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Market reports of white striping in broiler breast fillets have been increasing, which has generated concerns in the broiler meat industry regarding negative effects on consumer acceptance. This study was conducted to macro- and microscopically characterize the condition of white striping at varying degrees of severity on Cobb 500 broiler breast fillets slaughtered at 42 d of age. Carcasses of 2,512 broilers presenting white striping were slaughtered and macroscopically classified according to the degree of severity of the striations as moderate or severe; further histological microscopic evaluation demonstrated degenerative myopathy in both moderate and severe cases, but 75% of those breast fillets were classified as moderate. Typically, the samples classified macroscopically as moderate showed microscopic necrosis only (65.17%) or moderate multifocal necrosis (9.83%), whereas those classified as severe showed diffuse and strong necrosis (25.00%). The proliferation of connective tissue was not observed for either of the degrees of white striping investigated, characterizing this profile as an acute occurrence.

A study was conducted to evaluate effects of supplementation of a monocomponent protease on growth performance and protein utilization in Nicholas turkeys from 1 to 26 d of age fed corn-soy diets with reduced levels of CP and amino acids. Poults were placed into 40 batteries of 15 birds, and allocated to 5 treatments with 8 replicates each. A positive control diet [PC, 27.94% CP, 1.69 digestible Lys (DLys)] and a negative control diet (NC1; 24.21% CP, 1.46% DLys) were formulated. A second NC diet (NC2; 23.20% CP) was formulated with reduced CP and amino acids (AA) with expected improvements provided by a protease (1.014% CP, 0.024% DLys, 0.055% digestible TSAA, and 0.077% digestible Thr). The protease (75,000 PROT/g) was added at 200 mg/kg, at the expense of Celite (indigestible marker and filler) to create the NC1+P and NC2+P. Ileal contents were collected from all birds for apparent CP and AA digestibility determinations on d 26. A factorial arrangement of 2 × 2 + 1 was used (CP level × protease supplementation + PC). Turkeys fed the PC diet were 8.1% and 9.8% heavier (P < 0.05) compared with those fed the NC1 and NC2 diets and adding protease had no effect on BWG. Improvement in FCR (P < 0.05) were observed in birds fed the NC1 and NC2 diets. There was a main effect of protease (P < 0.0535) on FCR ratio, with birds fed diets with protease having better FCR than those without. There were no effects of the treatments on feed intake and carcass yield. Digestibility of CP was increased (P < 0.05) for turkeys fed the NC1+P diets in comparison to those fed the other diets, except the PC diet. Apparent digestibilities of Asp, Cys, Glu, Ile, Lys, Thr, and Val were affected by treatment, with birds fed the PC diet having the lowest digestibilities (P < 0.05). Poults fed protease-containing diets had better (main effect, P < 0.05) CP, Lys, and Cys digestibilities than those fed the diets without protease. Overall, the effects of the protease were limited but significant on FCR and specific AA digestibilities.

The objective of this study was to investigate the effects of maternal dietary Zn, Mn, and Cu sources on egg production, eggshell quality, hatchability, and hatched chick grading. Inorganic sources of Zn, Mn, and Cu (IZMC) as zinc sulfate monohydrate (35% Zn), manganese sulfate monohydrate (31% Mn), and copper sulfate pentahydrate (25% Zn) or organic sources of Zn, Mn, and Cu as amino acid-mineral complexes (OZMC) were used. The 3 experimental treatments consisted of diets supplemented with 1) 100, 100, and 10 mg/kg of Zn, Mn, and Cu, respectively, from IZMC (control); 2) 60, 60, and 3 mg/kg of Zn, Mn, and Cu, respectively, from IZMC plus 40, 40, and 7 mg/kg of Zn, Mn, and Cu, respectively, from OZMC (ISO); and 3) a diet with 100, 100, and 10 mg/kg of Zn, Mn, and Cu, respectively, from IZMC as in the control plus 40, 40, and 7 ppm of supplemental Zn, Mn, and Cu from OZMC (on top). Treatments were fed from 22 to 68 wk of age. Each treatment had 10 replications of 20 females and 2 males. Feeding the ISO diet compared with the control diet increased eggshell weight and thickness (P < 0.05) and decreased early embryo mortality (P < 0.01). Feeding the on top diet compared with the control diet resulted in thicker and heavier eggshells (P < 0.05). An improvement in eggshell quality was observed in breeder hens consuming the OZMC-supplemented ISO diet or the on top diet with IZMC.

