Broiler Hens Research Articles

Fertility, Body Weight and Survivability of Two Lines of Broiler Stock under Selection

This study was conducted to evaluate the performance of two lines of broiler breeders under selection. The traits of interest were fertility, body weight and survival rate. A total of 120 day-old broiler chicks were hatched from two lines of broiler breeder chickens under selection (Sire and Dam lines). The chicks were hatched from a population of breeder hens and cocks with a mating ratio of 1 broiler cock to 6 broiler hens (1:6). Eggs were collected and pedigreed according to the lines and sire information. The eggs were weighed on a Camry model digital sensitive scale in grams. Eggs were set and hatched in a Buckeye incubator. Each hatched chick was tagged and weighed at hatching and then weekly up to 8 weeks. Data were analyzed using general linear model (GLM). Correlation and regression analysis were based on pooled data from both lines. Results showed that the lines differed with respect to fertility (67.67% and 83.00%), hatchability (77.79 and 49.00) and survival rate (77.78 and 94.14). Also changes in body weight increased as their ages increased with the dam line being superior. There was a low R2 value of between 0.05-0.33 when egg weight and hatch weight were pooled and considered as independent variables. In conclusion the lines were superior to each other differently as the sire line had better egg weight and hatchability while the dam line was better in fertility, survival rate and body weight performance. This variation in traits can be used in selection for hybrid strain in the broiler.

Fertility, Body Weight and Survivability of Two Lines of Broiler Stock under Selection

This study was conducted to evaluate the performance of two lines of broiler breeders under selection. The traits of interest were fertility, body weight and survival rate. A total of 120 day-old broiler chicks were hatched from two lines of broiler breeder chickens under selection (Sire and Dam lines). The chicks were hatched from a population of breeder hens and cocks with a mating ratio of 1 broiler cock to 6 broiler hens (1:6). Eggs were collected and pedigreed according to the lines and sire information. The eggs were weighed on a Camry model digital sensitive scale in grams. Eggs were set and hatched in a Buckeye incubator. Each hatched chick was tagged and weighed at hatching and then weekly up to 8 weeks. Data were analyzed using general linear model (GLM). Correlation and regression analysis were based on pooled data from both lines. Results showed that the lines differed with respect to fertility (67.67% and 83.00%), hatchability (77.79 and 49.00) and survival rate (77.78 and 94.14).Also changes in body weight increased as their ages increased with the dam line being superior. There was a low R2 value of between 0.05 – 0.33 when egg weight and hatch weight were pooled and considered as independent variables. In conclusion the lines were superior to each other differently as the sire line had better egg weight and hatchability while the dam line was better in fertility, survival rate and body weight performance. This variation in traits can be used in selection for hybrid strain in the broiler

Broyler de Gentamisinin Olumsuz Etkilerine Karşı Üzüm Çekirdeği (Vitis vinifera L.) Ekstresinin Yem Katkısı Olarak Kullanımı

In this study, it was aimed to determine the effects of V. vinifera L seed extract against the negative effects of performance parameters, organ weights and blood parameters due to the administration of gentamycin in broilers. A total of 240 Ross 308 chickens were divided into 4 groups with 6 replications of 10 birds per cage. Treatment groups: Control group was fed a basal diet only; group V was fed a diet supplemented with grape seed extract (100 mg/kg); group G was fed a basal diet and administered gentamycin (50 mg/kg body weight intramuscularly); group V+G was fed a diet supplemented with grape seed extract, and gentamycin in levels as in group V and G. The highest weight gain and feed intake at the 3rd, 4th, 5th and 6th weeks was observed in group C, and the lowest, statistically significant, was in group G. The highest carcass weight was in group C. The highest aspartate aminotransferase and alanine aminotransferase levels were in group G. The lowest red blood cell value was in group C. Liver weight was increased significantly in group G. In this study, it was observed that the use of gentamycin harmed the health of broiler hens, but these effects could be reduced partially with the grape seed extract added to the feed. For this reason, grape seed extract may be used as a feed additive with healing effect.

