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The impact of utilizing chopped computer and bond paper as a litter material on growth performance of broilers reared to market age was evaluated. In the first experiment, broilers were placed in pens at 10 birds per square meter, and four different litter treatments were used; 1) 100% chopped computer and bond paper (CCP); 2) a mix of 75% CCP and 25% wood shavings (WS); 3) 50% CCP and 50% WS; 4) 100% WS. Experiment 2 evaluated the same treatments, but with densities of 14 birds per square meter. Litter treatments had no effect on body weight gain, feed consumption, conversion, or mortality for either of the two experiments. No differences were found for percentage litter moisture among treatments. Chopped computer and bond paper alone or mixed in different percentages with WS can be used as an alternate litter material for rearing broilers as long as there is good waterer management, especially with open watering systems. These systems may have the tendency to increase the incidence of litter caking.

Problems with indoor husbandry and immunological challenges are some of the stressors that broilers may face which can affect production. Infectious diseases can compound the effects of excessive concentrations of ammonia causing respiratory and ocular inflammation and increased lacrimal production in broiler chickens. The objectives of this investigation were to establish normal values of tear production in chicks and compare the practicality of the different methods. Palpebral fissure length (PFL) and tear production were evaluated in Cobb 500 chicks at 5 d old and then at 5 d of age by the following methods: modified Schirmer's test I (mSTT1), phenol red cotton thread tear test (PRCTTT), and standardized endodontic absorbent paper point test (EAPPTT). Ten chicks at the age of 5 and 42 d were evaluated for each method. In addition, at 42 d, when the palpebral fissure permitted, a regular-sized Schirmer tear test I (STT1) was performed in another group of 10 chickens. Overall, PFL and the secretion of the aqueous phase of the tear film increased with age. Mean mSTT1 results were 5.00 ± 1.83 mm and 10.45 ± 2.58 mm for 5- and 42-d-old chicks, respectively. Mean PRCTTT results were 12.37 ± 1.80 mm and 25.58 ± 4.8 mm for 5- and 42-d-old chicks, respectively. Mean EAPPTT results were 7.13 ± 0.72 mm and 12.03 ± 0.92 mm for 5- and 42-d-old chicks, respectively. Mean STT1 for 42-d-old chicks was 11.40 ± 2.60 mm. Results obtained with endodontic paper points showed the lowest coefficient of variation and investigators found the test easier to perform. These values reported for broilers at different ages may be applied in poultry ophthalmology to help the diagnosis of lacrimal production disorders and to detect early disease symptoms that could cause economic losses in poultry production.

The suitability of recycled paper chips (RPC), formed by completely reprocessing waste newspaper, as litter material for rearing broilers was investigated in two successive trials. In Trial 1, broilers were reared in pens prepared with a 9-cm layer of either unused RPC or pine shavings (PS). In Trial 2, broilers were reared in pens prepared by adding 3 cm of clean RPC or PS to used litter of the same type remaining from Trial 1. Mortality, BW, feed consumption and conversion, carcass yield, and incidences of breast blisters and leg abnormalities were not influenced by litter treatments. Litter moisture was greater in RPC during Week 3 of Trial 1, but did not differ between treatments at other times during either trial. Litter caking was greater in RPC throughout Trial 1, but did not differ between treatments during Trial 2. Populations of aerobic, psychrotrophic, and coliform bacteria, and fungi (yeasts and molds) in the two litter types did not differ during the rearing period of either trial. Populations of aerobic bacteria and fungi were greater in unused PS, and fungi populations were greater in used PS prior to initiation of Trial 2. Populations of psychrotrophic bacteria were greater in used PS 6 days after bird removal in Trial 2. Generally, RPC are comparable to PS and have potential as an alternative litter material for rearing broilers.

The suitability of three types of recycled paper products for use as broiler litter was studied in three trials using a total of 9,600 broilers. Litter, consisting of hardwood sawdust (SD) as a control, shredded newspaper (SN), processed newspaper (PN), or processed cardboard (PC), was placed in each of four replicate pens in the first trial and reused in subsequent trials. Body weights at 28 and 49 days were significantly influenced by treatment with broilers reared on SN weighing more than SD controls. Broilers on PC were the lightest. Statistically, the PN broilers were heavier than SD broilers at 28 days but similar to controls by market age. Feed conversion was improved with SN at 28 days but did not differ by 49 days. Mortality was not significantly affected by litter material. The moisture content of paper litters was numerically higher than that of the SD control with significantly greater litter caking occurring in the paper litters. However, only broilers on PC had a greater incidence of breast blisters. Overall and total disease condemnation were not influenced by litter material. Skin color scores were improved with the PN treatment.

Three experiments were conducted to determine the response of bobwhite quail chicks when reared in pens with and without brooding paper. Half the chicks in each experiment was brooded Days 1 to 7 on brooding paper, which covered the litter within a brooder ring. The other half was brooded on either new or reused litter without paper. Results of all three experiments showed a consistent trend of higher 1-week body weights and lower cumulative 1 to 3 week mortality when birds were reared in pens without paper. Overall, no net performance advantages were found for rearing quail with brooding paper at the termination of the 3-week trials.

The effects of formulating broiler diets that contain sources of either rapidly or slowly digestible protein and 2 different dietary fiber sources on growth performance were studied in broilers chickens from 0 to 36 d of age. A total of 1,920 one-day-old, male Ross 708 broiler chickens were randomly allocated and housed in 48 floor pens (40 birds/pen) to one of 4 dietary treatments. Birds were allotted according to a completely randomized block design using a factorial arrangement of treatments with 2 protein digestion rates (rapidly or slowly) and 2 dietary fiber sources [3% oat hulls (OH) or 3% sugar beet pulp (SBP)] from 0 to 36 d of age. All diets were formulated to be isocaloric and isonitrogenous. The pen was the experimental unit for all variables studied (12 replicates/treatment). Data were analyzed using the MIXED procedure of SAS, and the model included the main effects of the protein digestion rate, dietary fiber source, and their interaction. There were 3 experimental feeding phases; starter (from day 0-14), grower (from day 14-28), and finisher (from day 28-36). Results indicated that broilers fed diets containing sources that supplied more rapidly digestible protein had 4% greater (P < 0.01) ADG and improved (P < 0.01) the feed conversion ratio (FCR) by 5% throughout the experiment, most notably after the starter phase. Diets containing 3% OH increased (P < 0.05) the ADFI and ADG (P < 0.05) in the starter phase compared with broilers fed diets containing 3% SBP, without affecting the FCR. The ADG and FCR of broilers fed diets containing sources of slowly digestible protein were improved (P < 0.05) to the level of broilers fed rapidly digestible protein containing diets with the addition of 3% OH. It is concluded that broiler diets should be formulated to contain a high concentration of ingredients that supply rapidly digestible protein, but if this is cost-prohibitive, then 3% OH could be used to increase the ADFI and ADG and potentially protein digestion rates to reduce the FCR.

