Physical and chemical properties of meat from scavenging chickens and helmeted guinea fowls in response to age and sex

1. The effects of age and sex on body weight, carcass traits, physical and chemical properties of breast muscle from chickens and helmeted guinea fowls managed under village free-range conditions were assessed in random samples of 48 guinea fowls and 48 chickens obtained from local markets.

2. Guinea fowls had higher body weight, hot carcass weight, cold dressed weight and breast weight than chickens.

3. Guinea fowls had more dry matter, protein and less fat than chickens. Ash content did not differ between guinea fowls and chickens. Protein and fat increased, whereas dry matter and ash decreased with age (P < 0.05)

4. Chicken meat was lighter, less red and more yellow than guinea fowl meat. Cooking loss was higher in guinea fowls, male and grower birds than chickens, females and adult birds, respectively. Shear force was affected by age, as mature birds had a higher value than growers.

5. Guinea fowl carcasses contained more meat that was leaner, higher in protein and redder compared with chicken meat. As age increased the meat increased in protein and fat content and shear force, whereas colour became darker, redder and yellower.     

Production traits of artificially and naturally hatched geese in intensive and free-range systems – II: slaughter,carcass and meat quality traits

1. This study investigates the slaughter, carcass and meat quality traits of artificially and naturally hatched geese in intensive and free-range production systems.

2. The study was conducted with 114 naturally hatched and 102 artificially hatched geese. From each replicate of the intensive and free-range systems, one female and one male goose were slaughtered at the ages of 14, 16 and 18 weeks (a total of 32 geese per slaughter week).

3. Artificially hatched geese had higher slaughter weights (5280 vs. 4404 g), carcass weights (3520 vs. 2863), dressing percentages (66.6–65.2% vs. 65.0–63.6%) and carcass part, feather and edible inner organ weights. The ratio of both edible inner organs and abdominal fat was higher in naturally hatched geese. Breast meat L*, a* and pH values and thigh meat dry matter values were higher in artificially hatched geese, whereas thigh meat b* and pH values were higher in naturally hatched geese.

4. Intensively reared geese had higher slaughter weights (4900 vs. 4783 g), carcass weights (3253 vs. 3130 g) and abdominal fat weights (280 vs. 250 g), as well as higher dressing percentages (66.3–64.9% vs. 65.3–63.9%). Breast meat b* and thigh meat L* values were higher in the intensive system, while breast and thigh pH values, dripping loss and cooking loss were higher in the free-range system. Water-holding capacity was higher in the intensive system.

5. In conclusion, artificially hatched, intensively reared geese had the highest slaughter weights; however, both artificially and naturally hatched geese raised in a free-range system reached acceptable slaughter weights and can thus be recommended for use with this type of production system.     

Carcass characteristics,composition, physico-chemical,microbial and sensory quality of emu meat

1. In order to investigate whether emu meat is a potential red meat alternative, this work was carried out with the objective of studying the carcass characteristics, proximate composition, physico-chemical and microbial characteristics and sensory attributes of emu meat.

2. Carcass characteristics clearly indicate that emus are a significant source of lean meat, fat, skin and edible by-products and these findings confirm earlier reports.

3. Proximate composition of emu meat indicated higher protein and ash content and lower fat, total lipids and cholesterol content than meat from other meat animals.

4. The pH, water holding capacity, collagen content and solubility, protein extractability, muscle fibre diameter and Warner–Bratzler shear force values of emu meat are similar to the earlier reports for meats from other food animals.

5. Emu meat is dark, cherry red in colour with significantly higher myoglobin content and the myoglobin is more prone to oxidation as evidenced by higher initial metmyoglobin percentage. The initial thiobarbituric acid reactive substances (TBARS) values and free fatty acids percentage in emu meat were higher than those in meats from other species.

6. Sensory evaluation of cooked emu meat curry revealed highly acceptable scores relative to goat meat curry, the most preferred meat in India.

7. The study shows the potential of emu meat as a new source of low fat, quality meat proteins. However, more studies are required to elucidate the effect of age, sex, muscles, pre-slaughter and post-slaughter factors on different carcass and meat quality characteristics.     

Effects of dietary oregano and garlic essential oils on carcass characteristics,meat composition,colour, pH and sensory quality of broiler meat

1. An experiment was conducted to determine the individual and combined effects of two essential oils, oregano and garlic, on carcass characteristics, meat composition, colour, pH and sensory quality of broiler meat.

2. The diets were supplemented with no essential oil (control), oregano essential oil or garlic essential oil at 300 mg/kg and oregano essential oil at 150 mg/kg + garlic essential oil at 150 mg/kg.

