Female Broiler Research Articles

Effect of turmeric and garlic supplementation to fermented Sauropus androgynus-bay leaves containing diet on fat deposition and broiler meat composition

This study aimed to examine the effect of turmeric and garlic inclusion to fermented Sauropus androgynus-bay leaves (FSBL) containing diet on fat deposition, and chemical composition of broiler meats. Two hundred 15-day-old female broilers were distributed into 5 treatment groups with 4 replications as follows. Control feeds with commercial feed additive (T0); Feeds with 1.25% FSBL (T1); Feed with FSBL plus 1 g turmeric (T2); Feed with FSBL plus 2 g garlic (T3); Feed with FSBL plus 1 g of turmeric and 2 g garlic (T4). It was shown that the fat deposition in the abdomen was significantly affected (P<0.01). Furthermore, the inclusion of turmeric and garlic to FSBL containing diet did not affect fat, protein, moisture and ash contents, but increased arginine, methionine and histidine (P<0.01). The addition of turmeric and/or garlic to the FSBL containing diet significantly influenced lauric acid, myristic acid, linolenic acid, cis-11-eicosenoic acid, cis-4,7,10,13,16,19-docosahexaenoic acid (P<0.05), n-3 fatty acid and n-6/n-3 fatty acid ratio (P<0.01). In conclusion, turmeric plus garlic supplementation improved amino acid profiles and changed fatty acid profiles. The possible interaction should be considered when we formulated feed additive from medicinal plant mixtures

Efficacy of probiotic Enterococcus faecium in combination with diclazuril against coccidiosis in experimentally infected broilers.

The study was conducted to investigate the combination of a probiotic strain of Enterococcus faecium and diclazuril to control coccidiosis in broilers. A total of 240 one-day-old female broiler chicks were divided into eight groups (30 chicks per group): prophylactic groups (G1, G2 and G3) and therapeutic groups (G4, G5 and G6) and two control groups (untreated infected, G7 and untreated uninfected, G8 controls). In the prophylactic approach, diclazuril alone (G1), probiotic alone (G2) or a mixture of both probiotic and diclazuril (G3) was orally administered to the chicks via drinking water 10days prior to the infection. However, in the therapeutic approach, G4, G5 and G6 birds were administered diclazuril alone, probiotic alone and diclazuril+probiotic mix, respectively, in drinking water for five consecutive days after the appearance of clinical signs of coccidiosis. Birds of both approaches and G7 were experimentally infected with 25×103 Eimeria-sporulated oocysts. Chicks in G3 showed the highest weight gain, the lowest lesion score, a low oocyst count and mortality rate among the challenged groups. Moderate lesion scores and oocyst counts were observed in chickens administered probiotics prophylactically. In the therapeutic approach, broilers in G6 but not G5 displayed a decreased mortality rate and lesion score in comparison to those in G7 and G8. However, the result of the probiotic-treated group was not significantly different from that in the untreated infected control group. The probiotic supplementation as a prophylactic approach can decrease the adverse effects of eimerian infection. In addition, the probiotic and diclazuril mix achieved a considerable improvement in the growth performance. Therefore, probiotic plus diclazuril combination achieved a synergistic effect. Investigation into the synergism/antagonism between a probiotic and diclazuril as anticoccidial agent and the difference in the timing of administration.

Optimum standardized ileal digestible tryptophan intake for broiler chickens

Six feeding trials were conducted to determine the optimum intake of standardized ileal digestible (SID) tryptophan of male and female broiler chickens in the starter (0 to 14 d), grower (14 to 28 d), and finisher (28 to 42 d) phases. In each trial, 640 broiler chickens were randomly assigned to 1 of 8 treatments, with 4 replicates of 20 broiler chickens. Diets were formulated by mixing a high and a low protein diet in different proportions, and dietary concentrations of SID Trp ranged 0.56 to 2.94, 0.54 to 2.75, and 0.52 to 2.60 g/kg in the starter, grower, and finisher phases, respectively. Tryptophan intake was regressed against average daily gain (ADG) and feed conversion ratio (FCR) using polynomial regression and broken-line regression model and the model that better fitted data was chosen according to Bayesian information criterion. Broiler chickens responded quadratically to increasing dietary Trp concentration and ADG was maximized at 86, 264, and 441 mg SID Trp/d for male broiler chickens (R2 = 0.96; P < 0.01) and at 76.5, 237, and 278 mg SID Trp/d for females (R2 = 0.97; P < 0.01) in the starter, grower and finisher phases, respectively. Feed conversion ratio was optimized at 69.9, 247, and 338 mg SID Trp/d for males (R2 = 0.91; P < 0.01) and 67.8, 223, and 280 mg SID Trp/d for females (R2 = 0.93; P < 0.01) in the starter, grower, and finisher phases, respectively. The optimum SID Trp intake for each sex and phase was determined based on ADG.

