Effects of finisher diet nutrients density and slaughter age on energy and protein efficiency, productive and economic performance and meat quality of broilers.

BACKGROUND: The current broilers have been greatly optimized for weight gain and breast yield, which necessitates the provision of nutrients-dense diets for maximum potential. OBJECTIVES: The current study aimed to evaluate the effect of finisher diet nutrients density (ND) on energy and protein efficiency, productive and economic performance and breast meat quality of broilers raised until different slaughter age. METHODS: A total of 600 23-day-old broiler male chicks (Cobb-500) were assigned to 10 treatments with six replicates and 10 birds each. Experimental treatments were included factorial arrangement of five increment (2.5%) levels of finisher diet ND (92.5%, 95%, 97.5%, 100% and 102.5% as strain recommendation) and slaughtered at 38 or 46 days of age. The relative difference in the energy level of experimental diets was used to increase ND levels at the same ratio. RESULTS: Feed intake (FI) and breast meat quality traits exception water holding capacity (WHC) were not affected by finisher diet ND. In response to increasing finisher diet ND, energy and protein efficiency, productive traits, bio-economic index (BEI) and breast relative weight (BRW) linearly improved. However, residual feed intake and breast meat WHC improved with a quadratic trend. By using broken-line regression analysis, the optimum dietary ND was obtained at 97.5%-102% of strain recommendation. Energy and protein efficiency, feed conversion ratio and BEI deteriorated by prolonging rearing period. The BRW, meat lightness (L*), redness (a*), hue angle (h*) and WHC values for the birds slaughtered at 46 days of age were significantly higher, and cooking loss was lower than those slaughtered at 38 days old. CONCLUSIONS: Broilers during the finisher period are not able to regulate their FIs with diet ND. The energy and protein efficiency, productive and economic performance were reduced when broilers were fed diluted diet or the rearing period was prolonged.

Effect of crossbreeding on growth performance, meat quality, and the economics of production of the pure and reciprocal crosses between the Sasso and Wassachie chickens.

The interplay between genetics and economics is important in understanding how crossbreeding can be harnessed to optimize sustainable poultry production, meat quality, and economic viability. This study was conducted to investigate the effect of crossbreeding on growth performance, meat quality, and production economics. A total of 451 unsexed day-old chicks were raised for 12 wk in a pure (Sasso X Sasso [SS]; Wassachie X Wassachie [WW]) and reciprocal cross (Sasso X Wassachie [SW]; Wassachie X Sasso [WS]) design. Data was collected on growth performance, meat quality, sensory evaluation, proximate analysis, and production economics. Genotype did not affect (P > 0.05) moisture, dry matter, ash, sensory evaluation, pH, and meat temperature. The carcass weights, final body weight, and cumulative weight gain of the hybrids were intermediate while the SS recorded the highest (P < 0.05) values. Drip loss between the WW and the reciprocal crosses was similar (P > 0.05) but lower (P < 0.05) than the SS genotype. Protein contents between the purebreds were similar likewise the crossbreds (P > 0.05). The SW cross recorded a higher (P < 0.05) lipid content compared to the WW cross while the WS recorded a higher (P < 0.05) protein content compared to the SS. The SS incurred higher feeding costs, and gross and net returns followed by the SW and then the WS with the WW having the lowest values. Crossbreeding improved growth performance, carcass traits, meat quality, chemical composition, and the gains in the crossbreds with the SW genotype having better results. The SW cross is recommended for better performance.

Performance and economic efficiency of laying hens in response to adding zeolite to feed and litter.

This study investigated the effect of different levels of zeolite in laying hen (Silver Montazah) diet and litter on productive performance, egg quality criteria, and economics during the second stage of production (40-56 wk of age). An experiment with a 3 × 4 factorial design was performed to study the effects of four levels of zeolite (0, 10, 15, and 20 g/kg feed) in the diet and three levels of zeolite (0, 1.5, and 2 kg/m2) in the litter. Adding zeolite to diet and litter significantly improved final BW and BW change, egg number, egg weight, egg mass, laying rate, feed consumption (FC), and feed conversion ratio (FCR), as well as egg quality criteria when compared to the unsupplemented group. Additionally, adding zeolite at a level of 2 kg /m2 litter and 20 g/kg diet achieved the greatest enhancement in productive performance features. Therefore, it can be suggested that the greatest results were obtained in laying farms when zeolite was added as a litter addition and as a supplement to feed.