Innate immune training and metabolic reprogramming in primary monocytes of broiler and laying hens

Recently, we have reported trained innate immunity in laying chicken monocytes. In the present study, we further investigated trained innate immunity of monocytes in layers and broilers. Monocytes of both breeds isolated from blood were trained in vitro with β-glucan, rec-chicken IL-4 or a combination of both, and restimulated with lipopolysaccharide (LPS), after which inflammation and metabolism-related responses were measured. Training of laying and broiler hen monocytes resulted in increased mRNA levels of IL-1β, iNOS and HIF-1α, but enhanced surface expression of CD40 and NO production was only observed in layers. Our in vitro study demonstrates that monocytes from different genetic backgrounds can be trained. However, the observed differences suggest a differential effect on immune functionality associated with innate training. Whether these differences in immune functions between layers and broilers have effect on disease resistance remains to be elucidated.

Microbiota Changes Due to Grape Seed Extract Diet Improved Intestinal Homeostasis and Decreased Fatness in Parental Broiler Hens.

In poultry, the selection of broilers for growth performance has induced a deterioration in the health of the parental hens associated with poor reproductive efficiency. To improve these parameters, we administered to laying parental broiler hens a regular diet supplemented or not (Control) with a moderate (1%) or a high level (2%) of grape seed extract (GSE). The 1% GSE diet was administered from a young age (from 4 to 40 weeks of age) and the high level of 2% GSE was administered only during a 2-week period (from 38 to 40 weeks of age) in the laying period. The analysis of 40-week-old hens showed that 2% GSE displayed a reduction in the fat tissue and an improvement in fertility with heavier and more resistant eggs. Seven monomer phenolic metabolites of GSE were significantly measured in the plasma of the 2% GSE hens. GSE supplementation increased the relative abundance of the following bacteria populations: Bifidobacteriaceae, Lactobacilliaceae and Lachnospiraceae. In conclusion, a supplementation period of only 2 weeks with 2% GSE is sufficient to improve the metabolic and laying parameters of breeder hens through a modification in the microbiota.

A grape seed extract maternal dietary supplementation improves egg quality and reduces ovarian steroidogenesis without affecting fertility parameters in reproductive hens.

In broiler hens, the genetic selection increased susceptibility to metabolic disorders and reproductive dysfunctions. In human ovarian cells, grape seed extracts (GSE) improved steroid production. Here, we investigated the effects of a GSE dietary supplementation on egg production and quality, fertility parameters, Reactive Oxygen Species (ROS) and steroid content in yolk egg associated to plasma adipokines in broiler hens. For this, we designed two in vivo experiments, the first one included three groups of hens: A (control), B and C (supplemented with GSE at 0.5% and 1% of the total diet composition, respectively, since week 4), and the second one used two groups of hens: A (control) and D (supplemented with GSE at 1% of the total diet composition since hatching). We assessed the egg production from 23th to 40th weeks and quality at 33th week. After artificial inseminations, the fertility parameters were calculated. In egg yolk, Reactive Oxygen Species (ROS) level and steroid production were evaluated by Ros-Glo H202 and ELISA assay, respectively. Expression of steroidogenic enzymes and adipokines and their receptors was determined by RT-qPCR in ovarian cells and plasma adipokines (RARRES2, ADIPOQ and NAMPT) were evaluated by specific ELISA assays. The fertility parameters and egg production were unaffected by GSE supplementation whatever the experiment (exp.). However, the rate of double-yolk eggs decreased for all GSE supplemented groups (exp. 1 P <0.01, exp.2, P<0.02). In exp.1, C group eggs were bigger and larger (P<0.0001) and the shell elasticity was higher for both B and C (P<0.0003) as compared to control. In the egg yolk, GSE supplementation in both exp. reduced ROS content and steroidogenesis consistent with a decrease in P450 aromatase and StAR mRNA expression and basal in vitro progesterone secretion in granulosa cells (P<0.001). Interestingly, in both exp. RARRES2 plasma levels were positively correlated while ADIPOQ and NAMPT plasma levels were negatively correlated, with steroids and ROS in yolk (P<0.0001). Taken together, maternal dietary GSE supplementation did not affect egg production and fertility parameters whereas it reduced ROS content and steroidogenesis in yolk egg. Furthermore, it ameliorated egg quality by decreasing the number of double-yolk eggs and by improving the size of normal eggs and the elasticity of the shell. Taken together, our data suggest the possibility of using dietary maternal GSE to improve egg quality.

