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1.
The effects of 0, 40 and 80 g/kg alfalfa meal on growth performance, carcass traits and meat quality of Chinese yellow‐feathered broilers fed diets containing or lacking wheat (0 or 200 g/kg) as part of the energy source, were examined using random design with a 2 × 3 factorial arrangement of treatments. Dressing percentage and semi‐eviscerated proportion were lower, and meat color a* (redness) value was higher in birds fed diets containing wheat than diets lacking wheat (P < 0.05). Drip loss was reduced by the addition of alfalfa meal to diets containing or lacking wheat (P < 0.05). Average sensory score of breast meat was higher in chickens fed corn‐based diets than in those fed wheat (P < 0.05). Meat from those supplemented with 40 g/kg alfalfa meal had better taste than the other two levels (P < 0.05). The inclusion of wheat significantly reduced the activities of creatine kinase and calpain of breast muscle (P < 0.05). In conclusion, Chinese yellow‐feathered broilers fed diets containing wheat had better meat color and lower drip loss than those fed the diets without wheat, and adding 40 g/kg alfalfa meal generally improved meat quality and taste.  相似文献   

2.
A study was conducted to evaluate four different cholecalciferol levels (NRC; modified), using diets supplemented with 200 (control), 1500, 2500 or 3500 IU/kg of cholecalciferol (VIT‐D3). Each treatment was assigned to 3 pens of 17 broiler chicks of a commercial strain grown in an open‐sided house with sidewall curtains. At 21and 42 days, BW and feed conversion (FCR) were determined. At 42 days, five birds per pen were slaughtered to evaluate tibia and toe ash of the right leg, and incidence and severity of tibial dyschondroplasia (TD) of the left tibia and also measured dressing percentage and breast meat yield. Serum calcium and phosphorus concentrations were also determined. Haemagglutination inhibition antibody titre against Newcastle disease virus and lymphoid organs weight/body weight ratio were also determined. At both 21 and 42 days, the BW of birds fed 1500 IU/kg to 3500 IU/kg of VIT‐D3 was significantly greater than birds fed 200 IU/kg. Similarly, better FCR was observed in birds those fed diets of high level of VIT‐D3. No significant difference was observed for mortality at any age. Better dressing percentage and breast meat yield were noted in birds fed diets containing 2500 or 3500 IU/kg VIT‐D3. Both tibia and toe ash contents were increased (p < 0.05) progressively with increased concentrations of cholecalciferol in feed. The incidence of TD (percentage of birds having TD scores greater than zero) was significantly (p < 0.05) influenced by level of 3500 IU VIT‐D3/kg at 42 days. The severity of TD in birds fed diets containing 200 IU/kg VIT‐D3 was apparently higher than birds fed diets with higher levels of VIT‐D3. Concentrations of calcium and phosphorus minerals in the serum increased progressively with the high level of VIT‐D3 supplementation to birds at both 21 and 42 days of age. Feeding levels of 1500 or 3500 IU of vitamin D3 did positively affect the immune system within the parameters measured. It may be concluded that performance, bone mineralization, blood chemistry and immunity against disease in broilers could be maintained when supplementing high level of VIT‐D3 incorporated in broiler diets.  相似文献   

3.
This study investigated the effects of beak trimming on a local broiler breed. A total of 648 one‐day‐old birds were randomly allocated into three treatments: no trimming (NBT), infrared beak trimming (IRBT), and hot‐blade beak trimming (HBBT). The performance, beak length, behavior, carcass traits, organ percentages, and meat quality were inspected. The body weight (BW) from 7 to 35 days in the IRBT group was significantly lower than that in the NBT group, and the BW from 7 to 49 days was lower than that in the HBBT group (p < .05). Compared with untrimmed birds, birds in the IRBT group had lower average daily feed intake (ADFI) from 15 to 21 days, and higher heart percentage and L* value in the breast muscle. The upper beak length at 28 and 49 days of age were longest in untrimmed birds, intermediate in birds in the HBBT group, and shortest in the IRBT groups (p <.05). No evidence was found that HBBT caused changes in performance, behavior, carcass traits, organ percentages, and meat quality except for lower change in spleen percentage. Taken together, IRBT had more influence at inhibiting early BW, ADFI, and upper beak length than HBBT in the local broiler breed.  相似文献   