The effect of qualitative feed restriction in broiler breeder pullets on fear and motivation to explore

Restrictively fed broiler breeders are known to have increased motivation to explore and reduced fearfulness because hunger increases the motivation to search for and to acquire food, forcing the birds to face and engage with aversive stimuli that they would otherwise avoid. The aim of this study was to compare the effects of four dietary treatments on the level of fear and motivation to explore during rearing. In total, 1200 female breeder chicks of the genotype Ross 308 were housed in 24 pens, six pens of 50 birds per treatment. The treatments were: 1) standard feed (Control), 2) feed containing insoluble fibres (Insoluble), 3) feed containing a mix of both insoluble and soluble fibres (Mixed) and 4) standard feed supplemented with maize silage (Roughage). The treatments followed a qualitative restriction feeding strategy meant to allow the birds to consume larger portions of feed, increasing feeding time and reducing hunger and frustration. A novel object (NO) test was performed in the home pens at 6, 13 and 18 weeks of age. The test was performed two times at each age: 1 h before feeding and 5 h after feeding. In addition, at 7 weeks of age, 12 birds from each pen from all treatment groups were subjected to a tonic immobility (TI) test. We hypothesised that the Control birds would be less fearful in the TI test and keep a shorter distance to the NO than the treatment birds. For the NO test, there was an effect of the interaction between treatment and time of day on the likelihood of the birds to approach the NO at all ages (P ≤ 0.0001). At 13 weeks of age, in the afternoon, birds from the Mixed treatment were more likely to approach the NO compared to the birds from the Insoluble and Roughage treatments (P = 0.003) and tended to be more likely to approach than Control birds (P = 0.009). This suggests that the Mixed birds were in a hungrier state at that moment and therefore more willing to approach a NO than the birds fed the other dietary treatments. There was no effect of treatment on the latency to touch the NO or on the TI test. The results show minimal effects of the three qualitative dietary treatments on fearfulness and motivation to explore in female broiler breeders during rearing and, therefore, do not provide evidence of decreased sensation of hunger.

Reduction in dietary lysine increases muscle free amino acids through changes in protein metabolism in chickens

Taste is crucial to meat quality, and free Glu is an important taste-active component in meat. Our recent study showed that the short-term feeding of a low-Lys diet increases the concentration of free Glu and other free amino acids in chicken muscle and improves its taste. Here, we investigated the mechanisms by which the feeding of a low-Lys diet increases free Glu in chicken muscle. Two groups (n = 10 per group) of 28-day-old female Ross strain broiler chickens were fed diets with a graded Lys content of 90% or 100% of the recommended Lys requirement (according to National Research Council [1994] guidelines) for 10 D. Free amino acid concentrations and the mRNA abundance of protein metabolism–related genes were measured in breast muscle, and breast muscle metabolome analysis was conducted. Free Glu in muscle was increased by 51.8% in the Lys 90% group compared with the Lys 100% group (P < 0.01). Free threonine, glutamine, glycine, valine, isoleucine, leucine, tyrosine, phenylalanine, histidine, and 3-methyl-histidine concentrations in breast muscle were also increased in the Lys 90% group (P < 0.05). Metabolome analysis also showed that free amino acids were increased in the Lys 90% group. The mRNA abundance of μ-calpain, caspase-3, and 20S proteasome C2 subunit were increased in the Lys 90% group (P < 0.05). Moreover, the free Glu concentration in muscle was correlated with mRNA abundance of μ-calpain (r = 0.74, P < 0.01), caspase 3 (r = 0.69, P < 0.01), 20S proteasome C2 subunit (r = 0.65, P < 0.01), and cathepsin B (r = 0.52, P < 0.05). Our study suggests that the feeding of a low-Lys diet to chickens increased the free Glu content of breast muscle by promoting protein degradation.

