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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.

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.

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.

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.

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.

The University of Georgia maintains two meat-type chicken control strains: the Athens Random Bred (ARB) and the Athens Canadian Random Bred (ACRB). The Athens Random Bred was developed from colored plumage commercial meat chicken strains in 1956. The ACRB is a replicate population of the Ottawa Meat Control strain which was developed in 1955 from white plumage commercial meat-type chickens. These genetic lines have been extremely valuable research resources and have been used extensively to provide comparative context to modern meat-type strains. The ACRB may be the oldest pedigreed control commercial meat-type chicken still in existence today. This paper reviews the history of the breed backgrounds for both control populations and reviews research utilizing the ACRB.

This paper, the second from a comprehensive study, describes the effects of varying growth rate by feeding at different planes of nutrition with a constant ME:CP ratio on muscle characteristics and meat quality in 2 distinct broiler breeds of male chickens (Arbor Acres, a commercial line; and Beijing-You, a Chinese nonimproved line). Experimental diets, differing on average by 2% CP, were formulated with high-, medium-, or low-nutrient densities for 3 growing phases. Male hatchlings (216 of each breed) were randomly assigned to 6 pens of 12 birds in each treatment. Altered histological characteristics of muscle fibers, early postmortem muscle metabolism, and meat quality were investigated in the pectoralis major and biceps femoris. At their market age, Arbor Acres broilers had significantly higher concentrations of plasma protein and lipid metabolites, ratios of white to red and intermediate fibers, pH, L* and b* values, and lower concentrations of plasma glucose metabolites, muscle-fiber diameter, muscle contents of energy stores, a* value, drip loss, and shear force than the values found for the Beijing-You chickens (P < 0.01). Higher nutrient density increased the size of the muscle fibers, decreased glycogen reserve, and reduced the rate and extent of acidification in the Arbor Acres chickens, while accelerating transformation of red and intermediate-to-white fibers, enhancing energy stores, and hastening the decrease in pH postmortem in the Beijing-You chickens (P < 0.05). In each breed, most meat quality variables (e.g., shear force, drip loss, and color) were consistent with the histological and biochemical changes caused by the feeding strategy. Together, dietary nutrient density can influence meat quality as a result of altered histological and initial energy and metabolic characteristics of the muscle. Many of the responses to diet are breed and tissue dependent in broiler chickens.

This paper summarizes the results from 3 simulated in-house catastrophic mortality composting experiments. Experiment 1 evaluated the impact of water-based foam mass depopulation on in-house composting of the carcasses and litter and showed that water-based foam improved windrow temperatures. Experiment 2 evaluated the impact of freezing samples on virus recovery from windrow compost tissue and the choice of tissue for virus sampling within the bird. Experiment 2 documented that freezing the samples had minimal impact on processing and that virus recovery was more consistent among inoculated breast meat than inoculated tracheas. Experiment 3 evaluated the impact of sawdust, straw, and sawdust-straw base layer litter material on in-house mortality composting. All litter materials were able to reach and maintain temperatures in excess of 60°C for multiple days. No viral hemagglutination activity was observed after d 2 during any of the 3 experiments.

This paper is concerned with the effects of photoperiod on ovarian morphology and carcass traits at sexual maturity in egg-type hens. Two hundred fifty-six commercial egg-type pullets were initially subjected to a photoperiod of 23L:1D, which was reduced to 22L:2D at 1 wk, to 18L:6D at 2 wk, and to 16L:8D at 3 wk. From 4 to 20 wk, the photoperiod was 8L:16D. At 20 wk, 32 pullets were individually caged in individually lit cages, with 8 cages per unit. Two cage units were placed into 4 photoperiods of 17L:7D, 15L:9D, 13L:11D, and 11L:13D, respectively. Each bird was processed when it reached sexual maturity (SM), and carcass and ovarian morphology were assessed. The results showed that photoperiod had an effect on the timing of SM, and the age at first egg was 5.7 d earlier for hens exposed to the 17L:7D photoperiod than the 11L:13D photoperiod. However, photoperiod had no effect on BW at SM. A photoperiod of 11L:13D limited ovarian follicle formation and increased carcass protein and lipid compared with birds on longer photoperiods, whereas the 17L:7D photoperiod restricted ovary and oviduct full development. These results indicated that excessively long and short photoperiods can restrict reproductive development in egg-type hens.

