Effects of initial body weight and litter material on broiler production

The potential of pumice as a litter material and its influence on growth performance, carcass parameters, litter quality traits, behavior, and welfare in broiler chickens

This study evaluated the possibilities of pumice (light stones) as litter material in broiler production. Experimental treatments included wood shavings (WS), acidic pumice (AP), and basic pumice (BP) alone, and in combination; wood shaving + acidic pumice (WSAP) and wood shaving + basic pumice (WSBP) in a ratio of 1:1. Two trials were performed, one in summer, and the other in winter. Each trial involved 750 mixed-sex Ross (308) broilers. Also, there were 15 replicate pens with 50 broilers and a stocking density of 12.5 birds/m2 for each pen at the beginning of each trial. Performance, litter quality, carcass parameters, body and leg abnormalities, body temperature, fear and stress responses, proportional asymmetry, and some behavior expressions were investigated. The litter treatment influenced the final live body weight, litter moisture, ammonia concentration, footpad dermatitis, hock burn, breast blister, hot carcass yield, heart, liver, spleen, abdominal fat, wing and neck ratio, breast and back cleanliness, and the expression of dust bathing and foraging behaviors (P < 0.01; P < 0.05). Furthermore, there was a seasonal effect on live body weight, feed conversion ratio, livability, litter pH, 42-day litter moisture, hot carcass yield, back cleanliness, footpad dermatitis, hock burn, footpad temperature, heterophil-to-lymphocyte ratio, and expression of pecking behavior (P < 0.01; P < 0.05). It is suggested that acidic pumice stone alone or in a mixture with wood shavings could be used as a reliable litter material, alternative to wood shavings.

Effects of Salvinia as a broiler litter material on growth performance, behavior, welfare parameters, litter characters, and ammonia emission

The type of litter material has direct impacts on production, behavioral, and welfare parameters of broilers. The price of conventionally-used litter materials is increasing. Salvinia molesta is a fast-growing aquatic plant which has become an environmental issue in some areas. This study assessed the suitability of air-dried Salvinia plants (SAL) as an alternate litter material to paddy husk (PH). Resulting in a completely randomized experiment, a total of 240 broilers was raised in 12 floor-pens each provided with either PH or SAL as litter materials, from 11 to 36 d. Scan sampling technique was employed to record the birds' engagement in 15 predetermined behaviors. Foot pad dermatitis (FPD), hock burn damage (HBD) and plumage cleanliness (PC) were assessed using Welfare Quality Scoring System. Litter samples were analyzed for pH, dry matter%, water holding capacity, porosity, N%, tapped-density and ammonia emission rate. The litter material had no significant effect (P > 0.05) on mortality, growth performance parameters, dressing % and visceral organ weight. The scores for FPD and PC were unaffected by the litter materials. SAL litter reported significantly lower (P < 0.05) HBD scores. The percentages of birds engaged in eating and wing flapping behaviors were significantly lower on SAL. Litter type had no significant influence on the color, aroma, flavor, texture and overall acceptability of breast meat. Air-dried Salvinia plants reported acidic pH. SAL litter gave a significantly higher tapped-density. Ammonia emission rate of SAL litter was significantly lower than that of PH. However, the final litter N content was higher for PH (3.7%) than SAL (3.2%). The study proposes air-dried Salvinia plants as a litter material for broilers since it gives growth performance comparable to PH with reduced hock burn damage incidences. Effects of SAL on behavior and the fertilizer value of the spent litter are to be studied further.

Role of steroid growth promoter on growth performance and meat quality traits in broiler

Growth promoters are added with broiler feed to boost the overall feed efficiency and growth rate. The current study investigated the effect of dexamethasone (DEX)—a commonly used growth promoter—on the broiler growth rate, meat quality, and muscle biology. Four homogenous groups (20 chicks/group) of broiler one-day-old chicks were fed commercial broiler feed where the treatment groups received 3, 5, and 7 mg/kg of DEX with their diet for 28 d. Feed consumption and body weight were monitored on a daily basis. Muscle samples were collected on 7, 14, 21, and 28 d of the experiment to investigate meat quality and muscular biology. The residue of DEX in meat was detected using thin-layer chromatography. We observed that DEX had substantially decreased (P < 0.05) feed intake, feed efficiency, and overall weight gain in the broiler. While the weight of breast and thigh meat was decreased, the relative meat weight (meat/body weight) was increased significantly in chicks fed DEX. Simultaneously, body fat decreased while the percentage of fat increased significantly (P < 0.05) in the DEX groups. Contrariwise, DEX improved the investigated meat quality parameters with the potential threat of accumulation of DEX residue in the meat at a high dose (7 mg/kg). We also observed that DEX significantly increased the number of myofibers and decreased the cross-sectional area of myofibers. Based on these findings, we conclude that DEX reduces feed intake, feed efficiency, and growth rate, but might improve meat quality with a potential risk of residual DEX accumulation if fed at a high dose.