4.
The present study aimed at evaluating the effects of different doses of humic substances (HS) in waterer pan on broiler performances and meat quality. For the trial, 480 chicks (ROSS 308) were allocated into four groups (HS0, HS150, HS300 and HS450) of 120 equally mixed‐sex birds, each receiving a drinking water supplemented with 0, 150, 300 and 450 ppm of a humic acid (provided by 0.0%, 0.5%, 1.0% and 1.5% of HS, v/v) respectively. At the age of 21 and 42 days, feed consumption and live weight were taken. At the age of 42 days, 16 birds per treatment were slaughtered, dressing percentages, digestive tract traits were evaluated and samples of breast (pectoralis major) and thigh (iliotibialis) meat were taken to evaluate the changes in colour characteristics (CIE L*, a* and b*) and chemical composition. The body weight gain increased by the HS300 in relation to the HS0 and HS450, and decreased by the HS450 in relation to the HS0. The feed consumption of birds in the HS450 and feed efficiency of birds in the HS300 were lower and higher than those in the other treatments respectively. The carcass weight of broilers in the HS150 and HS300 were higher than those of in the HS0 and HS450. The carcass weight decreased by the HS450 in relation to the other treatments. The dressing percentage increased by the HS150 in relation to the HS450. The HS450 resulted in breast and thigh meat colour that were lighter than those found in the HS0 birds. The HS450 increased fat content of thigh meat in relation to the HS0. It was concluded that the humic acid supplementation at 300 ppm and 450 ppm appears to have a measurable impact on live performance improving feed efficiency and lightness of breast and thigh meat colours in broilers respectively.  相似文献   

5.
We comprehensively evaluated meat quality in chickens fed a diet consisting of wood charcoal and vinegar (WCV) using food scientific and histological approaches. In culled hens, lipid and fatty acid in Musculus semimembranosus, cooking loss and sensory tests of whole thigh meat, and meat texture of breast meat were observed. In male broilers, cross section of M. semimembranosus was used for observations on muscle area, perimysium, non‐collagen total protein and total collagen content, and anti‐collagen I and III reactions. In frozen male broilers, conventional morphology of M. semimembranosus as well as chicken anti‐collagen III reaction to selected muscles of thigh meat and breast meat were compared between the control and WCV‐fed birds. Increased lipid and fatty acids, decreased cooking loss, high score in total evaluation for sensory test of thigh meat, and decreased meat texture values were observed for culled hens fed WCV. The higher values of muscle area, total collagen and collagen III were observed for broilers fed WCV. No perimysium collapse for M. semitendinosus or increased collagen III reactions of M. tensor fasciae latae, the flexor muscle group and M. pectoralis superficialis were observed for frozen muscles in the WCV group. These total results suggest that WCV produces palatable and tender meat by increasing collagen III.  相似文献   

6.
The effect of hatch location and diet density on the prevalence of footpad dermatitis and growth performance in broiler chickens was studied. Broilers (Ross 308), incubated at 2 different hatch locations but originating from the same parent stock, were subjected to 2 feeding programs differing in energy content (2,750 vs. 2,950, 2,850 vs. 3,050, 2,900 vs. 3,100, and 2,900 vs. 3,100 kcal/kg for starter, grower I, grower II, and finisher diets, respectively) in a 2 × 2 factorial design (6 replicates per treatment combination). Broilers were housed under conditions and managed according to Dutch practice. Hatch location did not affect hatching results nor the prevalence and severity of footpad dermatitis, but did affect BW gain, feed, and water intake. A significant interaction was found between hatch location and feeding program; broilers fed the low-energy (LE) program had a better performance when hatched at Location 2 than at Location 1, whereas performance was similar for the high-energy (HE) broilers hatched at both locations. Broilers fed the LE program had similar BW gain but a higher feed conversion due to a higher feed intake as compared to broilers fed the HE program. In addition, moisture content of the litter in the pens with LE birds was higher than in pens with HE birds. As a result, broilers fed the LE program had more footpad dermatitis and hock burns at d 36 as compared to broilers fed the HE program. It is concluded that the HE feeding program is preferred to prevent footpad dermatitis and hock burn, and with respect to growth performance. The differences in growth performance between the 2 hatch locations merit further study but indicate the importance of the incubation and hatching environment and posthatch handling in relation to the growth performance of broilers on-farm.  相似文献   