To comprehensively assess conventional vs. some alternative laying-hen housing systems under U.S. production conditions, a multi-institute and multi-disciplinary project, known as the Coalition for Sustainable Egg Supply (CSES) study, was carried out at a commercial egg production farm in the Midwestern United States over two single-cycle production flocks. The housing systems studied include a conventional cage house (200,000 hen capacity), an aviary house (50,000 hen capacity), and an enriched colony house (50,000 hen capacity). As an integral part of the CSES project, continual environmental monitoring over a 27-month period described in this paper quantifies indoor gaseous and particulate matter concentrations, thermal environment, and building ventilation rate of each house. Results showed that similar indoor thermal environments in all three houses were maintained through ventilation management and environmental control. Gaseous and particulate matter concentrations of the enriched colony house were comparable with those of the conventional cage house. In comparison, the aviary house had poorer indoor air quality, especially in wintertime, resulting from the presence of floor litter (higher ammonia levels) and hens' activities (higher particulate matter levels) in it. Specifically, daily mean indoor ammonia concentrations had the 95% confidence interval values of 3.8 to 4.2 (overall mean of 4.0) ppm for the conventional cage house; 6.2 to 7.2 (overall mean of 6.7) ppm for the aviary house; and 2.7 to 3.0 (overall mean of 2.8) ppm for the enriched colony house. The 95% confidence interval (overall mean) values of daily mean indoor carbon dioxide concentrations were 1997 to 2170 (2083) ppm for the conventional cage house, 2367 to 2582 (2475) ppm for the aviary house, and 2124 to 2309 (2216) ppm for the enriched colony house. Daily mean indoor methane concentrations were similar for all three houses, with 95% confidence interval values of 11.1 to 11.9 (overall mean of 11.5) ppm. The 95% confidence interval values (overall mean) of daily mean PM10 and PM2.5 concentrations, in mg/m3, were, respectively, 0.57 to 0.61 (0.59) and 0.033 to 0.037 (0.035) for the conventional cage house, 3.61 to 4.29 (3.95) and 0.374 to 0.446 (0.410) for the aviary house, and 0.42 to 0.46 (0.44) and 0.054 to 0.059 (0.056) for the enriched colony house. Investigation of mitigation practices to improve indoor air quality of the litter-floor aviary housing system is warranted.

Enteric disorders predispose poultry to malnutrition. The objectives of this paper were 1) to simulate the inanition of poult enteritis mortality syndrome by restricting feed intake and 2) to develop a drinking water supplement that supports the immune functions of poults with inanition. Poults were restricted to 14 g of feed/d for 7 d beginning at 14 d of age then fed ad libitum until 36 d (recovery). The control was fed ad libitum. During the feed-restriction period, duplicate groups of 6 poults received 1 of 5 drinking water treatments: 1) restricted feed, unsupplemented water; 2) restricted feed + electrolytes (RE); 3) RE + glucose + citric acid (REGC); 4) REGC + betaine (REGCB); or 5) REGCB + zinc-methionine (REGCBZ). Immunological functions were assessed by inoculating poults with SRBC and B. abortus (BA) antigen at 15, 22, and 29 d of age. Antibody (Ab) titers were determined 7 d later for primary, secondary, and recovery responses. The primary and secondary total Ab titers to SRBC for restricted feed were 4.71 and 6.16 log3, which where lower (P < 0.05) than for controls (8.00 and 9.66 log3) and the other treatments. The recovery Ab titer for controls was 10.7, significantly higher than restricted feed (8.71) and RE (8.10) groups but not different from other treatments. The primary total Ab responses to BA were significantly lower in the restricted feed and RE groups as compared with the control and other treatments. Although feed restriction of poults to maintenance reduces the humoral immune responses, these responses can be significantly improved by drinking water containing electrolytes and especially sources of energy such as glucose and citric acid.