Carcass traits and meat quality assessment of two slow-growing chicks strains fed Acheta domesticus larval meal.

Presently, there has been a noticeable rise in the consumption of poultry meat within the general population, particularly focusing on poultry sourced from alternative rearing systems as opposed to intensive ones. This study evaluated the impact of incorporating house cricket (Acheta domesticus,AD) larvae meal into the diet of 2 slow-growing chicken strains on their carcass traits and meat quality. A total of 256 one-day-old male chicks were utilized, with 128 belonging to the Red (R) strain and 128 to the Naked Neck (NN) strain. Chicks from each strain were randomly assigned to 16 replicates of 8 chicks each. Eight replicates were allocated to 2 distinct treatments (n=64 chicks/treatment) based on the diet employed: the control treatments for the Red (R-C) and Naked Neck (NN-C) strains were fed soybean meal, while the other 2 treatments were fed AD meal (R-AD and NN-AD). Three different rations were used throughout the growth cycle of the animals, tailored to meet the nutritional needs of the birds. All chickens were slaughtered at 95 d of age, and eight chickens per treatment were randomly chosen to assess carcass traits and meat quality. Near-infrared reflectance spectroscopy (NIRS) was employed to classify meat based on the feed and the chick strain, achieving a correct discrimination of 100% of the samples. The carcass traits exhibited significant alterations due to the inclusion of insect larval meal in the diet, resulting in reduced values across all parameters for chickens consuming AD meal, irrespective of genotype. The pH and cooking losses were generally higher for chicks fed cricket meal, as occurred with moisture. However, protein content was lower in the meat of chicks consuming cricket meal. Fat content showed lower values for NN chickens. There were minimal differences in the fatty acid profile, with lower C18:3n-3 values for chickens fed cricket meal. Therefore, including Acheta domesticus meal in the diets of slow-growing chick strains is a viable alternative to replace soybean meal. It provides meat quality characteristics comparable to those obtained in conventional systems.

A true facultative carnivore? Effects of replacing ground chicken carcasses with soybean meal on the growth of captive broad-snouted caiman (Caiman latirostris) and its economics implications.

A specific diet for broad-snouted caiman, Caiman latirostris has not been designed despite the value of farm-raised caiman as an aquaculture product. To fill this gap, the objectives of this study were to evaluate the performance dietary replacement of ground chicken carcasses by of soybean meal (SM) as diet complement for C. latirostris. We conducted a 3-month growth trial to determine effects of graded levels of dietary SM on caiman growth as measured by increase in body length, body weight gain, food consumption (FC) and food conversion rate (FCR). Forty-eight hatchling caimans were fed with diets, composed primarily of practical feed ingredients, with 0, 25, or 40% dietary SM. Diets were fed three times per week for 90 days under temperature controlled. Body lengths and body weights were measured at 30-day intervals, and FC samples were taken between the 31-60-day interval. The results of this study indicate that the inclusion of SM in the diet of C. latirostris at levels of 25% increases in body length, body weight gain, FC and improve the FCR indicated that a concentration of 25% dietary SM (as fed) was adequate for growth of caimans under the conditions of this study. Results suggest that SM have a real nutritional contribution in the diet of broad-snouted caiman and can be used as an ingredient of the diet of the crocodilians raised in captivity, reducing production costs for sustainable use and conservation programs of this species.

Growth performance, economic efficiency, meat quality, and gene expression in two broiler breeds fed different levels of tomato pomace.