7.
Two experiments (EXP) were conducted to evaluate the interactive effects of dietary AME and amino acid (AA) density (total basis) on broiler chickens from 42 to 56 d of age. In EXP 1, diets were formulated to contain low AME (3,140 kcal/kg) and moderate AME (3,240 kcal/kg) in combination with moderate AA (16.2% CP, 0.88% Lys, and 0.75% TSAA) and high AA (18.0% CP, 0.98% Lys, and 0.83% TSAA) and fed to male broilers. Dietary treatments in EXP 2 were diets formulated to contain moderate AME (3,220 kcal/kg) and high AME (3,310 kcal/kg) combined with moderate and high AA concentrations used in EXP 1 and fed to male and female broilers. In general, dietary AME and AA did not interact to influence growth and meat yield responses. Broilers provided the low AME diet in EXP 1 consumed more feed and had poorer feed conversion but had higher total breast meat yield than birds fed the moderate AME diet. In EXP 2, broilers fed the high AME diet from 42 to 56 d had increased BW gain, decreased feed consumption, and improved feed conversion. Feeding the high AA diets in both EXP decreased feed consumption, improved feed conversion, and increased total breast meat yield. Nutritionists establishing nutritional programs for heavy broilers late in development from 2.5 to 3.6 kg may need to consider increasing AA density to optimize breast meat yield. Increasing the AME content of the diet improves feed conversion but not breast meat yield.  相似文献   

8.
本试验旨在研究不同油脂对肉鸡生长性能、屠宰性能及肉品质的影响。选取1日龄罗斯308肉鸡3 600只,随机分为4个处理,每个处理3个重复,每个重复300只,公、母各半。1～7 d,各处理组肉鸡饲喂相同日粮(豆油水平相同);7 d后日粮分别添加相同水平(中期3%和后期5%)的豆油、鸭油、棕榈油、米糠油。试验期37 d。结果表明:各处理组肉鸡各阶段及全期生长性能无显著差异(P>0.05);与豆油组相比,其他油脂有升高全期肉鸡耗料增重比和胸肌率的趋势(P<0.1);各处理组肉鸡胴体出成率无显著差异(P>0.05),但棕榈油组肉鸡胴体出成率最高,腹脂率最低;豆油组鸡胸肌离心损失最大,米糠油组胸肌滴水损失最大,肉品质较差;棕榈油组硫代巴比妥酸值和剪切力最小,且胸肌亮度和黄度较低,肉品质较好。综上所述,日粮中使用豆油有利于改善肉鸡生长性能,使用棕榈油能够提高胴体出成率和胸肌率,降低腹脂沉积,对肉品质有一定的改善作用。  相似文献   

9.
1. Pectoralis major (P. major) muscle pH and meat quality traits were studied in relation to bird response to ante-mortem stress in three chicken lines: a fast-growing standard line (FGL), a slow-growing French 'Label Rouge' line (SGL) and a heavy line (HL). Ninety-nine birds of the three genetic types were slaughtered at their usual marketing age (6, 12 and 6 weeks for FGL, SGL and HL birds, respectively) on the same day. The birds of each line were divided into three different ante-mortem treatment groups: minimum stress (shackling for 10 s) (C), shackling for 2 min (SH) and acute heat plus shackling stress (exposure to 35 degrees C for 3.5 h and shackling for 2 min before stunning) (H + SH). 2. Regardless of chicken line, wing flapping duration (WFD) between hanging and stunning was strongly negatively related to P. major muscle pH at 15 min post-mortem. It was also moderately negatively related to P. major muscle glycolytic potential (GP), which represents glycogen level at death. Increasing WFD induced an increased ultimate pH (pHu) only in HL. The consequences of increased WFD for breast meat traits were dependent on the chicken line: it induced lower L* and b* and higher a* and drip loss in SGL while it only increased breast a* in HL birds. By contrast, WFD variations did not alter breast meat quality traits of FGL birds. Regardless of the chicken line, increased GP was associated with lower pHu and higher L* and drip loss. In SGL, it also increased b* and decreased curing-cooking yield of breast meat. 3. Struggling activity on the shackle line and muscle glycogen content at death could partly explain line and pre-slaughter variations in breast meat pH and quality traits. The water holding capacity of the raw and cooked meat was impaired by long shackling in the case of SGL birds while it was barely affected by ante-mortem conditions in the two standard lines. In conditions which minimised bird struggling (C), SGL and FGL birds had meat with a better water holding ability than that of broilers from the heavy line. However, when broilers were subjected to SH or H + SH conditions, the breast meat water holding capacity of SGL birds was lowered to the same level as that of the heavy line birds.  相似文献   