Effects of the DMRT1 genotype on the body weight and gut microbiota in the broiler chicken

Intestinal microbiota is a critical determinant of growth and risk of metabolic diseases. Our previous studies showed that the locus rs16775833 within the DMRT1 gene is significantly associated with variation in the population structure of the gut microbiota, which is involved in determining the BW of the chicken. To assess the accuracy of correlation of rs16775833 located in the DMRT1 gene on microbial population and BW in birds, 2 genotypes GG and TT in the rs16775833 were identified in Chinese Yellow broiler breeders. We found that BW in the TT genotype group was significantly higher than in the GG genotype group at 7 and 13 wk of age in 777 female chickens. A full-length 16S rRNA sequencing approach was used to further evaluate the fecal bacterial composition of female broilers in 11 TT genotype chickens with high weight (HW-TT) and 11 GG genotype chickens with low weight (LW-GG) at 91 D of age. Partial least squares discriminant analysis revealed that the microbiota of the HW-TT and LW-GG females were clearly separated into 2 clusters. Furthermore, we identified 13 significantly different (P < 0.05) microbes at the genus level and 17 significantly different (P < 0.05) species between the HW-TT and LW-GG groups. Our data show that rs16775833 can modulate the microbial community structure and is associated with the BW of birds. To our knowledge, this is the first time that DMRT1 has been identified as a specific host factor, which is not only involved in sex determination but also has an effect on microbial function that might regulate animal growth.

Suplemento de 1,25-dihidroxicolecalciferol e redução de cálcio e fósforo disponível para frangos de corte fêmeas

A indústria avícola tem buscado programas nutricionais eficazes a fim de se obter o suprimento exato de nutrientes aos animais, reduzir os custos e minimizar os impactos ambientais advindos de excretas da produção animal. Dentre tais nutrientes, têm-se as vitaminas e os minerais, essenciais para o desenvolvimento animal, uma vez que participam em inúmeros processos fisiológicos. Objetivou-se avaliar o desempenho e o rendimento de carcaça e de cortes nobres de frangos de corte fêmeas alimentados com rações suplementadas com 1,25-dihidroxicolecalciferol (1,25(OH)2D3) e níveis reduzidos de cálcio (Ca) e fósforo disponível (Pdisp). Foi utilizado um delineamento em blocos casualizados, com seis tratamentos (0,0; 1,0; 2,0; 3,0; 4,0 e 5,0 µg de vitamina D3 ativa/kg de ração), e seis repetições com 17 aves cada (n=612). A vitamina D3 ativa estudada (1,25(OH)2D3-glicosídeo) foi de origem vegetal, advinda da Solanum glaucophyllum. No uso suplementar até 5 µg 1,25(OH)2D3/kg de ração associado aos níveis subótimos de Ca e Pdisp verificou-se decréscimo linear no consumo de ração (p&lt;0,05), melhoria da conversão alimentar (p&lt;0,05) e resultados satisfatórios de rendimentos de carcaça e de cortes nobres comerciais (peito e coxa + sobrecoxa) de frangos de corte fêmeas aos 42 dias de idade.

Alternative procedure for determining lysine maintenance requirement in poultry

ABSTRACT The objective with this study was to determine the lysine maintenance requirements (LMR) of male and female broilers as animal models. A total of 252 birds were used for nitrogen balance trials during three periods (I: 6-21, II: 22-37, and III: 38-53 days). Six lysine levels were used (2.76, 5.88, 8.99, 12.1, 15.2, and 18.3 g kg−1) with six replications. A control group also included, totalizing seven treatments for males and females for each assay. The experimental period was [...]