3. Dietary oregano and garlic oil supplementation did not affect carcass yields, the relative weight of carcass parts, breast and thigh meat composition, pH or b* value of breast meat. Oregano + garlic oil supplementation significantly decreased the L* value. The a* value of breast meat in birds given a diet supplemented with oregano oil was lower than that in birds given a diet supplemented with garlic oil and oregano oil + garlic oil. The essential oil addition had no positive effect on the oxidative stability. There was no difference between the treatments in breast appearance.

4. The juiciness, flavour, oxidised flavour and acceptability of breast meat samples were affected by treatments.     

Carcass yield and meat quality in broilers fed with canola meal

1. This study evaluated the effects of canola meal in broiler diets on carcass yield, carcass composition, and instrumental and sensory analyses of meat.

2. A total of 320 one-day-old Cobb broilers were used in a 35-d experiment using a completely randomised design with 5 concentrations of canola meal (0, 10, 20, 30 and 40%) as a dietary substitute for soya bean meal.

3. Polynomial regression at 5% significance was used to evaluate the effects of canola meal content. The following variables were measured: carcass yield, chemical composition of meat, and instrumental and sensorial analyses.

4. The results showed that carcass yield exhibited a quadratic effect that was crescent to the level of 18% of canola meal based on the weight of the leg and a quadratic increase at concentrations up to 8.4% of canola meal based on the weight of the chest. The yield of the chest exhibited a linear behaviour.

5. The chemical composition of leg meat, instrumental analysis of breast meat and sensory characteristics of the breast meat was not significantly affected by the inclusion of canola meal. The chemical composition of the breast meat exhibited an increased linear effect in terms of dry matter and ether extract and a decreased linear behaviour in terms of the ash content.

6. In conclusion, soya bean meal can be substituted with canola meal at concentrations up to 20% of the total diet without affecting carcass yield, composition of meat or the instrumental or sensory characteristics of the meat of broilers.     

Influence of Juniper (Juniperus communis) oil on growth performance and meat quality as a natural antioxidant in quail diets

1. This study aimed to evaluate the effects of juniper oil on growth performance and meat quality in quails to determine its use as a safe and natural method to reduce overdependence on the use of antibiotic.

2. A total of 1000 1-d-old Pharaoh (Coturnix coturnix Pharaoh) quails, including both males and females, were divided into 4 groups containing 250 quails and treated as follows: (1) a control group with 0 mg volatile oil/kg diet; (2) 100 mg/kg juniper oil; (3) 150 mg/kg juniper oil and (4) 200 mg/kg juniper oil. The diets were prepared fresh for each treatment. The experiment was carried out for 42 d.

3. The results of the study showed that supplementation with juniper oil (100 and 150 mg/kg) caused a significant increase in live weight, live weight gain and carcass yields during the growing and finishing periods. Feed intake and feed conversion ratio were not significantly influenced by treatments.

4. The quails given rations containing juniper oil had reduced thiobarbituric acid levels in raw thigh meat samples at different storage times. Juniper oil was found to have significant antioxidant activity and prevented lipid oxidation in stored meat.

5. In conclusion, natural antioxidants such as a juniper oil can be used instead of synthetic antioxidants to retard lipid oxidation in animal diets to improve meat product quality and animal performance.     

Effects of method of processing and chilling of Turkey carcasses on processing losses,water absorption and yields

1. The effects of wet or dry plucking, wet or dry evisceration procedures and method of chilling on processing losses and water uptake during chilling were studied using 19‐week‐old female large white turkeys.

2. Dry plucking increased weight loss due to plucking and eviscerating, and reduced chilled carcass yield.

3. Dry eviscerating increased carcass water uptake during chilling.

4. Pre‐chilling with running water increased carcass water uptake compared with chilling in ice and water alone.

5. Water uptake during chilling appeared to be increased by longer eviscerating time.     

Effects of evisceration and storage temperature on changes in meat quality of traditional farm‐fresh Turkeys

1. Conditions affecting the keeping quality of traditional farm‐fresh turkeys were investigated.

2. Storage of uneviscerated Wrolstad turkeys at 4 °C for 10 days caused no statistically significant changes in meat flavour or texture.

3. During further storage at —2 °C, however, there was a slight but significant change in flavour, which became more marked with time in birds which had been eviscerated after the initial period at 4 °C.

4. Both eviscerated and uneviscerated birds became slightly tougher during storage.

5. Initial holding at 4 °C increased the numbers of psychrotrophic bacteria on the skin by about 10³ but subsequent changes at — 2 °C were slight for uneviscerated birds.