The Cobb × Cobb 500 slow-feathering male is a fast early-growth broiler grown under variable feeding programs and amino acid (AA) densities. An experiment was conducted using diets with increased ideal protein densities in a feeding program of 1 to 7 d, 8 to 21 d, 22 to 35d, and 36 to 42 d. Diets had ratios between essential digestible (D) AA and DLys (DAA:DLys) as follows: TSAA, 75%; DThr, 65%; DVal, 75% (from 1 to 7 d) and 77% (from 8 to 42 d); DIle, 67%; DArg, 104%; and DTrp, 17%. A completely randomized experimental design in a 3 × 3 factorial arrangement of 3 AA densities (low, moderate, and high) from 1 to 21 d (phase I) and 3 AA densities from 22 to 42 d (phase II) was used. The moderate dietary program was set with DLys at 1.26, 1.15, 1.05, and 0.95% from the prestarter to finisher phase. Replications per treatment were 30 from 1 to 21 d and 10 from 22 to 42 d. Birds fed the high-AA-density diets in phase I had the best BW gain at 35 and 42 d (P < 0.05) and the lowest FCR (P < 0.05) when combined with the high- or moderate-AA-density diets in phase II. The high- and moderate-AA-density diets in phase I maximized BW gain at 42 d when combined with either the high- or moderate-AA-density diet in phase II (P < 0.05). Percentages of breast fillets, breast tenders, and thighs were not affected by treatment in phase I; however, breast fillet percentage was maximized with when the moderate- or high-AA-density diets (P < 0.05) were fed in phase II, whereas breast tenders and thighs were maximized only when the high-AA-density diets (P < 0.01) were fed in phase II. Commercial application will depend on ingredient costs and meat market prices at decision time based on the program that results in the lowest cost per sellable product.

Some plant oils have been labeled “functional oils” because they have biological activities beyond their energy value. Recently, it has been shown that the effects of some functional oils on broiler performance are similar to the effects of antibiotic growth promoters. A commercial mixture of functional oils (containing castor oil and cashew nut shell liquid as the active ingredients) in diets with 3 ME levels (industry standard, industry standard minus 100 kcal/kg, and industry standard minus 200 kcal/kg) was used to study the effects on the performance of 2,250 broiler chicks from 1 to 42 d of age. In addition, the effects of supplementing the functional oils in the low-energy diets were studied in chicks from 21 to 42 d of age and from 35 to 42 d of age. Therefore, at the end of the experiment, there were 10 treatments, with 9 floor pens per treatment. Adding functional oils to the feed not only improved the BW gains and FCR of the birds compared with diets with the same ME, but it also allowed for a decrease in ME of 100 kcal/kg without negatively affecting performance parameters. These improvements in performance might be related to the antimicrobial and anti-inflammatory activities of the functional oils.

Broiler responses of economic interest, such as BW gain, FCR, and breast meat yield (BMY), can be optimized by increasing amino acid (AA) concentrations, improving the AA balance, or both. The AA requirements to maximize a response are lowest for BW gain, increased for FCR, and highest for BMY. A maximum performance response is reached when the response plateaus, whereas an optimal response is the one providing the highest return per input. These are usually not the same. Strategies used in linear feed formulation differ in how dietary AA are included in the diet; therefore, understanding how these strategies affect broiler responses is necessary to compare ultimate potential benefits. Minimum CP restrictions are still used even when TSAA, Lys, and Thr restrictions are set simultaneously, and AA requirements are presently expressed as either total or digestible. The use of ratios of essential AA to Lys is more popular now that synthetic Thr has become commercially available, and it will likely have an increase in use when l-valine and l-isoleucine have competitive prices. The present-day high-yield broiler has an increased responsiveness to AA density, especially for Lys, which contrasts with published requirements still in use. Increasing Lys and other AA at the beginning of the bird’s life has been shown to have some positive carryover effects on performance in later periods; however, increasing the Lys and essential AA in broiler diets in the last phases of production allows compensation for BMY because of the continuous high allometric growth rate of breast muscle. Gains in performance are expected to result from increases in dietary AA density; however, the decision regarding what AA density to use will depend on the cost of feed relative to the market price of meat.