Targeted differential monochromatic lighting improves broiler breeder reproductive performance

Light perception in birds is composed of the retina and extraretinal sites, located in the brain. Previous studies indicate that selective photostimulation of the eye decreased reproductive performance, whereas extraretinal photostimulation increases it. Differential photostimulation of the retina and extraretinal sites is based on the retina's sensitivity to green wavelengths and on the red wavelengths' ability to penetrate body tissues.We previously found that short-day exposure to green light within a long-day exposure to red light increases reproductive activity in female turkeys and broiler breeder hens. Furthermore, in a study conducted recently in our laboratory, we found that blue light repressed expression of green light receptor in the retina, which can further enhance reproduction activity in broiler breeders. Here, we examined the “brain activate/eye deactivate” hypothesis on gonadal axis activity and reproductive performance in a broiler breeder flock.Broiler breeder hens and roosters (ROSS 308) were divided into 5 light-treatment groups (controlled rooms with light-emitting diodes [LED] lamps): warm white (control), long-day (14 h) red (630 nm) and short-day (6 h) green (514 nm) (red-green), long-day green and short-day red (green-red), long-day red and short-day blue (456 nm) (red-blue), and long-day blue and short-day red (blue-red). Birds were reared from 20 to 55 wk of age. Eggs were collected daily. Weekly egg production calculated. All eggs were incubated for fertility and hatchability examination. Blood was drawn monthly for plasma analysis. At 35 wk of age (after peak production) and 55 wk of age (end of the experiment), 10 hens from each treatment group were euthanized, and selected tissues and glands were taken for gene expression trials.Providing long-day red light to extraretinal photoreceptors while maintaining retinal photoreceptors on short day with blue or green light significantly improved reproductive activities, manifested by elevated egg production and gonadal axis activity compared with Controls and primary breeder recommendations. Long-day green light reduced reproductive performances. We suggest that targeted photostimulation enhances reproductive and gonadal axis activities in broiler breeders.

The effect of silica-calcite sedimentary rock contained in the chicken broiler diet on the overall quality of chicken muscles

AbstractOpoka is a silica-calcite sedimentary rock chemically and structurally similar to diatomaceous earth (DE), composed mainly of silicon dioxide (SiO2), calcium carbonate (CaCO3), amorphous SiO. Opoka occurs predominantly in South Eastern Europe and Russia. Due to these specific properties investigation on the effect of opoka-enriched diet on chemical composition and overall quality of breast and leg muscles of broilers was initiated. Working samples showed a statistically significant increase in ash content or water content and a decrease in lipid content in the leg muscles of both male and female broilers (P&lt;0.01). Furthermore, the addition of opoka to the diet increased WHC of leg muscles in females and hardness or chewiness of these muscles in both genders (P&lt;0.05). The supplementation of broiler diet with opoka can be effectively applied to modify texture features of leg and breast muscle tissue which might, in turn, serve to regulate the nutritional and technological value of chicken meat.

Research Note: Comparative gastrointestinal, tibia, and plasma attributes in 48-day-old fast- and slow-growing broiler chicken strains

Emerging market differentiation for broiler meat from strains exhibiting a range of growth rates is necessitating comparative research on various physiological and production aspects of these strains. The objective of the present study was to compare select gastrointestinal, tibial, and plasma attributes in a sample of 48-day-old (50 male and 50 female) broilers obtained from fast-and slow-growing flocks maintained under similar feed and management regimens. Eight birds were randomly selected from a fast (B; representative of modern commercial strains) and each of the 4 slow-growing strains (SG; D, H, M, and E). The strains differed by estimated time to reach 2.2 kg bodyweight corresponding to 36, 50, 42, 44, and 50 D for B, D, H, M, and E, respectively. Blood samples were collected to determine plasma metabolites, and birds were subsequently euthanized, weighed, and necropsied for gizzard and small intestine weight, jejunal tissue for histomorphology, ceca digesta samples for concentration of short-chain fatty acids (SCFA) and left tibia for ash content. Gizzard was heavier (P < 0.01) for D, H, and M than that for B and E, whereas the small intestine was lighter (P < 0.01) for B, D, and H than for M and E. There were no (P > 0.05) strain differences on SCFA, jejunal villus height and crypt depth, plasma proteins, and electrolytes. Strains D, H, and M exhibited higher (P = 0.01) tibia ash concentration than B; E was intermediate and not different (P > 0.05) from any strain. Specifically, the tibia ash for B, D, H, SG 3, and E were 1.24, 1.44, 1.43, 1.49, and 1.39 g/kg BW, respectively. The B birds showed higher (P < 0.01) plasma concentrations of aspartate transaminase, creatine kinase, lactate dehydrogenase, and creatinine than SG strains. In conclusion, although B and some SG strains had lighter gastrointestinal tract indicative of energy efficiency, higher circulating plasma enzymes in B birds suggested impaired hepatic function. Moreover, lower tibia ash in B suggested disproportionate body mass relative to skeletal support.