Evaluation the Antibacterial Activity of the Brine, Nisin Solution, and Ozonated Water Against E. coli O157:H7 in the Experimentally Local Produced Soft Cheese

This study aimed to evaluate the antibacterial efficacy of brine solution in compared to nisin and ozonated water treatments against E. coli O157:H7 in experimentally local produced soft cheese (ELPSC). A total of 25 raw cow milk samples were collected from farmers and local markets in Baghdad city and utilized to manufacturing 25 of ELPSC samples following the traditional procedure in rural Iraq without salting or heat treatment. Bacteriological analysis for potential E. coli O157:H7 contamination was performed and confirmed by cultural, biochemical, and serological tests. Antibacterial activity of brine solution (7% w/v), nisin solution (100 IU/mL), and ozonated water (0.6 ppm) was performed for positive samples after 2 h contact time at ambient temperature. Positive isolates of E. coli O157:H7 were detected and confirmed as 3 out of 25 cheese samples (12%), with initial average bacterial count of 6.146 log10 CFU/g. The initial bacterial count was significantly (P<0.05) reduced to 3.778, 4.380 and 4.544 log10 CFU/g when subjected to brine salting, nisin solution, and ozonated water, respectively. Cheese samples exposed to brine had a significantly (P<0.05) higher reduction in the bacterial growth than those exposed to nisin or ozonated water treatments for each alone. More effective reduction in E. coli O157:H7 bacterial growth was not observed when brining exposure time elongated at ambient temperature to 6 h. These findings may be useful in raising the public knowledge about the use of brine solution as a domestic antibacterial approach for minimizing the possible risk of E. coli O157:H7 contamination in the local produced soft cheese.

Novel 61-bp Indel of RIN2 Is Associated With Fat and Hatching Weight Traits in Chickens

The Ras and Rab interactor 2 (RIN2) gene, which encodes RAS and Rab interacting protein 2, can interact with GTP-bound Rab5 and participate in early endocytosis. This study found a 61-bp insertion/deletion (indel) in the RIN2 intron region, and 3 genotypes II, ID, and DD were observed. Genotype analysis of mutation sites was performed on 665 individuals from F₂ population and 8 chicken breeds. It was found that the indel existed in each breed and that yellow feathered chickens were mainly of the DD genotype. Correlation analysis of growth and carcass traits in the F₂ population of Xinghua and White Recessive Rock chickens showed that the 61-bp indel was significantly correlated with abdominal fat weight, abdominal fat rate, fat width, and hatching weight (P < 0.05). RIN2 mRNA was expressed in all the tested tissues, and its expression in abdominal fat was higher than that in other tissues. In addition, the expression of the RIN2 mRNA in the abdominal fat of the DD genotype was significantly higher than that of the II genotype (P < 0.05). The transcriptional activity results showed that the luciferase activity of the pGL3-DD vector was significantly higher than that of the pGL3-II vector (P < 0.01). Moreover, the results indicate that the polymorphisms in transcription factor binding sites (TFBSs) of 61-bp indel may affect the transcriptional activity of RIN2, and thus alter fat traits in chicken. The results of this study showed that the 61-bp indel was closely related to abdominal fat-related and hatching weight traits of chickens, which may have reference value for molecular marker-assisted selection of chickens.