Effects in broiler hens of genetic lines differing in fertility, biotin supplementation, and age on relative abundance of oviductal transforming growth factor-β and carbonic anhydrase mRNA transcripts

There was evaluation of effects of biotin administration on oviductal abundance of transforming growth factor-β (TGF-β) and carbonic anhydrase (CA) mRNA transcript in younger and older broiler hens of relatively lesser and greater fertility lines. Additionally, effects of biotin supplementation on attenuation of age-related subfertility were evaluated. Hens from the relatively greater (Line D, n = 60) and lesser (Line B, n = 60) fertility rate line were randomly assigned to three treatment groups. Biotin was not or was administered in drinking water from 30 to 33 (younger age) and 53 to 56 (older age) wk of age to have access to no biotin (T0), or 0.3 (T1), or 0.45 (T2) mg/L of biotin. There was assessment the relative oviductal abundances of TGF-β and CA mRNA transcript abundances. Supplemental biotin and age had no effect on the relative abundance of oviductal TGF-β mRNA transcript in hens of Line D. There, however, was a ten-fold greater abundance of TGF-β in hens of the T0 group of Line B compared with Line D. Relative abundance of TGF-β mRNA transcript was greater in younger hens of Line B; however, biotin supplementation of older hens of the T2 group of Line B resulted in a similar TGF-β abundance to that of younger hens. Inconstant with the TGF-β abundance, CA abundance in hens of Line B was not affected by supplemental biotin or bird age. Overall, differences in TGF-β or CA abundances did not affect fertility of broiler hens.

Effect of maternal dietary supplementation with phytosterol esters on muscle development of broiler offspring.

Recently, embryo muscle development, which is crucial for postnatal skeletal muscle growth, has been investigated widely. Nutrients in ovo were suggested to be critical in embryo muscle development since the chick growth mostly relies on nutrients in eggs at the early developmental stage. Phytosterol esters (PE), which are derived from the reactions between phytosterols and fatty acids, were demonstrated to have important effects on lipid and cholesterol metabolism regulation. In order to reveal the effect of maternal lipid metabolism on the deposition of nutrients in eggs and the development of embryonic muscles, broiler hens were fed with a diet supplemented with 5% PE or control diet. Lipid deposition in eggs and growth of the hatched chicks were studied. We found that PE increased bile acid (BA) deposition in the eggs and serum of hens (p=0.02 and p<0.01, respectively), altered insulin and glucose level differentially in female and male offspring, and promoted body weight (p=0.02 for male and female on day 49), muscle fiber density (p=0.02 for female on day 49), and myogenin and myogenic determination factor (myoD) expression (p=0.03 and p=0.02 on day 49) by the activation of BA receptors in female, but not in male, offspring. Our study determined for the first time that PE promoted muscle development of chicks hatching from eggs laid by the hens, through regulating bile acid (BA) deposition and this may be attributed to the activation of BA receptors.

Electrochemical performances of activated carbon prepared using eggshell waste

This paper describes the preparation of activated carbon (Ac) from broiler hen eggshell (BES) and Country hen eggshell (CES) waste with the assistance of chemical activating agent orthophosphoric acid (H3PO4) and eggshell powder for 4:1 and 4:2 concentrations. XRD analysis affirmed the formation of Ac and the hexagonal structure of CaCO3 for both BES and CES samples. The average crystalline size, dislocation density, microstrain, lattice parameter, and cell volume values are found to be higher for CES. The FTIR spectra confirmed the presence of functional groups of BES and CES samples of Ac. UV-DRS spectra exhibited strong absorption in the visible region for BES and the bandgap value is found to be around 1.2 eV for both BES and CES. The surface morphology reveals the porous nature, irregular shape and uniform size particles of Ac. Cyclic voltammetry and electrochemical impedance spectroscopy measurements were performed to study the energy storage application. Though both BES and CES have showed the capacitive behavior, the sample BES exhibit higher specific capacitance of 155.8 F/g is achieved for BES than CES. Similarly, the Rs and Rct values are calculated from the impedance measurement and it is found to be lower for BES sample that indicates improved electrical conductivity.