Effects of Dietary Amino Acid Regimens on Live Performance and Processing Characteristics of Cobb MV × 700 Male and Female Broilers

The magnitude and timing of broiler responses to dietary amino acid (AA) density can vary between sexes and among genetic lines. Two experiments (Exp) were conducted to determine the responsiveness of Cobb MV × 700 broilers to changes in dietary AA density. In Exp 1, low (L), medium (M), and high (H) AA density diets were maintained across starter and grower phases in a 28 d growth performance trial (all males). In Exp 2, combinations of L, M, and H-AA density diets were varied across 4 feeding phases to evaluate the effect of 6 AA feeding regimens (HHHH, HHHM, HHMM, HMMM, MMMM, and HHLL) on growth performance, carcass composition, and breast muscle myopathies of broilers reared sex-separately. Body weight gain, feed intake (FI), and FCR responded positively to increased AA density during the starter and grower phases (0 to 28 d) of Exp 1. In Exp 2, broiler responses to AA density from 0 to 28 d diminished by the conclusion of the finisher phase (day 35), and FCR was the only measurement influenced by dietary AA density through day 46. Carcass characteristics and breast muscle myopathies were unaffected by AA density, with the exception of fat pad percentage, which decreased with increasing AA density. These data indicate that Cobb MV × 700 broilers may be less responsive to dietary AA density than other high-yielding broiler strains and further research to establish digestible AA:Lys ratios or dietary energy concentrations that optimize responses to increased AA density are warranted.

Effects of dietary supplementation of 4-O-methyl-glucuronoarabinoxylan on growth performance, thigh meat quality and development of small intestine in female Partridge-Shank broilers

AbstractRecently, Echinacea purpurea and its extracts have gained much interest due to their improvement on meat quality, but little information is available on the application of the purified Echinacea purpurea polysaccharide (4-O-methyl-glucuronoarabinoxylan, 4OMG). Thus, this trial aimed at assessing the effects of dietary supplementation of 4OMG on growth performance, thigh meat quality and small intestine development of broilers. A total of 240 1-day-old female broiler chicks were randomly distributed to four groups with three replicates of 20 within each group. Each group received either 0, 15, 20 or 25 g 4OMG/kg DM of diet. During the entire experiment, broilers had ad libitum access to water and feed, and the feed intake was recorded daily. All broilers were weighed before and end of the experiment. For each group, three pens with a total of 20 broilers were randomly selected to slaughter after 30 days. Increasing dietary supplementation of 4OMG linearly increased final live weight and daily body weight gain (P = 0.013) of broilers, Gain-to-Feed ratio (P &lt; 0.001), muscle pH (P = 0.024) and redness (P = 0.001), but decreased drip loss (P = 0.033), shear force value (P = 0.004) and hardness (P = 0.022) of the thigh meat. Broilers fed diet with higher 4OMG had greater weight index, villus height and ratio of villus height to crypt depth in both duodenum and jejunum. These results indicated that increasing dietary supplementation of 4OMG was beneficial for growth performance, meat quality and development of the small intestine of broilers.

Cobb MV × Cobb 700 broiler responses to eight varying levels of amino acid density with emphasis on digestible lysine

Summary The percentage of broiler complex processing plants slaughtering big birds (e.g., those greater than 3.5 kg) has steadily increased in the United States the past 15 yr. Precision amino acids in dietary formulation is key as the growing cycle for these birds is extended, as well as total feed consumed. Furthermore, broilers reared for big-bird slaughter plants are destined for specialty breast meat yield portioning, making digestible Lys one of the key nutrients in feed formulation. This work assesses dietary Lys levels in graduations across feed phases to 53 D in Cobb MV × Cobb 700 female and male broilers. Optimizing digestible Lys in the starter phase (to 14 D) occurred between 1.26 and 1.31%. On average, dietary Lys intake per bird needed to optimize live performance, and white meat yield was higher in male birds (64 g) than in female birds (58 g). Optimization of Lys amino acid density in the Cobb MV × Cobb 700 broilers resulted in increased white meat yields in larger broilers, resulting in increased fillet weights per bird with white striping and woody breast being unaffected.