Male broiler chicks (135 Indian River chicks (IR) and 135 Cobb chicks; n = 270) were weighed, wing banded, and distributed randomly into three iso-energetic and iso-nitrogenous diet groups for each breed (triplicate design, 45 bird/group, 15 bird/replicate). The chicks were fed the diets with levels of 0, 4, or 6% sun-dried tomato pomace (SDTP), respectively, for 42 consecutive days to determine the effect of consuming different levels of SDTP on growth performance, economic efficiency, meat quality, and gene expression in IR and Cobb broiler chickens. The inclusion of up to 6% SDTP in the diet of IR or Cobb chickens had no negative impact on growth performance parameters. Chickens from both the IR and Cobb breeds fed a diet containing 4% or 6% SDTP consumed more feed than those fed a diet containing 0% SDTP. Concomitantly, the groups fed a 6% SDTP diet of IR breed incurred a significantly higher feed cost, total variable cost (TVC), and total cost (TC). The inclusion of up to 6% SDTP in the feed of both breeds resulted in a non-significant increase in return parameters. The ultimate pH decreased as the SDTP concentration increased, with no significant differences in water holding capacity (WHC) or drip loss (48 h). No alteration in the mRNA expression of hepatic growth hormone receptor gene (GHR) or insulin like growth factor-1 (IGF-1) was found among the treatments for either the IR or Cobb breeds. Thus, up to 6% SDTP can be added to the diet of IR and Cobb broiler chickens without any adverse effects on the examined parameters.

Effects of different feeding regimens with protease supplementation on growth, amino acid digestibility, economic efficiency, blood biochemical parameters, and intestinal histology in broiler chickens.

BACKGROUND: This study was conducted to estimate the impacts of using varied feeding regimens with or without protease supplementation on the growth performance, apparent amino acid ileal digestibility (AID%), economic efficiency, intestinal histology, and blood biochemical parameters of broiler chickens. Three hundred one-day-old chicks (Ross 308 broiler) were randomly allotted to a 3 × 2 factorial design. The experimental design consisted of three feeding regimens; FR1: a recommended protein SBM diet, FR2: a low-protein SBM diet, and FR3: a low-protein diet with the inclusion of 5% DDGS and 5% SFM, with or without protease supplementation (250 mg/kg). RESULTS: Increased feed intake and feed conversion ratio were observed in the FR3 treatment during the starter stage and decreased body weight and body weight gain during the grower stage. However, there was no significant effect of the different feeding regimens, protease supplementation, or interaction on the overall performance. The economic value of diets also remained unaffected by the different feeding regimens, protease supplementation, or interaction. Protease supplementation resulted in lowering the AID% of tryptophan and leucine. Reduced AID% of methionine was evident in the FR2 + VE and FR3 - VE treatments. Histological findings substantiated the FR3 treatment mediated a decrease in the duodenal and jejunal villous height (VH), jejunal villous width (VW), and ileal VW, whereas, increase in the ileal crypt depth (CD). The FR2 + VE treatment reduced the VH:CD ratio in the duodenum. The duodenal CD and the jejunal goblet cell count were reduced as a consequence of protease supplementation. The FR3 + VE treatment documented a rise in duodenal CD, while an increase in the jejunal goblet cell count was observed in the FR3 - VE treatment. The FR3 treatment enhanced the IgM serum levels compared to the FR1 and FR2 treatments. IgM serum levels were also elevated following protease supplementation. FR3 + VE treatment increased IgM serum levels. The highest serum ALP was found in the FR3 treatment, whereas the lowest level was obtained in the FR2 treatment. CONCLUSION: Low-protein SBM-based diets could be used without affecting the birds' growth. Altered morphometric measures of the intestine and increased IgM and ALP levels indicated the low-protein SBM/DDGS-SFM diet-induced damage of the intestinal histoarchitecture and immune system of birds. These different diets and protease supplementation failed to affect economic efficiency positively.

Assessment of trade-offs between feed efficiency, growth-related traits, and immune activity in experimental lines of layer chickens.

BACKGROUND: In all organisms, life-history traits are constrained by trade-offs, which may represent physiological limitations or be related to energy resource management. To detect trade-offs within a population, one promising approach is the use of artificial selection, because intensive selection on one trait can induce unplanned changes in others. In chickens, the breeding industry has achieved remarkable genetic progress in production and feed efficiency over the last 60 years. However, this may have been accomplished at the expense of other important biological functions, such as immunity. In the present study, we used three experimental lines of layer chicken-two that have been divergently selected for feed efficiency and one that has been selected for increased antibody response to inactivated Newcastle disease virus (ND3)-to explore the impact of improved feed efficiency on animals' immunocompetence and, vice versa, the impact of improved antibody response on animals' growth and feed efficiency. RESULTS: There were detectable differences between the low (R+) and high (R-) feed-efficiency lines with respect to vaccine-specific antibody responses and counts of monocytes, heterophils, and/or T cell population. The ND3 line presented reduced body weight and feed intake compared to the control line. ND3 chickens also demonstrated an improved antibody response against a set of commercial viral vaccines, but lower blood leucocyte counts. CONCLUSIONS: This study demonstrates the value of using experimental chicken lines that are divergently selected for RFI or for a high antibody production, to investigate the modulation of immune parameters in relation to growth and feed efficiency. Our results provide further evidence that long-term selection for the improvement of one trait may have consequences on other important biological functions. Hence, strategies to ensure optimal trade-offs among competing functions will ultimately be required in multi-trait selection programs in livestock.