Three experiments, which included 4 broiler flocks, were conducted to examine the usefulness of a novel bedding material for rearing broilers. The control bedding was pine shavings. The novel bedding, aGroChips (AC), was a chopped material made from cotton lint waste, gypsum, and old newsprint using a proprietary paper manufacturing process (Novovita, Inc., Raleigh, NC). All birds were fed the same feeding program: starter from 0 to 3 wk, grower from 3 to 5 or 6 wk, and finisher during the last week. Birds were marketed at either 6 or 7 wk of age. Feed consumption by pen and individual bird BW were measured at 3 and 6 or 7 wk. Mean BW and feed conversion, adjusted to include weight of mortality, were calculated. A sample of birds (n = 10) from each pen was evaluated for hock and foot pad condition. Each pen was evaluated at the end of the trial for litter cake index in 3 of the 4 flocks. Litter cake index scores were generally higher for birds reared on AC litters. There were no other differences in bird performance for any of the flocks. In conclusion, broilers reared on AC bedding perform as well as those reared on pine shavings.

IN A previous paper by Baker et al. (1957) the effects of feeding Nicarbazin to laying hens on the yolk quality of their eggs was described. Neither the nature of the damage to the yolk nor the mechanisms involved in causing the damage were known. Experiments were designed to study the possible mechanisms involved. MATERIALS AND METHODS Eggs were obtained from hens fed Nicarbazin. The scoring system used to estimate yolk damage was the same as described previously (Baker et al., 1957). Water uptake of the yolk was determined according to the method of Orru (1939). The intact yolk was dried on filter paper, placed in a tared beaker and covered with the experimental solution. The system was incubated at 37°C. for 3 hours, the fluid drained off and the last traces of solution removed with filter paper by rolling the yolk over the paper. It proved to be practically . . .

Softwood chipping fines, a by-product of the paper manufacturing industry, was evaluated for its efficacy as poultry litter on a total of 1,200 broilers. There were no differences in 49-day body weights or feed conversion between broilers grown on softwood chipping fines and on pine shaving control litter. Broilers grown on chipping fines litter had 58% fewer breast downgrades and 64% more Grade A carcasses than those raised on pine shavings. High moisture level chipping fines litter treatments produced slightly elevated mortality, but overall mortality was low.

One hundred White Leghorn hens in each of two experiments were divided into two groups based on lysozyme content (negative moving fraction at pH 8.5) of the thick egg white. Paper electrophoresis was used to index 260 pullets for experiment 1 and 100 pullets in experiment 2. Fifty birds producing eggs of the highest and 50 with the lowest lysozyme content were used for egg quality studies in each experiment. Data were obtained on an individual hen basis for interior quality of fresh eggs, in Haugh units (H.U.), quality loss during storage, egg weight, shell quality and percent solids of albumen and yolk. Haugh unit values of fresh eggs were similar for high and low lysozyme eggs in both experiments. Differences in shell quality, egg weight and solids content of albumen were not significantly different in either experiment. Quality losses during storage were significantly different in both experiments. Quality losses during storage were significantly (P Differences in solids content of egg yolks were statistically significant (P

A study was conducted to evaluate the protective capability of 10 commonly used 12-egg foam (F) and pulp (P) cartons when packed and shipped in 15-dozen wire or plastic baskets and 30-dozen fiberboard cases. The study included 42 truck shipments in seven states. Eggs were graded for shell damage in 8 large packing plants, 9 central distribution warehouses, and 11 retail supermarkets. Range of damage was greater among foam cartons than among pulp cartons, although damage rate differences between the two groups were generally minimal. Test cartons F1 (foam flattop) and F2 (foam posted) had significantly less total eggshell damage than three other cartons (two F and one P) when the effect of master container was not considered. When cartons were packed in 30-dozen cases, there was no significant difference in total eggshell damage rates between F and P; however, test carton F1 had significantly less total damage than four other cartons (two F and two P). When cartons were packed in 15-dozen baskets, however, eggs in the pulp group had significantly less total damage than eggs in the foam group, and test carton F2 had significantly less total eggshell damage than four other cartons (three F and one P). Throughout the study, cartons F1, F2, P1, and P2 consistently performed at or above average and did not differ significantly from each other.

AS THE industry moves toward a program of non-storage eggs the year around, methods of preserving the quality of shell eggs during marketing becomes paramount. The use of oil treatment, carbon dioxide atmosphere, thermostabilization or plastic treatment has been suggested by various investigators (Evans and Carver, 1942; Sharp and Stewart, 1931; Funk, 1943; and Yushok and Romanoff, 1949, respectively). However, a direct comparison of the relative efficiency of these methods under varying seasonal and storage conditions has not been made. Flavor is one of the most important factors in consumer acceptability of shell eggs. Few preservation studies, however, have included flavor as a method of evaluation. Mallman and Davidson (1944) and Shenstone and Vickery (1957) reported that oil coatings did not retard the onset of stale flavors during storage. Sauter, Harns, Stadelman and McLaren (1954) found no significant differences in the flavor of fresh eggs produced in the different seasons.…

INTRODUCTION CHLORINATION of an entire poultry processing plant water system at 10, 20 and 45 parts per million chlorine was studied by Drewniak et al. (1954). Twenty parts per million chlorine significantly reduced the bacterial load on chicken carcasses prior to chilling. These results were confirmed by Patterson (1958), who sampled frozen birds produced in a plant using different levels of chlorination in the entire water supply. Without special precaution, however, long-term chlorination at this level can corrode steel, stainless steel, and brass currently used in poultry plant plumbing systems (Mercer and Somers, 1957). This factor makes whole-plant chlorination at 20 parts per million impractical in many areas without installing either deionizing systems to remove minerals and/or pH adjustment using sodium hydroxide. Ranken et al. (1965) and Barnes (1965) indicated that chlorination at 200 parts per million in the slush ice chilling of birds extends shelf-life slightly and reduces the…

IN STUDIES concerning nitrogen metabolism in chickens, the interrelated metabolism of the energy nutrients (carbohydrates and fats) and protein present a problem in the formulation of rations. The effects of dietary energy levels on nitrogen components of the urine has not been extensively investigated. The findings of urinary nitrogen components were reviewed by O’Dell et al. (1960). These workers also presented data on urinary nitrogen components as influenced by various protein sources. It was of interest in this laboratory to determine whether dietary energy levels would affect the nitrogen components of avian urine while being maintained on an iso-protein ration. MATERIALS AND METHODS Twelve hens (S.C. White Leghorn) were selected and placed in an air-conditioned room (75° ± 1°F.). Surgical techniques used for the separate collection of feces and urine were similar to those described by Dixon and Wilkinson (1957) and Dixon (1958) and modified by Richardson et al., (1960).