10.
1. This study was conducted to examine the effect of different levels of humic substances (HS) administered in drinking water on caecal microflora and mineral composition and colour characteristics of breast and thigh meats and the growth performance, carcass and gastrointestinal tract (GIT) traits of broiler chicks.

2. A total of 480 3-d-old broiler chickens were randomly allocated to 4 treatments with 4 cages per treatment and 30 bird (15 males and 15 females) chicks per cage. All birds were fed on commercial basal diet. The control birds (HS0) received drinking water with no additions, whereas birds in the other treatment groups received a drinking water with 7.5 (HS7.5), 15.0 (HS15.0) and 22.5 (HS22.5) g/kg HS. Mush feed were provided on an ad libitum basis. Body weight and feed intake of broilers were determined at d 0, 21, and 42, and feed conversion ratio was calculated. On d 42, 4 broilers (2 males and 2 females) from each cage were slaughtered and the breast and thigh meats were collected for mineral composition and quality measurements.

3. Performance, carcass and GIT traits and caecal microbial population of broiler chicks at d 42 were not affected by the dietary treatments. The lightness (L*) of breast and thigh meat decreased in broilers supplemented with 15 and 22.5 g/kg HS in drinking water. Although the redness (a*) of breast meat increased, yellowness of thigh meat decreased in broilers supplemented with 15 and 22.5 g/kg HS in drinking water (P < 0.05).

4. In conclusion, the 15 and 22.5 g/kg HS administration in drinking water can be applied for broiler chicks to maintain growth performance and improve meat quality without changing caecal microflora.  相似文献   


11.
1. Four factorial experiments were carried out to determine whether there is any interrelationship between dietary energy-to-protein (E:P) ratio (experiments 1, 2 and 3) or pelleting the diet (experiment 4) and the duration of food withdrawal (FW), in their effect on carcase quality of broiler male chickens. The quality was evaluated by yields of carcase and breast meat, abdominal fat pad size, and the content and composition of the fat in the meat. The effect of sex on the response to FW was also determined in experiment 3 and that of age in experiment 4. 2. The diet with an E:P ratio higher than recommended decreased the weights of carcase and breast meat significantly (P 0.05) in 2 of the 3 experiments, and consistently increased the size of the abdominal fat pad and the fat content in thigh, but not in breast meat. Abdominal fat pad and the fat in meat of birds fed on this diet contained a significantly higher amount of oleic acid and a lower amount of linoleic acid, than the fat of birds fed on the diets with the recommended and the low E:P ratios. The pellets increased significantly the weights of carcase and breast meat and the relative size of abdominal fat pad. 3. FW for 24 h decreased significantly the weight at slaughter in all 4 experiments, carcase weight in 3 experiments, and breast weight in 1 experiment. However, it did not affect the relative size of the abdominal fat pad, the fat content in thigh and breast meat, and the composition of fatty acids in these tissues and in abdominal fat. None of the variables mentioned was affected significantly by the interaction between the dietary factors evaluated, sex or age of the birds on the one hand, and FW on the other hand. 4. It is concluded that the effect of 24 h of FW on weight at slaughter, carcase and breast meat weights and on fattening, is not affected by dietary E:P ratio, pelleting the diet, or sex and age of the broilers.  相似文献   

