GENETIC CHANGES IN MEAT-TYPE CHICKENS IN THE LAST TWENTY YEARS

1981 ◽  
Vol 61 (3) ◽  
pp. 555-563 ◽  
Author(s):  
J. R. CHAMBERS ◽  
J. S. GAVORA ◽  
A. FORTIN
Keyword(s):  
Abdominal Fat ◽  
Carcass Weight ◽  
Feed Conversion ◽  
Genetic Changes ◽  
Body Weights ◽  
Genetically Improved ◽  
Experimental Strain ◽  
Selection For ◽  
Experimental Strains ◽  
Meat Type

Three experimental strains and two modern commercial stocks of meat-type chickens were compared in 1978. One experimental strain, K, an unselected control, represented broilers of 20 yr ago. A second experimental strain, A, selected for high broiler weight and a third, D, selected for high broiler and low adult weights had been derived from strain K and represented experimental strains genetically improved by artificial selection. All stocks were hatched and reared simultaneously using modern industrial practices. At 47 days, 70 birds of each sex and stock were slaughtered and the carcasses chemically analyzed. Also, 25 hens of each of strains A, D and K were slaughtered when 68 wk old and abdominal fat and carcass weight data were analyzed. The selection for higher broiler weight in strain A increased both broiler and adult body weights more and percent carcass fat less than the selection for high broiler and low adult weight in strain D. Relative to strain A, carcass weight of strain D was 10% lower in broilers and 16% lower in adult hens. Respective means for the modern commercial broilers, strain A broilers, and "broilers of 20 years ago" were 1552, 1001 and 676 g dressed carcass weight; 2.4, 1.6 and 1.4% abdominal fat; 17.2, 15.4 and 12.4% carcass fat (wet basis) and 1.90, 1.92 and 2.01 feed conversion. Thus, the modern broilers have a dramatically increased growth rate accompanied by higher fat content. The greater fat deposition may at least partly account for the lack of significant improvement in feed conversion.

Consequences of selection for growth and heat resistance on growth, feed conversion efficiency, commercial carcass traits and meat quality of Zebu crossbred cattle

1991 ◽  
Vol 42 (8) ◽  
pp. 1373 ◽  
Author(s):  
HM Burrow ◽  
HM Burrow ◽  
B Gulbransen ◽  
B Gulbransen ◽  
SK Johnson ◽  
...  
Keyword(s):  
Heat Resistance ◽  
Conversion Efficiency ◽  
Carcass Traits ◽  
Subcutaneous Fat ◽  
Carcass Weight ◽  
Control Line ◽  
Feed Conversion ◽  
Feed Conversion Efficiency ◽  
Significant Difference ◽  
Selection For

Thirty-five steers and 37 heifers were grown at pasture and finished in a feedlot to meet Australian domestic market specifications, i.e. 160-200 kg carcass weight with 5-9 mm subcutaneous fat at the P8 rump site. The animals were from lines that had been selected for either high growth rate to 600 days (UPWT) or for low rectal temperature under conditions of high ambient temperatures (TEMP) and from a control line (CONT). They were slaughtered in six groups at fortnightly intervals when liveweight of individuals was estimated to satisfy market requirements. Animals from the UPWT line were heavier at all ages than animals from the TEMP and CONT lines (P< 0.05) and had higher liveweight gains at pasture (P < 0.01). There was no difference between the lines in liveweight gains in the feedlot. At the same carcass weight, UPM animals had leaner carcasses (P < 0.01) but similar levels of marbling to CONT line animals. TEMP line animals were also leaner than CONT line animals (P < 0.0l ) , but had more marbling (P<0.01). There was no significant difference between lines in feed conversion efficiency. Steers were heavier (P < 0.001) than heifers at all ages, grew faster (P < 0.001) except during the immediate post-castration period, had higher feed intakes (P < 0.05) but better feed conversion efficiencies (P < 0.05), and at the same carcass weight were leaner (P < 0-01) and had less marbling (P < 0.05). Meat colour, cooking loss, ultimate pH and meat tenderness did not differ significantly between lines or sexes. These results are discussed with reference to the use of selection for growth or heat resistance to improve growth and carcass traits of beef herds in tropical areas.