Impacts of Microbial based Therapy on Growth Performance, Intestinal Health, Carcass Traits and Economic Efficiency of Clostridium perfringens-Infected Cobb and Arbor Acres Broilers.

The poultry farms need a safe and effective alternative for antibiotics that can counteract the negative impacts of necrotic enteritis (NE), which causes severe mortalities and economic losses. The current study was aimed to examine the influence of antibiotic (Flagymox) and the microbial-based administration on carcass traits in Clostridium (C.) perfringens-infected Cobb and Arbor Acres broilers. A total number of 360 Cobb and Arbor Acres broiler chicks (180 numbers per breed) were allocated to four groups; negative control group (without any treatments); positive control group (administration of C. perfringens at the rate of 1 × 109 cfu/bird via crop gavage twice daily from day 16 to 18 post-hatch); C. perfringens challenge plus antibiotic (Flagymox® ) group, and Clostridium perfringens challenge plus microbial-based treatment (Big-lactoα® ) group. The results indicated that the Flagymox and Big-lactoα treated Cobb breed group achieved a significant increase in their body weight (BW) than the positive control group at the third week post-infection. Also, the Arbor Acres breed gained significantly higher weight compared to the Cobb breed at the third week. Total weight gain (TWG) from 0 to the fifth week in the Cobb and Arbor Acres breeds were higher in the groups treated with Flagymox and Big-lactoα compared to the birds challenged with C. perfringens without any treatment, thus, increasing the total return (TR) in the treated groups. Economic efficiency showed no significant differences (p < .05) between the treatment groups of both the breeds. Although the treatment cost of Flagymox is higher than the microbial-based treatment (0.86 versus 0.35 LE), there were no mortalities reported in the microbial-based groups in both the breeds resulting in significantly low losses compared to the Flagymox treated groups. The groups treated with the microbial-based products in both breeds were superior in dressing percentage (75.16 and 77.06% for Cobb and Arbor Acres, respectively) compared to that of the other groups. In conclusion, microbial-based therapy improved the growth rate, carcass traits, survival rate, and economic efficiency in necrotic enteritis induced in Cobb and Arbor Acres broilers.

Can black soldier fly Desmodium intortum larvae-based diets enhance the performance of Cobb500 broiler chickens and smallholder farmers' profit in Kenya?

This study aimed to evaluate the performance of broiler chickens fed on 3 black soldier fly larvae (BSFL) (Hermetia illucens) and Greenleaf desmodium (Desmodium intortum)-based meals. We evaluated growth performance, carcass quality, and profitability under various commercial pathways (doorstep, retail, whole, and assorted). Desmodium and BSFL powders were formulated into 3 ratios: T1 25:75, T2 50:50, and T3 75:25. A commercial feed was used as a control. One hundred and twenty mixed-sex 1-day-old broiler chicks (Cobb) were reared in pens for 42 d in a completely randomized design. The chickens were weighed weekly to monitor their growth rate. After the 42-day rearing period, they were slaughtered for carcass quality evaluation and recording of the weights of internal organs. During the initial growth phase (7-21 d), significant effects of fish meal replacement were found on the chickens' average weight (P < 0.001), average daily body weight gain (P < 0.001), average daily feed intake (P < 0.001), and feed conversion ratio (P < 0.001). However, during the second phase (21-42 d), no significant effect of the replacement was detected except on average daily feed intake (P = 0.003). No significant differences were found in terms of the relative weights of internal organs. It was found that Desmodium-BSFL-based feeds were more profitable than the control feed, and the assorted and retail modes of sale generated more revenue compared to when the chickens were sold at doorstep and on whole-chicken basis. The return on investment was higher for a push-pull adopter compared to a non-adopter. The study found that a BSFL-Desmodium mixture can be a valuable replacement for the protein component in conventional feed and would provide a new impetus for the adoption of push-pull.