Two experiments were conducted to determine the effect of adding an exogenous protease to corn-, soybean meal-, and meat and bone meal-based broiler diets. In the first experiment, 1,764 male Ross 308 broiler chicks were placed in 63 floor pens, with 28 birds per pen. There were 7 treatments, with 9 replicates each, fed in the starter (d 1 to 21) and grower (d 22 to 40) phases. The dietary treatments were a positive control, formulated with 3,050 and 3,150 kcal of ME/kg and 22.5 and 20% CP in the starter and grower phases, respectively, and a negative control, formulated with a 4.4% reduction in ME and CP as compared with the positive control diets. A mono-component protease (75,000 protease/g) was added to the negative control diets at 0, 100, 200, 400, 800, and 1,600 ppm of feed. Broilers fed the positive control diet grew better and had a better feed-to-gain ratio (FE) than did those fed the negative control diets, regardless of enzyme supplementation. Protease supplementation had no effect on BW; however, FE was improved in a quadratic manner as protease was increased. In experiment 2, a factorial arrangement of 2 protein (7% difference in CP), 2 energy (3% difference in ME), and 2 protease (0 and 200 ppm) concentrations was used, resulting in 8 treatments replicated 11 times (22 male Cobb 500 broilers per replicate). No 3-way interactions were observed for live performance measures. Broilers fed the high-protein and high-energy diets performed better (P = 0.01) than those fed the low-protein and low-energy diets. Protease supplementation improved FE as well as digestibilities of fat and CP (P = 0.01), regardless of dietary protein or energy concentration. The protease used in these studies improved FE and dietary determined AME values as well as dietary CP and fat digestibility values.

Corn and soybean meal broiler feeds frequently have Val and Ile as the next-limiting amino acids after Met, Lys, and Thr. Supplementation of l-Val and l-Ile is soon likely to be feasible. One study was conducted to evaluate broilers fed diets having increased Val- and Ile-to-Lys ratios from 14 to 35 d. A total of 1,775 Cobb × Cobb 500 male broilers were fed a corn and soybean meal all-vegetable diet containing 1.10% digestible Lys. This diet was formulated without CP restriction by using synthetic Lys, Met, and Thr to attain the lowest Ile-to-Lys ratio while maintaining sulfur amino acids and Thr ratios to Lys of 75 and 65%; the diet was deficient in Val (ratio to Lys of 70%), with a minimum requirement ratio of Ile to Lys (65%). Graded increases in Val and Ile, respectively, were prepared using supplementation of l-Val and l-Ile at the expense of kaolin in 5 and 3% intervals to produce the following treatment ratios: 75 and 65%, 80 and 65%, 70 and 68%, 70 and 71%, 75 and 68%, and 80 and 71%. There were 9 replicate pens per treatment, with 25 male broilers per pen. Performance differences were detected mainly from 14 to 21 d of age; feed intake was reduced for broilers fed the basal diet, whereas BW gain and FCR were improved when Val- and Ile-to-Lys ratios were increased. From 14 to 35 d, the lowest levels of Val and Ile led to reduced BW gain but did not influence FCR. No differences were found among treatments for mortality and carcass yield, commercial cut yields, and abdominal fat yields. Diets formulated without minimum CP restrictions with Val- and Ile-to-Lys ratios of 70 and 65 resulted in impaired live performance. This was overcome when l-Val or l-Ile was supplemented to simultaneous ratios of Val and Ile to Lys of 75 and 65% or 70 and 68%.

Reduced performance is eventually observed when broilers are fed low-protein diets, even when industrial amino acids (AA) are provided to reach requirement levels. The reason for this detrimental effect has not been precisely determined, but it is possible that nonessential AA become limiting below a certain level of protein in the diet. The objective of this study was to evaluate the effects of Val, Ile, Gly, and Glu supplementation, individually or combined, in broiler diets with gradual reductions in protein. A total of 2,016 Ross × Ross 308 male broilers were fed 8 treatments with 9 replications (28 birds per pen) during a 42-d production period. Overall care of birds complied with animal welfare directives from the Universidade Federal do Rio Grande do Sul. The control diet (treatment 1) was formulated without restricting CP, maintaining a Gly + Ser:Lys ratio of 155 or 158%. The other treatments, when not supplemented with l-Glu, had a CP content dependent on the fixed ratios of AA to Lys, generating diets with lower CP contents than the control diet. Treatment 2 was formulated with l-Val; treatment 3 with l-Val and Gly; treatment 4 with l-Val + l-Glu; treatment 5 with l-Val + Gly + l-Glu; treatment 6 with l-Val + l-Ile; treatment 7 with l-Val + l-Ile + Gly; and treatment 8 with l-Val + l-Ile + Gly + l-Glu. Dietary CP varied with feeding phase and treatment and reached 2.5% as the greatest reduction obtained. Supplementation of Gly and Glu improved BW gain and feed conversion. Benefits attributable to Gly supplementation were observed mainly in the early phases of growth. Conversely, broilers fed diets supplemented with Glu exhibited advantages in growth throughout experimentation. Addition of Ile, Glu, and Gly increased breast meat yield compared with broilers fed diets supplemented with only l-Val. Supplementation of Ile improved breast meat yield. Good broiler growth and meat yield can be obtained with Gly and Glu supplementation in reduced-CP diets, which implies a need for nitrogen for the synthesis of nonessential AA.