Body weights, carcass characteristics, fat content, and their relationships in ganders of the Selected Chinese and Synthetic strains, and Embden-sired strain crosses

2005 ◽  
Vol 85 (4) ◽  
pp. 455-461
Author(s):  
J. N. B. Shrestha ◽  
A. A. Grunder
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Liver Weight ◽  
Abdominal Fat ◽  
The Other ◽  
Carcass Weight ◽  
Similar Proportion ◽  
Chinese Strain ◽  
Body Weights ◽  
Total Fat

In 1986, 247 ganders of the Selected Chinese and Selected Synthetic strains, and Large Embden and Small Embden- sired strain crosses at the Greenbelt farm of the Centre for Food and Animal Research in Ottawa, Canada, were evaluated. The Chinese and Synthetic (developed from the Pilgrim, Chinese and Hungarian) strains had been selected for four generations to increase egg production over a 24-wk laying period and body weight at 16 wk of age, and simultaneously decrease total fat content. Two Embden strains, Large and Small, denoting contrasting body sizes, had been imported from the United States of America for potential use in crossbreeding as terminal sire strains. Strains and strain crosses were ranked from high to low, for body weights at 9 and 16 wk of age, liveweight at slaughter and eviscerated carcass weight. Large Embden × Selected Chinese were largest followed by Small Embden × Selected Synthetic and Small Embden × Selected Chinese strain crosses, in turn followed by the Selected Chinese and Selected Synthetic strains. Small Embden-sired crosses were not significantly different except for body weight at 9 wk of age and eviscerated carcass weight. The Large Embden × Selected Chinese strain cross had a dressing percent of 63, significantly higher than 60–61% for the remaining strains or strain crosses. In general, the ranking of strains and strain crosses for liver weight was similar to rankings for body weights, except that the Small Embden-sired crosses were not significantly different from the Selected Chinese strain, and the Small and Large Embden-sired Selected Chinese crosses had similar liver weight. The Selected Synthetic strain had a significantly smaller neck than that of the other strains and strain crosses; Small Embden-sired crosses were not significantly different. Large Embden × Selected Chinese and Small Embden × Selected Synthetic strain crosses and the Selected Chinese strain had similar neck weight. When fat was expressed as a percentage of carcass weight, the strains and strain crosses had similar proportion of abdominal fat. On the other hand the Large Embden × Selected Chinese strain cross had significantly more intestinal fat (4.83%) than any of the strains and strain crosses (2.97 to 3.73%) and a similar proportion of total fat (10.87%) to the Small Embden × Selected Chinese strain cross (8.79%) but significantly more than the remaining strains and strain crosses (7.53 to 8.20%). The correlations of body weights at 9 and 16 wk of age with eviscerated carcass weight (0.65 and 0.90), abdominal fat weight (0.32 and 0.59), intestinal fat weight (0.27 and 0.55) and total fat weight (0.23 and 0.47) were deemed potentially useful. The correlations between percentage of fat parameters and body weights were low (0.20 a n d 0.37) or negligible. The inherent potential in the large-bodied Embden strain for growth can complement the small-bodied Selected Chinese strain that excels in egg production, fertility and hatchability to produce a strain cross with considerable promise for commercial production of goose meat. Key words: Chinese strain, Synthetic strain, Embden strain, body weights, abdominal and intestinal fat

scholarly journals Effect of genotype and sex on carcass characteristics of chickens raised in extensive system

2018 ◽  
Vol 34 (4) ◽  
pp. 405-417
Author(s):  
Lidija Peric ◽  
Vladimir Strugar ◽  
Snezana Bogosavljevic-Boskovic ◽  
Mirjana Djukic-Stojcic
Keyword(s):  
Carcass Characteristics ◽  
Abdominal Fat ◽  
Conversion Ratio ◽  
Meat Production ◽  
Production Traits ◽  
Feed Conversion ◽  
Breast Meat ◽  
Body Weights ◽  
Percentage Yield ◽  
Dressing Percentage

