma Ca, P and alkaline phosphatase and radius breaking strength were suitable indices of the Ca status of the hens.     

Comparative study of the effects of organic selenium on hen performance and productivity of broiler breeders

1. A 10-week experiment was conducted with Ross 308 broiler breeder chickens in cages to evaluate the influence of organic and inorganic sources of selenium (Se) supplementation. A total of 600 birds at 29 weeks of age were divided at random into 4 groups and fed on a maize–soya basal diet supplemented with different forms of Se.

2. The first (control) group was given the basal diet without Se supplementation, whereas the second, third and fourth groups were given, respectively, the basal diet with 0.3 mg/kg of inorganic Se in the form of sodium selenite or 0.3 and 0.5 mg/kg of organic Se in the form of Se enriched yeast (Se-yeast).

3. The experiment was carried out for 10 weeks to compare and evaluate the influence of Se supplementation on breeder performance, egg production, hatchability and the quality of eggs. Samples were collected for analysis at weeks 0, 5 and 10 of the experimental period.

4. At the end of the experiment (39 weeks), there was a reduction in mortality in breeders given diets supplemented with 0.5 mg/kg of Se-yeast. Supplementation of feed with 0.5 mg/kg organic Se increased egg production, percentage of settable eggs and hatchability.

5. Selenium supplementation increased egg weight and specific gravity compared to the control diet. However, no significant variation was found in albumen or yolk protein content at the end of week 10.

6. Selenium accumulation and glutathione peroxidase (GSHPx) activity were lower in the egg albumen and yolk of control compared with Se-supplemented treatments. Se accumulation and GSHPx activity were higher in the group given 0.3 mg/kg organic compared to 0.3 mg/kg of inorganic Se.

7. The results favour the use of Se-yeast at the dose of 0.5 mg/kg in broiler breeder diets for better productivity of eggs, settable eggs, hatchability and higher Se accumulation and antioxidant status in eggs.     

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.