Effects of graded levels of microbial fermented or enzymatically treated dried brewer's grains on growth, digestive and nutrient transporter genes expression and cost effectiveness in broiler chickens.

BACKGROUND: Poultry feed consists mainly of conventional grains and protein supplements, however, using treated unconventional agro-industrial by-products as replacements of corn soybean-based diet can minimize production costs and improve productivity. Therefore, in this study, the effects of fermented or enzymatically treated dried brewer grains (DBG) on growth, expression of digestive enzymes and nutrient transporters genes and the profitability of the rations were evaluated. A total of 1600 one-day-old Ross 308 broiler chicks were randomly distributed in 2 × 4 factorial arrangement (eight treatments with ten replicates, 20 birds/replicate). Experimental diets included two controls; negative control (basal corn-soybean diet; NC) and positive control (basal corn-soybean diet with exogenous enzymes; PC), and six diets in which basal diet was replaced by three levels of fermented DBG (FDBG; 5, 10 or 15%), or enzyme-treated DBG (DBG 5, 10 or 15%+Enz), for 38 days. RESULTS: The results described that feeding FDBG (three levels) or DBG5%+Enz improved (P < 0.05) BW gain and feed efficiency of broilers. Also, feeding FDBG10% yielded the best improvement in weight gain (10%), compared to NC group. Increasing the inclusion levels of DBG either fermented or enzymatically treated up-regulated (p < 0.01) expression of digestive-genes in proventriculus (PGC and PGA5, range 1.4-1.8 fold), pancreas (AMY2A, PNLIP, CELA1, and CCK; range 1.2-2.3 fold) and duodenum (CAT1, CAT2, GLUT1, GLUT2, LAT1, Pep1; range 1.3-3 fold) when compared to NC group. Feeding treated DBG significantly increased (p < 0.05, range 4.5-13.6%) gizzard relative weight compared to NC and PC groups. An additional benefit was lower (p < 0.01) cholesterol content from 66.9 mg/100 mg (NC) to 62.8 mg/100 mg (FDBG5 or 10%) in thigh meat. Furthermore, the least cost feed/kg body gain was achieved in FDBG10% and DBG5%+Enz groups, with approx. 16% reduction compared to NC cost, leading to increasing the income gross margin by 47% and 40% in FDBG10% and DBG5%+Enz groups, respectively. CONCLUSIONS: Substitution of corn-soybean based diet with 10% FDBG or 5% DBG+Enz resulted in better growth and higher economic efficiency of broilers chickens.

Supplemental phytase derived from E. coli in different concentrations on performance, bone mineralization and cost of broilers diets.

The trial was conducted to evaluate the supplementation of E. coli phytase on performance, weight and ash of bones, as well as to determine the bioavailability of P and cost/benefit of its use in diets. A total 1,890 Cobb male day old chicks were assigned to six treatments and seven replicates with 45 birds each, distributed in a completely randomized design. The treatments were: Positive Control; Negative Control (NC1) - reduction of 0.06% avP; Negative Control 2 (NC2) - reduction of 0.12% avP; NC2 + Phytase (120 OTU); NC2 + Phytase (180 OTU); NC2 + Phytase (240 OTU), being 1 OTU equivalent to approximately 2 FTU. With different phytase inclusions, it was possible to verify a gradual increase on body weight gain, feed intake, feed conversion ratio, viability and even the bone characteristics of broilers fed diets containing reduction of P. The closest levels to the highest studied (240 OTU) showed the best results. The replacement of dicalcium phosphate by phytase supplementation is economically viable when the cost per OTU does not exceed US$ 1.4 × 10-5, US$1.2 × 10-5 and US$ 1.0 × 10-5 for the concentrations of 120, 180 and 240 OTU, respectively.

Quantitative assessment of biosecurity in broiler farms using Biocheck.UGent in Central Luzon, Philippines.