Feather pecking is a multi-factorial behavioral disorder and a serious welfare issue in the poultry industry. Several studies report early life experience with litter to be a major determinant in the development of feather pecking. The current study aimed to test the large-scale on-farm efficiency of a simple and cheap husbandry procedure applied during the rearing period with the ultimate goal of reducing the incidence of feather pecking and plumage damage during the production stage in laying hens. Five laying hen-rearing farmers from across Norway participated in the study. These farmers were asked to create divisions within their hen rearing houses and to separate their chicks into 2 groups: one reared with access to a paper substrate from the first d of age, the other a control group without access to paper substrate during rearing. All flocks were visited at the production farms at 30 wk of age and observed for pecking behavior and feather damage. Birds in the control group had higher odds of having more feather damage compared to the birds from the treatment group. In addition, flocks provided with environmental enrichment at the production farms had a reduced incidence of feather pecking, irrespective of the treatment. These results indicate that husbandry procedures during both rearing and production stages have the potential to alleviate feather pecking and increase laying hen welfare.

This paper is an integral part of the special publication series that arose from the multidisciplinary and multi-institutional project of the Coalition for Sustainable Egg Supply (CSES). The CSES project involves 3 housing systems for egg production at the same research farm site in the Midwest, USA, namely, a conventional cage (CC) house, an aviary (AV) house, and an enriched colony (EC) house. The CC house (141.4 m L × 26.6 m W × 6.1 m H) had a nominal capacity of 200,000 hens (6 hens in a cage at a stocking density of 516 cm2/hen), and the cages were arranged in 10 rows, 8 tiers per cage row, with a perforated aisle walkway at 4-tier height. The AV house (154.2 m L × 21.3 m W × 3.0 m H) and the EC house (154.2 m L × 13.7 m W × 4.0 m H) each had a nominal capacity of 50,000 hens. The AV house had 6 rows of aviary colonies, and the EC house had 5 rows of 4-tier enriched colonies containing perches, nestbox, and scratch pads (60 hens per colony at a stocking density of 752 cm2/hen). The overarching goal of the CSES project, as stated in the opening article of this series, was to comprehensively evaluate the 3 egg production systems from the standpoints of animal behavior and well-being, environmental impact, egg safety and quality, food affordability, and worker health. So that all the area-specific papers would not have to repeat a detailed description of the production systems and the management practices, this paper is written to provide such a description and to be used as a common reference for the companion papers.

Genetic selection that has been carried out for several dozen years has led to significant progress in poultry production by improving productive traits and increasing the profitability of broiler breeder and layer hen production. After hatching, broilers and layers differ mainly in feed intake, growth rate, efficiency of nutrient utilization, and development of muscles and adipose tissue. A key role can be played by hormonal mechanisms of appetite control in broilers and layers. The paper discusses the consequences of different growth rates resulting from long-term genetic selection on feed intake, efficiency of nutrient utilization, and development of muscles and adipose tissue, with particular consideration of the hormonal mechanisms of appetite control in broilers and layers. The information presented in this review paper shows that it would be worth comparing these issues in a meta-analysis.

In modern rearing systems, turkey producers often face economic losses due to increased aggression, feather pecking, cannibalism, leg disorders, or injuries among birds, which are also significant welfare issues. The main underlying causes appear to relate to rapid growth, flock size, density, poor environmental complexity, or lighting, which may be deficient in providing the birds with an adequate physical or social environment. To date, there is little information regarding the effect of these factors on turkey welfare. This knowledge is, however, essential to ensure the welfare of turkeys and to improve their quality of life, but may also be beneficial to industry, allowing better bird performance, improved carcass quality, and reduced mortality and condemnations. This paper reviews the available scientific literature related to the behavior of turkeys as influenced by the physical and social environment that may be relevant to advances toward turkey production systems that take welfare into consideration. We addressed the effects that factors such as density, group size, space availability, maturation, lightning, feeding, and transport may have over parameters that may be relevant to ensure welfare of turkeys. Available scientific studies were based in experimental environments and identified individual factors corresponding to particular welfare problems. Most of the studies aimed at finding optimal levels of rearing conditions that allow avoiding or decreasing most severe welfare issues. This paper discusses the importance of these factors for development of production environments that would be better suited from a welfare and economic point of view.

Location of Salmonella during hatching of broiler chicks was studied in three experiments. Unincubated, fertile hatching eggs heated to 42 C were inoculated by immersion for 15 min in a 16 C physiological saline solution containing approximately 1 x 10(5) cfu/mL of a nalidixic acid-resistant strain of Salmonella typhimurium. All eggs were sanitized externally by wiping with a paper towel wet with 70% ethanol. When incubating eggs were transferred to a hatcher, each was placed in a closed paper bag to minimize cross-contamination. Unhatched eggs were sampled by cutting away the shell over the air cell, sanitizing the inner air cell membrane with 70% ethanol, and removing the contents through the membrane. Shells and membranes were crushed and mixed in 10 mL buffered peptone (BP). Yolks were dissected out, dipped in 70% ethanol, and mixed with 10 mL BP. Embryos or chicks and all surrounding fluid were rinsed in 100 mL BP. A total of 172 eggs was sampled. Shells and membranes were 100% Salmonella-positive 30 min after inoculation, but only 38% were positive after 17 to 21 days of incubation. No chick rinses were positive before pipping, but 15% were positive after pipping. Yolk samples were 2% positive before pipping versus 8% after pipping. A majority of chicks hatching from positive shells and membranes were Salmonella-negative.

A chicken growth study was conducted to determine if litter type influenced gut microbiota and performance in broilers. Seven bedding materials were investigated and included soft and hardwood sawdust, softwood shavings, shredded paper, chopped straw, rice hulls, and reused softwood shavings. Microbial profiling was done to investigate changes in cecal bacterial communities associated with litter material and age. Cecal microbiota were investigated at 14 and 28 d of age (n = 12 birds/litter material). At both ages, the cecal microbiota of chickens raised on reused litter was significantly (P0.05) different from that of chickens raised on any of the other litter materials, except softwood shavings at d 28. Cecal microbiota was also significantly different between birds raised on shredded paper and rice hulls at both ages. Age had a significant influence on cecal microbiota composition regardless of litter material. Similarity in cecal microbial communities among birds raised on the same litter treatment was greater at 28 d of age (29 to 40%) than at 14 d of age (25 to 32%). Bird performance on the different litter materials was measured by feed conversion ratio, live weight, and feed intake. Significant (P0.05) differences were detected in live weight at 14 d of age and feed intake at 14 and 28 d of age among birds (n = 160/treatment) raised on some of the different litter materials. However, no significant (P0.05) differences were observed in feed conversion ratio among birds raised on any of the 7 different litter materials at either 14 or 28 d of age. The type of litter material can influence colonization and development of cecal microbiota in chickens. Litter-induced changes in the gut microbiota may be partially responsible for some of the significant differences observed in early rates of growth; therefore, litter choice may have an important role in poultry gut health particularly in the absence of in-feed antibiotics.