Enhancing the Productive Performance of Broiler Chickens by Adding Spirulina platensis Compared with Probiotic, Prebiotics, and Oxytetracycline

This study was conducted in order to find out the effect of Spirulina platensis (S. platensis) algae mixed with drinking water (2%) on the production performance of broiler chickens infected with or without Enterococcus faecalis (E. faecalis) and compare it with the effects of probiotics (containing Lactobacillus acidophilus, L. casi, L. reuteri, and Bacillus subtillis), prebiotics (containing antioxidants and a group of vitamins) as well as oxytetracycline. The experiment included 350 one day old (Ross-308) broiler chicks, randomly divided into 7 groups by 50 chicks per group for 35 days. The groups were divided as follows: T1: infected experimentally with E. faecalis only, T2: treated with S. platensis, T3: infected experimentally with E. faecalis and treated with 2% S. platensis, T4: infected experimentally with E. faecalis and treated with probiotic, T5: infected experimentally with E. faecalis and treated with prebiotic, T6: infected experimentally with E. faecalis and treated with oxytetracycline, and T7: control group without any addition. Weekly live body weight and weekly body weight gain were measured as well as weekly feed intake and feed conversion rate for broiler chickens were estimated. The current study proved that S. platensis algae added to drinking water (2%) in T2 and T3 groups had caused a significant increase (P<0.05) in the weekly live body weight and weekly body weight gain, Spirulina also caused a significant decrease (P<0.05) in weekly feed intake and feed conversion rate for broiler chickens. Therefore, S. platensis could be a suitable alternative to some feed additives such as probiotics, prebiotics, and antibiotics in addition to the ability of Spirulina to reduce the symptoms of E. faecalis.

The efficacy of litter management strategies to prevent morbidity and mortality in broiler chickens: a systematic review and network meta-analysis

A systematic review and network meta-analysis (NMA) were conducted to address the question, 'What is the efficacy of litter management strategies to reduce morbidity, mortality, condemnation at slaughter, or total antibiotic use in broilers?' Eligible studies were clinical trials published in English evaluating the efficacy of litter management in broilers on morbidity, condemnations at slaughter, mortality, or total antibiotic use. Multiple databases and two conference proceedings were searched for relevant literature. After relevance screening and data extraction, there were 50 trials evaluating litter type, 22 trials evaluating litter additives, 10 trials comparing fresh to re-used litter, and six trials evaluating floor type. NMAs were conducted for mortality (61 trials) and for the presence or absence of footpad lesions (15 trials). There were no differences in mortality among the litter types, floor types, or additives. For footpad lesions, peat moss appeared beneficial compared to straw, based on a small number of comparisons. In a pairwise meta-analysis, there was no association between fresh versus used litter on the risk of mortality, although there was considerable heterogeneity among studies (I2 = 66%). There was poor reporting of key design features in many studies, and analyses rarely accounted for non-independence of observations within flocks.

Influence of beak trimming and inclusion of sodium butyrate in the diet on growth performance and digestive tract traits of brown-egg pullets differing in initial body weight

We studied the effects of beak trimming and sodium-butyrate inclusion in the diet on growth performance and gastrointestinal tract (GIT) traits of brown-egg pullets differing in initial BW. In experiment 1, a total of 6 treatments were organized as a 2 × 3 factorial with 2 BW at hatch (light, 33.9 g and heavy, 37.6 g) and 3 beak trimming protocols [mild (MI-0) or aggressive (AG-0) infrared power setting at hatch and traditional hot blade at 8 D of age (HB-8)] as main effects. Initial BW did not affect growth performance or GIT traits at any age. From hatch to 5 wk of age, HB-8 pullets had lower ADFI (P < 0.01) and ADG (P < 0.05) than MI-0 and AG-0 pullets but no differences were detected after this age. Beak trimming did not affect FCR, BW uniformity, GIT traits, or bacteria count in the excreta at any age. In experiment 2, a total of 12 treatments were organized as a 2 × 3 × 2 factorial, with 2 BW at hatch, 3 beak trimming protocol (as per in experiment 1), and 2 levels of a sodium-butyrate additive (0 vs. 0.3%) as main effects. At 7 D of life, beak treatment reduced pullet growth and AG-0 procedure impaired pullet uniformity (P < 0.001) but the birds recovered completely by day 14 (P < 0.001 for the interaction with time). Cumulatively (0 to 6 wk of age), pullets beak treated at hatch (MI-0 and AG-0) had greater ADFI than HB-8 pullets (P < 0.01). Sodium butyrate tended to improve ADG (P = 0.073) and FCR (P = 0.069) with most of the benefits observed for the first 2 wk of life. In summary, initial BW and beak trimming procedure did not affect final pullet growth in any of the 2 experiments, or GIT traits in experiment 1. Sodium butyrate tended to improve growth and FCR from 0 to 6 wk of age but did not affect BW uniformity.