The aim of this work was to examine the possibility of using different poultry breeds for meat production in extensive systems, concerning their slaughter traits. Total of 200 birds of two genotypes were used in this trial: fast-growing hybrid Ross 308 and pure breed White Rock. Chicks were raised indoors until the age of 4 weeks and subsequently they were enabled to access the range. The trial lasted for 13 weeks. At the end of the trial, 10 male and 10 female chicks per breed were sacrificed for the evaluation of slaughter traits - dressing percentage, yield and share of carcass parts. It was established that both genotype and sex significantly affected carcass traits while genotype affected production traits. Chickens of the Ross 308 hybrid had higher body weights, better feed conversion ratio and higher mortality rate. Chickens of the Ross 308 hybrid had dressing percentage compared to the White Rock breed, while the male chickens had higher dressing percentage compared to the female ones. Chickens of the Ross 308 hybrid had a significantly larger weight and share of breast meat, whereas those of the White Rock breed had a larger share of drumsticks and thighs. A significant influence of the genotype was determined on the amount of abdominal fat in the carcass. Chickens of the White Rock breed had a significantly lower fat content compared to the Ross 308 hybrid, which essentially makes them the genotype which is more suitable for the extensive fattening longer than 10 weeks.

scholarly journals Effects of a Combination of Lysolecithin, Synthetic Emulsifier, and Monoglycerides on Growth Performance, Intestinal Morphology, and Selected Carcass Traits in Broilers Fed Low-Energy Diets

Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3037
Author(s):  
Abdallah Ghazalah ◽  
Mamdouh Abd-Elsamee ◽  
Moataz Ibrahim ◽  
Sherein S. Abdelgayed ◽  
Mohamed Abdelkader ◽  
...  
Keyword(s):  
Growth Performance ◽  
Broiler Chickens ◽  
Carcass Traits ◽  
Liver Weight ◽  
Abdominal Fat ◽  
Low Energy ◽  
Intestinal Morphology ◽  
Carcass Weight ◽  
Feed Conversion ◽  
Low Energy Diet

This study aimed to evaluate the effect of supplementing a combination of lysolecithin, synthetic emulsifier, and monoglycerides (LEX) on growth performance, intestinal morphology, and selected carcass traits in broilers fed low-energy diets without added oil. Three hundred one-day-old Arbor Acres (AA) broilers (40.3 ± 3.3 g) were assigned to two dietary treatments with six replicates of 25 birds each and were fed a control low-energy diet without added oil supplemented with 0 and 250 g/t of LEX for 30 days. Growth performance was measured and recorded throughout the study. At slaughter, 60 birds per treatment were used to assess the effect of LEX on the carcass traits. Final average body weight and feed conversion ratio were improved (p < 0.05) in LEX treated birds compared to control. LEX supplementation was linked to higher (p < 0.05) carcass weight and yield and to lower (p < 0.05) abdominal fat and liver weight. Moisture content was higher (p < 0.05) in ground deboned broilers from LEX treatment. Villus height was increased (p < 0.05), and crypt depth reduced (p < 0.05) in the jejunum of birds treated with LEX. This study demonstrates that supplementation of LEX to a low-energy diet without added oil improved performance, carcass weight and yield, reduced abdominal fat deposition, and improved intestinal morphology in broiler chickens.

scholarly journals PRODUCTION PERFORMANCE AND SLAUGHTER TRAITS OF AN AUTOSEXING BROILER COMBINATION REARED EITHER SEX SEPARATE OR MIXED

2020 ◽  
Vol 23 (1) ◽  
pp. 12-19
Author(s):  
N. Mincheva
Keyword(s):  
Body Weight ◽  
Feed Intake ◽  
Live Weight ◽  
Abdominal Fat ◽  
Production Performance ◽  
Carcass Weight ◽  
Broiler Chicks ◽  
Body Parts ◽  
Feed Conversion ◽  
Final Body Weight