Obesity, insulin resistance, adiponectin, and PPAR-γ gene expression in broiler chicks fed diets supplemented with fat and green tea (Camellia sinensis) extract

Adipose tissue is an active endocrine organ secreting several adipokines, especially adiponectin, that play an important role in regulating insulin function in the body of mammals. Therefore, this study was aimed to investigate the association between abdominal fat deposit, insulin resistance, peroxisome proliferator-activated receptor gamma (PPAR-γ), and adiponectin gene (AG) expression in broiler chicks fed diets high in unsaturated fat supplemented with green tea extract (GTE). A total of 300 one-day-old female Ross 308 broiler chicks were allocated to 6 dietary treatments in a completely randomized design with a factorial arrangement of two levels of GTE (0 and 500 mg/kg diet) × three levels of fat inclusion [without fat (control group), soybean oil (SO), and tallow (Ta)]. Each treatment was replicated five times. At the end of the experiment (day 49), two chicks from each replicate weighing an average of pen weight were bled and then slaughtered for further analysis. Abdominal fat percentage, fasting concentration of blood glucose, triglyceride and insulin, glycogen reserves of breast and liver tissues, and PPAR-γ and AG expression were determined. The insulin resistance index of the Quantitative Insulin Sensitivity Check Index (QUICKI) was calculated using the fasting plasma glucose and insulin concentrations. The highest abdominal fat percentage and the lowest carcass yield were obtained in chicks fed SO-supplemented diet (P < 0.05). Chicks fed diet supplemented with SO showed the highest PPAR-γ gene expression (P < 0.05). SO-rich diets suppressed AG expression in chickens' abdominal fat tissue, and the birds fed with SO-supplemented diet showed a significant decrease in AG expression compared with the control (P < 0.05). Chicks fed diet supplemented with SO showed lower QUICKI and breast glycogen reserve compared with the control group (P < 0.05). A significant increase in blood glucose and triglyceride concentrations was observed in birds fed SO-supplemented diets (P < 0.05). AG and PPAR-γ expression increased and decreased by GTE, respectively. QUICKI tended (P = 0.09) to be greater in GTE-supplemented chicks; however, the effect of GTE supplementation on carcass yield, abdominal fat percentage, and blood insulin and glucose concentration was not significant. The findings of this study showed that SO-rich diets via increased PPAR-γ gene expression and decreased AG expression in abdominal fat may lead to insulin resistance in female broiler chicks.

Preventive, Behavioral, Productive, and Tissue Modification using Green Synthesized Selenium Nanoparticles in the Drinking Water of Two Broiler Breeds under Microbial Stress

ABSTRACT A study was conducted to investigate the influence of selenium nanoparticles (SeNPS) and inorganic selenium supplementation in the drinking water on behavior, performance, and immunity of Arbor Acres® and Ross®308 broilers exposed to E. coli O157:H7 1.6 × 108 challenge at the 10th day of age. 180 one-day-old female broilers were divided into six groups, each with 30 chicks. G1 and G4 were supplied with 1 mL SeNPS 100 mg.L-1/L, G2 and G5 were supplied with 1 mL inorganic selenium 100 mg.L-1/L, and G3 and G6 were supplied with non-supplemented water. Where, G1, G2, and G3 were Arbor Acres®, while G4, G5, and G6 were Ross®308 broilers. A total of 1280 samples (160 sera, 160 intestinal swabs and 960 organ samples including liver, spleen, bursa, heart, breast muscles, and thymus) were collected in a study period of 38 days. A highly significant increase (p<0.01) of weight gain, feed conversion, performance index, total protein, albumin, alanine aminotransferase, aspartate aminotransferase, immunoglobulin G and M, total antioxidant capacity, malondialdehyde, and superoxide dismutase was recorded in G4 Ross®308 compared to other supplemented and control groups. G1 Arbor Acres® and G4 Ross®308 broilers, also revealed a highly significant decline (p<0.01) in total bacterial and enterobacteriaceae counts of intestine and breast muscles compared to G2 Arbor Acres® and G5 Ross®308 broilers and to controls. Photomicrographs revealed a higher degree of cellular and tissue protection in G4 and G5 Ross®308 compared to G1 and G2 Arbor Acres® broilers. An improvement from SeNPS supplementation was detected on behavior, performance, bacterial load, immunological, antioxidant profiles, and tissue architecture in broilers breeds with special reference to Ross®308 compared to Arbor Acres® broilers.