12.
1. Valine (Val) is considered the 4th limiting amino acid for broilers fed on diets containing ingredients from vegetable origin. However, Val and Isoleucine (Ile) may be co-limiting for broilers fed on diets containing animal protein meals. An experiment was conducted to examine growth responses and meat yield of broilers provided diets varying in digestible Val (dVal) and digestible Ile (dIle) concentrations from 28 to 42 d of age. 2. Eight experimental diets varying in dVal (dVal to dLys ratios from 0·66 to 0·76) and dIle (dIle to dLys ratios from 0·57 to 0·67) were studied; digestible Lysine (Lys) was formulated to 9·9 g/kg in all diets. 3. Broilers fed on a negative control (NC) diet supplemented with crystalline Val (L-Val) and crystalline Ile (L-Ile), dVal to dLys = 0·76 and dIle to dLys = 0·67, grew faster and had higher breast meat yield than birds fed on NC + L-Ile (dVal to dLys = 0·66 and dIle to dLys = 0·67), NC + L-Val (dVal to dLys = 0·76 and dIle to dLys = 0·57), and NC + reduced L-Val and L-Ile (dVal to dLys = 0·71 and dIle to dLys = 0·62). 4. Feeding broilers on the NC + L-Val and L-Ile (dVal to dLys = 0·76 and dIle to dLys = 0·67) diets gave similar BW gain, carcase weight and yield and total breast meat weight and yield to birds fed on the positive control-fed broilers with no added L-Val and L-Ile (dVal to dLys = 0·76 and dIle to dLys = 0·67). 5. These results indicate that Val and Ile are co-limiting in diets containing poultry by-product meal.  相似文献   

13.
Feeding high-quality pellets to modern commercial broilers may maximize genetic potential; however, this typically requires an increased cost to produce feed. Therefore, it is important to determine if incremental improvements in feed form (FF) can increase performance of modern broiler strains. The current study was conducted to investigate the effects of feeding modest improvements in feed form (50, 60, 70, or 80% intact pellets; IP) to 2 commercial broiler strains (fast-growing or high-yield) on d 28 to 42 growth performance and processing variables. A common diet was manufactured to contain 80% IP, of which a portion was ground to create a total of 4 FF treatments varying in IP to ground pellet ratios: 50:50; 60:40; 70:30; and 80:20. Fast-growing (FG) birds demonstrated improvements in body weight (BW), BW gain (BWG), and feed conversion ratio (FCR) when compared to high-yield (HY) birds. For the main effect of FF, feeding 80 vs. 50% IP reduced d 28 to 42 FCR. Also, feeding birds 80% IP vs. all other FF treatments improved d 28 to 42 BWG and d 42 BW. A Strain × FF interaction established that FG broilers fed 50, 60, and 70% IP diets had higher d 43 total breast yield than HY birds fed the same FF treatments; however, both strains demonstrated similar total breast yield when 80% IP were fed, which suggests that FG broilers are less sensitive and HY broilers are more sensitive to increasing FF. These data suggest a distinct benefit for feeding improved FF from d 28 to 42 to modern broilers.  相似文献   

14.
Phytate is an antinutrient in animal feeds, reducing the availability and increasing the excretion of nutrients. Phytases are widely used to mitigate the negative influences of phytate. This trial was designed to compare the efficacy of 2 Escherichia coli-derived phytases on broiler performance and bone ash as influenced by dietary phytate level. A total of 1,024 Arbor Acres male broilers were used with 8 replicate pens of 16 birds/pen. Experimental diets were based on low available phosphorus (avP; 1.8 g/kg) with low (6.40 g/kg) or high (10.65 g/kg) phytate. The low-avP diets were then supplemented with mono-dicalcium phosphate to increase the avP level to 4.5 g/kg, 500 phytase units/kg of phytase A, or 500 phytase units/kg of phytase B to create 8 experimental diets. Feed intake, BW gain, FCR, and livability were influenced by a P source × phytase interaction. Feed intake, BW gain, and livability were reduced and FCR was higher in broilers fed low-avP diets, particularly in the presence of high phytate. Phytase A or phytase B improved feed intake, BW gain, and FCR, particularly in the high-phytate diet. However, broilers fed phytase A ate more and were heavier than broilers fed phytase B. Tibia ash was lowest in broilers fed the low-avP diet and highest in broilers fed the diet supplemented with mono-dicalcium phosphate. Phytase increased tibia ash, and broilers fed phytase A had an increase in tibia ash compared with broilers fed phytase B. In conclusion, high dietary phytate reduced broiler performance. Phytase A and phytase B improved bone ash and growth performance, especially in the high-phytate diets. However, phytase A was more efficacious than phytase B, regardless of the level of phytate.  相似文献   