Production and slaughter traits of autosexing broiler combination reared either sex separate or mixed were investigated. A total of 180 day-old feather sexed broiler chicks were divided into three groups (n=60)- two sex separate (male and female) and one mixed (1:1), each with two replications of 30 birds. Body weight and feed intake were followed on a weekly basis; the average daily feed intake and feed conversion were calculated. By the end of the experiment (day 49), slaughter analysis was performed on 20 birds: 5 broilers from each of sex separate groups, 5 males and 5 females from the mixed group with live weight close to the group average. The carcass weight (g), weights of carcass cuts, giblets and abdominal fat were determined. Slaughter yield and body parts ratios were calculated. The results demonstrated that sex separate rearing of broilers contributed to higher final body weight - by 6.9 % in females (P<0.05) and by 2.9 % in males (P>0.05), but had no effect on feed conversion. Sex separate rearing resulted in heavier carcasses by 3.6% (P<0.05) and more uniform weight as compared to mixed rearing. The sex effect on body weight and slaughter traits was more considerable in males with respect to carcass, thigh, back, wings and giblets weights (P<0.05) but not abdominal fat whose weight was higher in female broilers (P<0.05). Better uniformity of final body weight of broilers reared sex separate and the reduced variation in carcass weight and weight of cuts (breast and thigh) would facilitate slaughterhouse processing and would contribute to the realization of produce and meeting distribution network demands

scholarly journals A Research on the Comparative Effect of Active Dry Yeast and Inactivated-Stabilized Probiotic Yeast (Thepax) Added at Different Levels to Diets on Broiler Performance

2021 ◽  
Vol 9 (12) ◽  
pp. 2219-2225
Author(s):  
Süleyman Çalışlar ◽  
Rahmi Kanat
Keyword(s):  
Broiler Chickens ◽  
Body Weight Gain ◽  
Live Weight ◽  
Abdominal Fat ◽  
Carcass Weight ◽  
Feed Consumption ◽  
Control Group ◽  
Feed Conversion ◽  
Broiler Performance ◽  
Different Levels

This experiment was conducted to determine the effect of active yeast (AY) and inactive-stabilized yeast (Thepax) supplementation to the rations in different levels on broiler performance. In the experiment carried out according to the randomized plot design, there were 5 different treatment groups as control group (Group 1), 0.1% Thepax (Group 2), 0.2% Thepax (Group 3), 0.1% AY (Group 4) and 0.2% AY (Group 5). In the experiment, the effects of active and inactive yeasts on body weight gain (BWG), feed consumption, feed conversion rate, carcass weight (CW), carcass yield (CY), abdominal fat amount and mortality were investigated. In the present experiment, the final live weight, the cumulative feed consumption and feed conversion were insignificant. The statistical difference between the groups in the experiment was significant in carcass weight, but insignificant in the amount of abdominal fat and mortality rate. Inactive-stabilized yeast (Thepax 0.1%) was more effective than 0.2% AY on BWG. Only 0.1% Thepax increased the CW besides CY was high in 0.1%, 0.2% Thepax and 0.1% AY groups. It has been observed that active and inactive yeasts are used in broiler chickens without any problem.

scholarly journals Performance and body composition of young Nellore bulls slaughtered at different body weights

2019 ◽  
Vol 40 (5Supl1) ◽  
pp. 2453
Author(s):  
Ludmila Couto Gomes Passetti ◽  
Francisco de Assis Fonseca de Macedo ◽  
Alfredo Jorge Costa Teixeira ◽  
Anselmo Domingues Ferreira Santos ◽  
Alfredo Acosta Backes ◽  
...  
Keyword(s):  
Body Weight ◽  
Average Daily Gain ◽  
Carcass Weight ◽  
Feed Conversion ◽  
Muscle Area ◽  
Randomized Design ◽  
Body Weights ◽  
Quantitative Characteristics ◽  
Fat Thickness ◽  
Feed Costs