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

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&lt;0.05) and by 2.9 % in males (P&gt;0.05), but had no effect on feed conversion. Sex separate rearing resulted in heavier carcasses by 3.6% (P&lt;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&lt;0.05) but not abdominal fat whose weight was higher in female broilers (P&lt;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

Growth Performance, Blood Biochemical Profile, Carcass Traits and Chemical Composition of Meat in Female Broiler as Affected by Feed Restriction and Garlic Supplementation

Growth Performance, Blood Biochemical Profile, Carcass Traits and Chemical Composition of Meat in Female Broiler as Affected by Feed Restriction and Garlic Supplementation

In vivo assessment of body composition and growth potential of modern broiler using dual-energy X-ray absorptiometry

Context Genetic improvements in modern strains have led to continuous increments in broiler growth rates, which, as a consequence, have resulted in higher economic returns for broiler producers over the last decades. Aim The present study was conducted to characterise the potential growth of the body and feathers of Cobb 500, Hubbard Flex and Ross 308 male and female broilers, as well as to assess the changes in chemical composition that occur up to 16 weeks of age. Methods Birds were fed isoenergetic diets divided in four phases and formulated to marginally exceed the nutritional requirements of the strains throughout the growing period. They were maintained in a controlled environment so as not to limit growth. A dual energy X-ray absorptiometry (DXA) scanner was used to follow the in vivo body composition of 12 broilers of each strain and sex (total of 72 broilers), and the feather weight and composition was determined in four birds of each strain and sex selected at intervals during the growing period (total of 288 broilers) through comparative slaughter with later chemical analysis. Key results Parameters of Gompertz growth curve to describe the strains were estimated for body and feather weight as well as for the growth of their chemical components. Conclusion Differences in the growth rates between strains were evident, indicating the possible differences in selection methods used by geneticists in the different breeding companies. These genetic parameters would explain part of the variation on broiler´s performance which impacts on the way they should be fed and housed during growth. Implications The accurate description of genetic growth potential is useful information to be associated with factorial models that predict nutritional and feed intake requirements of birds. The main advantage of DXA technology is to decrease the variation of body deposition on the Gompertz model, resulting from the use of the same bird throughout its life. Despite the speed of obtaining chemical values of the body, the method is unsuitable for measuring the growth of feathers, which is also important data to be collected and related to the broiler strains.

Evaluation of dietary probiotic (Bacillus subtilis KMP-BCP-1 and Bacillus licheniformis KMP-9) supplementation and their effects on broiler chickens in a tropical region

ABSTRACT The experiment aimed to investigate the effects of probiotic (Bacillus subtilis KMP-BCP-1 and Bacillus licheniformis KMP-9) supplementation on growth performance, ileal digestibility, jejunal histomorphology, colonic ammonia-nitrogen (NH3-N) and blood parameters in broiler chickens. A total of 288, one-day-old female Ross-308 broilers were randomly allotted into 4 treatments with 6 replicates of 12 birds. Treatments were (T1) basal diet (BD), (T2) BD with 200 ppm amoxicillin, (T3) and (T4) BD with probiotics at the levels of 2.5 × 107 and 5.0 × 107 cfu/kg feed, respectively. Supplementation of amoxicillin or probiotics improved (P < 0.05) average daily gain (ADG) and feed conversion ratio (FCR) on d 42. Compared to those fed with T1, broilers fed with T4 increased (P < 0.05) the ratio of jejunal villus height to crypt depth, and improved (P < 0.05) ileal digestibility of dry matter and protein. They also had the highest numbers of lactic acid bacteria (LAB) and Bacillus spp. as well as the ratio of LAB to Escherichia coli (P < 0.05). Probiotics at the level of 5.0 × 107 cfu/kg feed improved the growth performance of broilers in a tropical region by enhancing the balance of caecal bacteria, jejunal histomorphology and ileal digestibility.