Natural antibodies (NAb) are an important component of the first line of immune defense. Selective breeding for enhanced NAb levels in chickens may improve general disease resistance. It is unknown what the consequences of selection for NAb will be on the productive performance of laying hens. In this paper we describe the genetic relations between NAb titers binding keyhole limpet hemocyanin at 19 wk age and production traits in a white purebred leghorn chicken line observed in several time periods. A linear animal model was used to estimate (co)variance components, heritabilities, and correlations. Negative genetic correlations were found between egg weight and NAb titers, and between egg breaking strength and NAb titers. Positive genetic correlations were found between the feed conversion ratio (consumed feed/egg mass produced) and NAb titers, and egg production and NAb titers. Negative phenotypic correlations were found between body weight and NAb titers, between egg weight and NAb titers, and between egg breaking strength and NAb titers. Positive phenotypic correlations were found between egg production and NAb titers, and feed conversion ratio and NAb titers. In general, phenotypic correlations were more often significant, but less pronounced than genetic correlations. Other production traits were not found to be significant related to NAb titers. These findings suggest that there is a genetic tradeoff between levels of immunity and some production traits, although the underlying mechanism(s) remain(s) unclear. The results suggest possible consequences for production efficiency as a result of selective breeding for improved general disease resistance by natural antibodies.

This study estimated the genetic variance components of P utilization in Japanese quail. A parental generation was assembled from an unselected random-bred Japanese fattening quail line. Seven sires and 14 dams were randomly selected, and each sire was paired with 2 dams to produce full and half sibs. A total of 200 unsexed 1-d-old quail with known pedigree were wing-banded and raised during the first 4 d posthatch in groups in floor pens on wood shavings and fed a preexperimental diet that was adequate in all nutrients. Starting on d 5, quail were individually housed in metabolic compartments on P-free filter paper. This started a balance trial with 5 d of adaption and 5 d of total excreta collection. During this balance period, all quail were fed a low-P (3.9 g/kg of DM) corn-soybean meal-based diet with a Ca:P ratio of 1.6:1.0. Phosphorus and Ca utilization were determined individually using the difference in P or Ca intake and the total P or Ca excretion. The average P utilization was 72% and the average Ca utilization was 63%, each with very high variation. Heritabilities were estimated to be 0.09 (SE = 0.09) for P utilization and 0.09 (SE = 0.09) for Ca utilization. Heritabilities were close to the values reported in the literature for broilers and suggest that quail are suitable as a model animal. The SE of the heritability estimates were large. This implies that further studies with a larger sample size are needed to identify genetic and physiological mechanisms that influence P and Ca utilization in Japanese quail.

The effects of heating of eggs during storage, broiler breeder age, and length of egg storage on hatchability of fertile eggs were examined in this study. Eggs were collected from Ross 344 male × Ross 308 broiler breeders on paper flats, held overnight (1 d) at 18°C and 75% RH, and then transferred to plastic trays. In experiment 1, eggs were obtained at 28, 38, and 53 wk of flock age. During a further 10 d of storage, eggs either remained in the storage room (control) or were subjected to a heat treatment regimen of 26°C for 2 h, 37.8°C for 3 h, and 26°C for 2 h in a setter at d 5 of storage. In experiment 2, eggs from a flock at 28 wk of age were heated for 1 d of a 6-d storage period. Eggs from a 29-wk-old flock were either heated at d 1 or 5 of an 11-d storage period in experiment 3. In experiment 4, 27-wk-old flock eggs were heated twice at d 1 and 5 of an 11-d storage period. Control eggs stored for 6 or 11 d were coincubated as appropriate in each experiment. Heating eggs at d 5 of an 11-d storage period increased hatchability in experiment 1. Although no benefit of heating 28-wk-old flock eggs during 6 d of storage in experiment 2 was observed, heating eggs from a 29-wk-old flock at d 1 or 5 of an 11-d storage period increased hatchability in experiment 3. Further, heating eggs from a 27-wk-old flock twice during 11 d of storage increased hatchability in experiment 4. These effects were probably due to the fact that eggs from younger flocks had been reported to have many embryos at a stage of development where the hypoblast had not yet fully developed (less than EG-K12 to EG-K13), such that heating during extended storage advanced these embryos to a more resistant stage.

This paper provides an overview of results from a long-term (38 generations) selection experiment. Lines were developed from individual phenotypic selection for high or low body weight at 8 wk of age. Included are data for the selected lines, sublines in which selection was relaxed, crosses of the selected lines, and sublines in which the sex-linked dw gene was introduced. Periodically (and in some cases every generation) data were obtained for unselected traits. These unselected traits included feed consumption and intake behavior, reproduction, allomorphic relationships, and metabolic, immunological, endocrine, and molecular factors. These responses have been integrated into a resource allocation paradigm.