6. Eviscerated carcases had higher counts than uneviscerated birds after storage at — 2 °C and, although ‘off’ odours were not detected, spoilage appeared to be imminent at the end of the 20‐d period.     

Minimum light intensity threshold to prevent negative effects on broiler production and welfare

1. Research focused on lower light intensity levels is required to set minimum standards appropriate for production and welfare of intensively housed broilers. The objective of this research was to study light intensity (0.1 to 10 lx) effects on Ross × Ross 308 and 708 genotypes.

2. Three experiments (35 d each) using 18 720 broilers were conducted with the initial experiment using two replicates of 0.1, 1, 5 and 10 lx. The second and third experiments examined 0.5, 1, 5 and 10 lx with treatments replicated twice in each experiment in a randomised complete block design with experiment acting as a block. In each experiment, mixed sex broilers from each genotype were housed in 6 equally sized pens per room.

3. In Experiment 1, the introduction of 0.1 lx at d 7 caused high levels of mortality and poor growth rate from d 7 to 14 and was discontinued.

4. In Experiments 2 and 3, increasing light intensity increased body weight gain (0–35 d) and feed intake (0–35 d) in a quadratic and linear fashion, respectively. Similarly, mortality corrected gain to feed ratio (FCR, 0–35 d) demonstrated a quadratic response with a maximum at 5 lx. Carcass, breast meat and skin, abdominal fat and drum skin, as a percentage of live weight, increased while drum bone and wing yield decreased in a linear fashion with increasing light intensity. Total carcass composition was unaffected by light intensity.

5. Genotype effects were numerous. No interactions were found between genotype and light intensity.

6. Ocular dimensions and the incidence of foot pad lesions decreased in a quadratic and linear fashion, respectively, with increasing light intensity. In contrast, welfare-associated gait score and mortality levels were not affected by light intensity.

7. It was concluded that performance, breast meat yield and bird welfare improved with increasing light intensity. The data support 5 lx as a minimum light intensity in broiler production.     

Evaluation of bone strength,keel bone status,plumage condition and egg quality of two layer lines kept in small group housing systems

1. The aim of the present study was to determine the influence of large (54 or 60) and small (36 or 40) group sizes and tiers of the small group housing system “Eurovent German” on tibia and humerus bone breaking strength, keel bone status, plumage condition and egg quality for two commercial layer lines, Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB), at the same stocking density (890 or 830 cm²/bird).

2. In 4 consecutive trials, 4752 hens were recorded for keel bone status. Evaluation of plumage condition was made for 1440 hens and bone breaking strength was recorded for 1200 hens. A total of 4962 eggs were analysed for internal and external egg quality traits. Analyses involved 30 small group compartments per trial.

3. The layer line had a much more pronounced influence on humerus breaking strength than on tibia breaking strength.

4. Plumage condition, particularly on the neck, was positively correlated with humerus breaking strength in both layer lines.

5. An average of 34% of LB and 23% of LSL hens showed keel bone deformities, with higher proportions of slight deformities.

6. Slight keel bone deformities, rather than moderate to severe, increased significantly during the laying period.

7. Stocking density had no influence on bone breaking strength, keel bone status and egg quality traits.

8. LB layers had a 1.4-fold higher humerus, but only a 1.06-fold higher tibia breaking strength compared to LSL layers.

9. Tibia breaking strength was significantly affected by the interaction of group size and layer line. LSL layers in small groups had lower tibia breaking strengths than those of the large groups.     

Influence of site and variety on starch,hemicellulose and cellulose composition of wheats and their digestibilities by adult cockerels

1. It has been shown that both the variety of wheat and the environment under which growth took place influenced the quantities of starch and cell wall carbohydrate contents of wheat.

2. The different varieties of wheat investigated contained different proportions of water‐soluble to water‐insoluble hemicelluloses.

3. By comparison of the arabinose to xylose ratios it was concluded that water‐soluble and insoluble arabinoxylans of wheat were branched to the same degree.

4. Starch from six wheat varieties grown in the U.K. was very well digested by adult cockerels and true metabolisable energy values of the wheats were high.

5. Small amounts of cell wall carbohydrates were digested by adult cockerels.     

A mathematical representation of the Ovulatory cycle of the domestic hen

1. The ovulatory cycle of the domestic hen (Gallus domesticus) was postulated to be the result of the interaction of two independent systems.

2. A circadian system was postulated to control the restriction of ovulation to an 8‐h period of the day under conventional 14 h light: 10 h dark regimes.