Anti-Müllerian hormone type II receptor in avian follicle development.

Anti-Müllerian hormone (AMH) helps maintain the ovarian reserve by regulating primordial follicle activation and follicular selection in mammals, although its role within the avian ovary is unknown. In mammals, AMH is primarily produced in granulosa cells of preantral and early antral follicles. Similarly, in the hen, the granulosa cells of smaller follicles are the predominant source of AMH. The importance of AMH in mammalian ovarian dynamics suggests the protein and its specific Type II receptor, AMHRII, may have conserved functions in the hen. AMHRII mRNA expression is highest (P<0.01) in small follicles of the hen and decreases as follicle size increases. Similarly, expression of AMHRII and AMH is highest in granulosa cells from small follicles as compared to larger follicles. Dissection of 3-5 mm follicles into ooplasm and granulosa components shows that AMHRII mRNA levels are greater in ooplasm than granulosa cells. Furthermore, immunohistochemistry also revealed AMHRII staining in the oocyte and granulosa cells. AMH expression in mammals is elevated during periods of reproductive dormancy, possibly protecting the ovarian reserve. AMHRII and AMH mRNA were significantly higher (P<0.05) in nonlaying ovaries of broiler hens. In molting layer hens, AMHRII mRNA was significantly greater (P<0.05) compared to nonmolting hen ovaries. These results suggest that AMH may have a direct effect on the oocyte and, thereby, contribute to bidirectional communication between oocyte and granulosa cells. Enhanced expression of AMHRII and AMH during reproductive quiescence supports a potential role of AMH in protecting the ovarian reserve in hens.

Food restriction but not fish oil increases fertility in hens: role of RARRES2?

Overfed hens selected for their rapid growth become fatter and develop reproductive disorders. Herein, we aimed to demonstrate that food restriction leading to a weight reduction and/or a supplementation with fish oil may be effective in preventing reproductive disorders through the regulation of adipokine expression in broiler hens. This study included four groups of food restricted (Rt) or ad libitum hens (Ad, feeding at a rate 1.7 times greater than Rt hens) supplemented or unsupplemented with fish oil (1%). The Rt diet significantly increased plasma chemerin (RARRES2) levels during the laying period, delayed sexual maturity by one week and improved egg quality and fertility. These effects were associated with higher progesterone production in response to IGF1 (or LH) in cultured granulosa cells and in vivo egg yolk, as compared with Ad hens. Fish oil supplementation had similar effects to the Rt diet on progesterone (P < 0.05), but without any effect on fertility. Using RT-PCR, we found that RARRES2 levels were lower in theca cells of Rt hens and NAMPT levels were increased by the fish oil supplementation. A significant positive correlation between RARRES2 expression in granulosa cells and the weight of F1 preovulatory follicle was observed, as well as a negative correlation of plasma RARRES2 levels with hatchability. Thus, food restriction but not fish oil supplementation improved fertility, and this was associated with variations in RARRES2 plasma and ovarian expression in hens.

Framework and Evaluation of Total Material Requirement for Food Material: Specific TMR for Food Material in Japan

It is of great importance to consider strategic food production to cope with ongoing rapid increases in population. For effective mass food production, addition of fuel for heating, artificial fertilizers, and agricultural chemicals, etc. are indispensable. In order to supply these inputs, a large amount of mining activities accompanied with energy and mineral resources are required, and these are largely hidden flows from the perspective of the consumer. In this study, we have proposed a framework to quantify mining activities relevant to food production in terms of total material requirement (TMR), which has been applied to food material in Japan as a case study. Targeted food material were 41 types of domestic vegetables, 8 types of fruit, 16 types of seafood, and 5 types of livestock. Domestic and foreign livestock feed was also considered. The functional unit was set as “1 kg of food material to be shipped”. The results indicated that the specific TMR (kg-TMR/kg) for food material with similar production methods showed similar values. Generally, contributions by energy were dominant for vegetables cultivated in a greenhouse and fertilizer inputs were dominant for non-greenhouse cultivation. On the other hand, the specific TMR of livestock feed was relatively small compared to vegetables, with no major difference observable among the different feed types. The specific TMR for seafood production by set net fishing was relatively low compared to other fishing and the effects of fishing tools and energy were negligibly small, the effect of energy ascribed to fuel was dominant for other fishing types using boats. For livestock, the specific TMR for a beef cow was 5 〜 6 times as high as that for pigs or broiler hens.