15.
The present study assessed the effect of feeding palm oil (PO), sunflower oil (SO) and their combination on performance, fat deposition, fatty acid composition and lipogenic gene expression of broilers reared for 42 days. A total of 144 1‐day‐old broilers (Cobb500) were randomly allotted into four treatment diets with each having six replicates of six chicks in each replicate following a completely randomized design. Live weight gain and feed efficiency was significantly (P < 0.05) higher in birds fed with a combination of oil sources compared to controls. Birds fed with the combination of oil and SO alone had higher carcass yield and lower abdominal fat. Higher (P < 0.05) concentrations of unsaturated fatty acids (UFA) and lower concentrations of palmitic acid and saturated fatty acid (SFA) was found in birds fed SO alone and combinations of SO and PO. Furthermore, the outcomes showed that birds fed diet supplemented with SO and the combination of SO and PO down‐regulated gene expression of key hepatic lipogenic enzymes of fatty acids synthase (FAS), acetyl‐CoA carboxylase (ACC) and stearoyl‐CoA desaturase (SCD). These findings suggest that the diet containing the combination of 2% PO and 4% SO may reduce hepatic lipogenesis, as well as lower abdominal fat content of broilers.  相似文献   

16.
Fasting of up to 24 hr has been shown to increase intestinal permeability (IP) in chickens. The aim of this study was to determine whether fasting duration of 4.5 and 9 hr increased IP and whether l ‐glutamine (a non‐essential amino acid) supplementation before fasting provided some protection of barrier function as shown in other species. Ross 308 male broilers (n = 96) were fed either a control diet or the same diet supplemented with 1% glutamine from d0 to d38 post‐hatch. On d37, the birds were assigned to single‐bird metabolism cages and were fasted for either 0, 4.5, 9 or 19.5 hr. This study design was 2 × 4 factorial with two levels of glutamine and four levels of fasting. Birds in the 0‐hr fasting group had free access to feed. All birds had ad libitum access to water. To measure IP on day 38, following their respective fasting periods, birds were administered two separate oral gavages of fluorescein isothiocyanate dextran (FITC‐d) followed by lactulose, mannitol and rhamnose (LMR) sugars, 60 min apart. Whole blood was collected from the jugular vein 90 min post‐LMR sugar gavage. FITC‐d and L/M/R ratios were measured by spectrophotometry and high‐performance ionic chromatography respectively. Lipopolysaccharide (LPS) endotoxins in plasma of the birds fed the control diet were also measured using chicken‐specific LPS antibody ELISA. Serum FITC‐d and plasma L/M and L/R ratios for 4.5, 9 and 19.5 hr were significantly (p < .05) higher compared to the non‐fasting group. However, IP was not different in the glutamine‐supplemented group (p > .05) compared to the control group. LPS concentrations measured by the ELISA were below the detectable range. We conclude that fasting periods of 4.5 and 9 hr increased IP compared to non‐fasted birds and dietary glutamine supplementation did not ameliorate changes in IP.  相似文献   

17.
1. An experiment was conducted with 98 male and 98 female broiler chickens (Ross 308) to study the effect of growth rate, induced by different dietary means, sex and live weight (1500?g and 2000?g) at slaughter on production parameters, bone strength and sensorial characteristics of the breast meat.

2. The birds were divided into four groups and individually fed a standard commercial diet, a high energy diet or low energy diet from d?11 to slaughter at between d 28 and 39. Three groups were fed ad libitum and a further group was fed a restricted amount of the high energy feed. Half of the birds in each group were slaughtered at approximately 1500?g and the other half at 2000?g live weight.

3. The diets resulted in different growth rates. The chickens fed the high energy and the commercial diet had the highest growth rate at both live weights at slaughter. The restricted fed chickens had lower bone strength than the chickens fed the low energy diet.