3. The final phase of follicular maturation was postulated to commence after ovulation of the preceding ovum in the hierarchy.

4. Ovulation was postulated to occur when a mature follicle was present in the ovary during the appropriate phase of the circadian‐linked system.

5. The predicted times of oviposition were within the standard error of the observed times of oviposition under 21‐, 24‐ and 28‐h photoschedules.

6. It was concluded that this hypothesis for the control of the ovulatory cycle of the hen is consistent with current knowledge.     

The effects of restricted feeding on adrenal cortical activity in the immature domestic fowl

1. The effect of reducing food intake to 75% of the ad libitum intake was determined from hatching to 8 weeks in young Light Sussex chickens.

2. Restricted birds were lighter throughout the experiment.

3. Relative adrenal weight tended to be greater in restricted birds but the difference decreased with time.

4. There was no depletion of adrenal cholesterol: from week 5 there was a significantly greater amount in the adrenals of restricted birds.

5. After 1 week of restriction plasma corticosterone concentration was 73% greater than in controls. It decreased progressively, falling within the normal range at 5 weeks.

6. Restricted birds were hypoglycaemic from weeks 2 to 7 and hyper‐lipacidaemic throughout. A negative correlation between plasma glucose and free fatty acids was found.     

Improving the nutritional quality and shelf life of broiler meat by feeding diets supplemented with fermented pomegranate (Punica granatum L.) by-products

1. Four experimental diets containing 0, 0.5, 1.0 and 2.0% fermented pomegranate by-products (FPB) were supplied to 320d-old broilers to evaluate the effects of FPB on growth performance, nutritional composition, fatty acid profile and oxidative stability of meat.

2. Dietary supplementation of FPB linearly increased the weight gain and feed intake of broilers with linear reduction in feed conversion ratio.

3. The crude protein, iron, magnesium, and sodium content were linearly higher, whereas cholesterol was linearly lower in the breast meat of FPB-supplemented broilers. In thigh meat, linearly lower ether extract and cholesterol with higher moisture was noted in response to increasing levels of FPB.

4. The proportion of saturated fatty acids was both linearly and quadratically lower in breast and thigh meat, whereas those of monounsaturated fatty acids of breast (linear and quadratic) and n-3 fatty acids of breast and thigh (linear) meat was higher in the FPB-supplemented broilers. The n-6/n-3 ratio of breast meat was linearly lower in response to FPB supplementation. The hypocholesterolaemic to hypercholesterolaemic ratio of thigh meat was higher in the FPB-supplemented groups.

5. The thiobarbituric acid reactive substances and pH value were lower in the breast and thigh meat of FPB-supplemented broilers.

6. Thus, additive supplementation of the diet with up to 2% FPB improved the nutritional quality, fatty acid profile and shelf life of broiler meat.     

Effects of high inclusion rates of salseed meal in the diet of chicks

1. Starter diets containing either maize or salseed meal to replace the maize were fed to chicks over a period of 2 weeks.

2. Growth rate, food intake, food utilisation and proportion of dietary nitrogen retained were much poorer in chicks receiving salseed meal.

3. The chicks receiving salseed meal developed pathological lesions in liver and kidney.

4. The red blood cell count, white blood cell count, haemoglobin concentration and packed cell volume of the chicks receiving salseed meal were lower than those of chicks receiving maize.

5. The apparent metabolisable energy value of salseed meal was determined as 6.83 MJ/kg.     

The effects of grape seed in the diet of the Penedes chicken,on growth and on the chemical composition and sensory profile of meat

1. Effect of a diet with 5% grape seed inclusion, substituting for maize compared to a standard diet, was studied in the Penedes chicken.

2. A total of 128 chickens were used, half from each sex. Individual weights and feed intake were controlled weekly from the first d to 5th week and fortnightly until the 15th week. On the 16th week, chemical analyses of meat from 16 thighs from each diet and sex were carried out, as well as a sensory analysis of meat from 24 thighs. Differences between diet and sex were analysed using live body weight, feed intake, feed conversion rate (FCR), chemical composition and sensory attributes of the meat.

3. At the end of the experiment, no significant differences were observed on live body weight, feed intake and FCR due to diet.

4. Meat showed no differences due to diet in the percentages of protein, lipid and ash.

5. Meat from the grape seed diet showed a higher percentage of unsaturated fatty acids due to linoleic acid. It also showed a more nutty smell, a more metallic flavour and more stringiness. There was, also, less of a pork crackling odour and flavour, a less sweet flavour and less of a broiler meat flavour.     