Four experiments were conducted to evaluate the effects of brooder type and use of brooding paper (during 1st wk of brooding) on performance of Bobwhite quail (BWQ) chicks. In Experiment 1, 1,500 day-old BWQ chicks were equally divided between two treatments: pen brooding by infrared heat lamp (TR-LAMP) and pen brooding by quartz bar radiant heater (Q-BAR). In Experiments 2, 3, and 4, day-old BWQ chicks were assigned to four treatments: IR-LAMP with brooding paper; IR-LAMP without brooding paper; Q-BAR with brooding paper, and Q-BAR without brooding paper. Each treatment consisted of three pens of 215, 225, and 230 birds each for Experiments 2, 3, and 4, respectively. Body weight, feed consumption, and mortality were not significantly different among brooder types in Experiment 1. Neither brooder type nor brooding paper treatments significantly affected mortality in Experiments 2, 3, and 4. With both type brooders, birds reared with brooding paper showed a consistently, significant (P

The purpose of this paper was to compile all available literature comparing the relative performance of 2-hydroxy-4-methylthio butanoic acid (HMTBA) with DL-methionine (DLM) in broiler chickens and using multiple regression techniques, to estimate the predicted dose responses and relative performance of the 2 Met compounds for gain and feed conversion (FC). A database was developed that contained all available broiler studies in which HMTBA and DLM were both present in the same study; weight gain was recorded; Met addition, age of birds, and duration of study were defined; and an unsupplemented control treatment was present. Sixty-two references complied with these criteria and included 100 experiments with 427 observations for HMTBA and 411 for DLM. Multiple regression analysis of the database was used to identify the experimental and dietary conditions that contributed to the gain and FC responses of each source of Met activity. All identified variables contributed similarly to each Met source prediction model and both gain and FC models described a quadratic dose response. Under the average conditions of the database, the predicted responses for gain and FC models did not significantly differ between HMTBA and DLM. However, a trend was observed (P less than or equal to 0.1) for the peak gain response for HMTBA to be numerically greater than DLM, suggesting benefits of HMTBA over DLM in the region of supplementation that is commercially relevant. The experimental and nutritional conditions that contribute to the response to HTMBA and DLM were identified and are discussed in the paper. This statistical approach provided a means to summarize the results obtained from a multitude of studies conducted over the last 5 decades and has provided a meaningful estimate of the relative performance of the 2 sources of Met activity. The lack of differences between the 2 predicted models under experimental and commercial conditions supports an overall conclusion of equal performance of DLM and HTMBA when compared on an equal molar basis.

This paper presents the results of the research on the use of fish oil (FO) in combination with soybean oil (SO) in laying hens diet on physical and chemical properties of fresh eggs and those stored in a refrigerator for 28 d at + 4°C. Fatty acids (FA) profile, as well as thiobarbituric acid reactive substances (TBARS) values in yolks are also presented. The following feeding treatments have been used: C (control, without FO), E1 (0.3% FO + 4.7% SO), E2 (0.6% FO + 4.4% SO), E3 (0.9% FO + 4.1% SO), E4 (1.2% FO + 3.8% SO) and E5 (1.5% FO + 3.5% SO). Laying hens diets were balanced at the level of 176.10 g/kg crude protein and 11.50 MJ/kg ME. The results of the study showed that feeding treatments affected the relative shares of the eggs basic parts (P < 0.05). The egg storage duration significantly reduced Haugh units (HU), egg and albumen egg weight, and increased the yolk color intensity (P < 0.001). Fish oil share increment in the diets resulted in the EPA (eicosapentaenoic FA) content increase from 10.27 to 20.10 mg/100 g egg; DHA (docosahexaenoic FA) from 105.44 to 236.87 mg/100 g egg and ∑ n-3 PUFA (polyunsatureated FA) from 204.59 to 327.35 mg/100 g egg. The ∑ n-6 PUFA/∑ n-3 PUFA ratio decreased from 8.69 (C group) to 4.54 (E5 group). TBARS values were affected by feeding treatments as well as treatment-storage interactions (P < 0.01).

To meet the growing consumer demand for chicken meat, the poultry industry has selected broiler chickens for increasing efficiency and breast yield. While this high productivity means affordable and consistent product, it has come at a cost to broiler welfare. There has been increasing advocacy and consumer pressure on primary breeders, producers, processors, and retailers to improve the welfare of the billions of chickens processed annually. Several small-scale studies have reported better welfare outcomes for slower-growing strains compared to fast-growing, conventional strains. However, these studies often housed birds with range access or used strains with vastly different growth rates. Additionally, there may be traits other than growth, such as body conformation, that influence welfare. As the global poultry industries consider the implications of using slower growing strains, there was a need for a comprehensive, multidisciplinary examination of broiler chickens with a wide range of genotypes differing in growth rate and other phenotypic traits. Tomeet this need, our team designed a study to benchmark data on conventional and slower-growing strains of broiler chickens reared in standardized laboratory conditions. Over a 2-year period, we studied 7,528 broilers from 16 different genetic strains. In this paper, we compare the growth, efficiency, and mortality of broilers to one of two target weights (TW): 2.1 kg (TW1) and 3.2 kg (TW2). We categorized strains by their growth rate to TW2 as conventional (CONV), fastest-slow strains (FAST), moderate-slow strains (MOD), and slowest-slow strains (SLOW). When incubated, hatched, housed, managed, and fed the same, the categories of strains differed in body weights, growth rates, feed intake, and feed efficiency. At 48 d of age, strains in the CONV category were 835 to 1,264 g heavier than strains in the other categories. By TW2, differences in body weights and feed intake resulted in a 22 to 43-point difference in feed conversion ratios. Categories of strains did not differ in their overall mortality rates. Global Animal Partnership, Canada First Research Excellence Fund, Ontario Agri-Food Innovation Alliance, and Protekta