The biosecurity status of 397 broiler farms in Central Luzon, the highest poultry meat-producing region in the Philippines, was assessed using Biocheck.Ugent. This online biosecurity assessment tool quantifies biosecurity level or compliance of surveyed farms. The system generates scores that reflect the current biosecurity status of each farm in terms of the different external and internal biosecurity measures being implemented in each farm. It was initially developed for pigs and broilers but recently is available for layers, swine, and cattle (beef, dairy, and veal). The overall biosecurity score of broiler farms in Central Luzon was 71.2%, with average external and internal biosecurity scores of 68.5 and 77.2%, respectively. Bataan had the highest biosecurity scores (76.5%) compared with the other 6 provinces. This was also true for the external and internal biosecurity scores of the province, with mean scores of 72.1 and 80.1%, respectively. Of the 11 subcategories of external and internal biosecurity that were assessed, purchase of day-old chicks, feeds and water supply, supply of materials, cleaning and disinfection, and materials between compartments had scores higher than the global scores. Low scores were generated from transport of live animals and infrastructure and biological vectors. The mean biosecurity score of farms with traditional/conventional type of housing was 7.8% lower than that with tunnel vent housing. Every year as the farm gets older, there was a corresponding drop of 0.2% in the biosecurity score. Biosecurity measures are in place in broiler farms in the country. However, there were areas with low scores which need to be prioritized to improve and upgrade the farms' biosecurity status. To date, this is the first quantitative assessment of biosecurity in broiler farms in the Philippines. High biosecurity scores may entail greater protection from disease incursion.

Effects of broiler genetic strain and dietary amino acid reduction on (part I) growth performance and internal organ development.

Genetic selection in broilers has resulted in improved growth performance, meat yield, and feed conversion efficiency. However, consumers have become increasingly concerned about modern broiler welfare that is related to their rapid growth rate, which may be alleviated by nutrient dilution. This study was conducted to investigate the effects of dietary amino acid (AA) reduction on the growth performance and internal organ development of different genetic strains of broilers. A randomized completed block design with a factorial arrangement of 10 treatments (5 strains × 2 AA levels) was used. The 5 different strains of broilers were fed either a control diet, with digestible AA (lysine, total sulfur AA, and threonine) at the highest recommended levels for the 5 strains, or an AA-reduced diet, with the digestible AA being 20% lower than the control diet. Feed conversion ratio was increased by AA reduction in all 5 strains during day 0-14, 14-28, and 28-41 but was not affected from day 41-55. Body weight and feed intake responses to AA reduction varied in the different strains and ages of birds. Liver weight relative to BW on day 40, and weights of the duodenum and jejunum relative to BW on day 60 were increased by decreasing the dietary AA concentration. These results indicate that the birds had adjusted their organ growth and metabolism in response to increases in digestion, absorption, and utilization efficiency to accommodate a decrease in dietary AA content. Surprisingly, the cost of feed required to produce the same BW was decreased in 4 of 5 strains on both day 41 and 55, which was largely because of the lower price of the diets containing reduced AA levels and the later compensatory growth experienced by the birds fed AA-reduced diets. In the future, when dietary AA levels need to be adjusted to control growth rate and improve welfare status, the genetic strain, age of the birds, and targeted goals need to be taken into consideration.

An assessment of the impacts of litter treatments on the litter quality and broiler performance: A systematic review and meta-analysis.

OBJECTIVE: The choice of the most suitable litter treatment should be based on scientific evidence. This systematic review assessed the effectiveness of litter treatments on ammonia concentration, pH, moisture and pathogenic microbiota of the litter and their effects on body weight, feed intake, feed conversion and mortality of broilers. METHODS: The systematic literature search was conducted using PubMed (Medline), Google Scholar, ScienceDirect and Scielo databases to retrieve articles published from January 1998 to august 2019. Means, standard deviations and sample sizes were extracted from each study. The response variables were analyzed using the mean difference (MD) or standardized mean difference (SMD), (litter treatment minus control group). All variables were analyzed using random effects meta-analyses. RESULTS: Subgroup meta-analysis revealed that acidifiers reduce pH (P<0.001), moisture (P = 0.002) ammonia (P = 0.011) and pathogenic microbiota (P <0.001) of the litter and improves the weight gain (P = 0.019) and decreases the mortality rate of broilers (P<0.001) when compared with controls. Gypsum had a positive effect on ammonia reduction (P = 0.012) and improved feed conversion (P = 0.023). Alkalizing agents raise the pH (P = 0.035), worsen feed conversion (P<0.001), increase the mortality rate (P <0.001), decrease the moisture content (P<0.001) and reduce the pathogenic microbiota of the litter (P<0.001) once compared to controls. Superphosphate and adsorbents reduce, respectively, pH (P<0.001) and moisture (P = 0.007) of the litter compared to control groups. CONCLUSION: None of the litter treatments influenced the feed intake of broilers. Meta-analyses of the selected studies showed positive and significant effects of the litter treatments on broiler performance and litter quality when compared with controls. Alkalizing was associated with worse feed conversion and high mortality of broilers.