The effects of trienbolone acetate on carcass composition,conformation and skeletal growth of Turkeys

1. The carcasses of 66‐ and 73‐d‐old stag turkeys implanted with 20 mg trienbolone acetate (TA) at 49 d of age were analysed and the results compared with those of untreated controls.

2. Treatment with TA improved growth, increased carcass moisture and tended to decrease carcass fat and ash; protein content was not altered by implantation.

3. Treatment with TA produced a marked improvement in efficiency of conversion of dietary protein to carcass protein.

4. Carcass formation of 70‐ and 77‐d‐old turkeys of both sexes implanted with 20 mg TA at 49 d of age was not markedly different from that of controls in terms of the relative proportions of the major body components nor in relative skeletal proportions.

5. Implantation with TA reduced linear and appositional skeletal growth both relative to soft tissue growth and relative to skeletal growth of control turkeys.

6. The rate of bone remodelling was reduced more than the rate of appositional growth so that bone cortical thickness was increased.

7. The changes in the skeleton effected by TA are consistent with the hypothesis that the drug acts by decreasing the rate of protein turnover, with catabolism being depressed more than anabolism.     

The choline and sulphur amino acid requirements of broiler chickens fed on semi‐purified diets

1. Growth and food conversion efficiency of broilers were reduced at low dietary choline concentrations. These effects were accentuated by low dietary total sulphur amino acids (TSAA).

2. Increased mortality, perosis and other pathological changes involving a number of tissues were observed in birds fed on a low‐choline diet.

3. Methionine replaced part of the dietary requirement for choline at low dietary choline concentrations.

4. High dietary concentrations of choline (> 1 750 mg/kg) increased the requirement for dietary TSAA.

5. Increasing the dietary choline while maintaining the TSAA at an inadequate level may decrease performance.     

Production traits of artificially and naturally hatched geese in intensive and free-range systems: I. Growth traits

1. This study investigated the effect of incubation type and production system on geese growth traits.

2. A total of 216 geese were either naturally (114) or artificially (102) hatched and reared in intensive or free-range production systems (4 replicates each) until 18 weeks of age.

3. Weights of naturally hatched goslings (NHG) were significantly higher than artificially hatched goslings (AHG) at 2 weeks (644 vs. 536 g); however, weights of AHG were significantly higher than NHG at both 6 weeks (3245 vs. 3010 g) and 18 weeks (5212 vs. 4353 g).

4. AHG had better feed conversion ratios (FCRs) than NHG (6.21 vs. 6.46 at 18 weeks). Feed consumption of naturally hatched geese was found higher in first 4 weeks when compared to artificially hatched geese and artificially hatched geese consumed more feed than naturally hatched geese after 8 weeks.

5. Production system had insignificant effects on feed consumption, FCRs, viability and mutilation rates.

6. Slipped wings were more frequent in NHG than AHG (8.32% vs. 1.68% at 6 weeks; 23.84% vs. 5.12% between 7 and 18 weeks) and in free-range production when compared to intensive production (17.88% vs. 11.08% over the course of the production period).

7. The study results indicate that both artificially and NHG can be reared in free-range production systems without any loss in performance and in deference to animal welfare.     

Effects of dietary supplementation with Gynura procumbens (Merr.) on egg yolk cholesterol,excreta microflora and laying hen performance

1. The present study investigated the effects of dietary supplementation with Gynura procumbens on egg yolk and serum cholesterol and triglycerides, excreta microflora, laying performance and egg quality.

2. A total of 160 Hy-Line Brown layers (45 weeks old) were randomly assigned into 4 treatments on the basis of laying performance. Each treatment had 4 replicates with 10 birds each.

3. Dietary treatments were basal diet supplemented with 0 (control), 2.5, 5.0 and 7.5 g/kg diet G. procumbens during 56-d feeding period.

4. Serum (d 21, 42 and 56) and egg yolk (d 28, 42 and 56) cholesterol and triglycerides concentrations were linearly reduced with increasing dietary concentrations of G. procumbens.

5. Increasing dietary concentrations of G. procumbens linearly reduced the excreta total anaerobic bacteria (d 28), Clostridium sp. and Escherichia coli (d 28 and 56) populations.

6. Overall egg production and egg mass were linearly increased, and overall feed efficiency was linearly improved with increase in dietary G. procumbens.

7. Dietary increasing concentrations of G. procumbens linearly improved egg yolk colour (d 28 and 56) and breaking strength of eggs (d 56).

8. The results obtained in the present experiment indicate that dietary supplementation with G. procumbens could reduce the egg yolk cholesterol, suppresses harmful excreta microflora and improves layers performance.