Meat quality characteristics of chickens raised organically and intensively

The aim of the study was to evaluate selected physical and chemical characteristics of the breast muscles of organically and intensively raised chickens. The parameters determined are important to consumers in assessing meat quality. The experimental material consisted of crossbred chickens obtained from crossing a white broiler cock from Ross 308 parent stock with a brown dual-purpose Rhode Island Red R-66 hen (group E) and Ross 308 commercial crossbred broiler hens (group K). Chickens from group E were reared over 84 days in accordance with the requirements of organic farming, while the group K chickens were reared conventionally over 42 days. The results indicate differences in post mortem changes in the breast muscles of the organically and intensively raised chickens. The muscles of broiler chickens from organic farming were characterized by good nutritional value (1.73 pp more protein and 0.46 pp less fat) and a darker colour (L* 49.65), which may be a desirable feature for many consumers. However, the high pH24 level of the breast muscles of organic chickens indicates that the meat may be susceptible to microbiological contamination and can only be stored for a short period. Furthermore, it requires a greater shear force (54.12 N raw and 46.66 N cooked), which may indicate that the meat needs to be cooked longer.

Feeding regimen of breeder broiler hen influences growth performance of the broiler chickens

This experiment was conducted to evaluate the effect of feeding regimens for the breeder broiler hen on the performance of broiler chickens. Breeder broiler hens (196 hens and 28 roosters; age between 31 and 38 wk) were randomly assigned to 7 dietary treatments that differ in the proportion of daily allowance served at different times with 1 (100% at 0400h), 2 (50% at 0400 and 1600, or 75% and 25% at 0400 and 1600, respectively), 3 (33% at 0400, 1200 and 1600, or 50% at 0400 and 25% at 1200 and 1600), and 4 (33% at 0400, 22% at 0800, 1200 and 1600, or 55% at 0400 and 17% at 0800, 1200 and 1600) meals in every 24-h cycle. There were 4 replicates per treatment, each consisted of 7 hens and 1 rooster received experimental diets for 8 wk continuously. The growth performance, feed intake, feed conversion ratio, protein intake, protein conversion ratio, energy intake, and energy conversion ratio in the broiler chicken were evaluated for 42 d. Dietary regimens (frequency and timetable) for breeder broiler hens affected (P < 0.001) the feed intake, feed conversion ratio, protein intake, protein conversion ratio, energy intake, and energy conversion ratio in the offspring (d 0–42). Overall feed conversion, protein conversion and energy conversion in broiler chickens from breeder hens received daily allowances in 3 or 4 meals were improved compared to those from breeder hens received 100% dietary allowance as a single meal. It is concluded that providing the daily diet allowance of breeder broiler hens in 3 or 4 meals is likely to improve growth performance in their offspring.

Obesity-associated cardiac pathogenesis in broiler breeder hens: Pathological adaption of cardiac hypertrophy ,