The paper aimed to study the effects of light regime during the incubation on hatching performance, body development and serum biochemical indexes in Beijing You Chicken (BYC). A total of 1,408 BYC eggs were randomly allocated into 4 groups: 24 h dark as the control (Inc24D); 3 light regimes were 8 h light and 16 h dark group (Inc8L:16D); 12 h light and 12 h dark group (Inc12L:12D); 16 h light and 8 h dark group (Inc16L:8D), respectively. There were 352 eggs in each group, 4 replicates each group and 1 tray each replicate, 88 eggs each tray. Light-emitting diode (LED) strips, white light with temperature of 4,500 to 5,000 K, 150 to 200 lx were set up. The results showed that light regimes had no significant effects on hatching rate of eggs, hatching rate of fertile eggs and healthy rate of chicks (P > 0.05), but the hatching rate of eggs was the lowest in the Inc24D group (87.22%), and the highest in the Inc12L:12D group (93.64%); Lighted incubation significantly affected the incidence of leg problems of 1-day-old chicks (P < 0.05). The incidence rate of leg problems was the highest in the Inc24D group (4.21%), and was decreased in Inc12L:12D and Inc16L:8D groups (P < 0.05). Femur length in the Inc12L:12D group was greater than that in the Inc24D and Inc16L:8D groups (P = 0.011), but there were no differences between Inc8L:16D group and other three groups (P > 0.05). The relative brain weight of 1-day-old chicks was higher in Inc24D and Inc16L:8D groups than in Inc8L:16D group (P = 0.052), but had no difference with Inc12L:12D group. Light regimes during incubation had no effects on serum total protein, albumen, globulin, and urea nitrogen content of 1-day-old chicks (P > 0.05), while the globulin content in Inc12L:12D group was numerically greater than in other three groups (P = 0.063). Lysozyme content in Inc12L:12D group was higher than that in the Inc24D and Inc8L:16D groups (P < 0.05), but had no difference with that in Inc16L:8D group. Light regime had no effect on serum total antioxidant capability (T-AOC) (P > 0.05), but significantly affected the activities of glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) (P < 0.05). The GSH-Px and T-SOD activities in the Inc12L:12D group were higher than those in the Inc24D and Inc8L:16D groups. The MDA content of Inc24D was the highest (9.67 nmol/mL) compared to the others, which was very close to the significant level (P = 0.056). In conclusion, 12 h light and 12 h dark incubation has the potential to improve the hatching performance of BYC eggs, benefit for the long bone development, improve some serum immune and antioxidant indexes, and reduce the leg problems in 1-day-old chicks.

Scoring is a common method to evaluate eggshell translucency, and it mainly depends on the area and the density of translucent spots in eggshells. However, the lack of common scoring criteria and the difficulty of quantitatively measuring spots in eggshells impede effective comparisons between research papers and greatly hinder the progress of research on translucent eggshell. To make measurement of translucent eggshells more objective, we optimized the scoring method and compared it with 2 new methods: grayscale recognition and the colorimeter method. Briefly, a total of 354 eggs from 600, 395-day-old dwarf brown laying hens were collected and classified into 4 score groups according to their degree of translucency. This subjective process was repeated 5 times. Then, we captured the profile side of each egg using a camera and measured spot characteristics using grayscale recognition, which involved measuring the quantity of spots (QS), diameter of each spot (DS), average area of each spot (AAES), sum of spot areas (SUSA), sum of shell area (SUSHA), and ratio of SUSA to SUSHA (RSS) on the eggshell. Furthermore, the L, A, and B values of each egg at the sharp, middle, and blunt ends were separately measured using a colorimeter. As a result, average values of 31.31, 29.78, 29.81, and 9.08% of all eggs were divided into score levels 1, 2, 3, and 4 (from opaque to translucent), which correspond with RSS values of 1.34, 3.23, 6.21, and 11.89%, respectively. By grayscale recognition, QS, DS, AAES, SUSA, SUSHA, and RSS all increased along with increased translucency scores (P < 0.05). Using scoring, an egg with a specific RSS value was more easily assigned to a specific score level (50%) or adjacent score levels (50%). The L, A, and B values of eggshells in score level 1 were significantly different from those of eggshells in levels 3 or 4; however, there were no significant differences between any adjacent score levels. In summary, the present study explored objective reference metrics to measure eggshell translucency.

The paper presents findings about how the substitution of calcium, iron, zinc, and copper salts with glycine chelates affects specific reproductive parameters of pheasants, the hatching potential and nutritional components of pheasant eggs, and the fatty acid profiles and cholesterol content in pheasant yolk. 4 groups were created for the experiment: the control, in which the birds received a feed containing standard calcium, iron, zinc, and copper salts, and 3 experimental groups in which chelates were used to replace 25, 50, and 75% of the mineral salts. The group with the 75% chelate share was not supplemented with the salts, and cholecalciferol was replaced with calcitriol. The groups included pheasant females (7 birds) and 1 male, respectively, and were maintained in outdoor aviaries. The birds were administered granulated feed mixes ad libitum, with free access to water. Their feed intake was recorded each day. The birds were weighed at the beginning and end of the egg-laying period. The eggs were collected throughout the egg-laying period, and the eggs gathered at the culmination of the egg-laying period were used for hatching. The eggs were morphometrically analyzed and the hatching process and subsequent hatchling survival rates were investigated. Nutritional components in the eggs were determined, and the fatty acid profiles and cholesterol content were assayed in the yolk. The results showed the use of Ca, Fe, Zn, and Cu chelates in place of salts in the pheasant brood hen diet had contributed to enhancing the egg-laying performance, with a concurrent fall in the size and weight of the eggs. The highest egg-laying performance, with the lowest egg weight, was observed in the group that consumed the highest (75%) share of mineral chelates and received calcitriol supplementation. This corresponded with the highest incubation yield and hatchling survival. The thickest shells and highest crude ash percentages were identified in the eggs of the pheasant group that received a 50% by 50% proportion of salts and glycine chelates. In comparison with the control birds that received the mineral salts, the yolk of the pheasants that consumed the feed with the 75% share of calcitriol and Ca, Fe, Zn, and Cu chelates had a higher percentage of n-6 and n-3 polyunsaturated fatty acids (PUFAs), with a far more advantageous n-6/n-3 proportion. No differences related to the source and levels of Ca, Fe, Zn, and Cu in the feed were observed in the cholesterol content of the pheasant yolk.