The objective of this work was to evaluate the effect of slaughter body weight on the quantitative characteristics of carcasses and the yield of commercial cuts of young Nellore bulls. Twenty-four non-castrated, 11-month-old, feedlot-fed Nellore bulls were distributed in a completely randomized design, in three treatments: 350 kg, 400 kg or 450 kg of body weight at slaughter (SBW). Slaughter was performed in a commercial slaughterhouse. The data were analyzed by an ANOVA followed by a Tukey test (p ? 0.05). SBW had no relationship with dry matter intake (6.05 kg/day or 75.74 g/kg BW0.75), feed efficiency (22.16) or feed conversion (4.67). Average daily gain was different depending on the SBW. Animal slaughtered at 350 kg had gained 1.17 kg/day, whereas animals slaughtered at 400 and 450 kg had gained 1.49 and 1.47 kg/day, respectively. Cold carcass weight increased with SBW (189.50, 209.33, and 242.39, respectively). Other carcass characteristics, like pH at 48 h (5.75), cold dressing carcass (52.61%), chilling losses (1.79%), fat thickness (5.54 mm), marbling (3.34 points), intramuscular fat (6.68%), longissimus muscle area (63.10 cm2) and sarcomere length (1.60 ?m), were not affected by SBW, but SBW increased cold carcass weight. The treatments had effects on the primary and commercial cut weights. However, the cut yields for the forequarter (39.84%), hindquarter (47.82%) and side-cut (12.34%), and the secondary cuts: chuck (14.38%), hump steak (1.94%), shoulder clod (16.97%), brisket point end (5.56%), neck steak (1.00%), striploin (7.77%), outside flat (5.30%), topside (9.36%), tenderloin (2.16%), flank steak (3.41%), eyeround (2.67%), rump tail (1.20%), rump eye (3.89%), shank (4.44%), knuckle (5.25%) and rump cap (1.40%), were not affected by SBW. SBW did not influence (p > 0.05) the commercial cut compositions for all cuts in the forequarter and hindquarter. Finishing young bulls in a feedlot is a strategy to produce beef with reduced feed costs. After all, the slaughter body weight (350, 400 or 450 kg) influenced the quantitative characteristics of the carcass; however, it did not affect the yield of commercial cuts from young Nellore bulls.

EFFECTS ON BODY WEIGHT AND FEED CONVERSION OF BROILER CHICKENS FROM THREE COMMERCIAL CROSSES REARED WITH THE SEXES SEPARATED OR INTERMINGLED

1969 ◽  
Vol 49 (1) ◽  
pp. 23-28 ◽  
Author(s):  
W. F. Lamoreux ◽  
F. G. Proudfoot
Keyword(s):  
Body Weight ◽  
Broiler Chickens ◽  
Broiler Chicks ◽  
Feed Conversion ◽  
Single Strain ◽  
Body Weights ◽  
Type Strains ◽  
Meat Type

Two tests, each including 1,728 sexed broiler chicks, were conducted with the sexes both intermingled and separated. The chicks, progeny of three commercial meat-type strains of hens mated to a single strain of males, were hatched in the same incubators on the same day and reared in 48 pens in a windowless house.Results to nine weeks of age revealed no significant effects of rearing the sexes separately or intermingled, on body weight, feed conversion or uniformity of body weights.

scholarly journals Kinerja Produksi dan Kualitas Karkas Itik yang Diberi Ransum Mengandung Ampas Sagu

2018 ◽  
Vol 7 (1) ◽  
pp. 1-8
Author(s):  
Sylvia Ch. H. Hehanussa ◽  
Tabita N Ralahalu ◽  
Christine C E Latupeirissa
Keyword(s):  
Weight Gain ◽  
Abdominal Fat ◽  
Metabolizable Energy ◽  
Carcass Weight ◽  
Feed Consumption ◽  
Carcass Quality ◽  
Feed Conversion ◽  
Fat Percentage ◽  
Sago Waste