Evaluation of oats with varying hull inclusion in broiler diets up to 35 days.

Use of local feed ingredients in poultry feed, such as oats, can be limited by their perceived less than ideal nutritional content. Dehulling oats is expensive, and it may be that removing hull is detrimental to the bird in terms of gastrointestinal (GI) development, therefore maintaining some of the high-fiber oat hull (OH) might reduce costs and improve potential for inclusion in poultry diets. Male broilers were fed diets with oats replacing 30% of wheat in diets, either dehulled or with graded inclusions of OH from day of hatch until day 35. Each diet was fed to 8 pens of 8 birds and performance recorded weekly. Samples were collected at day 21 and 35 for analysis of ileal amino acid digestibility, apparent metabolizable energy (AME), and gross gut development measures. No detrimental effect was seen on bird weight with hull inclusion, though higher inclusion levels did deleteriously effect feed intake because of increased gut fill from the fiber. Nitrogen corrected AME was also adversely effected in the highest hull inclusion diets. However, amino acid digestibility was improved with hull addition, which may be because of an increase in GI tract length, improving nutrient absorption. Gizzard development was also significantly improved, and thereby, more efficient grinding of diet may also have improved digestibility. At a lower level of hull inclusion (3% total diet) where digestibility is improved without any detrimental effects on gut fill and intake. Oat hull is well known to improve gut development, especially of the gizzard, with resultant increases in digestibility. This is usually attributed to the mechanical effect of fiber in the gizzard having a grinding effect. However in this study, all fiber was finely ground, so the improvements seen cannot be attributed to a physical cause. Oat including diets with some hull remaining are a cost effective way of using oats as a raw material while maximizing bird performance.

External Societal Costs of Antimicrobial Resistance in Humans Attributable to Antimicrobial Use in Livestock.

Antimicrobial use (AMU) in animal agriculture contributes to antimicrobial resistance (AMR) in humans, which imposes significant health and economic costs on society. Economists call these costs negative externalities, societal costs that are not properly reflected in market prices. We review the relevant literature and develop a model to quantify the external costs of AMU in animal agriculture on AMR in humans. Parameters required for this estimate include (a) the health and economic burden of AMR in humans,(b) the impact of AMU in animal agriculture on AMR in animals, (c) the fraction of AMR in humans attributable to animal agriculture, and (d) AMU in animals. We use a well-documented historic case to estimate an externality cost of about US$1,500 per kilogram of fluoroquinolones administered in US broiler chicken production. Enhanced data collection, particularly on the third and fourth parameters, is urgently needed to quantify more fully the externalities of AMU in animal agriculture.

Effects of dietary inclusion of Zymomonas mobilis degraded cassava sifting on growth performance, apparent nutrient digestibility, ileal digesta viscosity, and economy of feed conversion of broiler chickens.

A study was carried out to evaluate the effect of dietary inclusion of Zymomonas mobilis degraded cassava sifting (ZDCS) on growth response, apparent nutrient digestibility, and ileal digesta viscosity of broiler chickens. Five diets containing undegraded and degraded cassava sifting were formulated to replace wheat offal at 0, 50, and 100% levels. Two hundred and forty (240) one-day-old Marshall broiler chickens were randomly allotted to the five dietary treatments in a completely randomized design (CRD); significant means were separated using Duncan's multiple range test at p < 0.05. The biodegradation of cassava sifting with Zymomonas mobilis significantly increased crude protein content by 44.59% while crude fiber and neutral detergent fiber significantly decreased by 23.08% and 6.38%, respectively. The results showed that birds fed 50% ZDCS had the best (p > 0.05) feed conversion ratio (FCR) at the starter phase. The replacement of wheat offal with 100% ZDCS improved (p < 0.05) the crude fiber digestibility at both starter and finisher phases. Also, the birds fed 100% ZDCS had the lowest (p < 0.05) value of ileal digesta viscosity. The birds fed 50% ZDCS had the highest (p < 0.05) values of gross revenue, gross profit, rate of return on investment, and economic efficiency while the least values for gross profit, rate of return on investment, and economic efficiency were obtained in 100% ZDCS. The study concluded that replacement of wheat offal with 50% ZDCS in the ration of broiler chickens improved FCR, crude fiber digestibility (CFD), and rate of return on investment and economic efficiency.