Broiler hens consuming feed to appetite (ad libitum; AL) show increased mortality. Feed restriction (R) typically improves reproductive performance and livability of hens. Rapidly growing broilers can exhibit increased mortality due to cardiac insufficiency but it is unknown whether the increased mortality of non-R broiler hens is also due to cardiac compromise. To assess cardiac growth and physiology in fully mature birds, 45-week-old hens were either continued on R rations or assigned to AL feeding for 7 or 21 days. AL hens exhibited increased bodyweight, adiposity, absolute and relative heart weight, ventricular hypertrophy, and cardiac protein/DNA ratio by d 21 (P < 0.05). Increased heart weights due to hypertrophic growth was attributed to enhanced IGF-1-Akt-FoxO1 signaling and its downstream target, translation initiation factor 4E-BP1 in conjunction with down-regulation of ubiquitin ligase atrogin-1/MAFbx (P < 0.05). Reduced activation of cardiac AMPK and downstream activation of ACC-1 in parallel with increased cardiac nitric oxide levels, calcineurin activity, and MAPK activation in AL hens (P < 0.05) suggested that metabolic derangement develops along the cardiovascular remodeling. These indictors of cardiac maladaptive hypertrophic growth were further supported by uregulation of heart failure markers, BNP and MHC-β (P < 0.05). Hens allowed AL feeding for 70 d exhibited a higher incidence of mortality (40% vs. 10%) in association with ascites, pericardial effusion, and ventricle dilation. A higher incidence of irregular ECG patterns and rhythmicity consistent with persistently elevated systolic blood pressure and ventricle fibrosis were observed in AL hens (P < 0.05). These observations support the conclusion that AL feeding in broiler hens results in maladaptive cardiac hypertrophy that progresses to overt pathogenesis in contractility and thereby increases mortality. Feed restriction provides clear physiological benefit to heart function of adult broiler hens.

Obesity-associated cardiac pathogenesis in broiler breeder hens: Development of metabolic cardiomyopathy ,

Feed intake is typically restricted (R) in broiler hens to avoid obesity and improve egg production and livability. To determine whether improved heart health contributes to improved livability, fully adult 45-week-old R hens were allowed to consume feed to appetite (ad libitum; AL) up to 10 wk (70 d). Mortality, contractile functions, and morphology at 70 d, and measurements of cardiac hypertrophic remodeling at 7 d and 21 d were made and compared between R and AL hens. Outcomes for cardiac electrophysiology and mortality, reported separately, found increased mortality in AL hens in association with cardiac pathological hypertrophy and contractile dysfunction. The present study aimed to delineate metabolic cardiomyopathies underlying the etiology of obesity-associated cardiac pathology. Metabolic measurements were made in hens continued on R rations or assigned to AL feeding after 7 d and 21 days. AL feeding increased plasma insulin, glucose, and non-esterified fatty acid (NEFA) concentrations by 21 d (P < 0.05). Metabolic cardiomyopathy in AL-hens was confirmed by cardiac triacylglycerol (TG) and ceramide accumulation consistent with up-regulation of related enzyme gene expressions, and by increased indices of oxidation stress (P < 0.05). In contrast to R hens, cardiac pyruvate dehydrogenase (PDH) activity and glucose transporter (GLUT) gene expressions increased progressively while carnitine palmitoyltransferase-1 (CPT-1) transcript levels in AL hens declined from 7 d to 21 d (P < 0.05), reflecting a shift from an oxidative to a more glycolytic metabolism, a typical metabolic derangement associated with cardiac hypertrophic remodeling. Cardiac pathogenesis in AL hens was further indicated by increased leukocyte infiltrates, interleukin-1β (IL-1β) and IL-6 production, cellular apoptosis, interstitial fibrosis, and expression of the heart failure marker myosin heavy chain (MHC-β; cardiac muscle beta) (P < 0.05). Results support the conclusion that diabetic conditions, cardiac inflammation and lipotoxic metabolic derangements act as pathological cues to trigger pathogenic changes along cardiac hypertrophy in AL hens.