MSTN, mTOR and FoxO4 are involved in the enhancement of breast muscle growth by methionine in broilers with lower hatching weight

Broilers with lower hatching weight (HW) present poorer performance than those with high HW, but there is limited research on the growth regulation of broilers with lower HW. The objective of this study was to investigate the effect of dietary methionine (Met) levels on the growth performance and breast muscle yield of broilers with different HW and underlying mechanisms. A total of 192 one-day-old Arbor Acres broiler chicks with different HW (heavy: 48.3±0.1 g, and light: 41.7±0.1 g) were allocated to a 2×2 factorial arrangement with 6 replicates of 8 chicks per replicate cage. Control starter (1-21 d) and finisher (22-42 d) diets were formulated to contain 0.50% and 0.43% Met, respectively. Corresponding values for a high Met treatment were 0.60% and 0.53%. Light chicks had lower body weight gain (BWG) and breast muscle yield than heavy chicks when the broilers were fed the control diets. High Met diets improved BWG, gain to feed ratio and breast muscle yield in light but not heavy chicks. Decreased DNA content and increased RNA/DNA and protein/DNA ratios in breast muscle were induced by high Met diets only in light chicks. MSTN mRNA level was decreased by high Met diets only in light chicks, and this decrease was accompanied by a significant increase in MSTN gene exon 1 methylation. In addition, high Met diets increased mTOR phosphorylation, but decreased FoxO4 phosphorylation in breast muscle of light chicks. In conclusion, the BWG and breast muscle yield of light chicks were improved by increasing dietary Met levels probably through alterations of MSTN transcription and phosphorylation of mTOR and FoxO4.

Effect of litter moisture on the development of footpad dermatitis in broiler chickens

Broiler chicks were reared on either wet litter or dry litter to compare the development of footpad dermatitis (FPD). Broilers reared on wet litter first developed FPD at 14 days of age. Their FPD scores increased sharply after 21 days of age, reaching 2.92 at 42 days. In broilers reared on dry litter, FPD was first observed at 28 days of age, and the FPD score was only 0.70 at 42 days. When 21- or 28-day-old broilers that had been reared on wet litter and had developed FPD were moved to dry litter, the progression of FPD was suppressed or delayed. These results suggest that reducing litter moisture is effective in preventing FPD and suppressing disease progression.

Methionine improves the performance and breast muscle growth of broilers with lower hatching weight by altering the expression of genes associated with the insulin-like growth factor-I signalling pathway

The present study aimed to investigate the responses of broilers with different hatching weights (HW) to dietary methionine (Met). A total of 192 1-d-old Arbor Acres broiler chicks with different HW (heavy: 48·3 (sem 0·1) g and light: 41·7 (sem 0·1) g) were allocated to a 2 (HW) × 2 (Met) factorial arrangement with six replicates of eight chicks. Control starter (1-21 d) and finisher (22-42 d) diets contained 0·50 and 0·43 % Met, respectively. Corresponding values for a high-Met treatment were 0·60 and 0·53 %. Light chicks had poorer (P< 0·05) growth performance and breast muscle weight and lower (P< 0·05) insulin-like growth factor-I (IGF-I) concentration and mRNA level in breast muscle than heavy chicks when both were fed the control diets. High-Met diets improved performance and promoted breast muscle growth and IGF-I concentration in light chicks (P< 0·05). Increased IGF-I and target of rapamycin (TOR) mRNA levels as well as decreased eIF4E-binding protein 1 (4EBP1), atrogin-1 and forkhead box O 4 (FOXO4) mRNA levels were induced by high-Met diets in light chicks (P< 0·05). In conclusion, the Met requirement of broilers might depend on their HW and Met levels used in the control diets in the present study were adequate for heavy chicks but inadequate for light chicks, resulting in poorer performance and breast muscle growth, which were improved by increasing dietary Met supply presumably through alterations in IGF-I synthesis and gene expression of the TOR/4EBP1 and FOXO4/atrogin-1 pathway.