The aim of the study was to determine the effect sago waste in the rations on performance and carcass quality of duck as meat producer. The treatments of this experiment were R0 (0% sago waste/control diet), R1 (5% sago waste), R2 (10% sago waste), and R3 (15% sago waste). The experimental died contained 16% crude protein and 2900 kcal /kg metabolizable energy. Ducks used in this experiment was 6 weeks old male of ducks Mojosari and Pekin cross breed. The research design use was a complete Randomized Design using 4 feeding treatment, 5 replications, and 3 ducks per replication pens. The parameters measured were: feed intake, weight gain, feed conversion, carcass weight, carcass percentage and abdominal fat percentage. The results showed that the used of sago waste had no significant effect on feed consumption, weight gain, feed conversion, carcass weight, carcass and abdominal fat percentage. It can be concluded that used of sago waste up to 20% has no negative effects on performance and carcass quality of ducks. Keywords: abdominal fat, carcass quality, duck, sago waste   ABSTRAK Penelitian ini bertujuan untuk mengkaji pengaruh penggunaan ampas sagu dalam ransum terhadap kinerja produksi dan kualitas karkas itik sebagai penghasil daging. Perlakuan pakan yang dicobakan dalam penelitian ini adalah R0 (tanpa ampas sagu), R1 (ampas sagu 5%), R2 (ampas sagu 10%), dan R3 (ampas sagu 15%). Ransum disusun mengandung protein kasar 16% dan energi metabolis 2900 kkal/kg. Itik yang digunakan adalah itik jantan persilangan Mojosari dan Pekin berumur 6 minggu. Rancangan penelitian yang digunakan adalah rancangan acak lengkap pola searah dengan 4 perlakuan pakan dengan 5 ulangan, dan 3 ekor itik untuk tiap ulangan. Parameter yang diamati adalah: konsumsi ransum, pertambahan berat badan, konversi ransum, berat karkas, persentase karkas dan persentase lemak abdominal. Hasil penelitian menunjukkan bahwa penggunaan ampas sagu tidak berpengaruh signifikan terhadap konsumsi ransum, pertambahan bobot badan, konversi ransum, berat karkas, persentase karkas dan lemak abdominal. Dengan demikian dapat disimpulkan bahwa penggunaan ampas sagu sampai taraf 20% tidak berpengaruh negatif terhadap kinerja produksi dan kualitas karkas itik. Kata kunci: ampas sagu, itik, kualitas karkas, lemak abdominal

scholarly journals Effect of Salix Tetrasperma Roxb. Extract on The Value of Feed Conversion Ratio, Carcass Weight, and Abdominal Fat Content of Broiler Chicken with Heat Stress Condition

2020 ◽  
Vol 151 ◽  
pp. 01034
Author(s):  
Sugito Sugito ◽  
Erdiansyah Rahmi ◽  
Mira Delima ◽  
Nurliana Nurliana ◽  
Rusli Rusli ◽  
...  
Keyword(s):  
Drinking Water ◽  
Heat Stress ◽  
Plant Extract ◽  
Broiler Chickens ◽  
Abdominal Fat ◽  
Fat Content ◽  
Conversion Ratio ◽  
Feed Conversion Ratio ◽  
Carcass Weight ◽  
Feed Conversion

Heat stress on broiler chickens has an impact on the value of feed conversion ratio (FCR), carcass weight, and abdominal fat content. These impacts can be reduced by administering plant extracts, such as salix plant extract. However, the effect of this plant extract on normal condition is still unknown. This study aimed to determine the effect of salix extract to the value of feed conversion ratio, carcass weight, and abdominal fat content in chickens with heat stress and compared with chickens in normal conditions. This study used 30 samples of 21-day old broiler chickens. This research was conducted using a complete factorial randomized design with 2 x 3 treatment factors and 5 repetitions. The first factor consisted of two treatment conditions, namely heat stress (HS) and no heat stress (nHS), while the second factor consisted of three doses of salix extract treatment, dose 0 (ES-0), 50 (ES-50), and 100 (ES-100) mg/L of drinking water. Heat stress was conducted by increasing the temperature of the cage to 34 ± 1 °C for 4 hours per day. Salix extract was added in drinking water and given 2 hours before the temperature reached 34 ± 1 °C. Chickens without heat stress were kept in the cage at 25 ± 1 °C using air-condition (AC). Data were analyzed using two way ANOVA using SPSS 20. The results showed that administration of salix extract on heat stress chickens did not affect the FCR value and carcass weight, but had a significant effect (P ≤ 0.05) on abdominal fat weight. Fat content in the abdominal was higher (P≤ 0.05) in chickens with heat stress and given salix extract than non heat stress.

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