The paper aimed to study the effects of lighting pattern and photoperiod alone and in combination on egg production, egg quality in Beijing You Chicken (BYC). A total of 630 19-wk-old BYC laying hens were randomly allocated to 6 groups with 105 birds each, 3 replicates per group, reared in individually lit floor pens with separate outdoor areas. A 2 × 3 factorial experiment (2 lighting patterns: continuous and intermittent lighting; 3 photoperiods: 16, 14, 12 h) was arranged, including 16L:8D (6:00 to 22:00) for group 1; 12L:2D:4L:6D (6:00 to 18:00, 20:00 to 24:00) for group 2; 14L:10D (6:00 to 20:00) for group 3; 10L:2D:4L:8D (6:00 to 16:00, 18:00 to 22:00) for group 4; 12L:12D (6:00 to 18:00) for group 5, and 8L:4D:4L:8D (6:00 to 14:00, 18:00 to 22:00) for group 6, respectively. Egg production parameters were calculated for 22 to 43, 44 to 57, and 22 to 57 wk, and egg quality parameters were measured at the end of 37 and 57 wk. The results showed that the egg production of BYC was not significantly affected by lighting pattern, photoperiod alone, or in combination during 22 to 43 and 22 to 57 wk (P0.05), but average feed intake in 12 h groups was significantly higher than those in 14 and 16 h groups during 22 to 43 and 22 to 57 wk (P0.05). Egg mass and feed egg ratio were significantly affected by lighting pattern, photoperiod alone, and in combination during 44 to 57 wk (P0.05). Egg mass was significantly higher (P = 0.05) and feed egg ratio was significantly lower (P = 0.03) in continuous groups than in intermittent groups. There were significant effects for eggshell thickness, albumen height, haugh unit, and egg grade by lighting pattern alone (P0.05) at 37 wk. The study suggested that 1) the egg production was not significantly affected by lighting pattern alone during 22 to 57 wk (P0.05), but the photoperiod significantly affected average feed intake (P0.05); 2) continuous lighting is better for the egg production during 44 to 57 wk, and intermittent lighting is better for egg quality of the native bird at 37 wk; 3) 12 h lighting is enough for meeting the requirement of the native chicken during the laying period; (4) no change in photoperiod from the rearing to the production phase (12 to 12 L) will have long-lasting effects on egg production or egg quality under the present condition.

This paper is the second of a series reported from the Utah Station on the transfer of dietary DDT to eggs and poultry tissues. The first paper was reported by Bryson et al. (1950) on the accumulation of DDT in poultry products. The published literature on this topic has been reviewed and reported by Bryson et al. (1950). EXPERIMENTAL THE alfalfa hay fed in this experiment was from the same field described by Harris et al. (1949). This alfalfa was dusted with 0, 1, 2, and 4 pounds of technical DDT per acre. The harvested hay was ground into meal and 15 percent of this meal was included in the laying mash. DDT was also added to a similar mash made from untreated alfalfa meal at levels of 0, 50, 100, and 200 p.p.m. These diets are reported in Table 1. The design of this experiment is as follows: A . . .

I. Introduction The purpose of this paper, which is one of a series on the various problems of the biology and economics of egg production in the domestic fowl, is a presentation of constants showing the relationship between monthly egg production aud annual egg record in the pullet year in the White Wyandotte breed. From the purely biological side the present paper is a contribution of detail to the quantitative measurement of the interrelationship of the variables which must be considered in any comprehensive study of the broad problem of the physiology of egg production. The specific purposes of the determination of the various coefficients have been fully enough stated in preceding papers,* and will not be reiterated here. A comparative discussion of these correlations for the economically more important breeds of fowl is in preparation; the constants here presented will then be discussed in greater detail. In the meantime, . . .

A SURVEY of the literature on the vitamin A requirements of the growing chick revealed that at least eight papers on this subject have appeared since 1926. (Almquist and Meechi, 1939; Bearse and Miller, 1937; Biely and Chalmers, 1936; Record, et al. 1937; Ringrose and Norris, 1936; Sherwood and Fraps, 1936; Tepper and Durgin, 1938; Wilson, et al. 1936). These papers were examined with the following criteria in mind: (1) Practicality of the ration used, (2) Nutritional adequacy of the ration, except for vitamin A, (3) The number of birds per test group, (4) The attainment of what might be considered normal weight at 8 weeks of age, (5) The presence of a group whose growth response is less than normal, (6) The use of a practical source of vitamin A or carotene, and (7) relatively small differences between levels of vitamin A. None of the experiments noted met all . . .

IN THE first paper of this series (Lorenz and Starr, 1952; referred to hereafter as 1) the results of a study of washing eggs by different methods in the laboratory were discussed and pertinent literature was reviewed. The experiment reported here was intended to obtain more extensive information on some of the variables discussed in that paper and to compare washing in the laboratory with washing on the ranch. MATERIALS AND METHODS Eggs from a single nearby poultry ranch only were used in this trial. Three days each week during 4 consecutive weeks the entire day’s production of this ranch was brought to the laboratory immediately after the final collection for that day. These eggs were then segregated at once according to cleanliness, and eggs that had checked or grossly imperfect shells were removed. The sound shelled eggs were then cleaned at once, except for two instances in which washing . . .

This paper supplements a previous article on the same subject which appeared in P oultry S cience , Vol. 6, No. 3. In the former article the data was secured from fourteen White Leghorn hens. The material in this paper was obtained from thirteen Rhode Island Red hens. The experiment was conducted in the same manner as the one previously reported, except that the period over which the hens were trapnested and eggs were examined was of two month’s duration instead of three. The White Leghorn hens used in the other experiment were obtained from a flock in-which practically no, or at least very slight, losses from bacillary white diarrhea were said to have occurred during the past two or three years. On the other hand, the Rhode Island Red hens employed in this experiment came from a flock in which rather heavy losses occurred during the previous spring. The owner of . . .

THE work described in this paper was undertaken in an attempt to obtain further information on comparative physical, chemical and cooking qualities of eggs stored by five different methods of preservation that could be easily duplicated in the home. Methods chosen for study were waterglass, freezing, application of a commercial creamy emulsion, oiling, and coating with a plastic. The eggs were tested at the end of three and six months’ storage. EXPERIMENTAL METHODS Clean, grade AA eggs from New Hampshire hens were delivered daily from the college poultry farm to the laboratory during a three-week period. All eggs except those to be frozen were dated, numbered, weighed and marked with their individual fresh weights. The eggs treated by means of commercial creamy emulsion, oiling and plastic coating were packed, small end down, in paper egg cartons. All eggs were stored in the dark at 50 to 60°F. and at a . . .