Reducing the level of nonphytate P (NPP) in diets for laying hens without negatively affecting their productivity and heath is crucial for sustainable egg production. A meta-analytical approach using a full quadratic model was applied to quantify relationships between dietary NPP and phytase levels and performance of laying hens. Egg production (EP, %), egg mass (EM, g/hen/day), and feed conversion ratio (FCR) were considered as model outputs. A data set containing 168 P or P plus phytase treatments was extracted from 12 published papers. The data were assembled from 14 trials with a total of 8,752 hens in the range of 36 to 76 wk of age. The EP, EM, and FCR were analyzed using a linear mixed model that included the linear and quadratic effects of dietary NPP and phytase levels and their interactions. Except for the quadratic effect of dietary phytase on FCR, all other model components (that is, intercept, linear, quadratic, and interactions) were significant (P

The objectives of this paper were to identify the phenotypic egg-laying patterns in a White Leghorn line mainly selected for egg production, to estimate genetic parameters of traits related to egg production and to evaluate the genetic association between these by principal components analysis to identify trait(s) that could be used as selection criteria to improve egg production. Records of 54 wk of egg production from a White Leghorn population were used. The data set contained records of the length:width ratio of eggs at 32, 37, and 40 wk of age; egg weight at 32, 37, and 40 wk of age; BW at 54 and 62 wk of age; age at first egg; early partial egg production rate from 17 to 30 wk and from 17 to 40 wk of age; late partial egg production rate from 30 to 70 wk and from 40 to 70 wk of age; and total egg production rate (TEP). The estimates of genetic parameters between these traits were estimated by the restricted maximum likelihood method. Multivariate analyses were performed: a hierarchical cluster analysis, a nonhierarchical clustering analysis by the k-means method of weekly egg production rate to describe the egg-laying patterns of hens, and a principal components analysis using the breeding values of all traits. The highest heritability estimates were obtained for BW at 54 wk of age (0.68 ± 0.07) and age at first egg (0.53 ± 0.07). It is recommended that a preliminary clustering analysis be performed to obtain the population structure that takes into account the pattern of egg production, rather than the TEP, because hens may have the same final egg production with different patterns of egg laying. Early partial production periods were not good indicators for use in improving total egg production because these traits presented an overestimated genetic correlation with TEP because of the part-whole genetic correlation component. Egg production might be improved by selecting individuals based on TEP.

Broiler litter (manure plus bedding) represents the single largest waste by-product generated by the broiler industry. In 1990, 5.86 billion broilers were produced in the United States (National Agricultural Statistic Service, USDA). On a dry-weight basis, using averages cited in the present paper for litter (1.0 metric ton per 1,000 broilers per flock) and nutrient composition (3.88% total N, 4.25% P2 O5, and 2.68% K2 O), the total annual United States broiler nutrient production is estimated at 227,368, 249,050, and 157,048 metric tons of N, P2 O5, and K2 O, respectively. However, there are substantial variations in both litter production rates and composition values among reports that can greatly influence these estimates. Litter rates and values are influenced by amount and type of bedding, frequency of removal, broiler market weights, nutrition and feed utilization efficiency, and numerous management factors. Understanding these sources of variability is helpful in the implementation of strategies for litter enrichment. In the future, a totally integrated approach may be necessary for the production of litter that is designed for specific applications and markets.

Northern fowl mites (NFM) are external parasites that can lower egg production and cause anemia and even death in laying hens. An experiment was conducted with New Hampshire Red and Single Comb White Leghorn laying hens. Hens were individually caged and provided a complete laying diet and water ad libitum. Hens were assigned to groups in a way that assured that treatments, within each breed, would be applied to comparable numbers of birds with light and heavy mite infestations. Each hen was sprayed around the vent with either water or 10% garlic juice in water. Spraying continued each week for 3 wk. During the fourth week, each bird was scored for the presence of NFM on its skin and feathers. A small snippet of feathers was removed from below the vent of each hen and placed in a labeled petri dish with a round, white filter paper insert. The NFM content of each dish was scored by two individuals approximately 1 h after sampling. There was no significant difference in the NFM scores for hens based on breed or future treatment. After the birds were treated for 3 wk, there was no significant difference in external NFM scores based on breed. There were significantly fewer NFM on the birds treated with garlic juice compared with controls, based on external and petri dish scoring (P0.002 and P0.04, respectively). The reduction in external NFM score was also significant (P0.004), with controls declining approximately 0.2 units, whereas garlic-treated hens had a 1.8-unit decrease in external NFM score. Topical application of garlic juice may be an effective way to decrease NFM in laying hens.