Assessment of In Ovo Administration of Bifidobacterium bifidum and Bifidobacterium longum on Performance, Ileal Histomorphometry, Blood Hematological, and Biochemical Parameters of Broilers.

Bifidobacterium is one of the most promising probiotics which was recently used as an alternative growth promoter in poultry. This trial was considered to evaluate the potential effects of in ovo administration of Bifidobacterium bifidum and Bifidobacterium longum on growth performance and biochemical parameters of broilers. Three hundred broiler breeder eggs were incubated and candled individually at day 17 of embryogenesis; then, eggs that had live embryos were randomly divided into six groups. The first and second groups were of intact (without injection) and vehicle-injected (sterile distilled water) control groups, respectively. Other groups were in ovo injected with 1 × 109 and 1 × 107 CFU B. bifidum, and 1 × 109 and 1 × 107 CFU B. longum, respectively. Hatchability was significantly (P < 0.001) affected by in ovo inoculation of bifidobacteria strains. Body weight gain and feed conversion ratio were significantly improved (P = 0.014 and 0.019, respectively) in all treatment groups. Protein fractions, aspartate aminotransferase, and alanine aminotransferase activities were not significantly altered by bifidobacteria strains in ovo injection. Regarding ileal histomorphometry parameters, a significant elevation in villus height and villus height/crypt depth ratio values were recorded while crypt depth was insignificantly affected by in ovo treatments. It could be concluded that the tested manual method of in-yolk sac injection at day 17 of incubation is more favorable in easier delivering of bifidobacteria strains which improve broiler growth performance and ileal development without any undesirable effects on blood indices and liver and renal functions.

Influence of selected plant seeds on the performance, carcass characteristics, sensory evaluation, and economics of broiler chicken.

The immergence of antibiotic resistance, in livestock especially poultry, led to the ban of antibiotics as a growth promoter in some part of the world. This brought about the investigations into the development of various alternatives to antibiotics that will not compromise the integrity of poultry products for safe consumption. Therefore, this study examined the possible impacts of selected plants seeds (pawpaw, mustard, and black cumin) as feed additives on the performance, carcass characteristics, and sensory evaluation of broilers. A total of 180 day-old Arbor Acre Plus chicks were randomly assigned to five treatments of four replicates in a completely randomized design. The five treatments were three plant seed additives: pawpaw (PPS), mustard (MUS), and black cumin (BCS), treatment without additives (CON, i.e., no plants seeds/medications), and treatment with medications and antibiotics (ANT). During the feeding trials that lasted for 8 weeks, body weight gain, feed intake, and feed conversion ratio (FCR) were considered performance data. At the end of the feeding trials, two birds per replicate were slaughtered for carcass parameters and sensory evaluation. Data collected were subjected to analysis of variance. Mustard seed (Brassica juncea) significantly (P = 0.018) supported carcass growth. Further, the highest feed intake was obtained in MUS while the lowest was obtained in CON birds. The PPS had higher (P = 0.013) BWG than in other treatments while the lowest was obtained in CON. Values of FCR were lowest (P = 0.15) in PPS while the highest in CON birds. Furthermore, MUS and PPS had significantly (P = 0.018) and (P = 0.03) higher live weight than CON and ANT, while MUS had higher dressed weight percentage than CON and ANT birds. Broiler meat under diet supplemented with black cumin was relatively found to be most acceptable while meat under mustard seed was the least acceptable. In contrast, the average cost realized per bird was obtained in PPS while the lowest was in CON and ANT. However, broiler diet supplemented with BCS brings about a corresponding decrease in percentage feeding cost reduction among plant supplements.