Primary Newcastle disease vaccination of broilers: comparison of the antibody seroresponse and adverse vaccinal reaction after eye–nose drop or coarse spray application, and implication of the results for a previously developed coarse dry powder vaccine

ABSTRACTTo compare antibody seroresponse and adverse vaccinal reaction induced by Newcastle disease (ND) vaccination after eye–nose drop or coarse spray, groups of SPF broiler hens were vaccinated at day 4 (day of hatch is day 0) and intratracheally inoculated with Escherichia coli at day 11. Body weight gain (BWG) was assessed between day 4 and day 18; colibacillosis lesions and serum antibodies were determined at day 18. Meaningful comparison requires similar vaccine uptake. Vaccine virus loss during spray relative to eye–nose drop, which was assessed by comparing the results of endpoint titrations, was 3 log10. Colibacillosis lesions in birds spray vaccinated with 106.4 EID50/chicken were significantly more severe (P < 0.05), compared to those in birds eye–nose drop vaccinated with 103.4 EID50/chicken, while the seroresponse was slightly but significantly (P < 0.05) stronger. Colibacillosis lesion scores inversely paralleled BWG. It is concluded that: (1) There is room to improve the coarse ND vaccine spray used regarding adverse vaccinal reaction, while maintaining a sufficient immune response. This is also applicable to the coarse ND powder vaccine studied in previous research, which induced similar antibody response and adverse vaccinal reaction as the spray vaccine used here. (2) The vaccine virus dose influences the colibacillosis susceptibility at seven days post vaccination, as the dynamics of the vaccine virus infection is likely dose-dependent. (3) Low vaccine virus doses likely result in heterogeneous vaccine-take followed by vaccine virus spread from vaccine shedding birds to their non-vaccine virus infected flock mates (“rolling vaccinal reaction”).

Effects of aging on characteristics of breast meat from free-range broiler hens at 12 or 70 weeks of age

We evaluated the effect of broiler age and aging process on the meat characteristics of breast fillets from female free-range broilers slaughtered at 12 weeks of age (Wk12) and 70 weeks of age (Wk70). We used breast meat from female ISA Label (n = 60) broilers. Ten samples of each broiler age were aged in an incubator (2°C ± 0.5°C) for 3 and 7 days. Ten samples for each broiler age were analysed 4 h post-slaughter (Control group). Compared with breast meat from Wk12, breast meat from Wk70 showed higher shear force (30.52 N vs 27.19; P = 0.0322) and total collagen (4.33 g/kg vs 3.77 g/kg; P = 0.0149), which were reduced during aging to 15.49 N and 3.92 mg/100 g, respectively. The aging process did not affect the lipid oxidation of breast meat from Wk70. After aging for 3 days, breast meat from Wk70 had similar protein and fat contents to those of meat from Wk12 (21.29% and 1.04%, on average, respectively). Breast meat from Wk70 also showed lower concentrations of docosahexaenoic (0.32% vs 0.65%; P &lt; 0.0001) and eicosapentaenoic (0.01% vs 0.12%; P &lt; 0.0001) fatty acids than meat from Wk12. The use of free-range hen meat is beneficial to the industry because of the lower storage and cooking losses, which may influence the final yield, besides its lower polyunsaturated fatty acid concentration, which makes it less vulnerable to rancidification. Aging for at least 3 days at 2°C is satisfactory to promote the tenderisation of meat from free-range broiler hens.

Isolation, Characterization and Identification of Bacterial Isolates From the Poultry Environment at Rajshahi Metropolis, Bangladesh

Bacterial isolates from commercial poultry feeds and from eggs, ovaries and oviducts of the broiler hens (Gallus domesticus L.) were used for characterization, bacterial load estimation, antibiogram profile analyses and identification. The presence of both Gram-positive and Gram-negative bacteria in the environment was indicated and bacterial loads in terms of total viable counts (TVCs) of the isolates were much higher in the reproductive organs than in the poultry feeds. Majority (33.33%) of the isolates was sensitive, 28.33% hypersensitive, 25.0% resistant and 13.33% intermediate against eight antibiotics. Three bacteria Bacillus cereus, Sphingobacterium daejeonens and Bacillus sp. were confirmed by 16S rDNA gene sequencing. Pathogenic bacterial contamination in the poultry feeds and reproductive organs of broiler chickens reinforces the need for proper hygiene in the processing of the poultry products for human consumption and a need for implementing measures that guard against the misuse of antimicrobial drugs in chicken feeds is therefore emphasized.

Relationship between Body Weight Performance and Plasma Thyroid Hormones in Broiler Hens

Relationship between Body Weight Performance and Plasma Thyroid Hormones in Broiler Hens