Six rooms, identical and environmentally controlled, and each housing 14 caged turkey breeder hens, were exposed to light schedules to provide continuous and intermittent photoperiods of 14, 12, and 10 h as follows: 1) 14 h, continuous; 2) 14 h, intermittent; 3) 12 h, continuous; 4) 12 h, intermittent; 5) 10 h, continuous; and 6) 10 h, intermittent. Observations were made regarding: 1) the number of flies on feeders, in jug traps, on sticky fly tapes for 24 h, and sticky fly tapes for 1 h; 2) fly spots on paper sheets and fly spots on hanging cords. There were significantly (P

Beta-adrenergic agonists have been shown to be capable of improving growth performance in poultry when added to the feed at 1.0 ppm. However, no reference has been made concerning the cardiovascular responses when one of these agents is added to the feed at a lower concentration during the whole production cycle. The aim of this paper was to assess the effects on the ascites syndrome of 0.25 ppm clenbuterol in the feed, throughout 52 d, in broiler chicks. Results showed a lack of difference in growth and feed conversion rate between the untreated control groups and the experimental group. There were differences in mortality due to the ascites syndrome, abdominal fat:body weight ratio, and ventricular index. A statistically significant positive correlation was also found between ventricular index and mortality rate (r = 0.98). If adequate withdrawal times are ensured, the use of clenbuterol at 0.25 ppm is suggested to reduce mortality due to the ascites syndrome in broilers.

The research described in this paper relates the changes in serum concentration of calcium, phosphorus, and 1,25-dihydroxycholecalciferol [l,25(OH)2 D3] to changes in tibial ash percentage and the incidence of endochondral ossification defects (EOD) in flocks of commercially reared broiler chickens at 14 d of age. Sequential studies of six Australian broiler flocks representing three major genetic lines were undertaken at weekly intervals from 1 to 28 d of age. Serum collected from birds was analyzed for total calcium, inorganic phosphorus, and l,25(OH)2 D3. Tibial ash percentage was also determined at weekly intervals, and the incidence of EOD was determined at 14 d of age by examining sagittal sections of the proximal tibiotarsus. The EOD observed in the 14-d-old broiler chickens were characterized by enlarged zones of proliferating chondrocytes, similar to that which occurs during calcium- or vitamin D-dependent rickets. Three flocks had a 50% incidence of EOD at 14 d of age and were classified as severely affected. The other three flocks had incidences ranging from 12 to 16% and were classified as mildly affected. Broiler flocks severely affected with EOD (50% incidence at Day 14) had lower (P ≤ .05) concentrations of l,25(OH)2 D3 than flocks mildly affected (12 to 16% incidence). Tibial ash percentages were lower (P ≤ .05) in the severely affected flocks between Days 14 to 28, and it is likely that a lower rate of ash accretion between Days 7 to 14 precedes the development of the EOD. From these studies it is evident that flocks with a high incidence of EOD have significantly lower bone ash and 1,25 (OH)2 D3 compared with mildly affected flocks, and it seems probable that higher systemic concentrations of l,25(OH)2 D3 between 7 to 14 d of age will enhance the ability of broiler chickens to effectively mineralize the cartilaginous growth plates in the appendicular skeleton during early bone maturation.