THE preceding papers in this series by Cuckler et al. (1956) and Cuckler and Malanga (1956) showed that nithiazide [1-ethyl-3-(5-nitro-2-thiazolyl) urea] was the most effective antihistomonad (blackhead) agent in a series of closely related compounds. Furthermore, nithiazide was found more potent and less toxic than 2-amino-5-nitrothiazole in experimental enterohepatitis. This paper presents the results of studies on the absorption and excretion of nithiazide by turkeys and chickens and the effect of this compound on their growth, maturation and reproduction. These studies have shown that chickens and turkeys tolerated nithiazide better than 2-amino-5-nitrothiazole or 2-acetylamino-5-nitrothiazole, chemically related compounds. MATERIALS AND METHODS The turkeys and chickens used in these studies were obtained from commercial sources when 1 day of age. Straight run Beltsville White turkeys and White Rock cross chicks were used in the laboratory experiments, and the birds were kept in electrically heated battery brooders. The floor-pen growth trials involved White . . .

INTRODUCTION SELECTION is considered to be the best tool for genetic improvement in a given population. Heritability of a character is an important factor affecting genetic improvement. In a previous paper, Issawi et al. (1963) studied heritability of fertility and hatchability in Fayoumi. The present paper deals with the study of heritability of body weight in Fayoumi. REVIEW OF LITERATURE Many investigators estimated heritability of body weight in chickens. Spector (1956) summarized the different estimates of this character and concluded that it was highly heritable. In Single Comb White Leghorn, Lerner et al. (1949) stated that heritability of body weight at twelve weeks of age was 0.475, and 0.597 and 0.506 on the basis of the contribution of sire, dam, and both, respectively. Fagan (1949), reported similar figures for heritability of body weight at twelve weeks of age, being in the range from 0.35–0.50. El-Ibiary and Shaffner (1951), reported…

This paper is a preliminary report on some results obtained in attempting to estimate the gross maintenance requirement of White Leghorn chickens from data obtained from feeding experiments specially planned for that purpose. The expression, “gross maintenance requirement,” as employed here, is used to designate that weight of feed (in grams) which a chicken requires each day for all purposes, except for increasing its live weight and for producing eggs. The feeding experiments were so planned that a number of pens of chickens were fed at levels of feed intake which differed from one another by a fixed amount, all the levels of feed intake being less than that required for maintaining live weight. The daily allowance of feed for each pen was weighed and placed in small paper bags before the experiment was started, and each morning during the experiment proper one of these bags was emptied into the . . .

IN A previous paper (Shao and Hill, 1968) it was reported that thiouracil as a dietary supplement reduced the concentration of free lysine, threonine, tryptophan, methionine and leucine in the blood plasma of chicks. The present paper gives the results of experiments in which thiouracil and/or iodinated casein were added to a basal diet and extends the observations to several additional amino acids. EXPERIMENTAL The basal diet, essentially a wheat, corn soybean meal mixture, was described in detail by Shao and Hill (1968). White Plymouth Rock pullets were fed this diet from day old to 7 days of age and then divided on the basis of weight into lots of 12 chicks each. The experimental diets were assigned to these lots at random, each diet to 4 lots and the experiments continued for another 14 to 15 days. Blood samples were removed from each chick in two lots per treatment…

THIS paper presents an analysis of a set of feather measurements obtained at the Beltsville Research Center during the course of an experiment designed to determine the effects of certain mineral supplements, particularly inorganic sulphur compounds, on the molt of White Leghorn hens. Since the molt is usually accompanied by a cessation of egg production, the importance of favorably influencing the growth of feathers, if it is possible to do so, is obvious. In view of the fact that feathers contain considerable amounts of sulphur, it was thought that the feeding of sulphur compounds might have some effect on the rate of growth and mature length of the new tail and wing feathers which were grown after the old feathers were dropped during the molt. The general plan of this experiment, including a description of the sulphur compounds fed, has been given in an earlier paper (Hendricks, 1933). Three groups . . .

SEASONAL variation in the rate of egg production is associated with seasonal variation in length of day. The excellent paper of Whetham (1933) summarized a very large amount of data from a wide range of latitudes, all showing correlated changes in day length and rate of egg production. Kennard and Chamberlin (1931) showed that seasonal variation can be modified by use of supplementary artificial light, confirming the work of several earlier laboratory workers and of many poultrymen. Kennard and Chamberlin also showed the close relationship of body weight and rate of egg production. A good review of the earlier literature is contained in the paper of Callenbach, Nicholas and Murphy (1944). Several analyses of egg production data for the purpose of describing the relation of time in production and rate of production have been made. Harris et al. (1921) reported that annual production within a genetically similar flock maintained under . . .

WORK leading to the development of a ration for the uniform production of perosis (slipped tendon) in chicks was presented in the previous paper. In this paper we wish to give the results obtained from studies on factors which prevent the development of this syndrome. Jukes (1937) has recently reviewed the meager work available on the perosis-preventing properties of certain feeds. EXPERIMENTAL Day-old White Leghorn chicks were divided into groups of five chicks each and placed in suitable cages. In the majority of the work ration 604 was used as the basal ration, but results obtained with other closely related rations are also included. The supplements tested were added at the expense of the whole ration. The results are tabulated in Table 1. It is readily evident that the addition of 15 percent of rice bran gave complete protection in all trials. The result checks quite well with the conclusion . . .

THE first of the experiments discussed in this paper was started soon after the discovery that one of the commercial vitamin B12 supplements contained an unknown factor that stimulated the growth of young chickens (Stokstad et al., 1949). After it was found that the factor was an antibiotic (Stokstad and Jukes, 1950), the second experiment was conducted to determine whether the inclusion of an antibiotic in their diet during hot weather would stimulate the growth of young White Leghorn pullets fed a diet containing cottonseed meal as the chief source of protein. Because the stimulation of growth in the second experiment was relatively small in comparison with some of the results that were attributed to the antibiotics, it was considered advisable to conduct other experiments during cool weather. The data from the four experiments at the Southwest Poultry Experiment Station, Glendale, Arizona, are given and discussed in this paper. PROCEDURE . . .

IT IS common experience that chickens and other domesticated birds grow better if hatched at certain seasons than they do if hatched at other seasons of the year. Thus Goodale (1926) found that chicks hatched in the early part of the season grew more rapidly, to 30 days of age, than did those hatched later. Upp and Thompson (1927) likewise observed that there were differences in the rate of growth of chicks hatched at different seasons of the year. They conclude that weather has an influence on the growth of chickens. Somewhat similar results are reported in this paper for turkeys hatched only a few weeks apart. There is also a distinct indication of compensatory growth of the later hatched, initially slower growing birds. The same phenomenon has been demonstrated in the growth of razor clams by McMillin and Weymouth (1935). MATERIALS AND METHODS The data presented in this paper . . .