4. Breast meat from male broilers was juicer, more tender and less hard than breast meat from females. Chickens slaughtered at 2000?g live weight were juicer than those slaughtered at 1500?g. Chickens given the high energy feed ad libitum and restricted had different growth rates, but the sensory parameter related to texture showed no difference.

5. It was concluded that an increased slaughter weight might improve meat quality due to improved juiciness.  相似文献   

18.
The effect of provitamin A biofortified maize (PABM) diet inclusion on meat quality in male and female Ovambo chickens at 18 and 21 wk of age was evaluated. A total of 96 13-week-old Ovambo chickens were randomly distributed into 2 treatment groups and fed on white maize (WM) diet, the control, and PABM diet, a high provitamin A carotenoid maize. There was no significant effect of PABM, sex, and age on meat pH, drip loss (%), cooking loss (%) and shear force. The PABM fed chickens had higher redness (a*) and yellowness (b*) and lower lightness (L*) in the meat and skin color. Female birds had higher (P < 0.05) L* values than males on the skin. The a* value of the PABM fed male birds increased with age (P < 0.05). The PABM diet improved the skin and muscle color of the Ovambo chicken.  相似文献   

19.
The effects of dietary supplemental nicotinic acid (NA) on growth performance, carcass characteristics and meat quality were investigated in three genotypes of chicken. Fast‐growing AA (Arbor Acres) broilers were compared with two genotypes of a slow‐growing local breed, Beijing‐You, that had undergone selection for and against intramuscular fat content respectively (BJY+IMF and BJY?IMF). The treatments were arranged 3 × 4 factorial completely randomized design. Day‐old females (n = 624) were allocated to four treatments with six replicates per treatment and fed diets (basal contained ～25 mg NA/kg) supplemented with 0, 30, 60 and 120 mg NA/kg. A sample of 72 birds from each genotype was slaughtered at market time (8 weeks of age for AA and 16 weeks of age for BJY). The breast muscles of AA broilers were darker, had less redness and yellowness, lower drip loss and higher shear force as compared to the BJY genotypes (p < 0.01). The highest drip loss and the lowest shear force among the three genotypes were apparent in BJY+IMF (p < 0.01). Increasing supplementation from 0 to 60 mg NA/kg tended to increase average daily gain (ADG), average daily feed intake, width of intermuscular fat band, thickness of subcutaneous fat (including skin) and percentage of abdominal fat but, for most variables, values decreased slightly with 120 mg NA/kg. Increasing supplementation to 60 mg NA/kg decreased (quadratic, p < 0.001) drip loss, but it increased at 120 mg NA/kg. The present results indicate that (i) the AA broilers fed corn–soybean meal based‐diets require approximately 60 mg NA/kg to maximize ADG and meat product yield and decrease the drip loss of breast muscle; (ii) the addition of 30 mg NA/kg meets the requirement of BJY genotypes; and (iii) there seems to be no beneficial effect of NA supplementation on chicken meat quality except for limiting the drip loss.  相似文献   

20.
This study was conducted to evaluate the effect of dietary resveratrol (Res) supplementation on serum parameters, meat quality and muscle antioxidant status of broilers under heat stress (HS). A total of 270 21‐day‐old male Cobb broilers were randomly assigned to three treatment groups with six replicates of 15 birds each. The three treatment groups were as follows: the control group, in which birds were reared at 22 ± 1°C, and the HS and HS + Res (400 mg/kg) groups, in which birds were reared at 33 ± 1°C for 10 h (08.00–18.00 h) and 22 ± 1°C for the rest of the time. Compared with birds in the control group, birds in the HS group exhibited increased serum corticosterone (CORT) and triacylglycerol contents, L*, drip loss and muscle malondialdehyde content, and decreased serum glucose content, pH24 h, muscle total antioxidant capacity (T‐AOC), catalase (CAT) and glutathione peroxidase (GSH‐PX) activities (P < 0.05). Compared with birds in the HS group, birds in HS + Res group exhibited increased serum glucose content, a*, pH24 h, muscle T‐AOC and CAT activities, and decreased serum CORT and triacylglycerol contents, L*24 h, drip loss and muscle malondialdehyde content (P < 0.05). In conclusion, Res beneficially protects against HS‐impaired meat quality of broilers through regulating muscle antioxidant status.  相似文献   

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