Recently, Vazquez-Anon et al. (2006) published a paper in Poultry Science suggesting evidence for DL-2-hydroxy4-(methylthio) butanoic acid (DL-HMTBA) and DL-Met (DL-M) having different dose responses in growing broilers. The authors concluded that the 2 Met sources “have a different dose-response form, DL-HMTBA could outperform DL-M at commercial levels, and DL-M could outperform DL-HMTBA at deficient levels.” Additionally, it is suggested that relevant comparisons between the 2 Met sources should be conducted “at levels of commercial use.” These conclusions and suggestions are incorrect and misleading. When comparing essential nutrients or different sources of the same nutrient (L-Met in the present case), one should always evaluate the complete dose-response curve, starting with a deficient basal diet, followed by several incremental levels of the nutrients to be tested. Depending on the data structure of the respective dose-response trial, slope-ratio (linear response) or nonlinear models should be applied. These models can be used for estimation of comparative bioefficacy or bioavailability of any nutrients, such as P (Potter et al., 1995) or Fe (Boling et al., 1998). A simple example based on broiler weight gain data by Lemme et al. (2002) shall be used to demonstrate the statements above vs. the incorrect methodology and conclusions of Vazquez-Anon et al. (2006). Two Met sources, DL-M and diluted DL-M (65%, a product representing an internal standard with a known “relative efficacy” of 65%), were added at incremental levels to a Met-deficient commercial-type diet (Table 1). Using the proper exponential regression method to analyze the data sets, diluted DL-M (65%) had a calculated relative efficacy of 60% relative to DL-M (Lemme et al., 2002), confirming the validity of the used statistical method. Using a completely different approach to evaluate the data, the relative response rate of the basal diet was 64% of the maximum response (see Table 1). The relative response rates for the 0.06, 0.12, 0.18, and 0.24% supplemented DL-M levels were 84, 94, 99, and 100%, whereas the relative response rates for diluted DLM (65%) were 76, 86, 91, and 98%. Hypothetically, several different “effectiveness figures” were generated in this ex

This paper assesses the effects of substituting aerobically stabilized poultry manure for tap water on the performance of caged White Leghorn laying hens. Three separate feeding trials over a three-year period were conducted. In each feeding trial, aerobically stabilized poultry manure from an undercage oxidation ditch was substituted for tap water. For the three trials, egg production by the hens receiving the aerobically stabilized poultry manure exceeded that of the control group by an average of 2.6 ± 1.7%. No significant differences were observed in final body weights, mortality, or egg weights between the two groups of hens in any of the three feeding trials.

This paper examined the effect of N-correction on the true metabolizable energy (TME) values of mixed diets and single ingredients using mature White Leghorn roosters. The N-corrected TME (TMEn) values were consistently higher than the corresponding TME values, the results being significant (P less than .05) in about one-half of the samples tested. This indicated a net loss in body N in the birds during the experiments. The correlations between N input and N correction were highly (P less than .01) significant. This, however, explained only 46 to 48% of the variation in the TMEn data as being due to differences in the amount of N input. In view of the present results and the abnormal condition (fasted birds) in the TME assay, it is doubtful that birds would retain enough N from a single feeding to revert to a positive body N equilibrium. Therefore, positive N retention in such an assay would be indicative of incomplete feed passage through the birds. This appears to be the only valid reason for applying N correction to TME values. However, the variations associated with N correction of TME data raise some doubt concerning the validity of this assay as compared with the conventional apparent metabolizable energy assay.

Nine groups of 12 Small-type White turkey hens each were used to study dietary vitamin D3 and calcium and their effect on egg production, eggshell quality, and hatchability. The 3 × 3 factorial arrangement of treatments consisted of three levels of calcium (1.16, 2.25, and 3.34%) and three levels of vitamin D3 (cholecalciferol) at 900, 6,900, and 12,900 International Units per kg. of diet. Increasing dietary calcium to 2.25% significantly improved body weight, egg production and feed efficiency (feed/kg. eggs). The 3.34% level of calcium stimulated an increase in percentage hatchability of fertile eggs and produced the lowest percentage of 28-day embryonic mortalitites. Dietary vitamin D3 in excess of established requirements had no statistically significant effects on any of the parameters studied. Positive correlations were noted between beta-backscatter counts, shell weight, shell thickness and percentage calcium content of the egg. Percentage hatchability of fertile eggs was negatively associated with percentage moisture loss during the first seven days of incubation. The data presented in this paper show no beneficial action in the turkey hen from vitamin D3 fed in excess of recommendations, but dietary calcium in excess (3.34%) promoted an increase in hatchability and a decrease in embryonic mortality.