The existing literature is inconsistent with respect to optimal dietary concentrations of glycine (Gly) and serine (Ser) in broiler feed. Therefore, we conducted a meta-analysis to investigate the response of broilers to dietary levels of Gly using a full quadratic model based on mixed model methodology. Response was measured as ADG (g/d), ADFI (g/d), and G:F (g/g). In addition, the influence of other dietary constituents was evaluated. This meta-analysis was based on a data set comprising a total of 9,626 broilers in 10 peer-reviewed papers that investigated the response of broilers to different dietary concentrations of Gly, achieved by addition of free Gly. The fitted quadratic model, with either Gly+Ser or the calculated glycine equivalent (Glyequi) of both amino acids as the independent variable, revealed that all model terms were significant (P ≤ 0.05), and hence proved a curvilinear relationship between these independent variables and response traits. The R(2) value and root MS error confirmed a strong relationship between observed and predicted traits. A comparison of the influence of Gly+Ser and Glyequi on response traits revealed that both approaches produced similar results. Because Glyequi should meet the physiological values of a diet better than Gly+Ser, models with 2 independent variables were conducted using Glyequi. The second independent variables were methionine (Met):TSAA ratio and the concentrations of cysteine (Cys) and CP. In models with one or 2 independent variables, the impact of dietary Gly on ADFI was low. By contrast, G:F was markedly influenced by dietary Gly; this effect intensified at lower Met:TSAA ratios and higher Cys and CP levels. ADG was also a function of Glyequi and the second independent variables. For ADG, an optimal Met:TSAA ratio of 0.655 and Cys concentration of 0.302% was calculated. Following the nonlinear nature of relationship, generally applicable replacement values could not be calculated. However, it was concluded that consideration of dietary Cys can diminish the requirement for Glyequi, and therefore, enable a reduction in the CP of broiler diets without limiting growth performance.

In a companion study, the effects of dietary antibiotic alternative and coccidial vaccination on the growth performance of male broilers have been reported. In this paper, the effects of dietary probiotics and coccidial vaccination on diversity and composition of cecal microbiota were investigated using a 3 (diets) × 2 (vaccinated or non-vaccinated) factorial setting of treatments. Three diets, including a corn and soybean-meal control diet, an antibiotic diet (a control diet supplemented with bacitracin and salinomycin), and a probiotic diet (a control diet supplemented with Bacillus subtilis) were provided to broiler chicken from day 0 to 42. To simulate an Eimeria challenge in the field, all chicks were gavaged with a 20× dose of commercial coccidial vaccine containing live Eimeria oocysts on day 14. Cecal contents were collected on day 42. High-throughput sequencing of the 16S rRNA gene was used to determine microbial diversity and composition. Coccidial vaccination to broilers reduced bacterial diversity (Shannon index) of the cecal microbiota. There was a significant interaction between the dietary additive and coccidial vaccination on the observed bacterial species number. Diets supplemented with B. subtilis increased bacterial species of non-vaccinated broilers but decreased bacterial species of vaccinated broilers. In contrast, diets supplemented with antibiotics reduced bacterial species of broilers from both groups. Interactions between dietary additive and coccidial vaccination were also observed on microbial composition. Vaccinated broilers fed the B. subtilis diet exhibited the lowest Firmicutes percentage and highest Bacteroidetes percentage within the microbial community. In addition, vaccinated broilers fed the B. subtilis diet exhibited the highest Rikenella microfusus percentage. From this study, the coccidial vaccination on the day of hatch reduced the microbial diversity of broilers at a later age. The inclusion of B. subtilis-probiotics in the feed of vaccinated broilers may reduce microbial diversity in cecal content by increasing the proportion of a predominant bacterial species, R. microfusus, in the microbial community.

This paper aimed to study the dietary effects of Bacillus subtilis fmbj (BS fmbj) on growth performance, small intestinal histomorphology, and its antioxidant capacity of broilers at 21 d of raising. A total of 300 1-d old male Arbor Acres broilers were randomly assigned to 5 groups: broilers fed the basal diets with 0 g/kg BS fmbj (CON), 0.2 g/kg BS fmbj (BS-1), 0.3 g/kg BS fmbj (BS-2), 0.4 g/kg BS fmbj (BS-3), and 0.5 g/kg BS fmbj (BS-4). The results showed that there were no differences in the growth performance among treatments during the trail. Dietary BS fmbj in broiler diets increased (P < 0.05) the serum immunoglobulin A (IgA) and immunoglobulin G (IgG) concentration, and enhanced the secretory immunoglobulin A (sIgA) level of small intestine (jejunum and ileum) compared with those in the CON group. The BS groups could improve (P < 0.05) the values of villus length, villus width, crypt depth, and villus area of small intestine compared with that in the CON group. Compared with the CON group, the BS group increased (P < 0.05) small intestinal antioxidant capacity and its mitochondrial antioxidant capacity, and also improved the antioxidant related-gene expression. The BS group exerted a lower (P < 0.05) level of oxidative damages in small intestine than that of the CON group. In conclusion, dietary BS fmbj in broiler diets was potential to improve the small intestinal histomorphology, small intestinal antioxidant capacity, and its mitochondrial antioxidant capacity. Thus this BS fmbj might be considered to be an important additive for the poultry industry.

The intestinal gut health is one of the primary determinants of broiler growth and performance. Among the various enteric diseases, necrotic enteritis (NE) is an enterotoxemic disease caused by Clostridium perfringens, which can result in severe economic losses in poultry farming. Antibiotics like bacitracin methylene disalicylate (BMD) and avilamycin (AVL) are commonly used antibiotic growth promoters (AGP) in poultry feed to control necrotic enteritis in birds. Bacillus subtilis PB6 was reported to prevent necrotic enteritis and improve performance in birds. This paper investigated the influence of Bacillus subtilis PB6 in improving the performance of broiler birds in comparison with BMD and avilamycin. A 35 day trial was conducted with 240 day-old commercial broiler chicks (VenCobb 400), which were divided into four treatment groups, where each treatment group was composed of 6 replicates each containing 10 birds, for a total of 60 birds per treatment. The treatment groups included a negative control (no AGP), Bacillus subtilis PB6, BMD, and avilamycin. The parameters analyzed included body weight, feed conversion ratio (FCR), mortality, villus histomorphometry, and European efficiency factor (EEF). Bacillus subtilis PB6 significantly (P < 0.05) improved body weight and FCR (8 points) compared to the control. The group supplemented with B. subtilis PB6 or BMD had higher (P < 0.05) body weight compared to all other treatment groups. The supplementation of B. subtilis PB6 significantly improved the villus height (P < 0.05) compared to control and other AGP groups. The EEF was found to be the highest in the B. subtilis PB6 supplemented group at 35th day as compared to other treatment groups. The combined data from this study indicate that supplementation of B. subtilis PB6 improves overall performance of broilers compared to BMD and avilamycin, and can be used as potential AGP replacement in poultry farming.