This study evaluated the effects of sources and levels of Se in broiler breeder diets on egg production and Se concentration in eggs. Fifty Cobb 500 hens, 22 wk of age, were individually placed in steel cages and fed a basal diet without Se supplementation for 3 wk. Birds were then provided 5 dietary treatments with 10 replicates of 1 individual hen, which had dietary Se supplied from sodium selenite (inorganic; Na2SeO3, 45% Se) or from Zn-l-Se-methionine (organic; ZnSeMet, 0.1% Se) as follows: treatment 1, 0.15% Se from Na2SeO3; treatment 2, 0.30% Se from Na2SeO3; treatment 3, 0.15% Se from ZnSeMet; treatment 4, 0.30% Se from ZnSeMet; treatment 5, 0.15% Se from Na2SeO3 + 0.15% Se from ZnSeMet. Evaluations were conducted in 2 periods of 4 wk each. Experimental diets were prepared through the supplementation of corn-soybean meal diets. Egg production and egg weight were recorded daily, whereas specific gravity was measured twice a week from 25 to 32 wk. In the first period, the hens fed 0.30 ppm of organic Se produced more eggs (P < 0.05), whereas no difference (P > 0.05) in egg production was found in the second period. Period evaluations showed that egg weight was not different (P > 0.05), whereas specific gravity decreased (P < 0.05) and Se concentration in eggs increased (P < 0.05) in the second period, regardless of Se source. A comparison between treatments with single Se sources demonstrated that the concentration of Se in eggs followed the increased levels in the feeds when ZnSeMet was used (P < 0.05). However, the supplementation of a combination of sources (Na2SeO3 and ZnSeMet) produced similar egg Se concentrations.

The purpose of this study was to investigate the effects of drinking water supplementation with graded increases of Na and K salts on the performance and gut contents of broilers before processing. Birds had no water, tap water, or water supplemented with sodium bicarbonate or potassium chloride in the concentrations of 0.15, 0.30, and 0.45% in the last 12 and 24 h before processing. The last 12 h coincided with preslaughter feed withdrawal. Cobb × Cobb 500 male broilers (46 d old) were set in a completely randomized experimental design with 8 treatments and 9 replications of 9 birds each. Birds were individually processed within a period of 12 h of feed withdrawal every 2 h. Individual weighing was followed with electrical stunning and removal of intestinal contents of the upper (crop through the gizzard) and lower segment (duodenum through cloaca). Water intake increased linearly with greater salt concentrations in the water (P < 0.05). Body weight loss increased linearly through the feed withdrawal; however, it was greater with birds without water access (P < 0.0001). There were no effects of treatments on the yields of carcass and cuts as well as on the intestinal contents at all evaluated times. Intestinal contents from upper and lower segments were decreased with time, but responses to the water treatments were not observed (P > 0.05). It is concluded that increasing water intake through the use of Na and K salts did not affect the rate of gut emptying before processing.

Considerable controversy still remains on the use of antimicrobials to promote growth in animals raised for human consumption. Therefore, alternative strategies have been actively researched to replace these antimicrobials. This study evaluated the performance of broilers fed Sangrovit (1.5% sanguinarine, a quaternary benzo[c]phenanthridine alkaloid extracted from plants), a blend of organic acids (40% lactic, 7% acetic, 5% phosphoric, and 1% butyric) or a combination of Sangrovit and organic acids. One-day-old male broiler chicks (Cobb × Cobb 500) were placed in 44 floor pens, with 35 birds per pen. Birds were fed corn-soybean meal all-vegetable diets without growth promoters or anticoccidials, and were vaccinated for coccidiosis at placement. Four treatments and 11 replications were used. A negative control treatment, Sangrovit 50, 25 ppm (1 to 21 d and 22 to 42 d, respectively) of organic acids (8 kg/ton from 1 to 7 d, 6 kg/ton from 7 to 21 d, 4 kg/ton from 21 to 35 d, 2 kg/ton from 35 to 42 d), or both additives were tested. Body weight, feed intake, feed conversion, and intestinal villus height and crypt depth were evaluated weekly. Birds fed Sangrovit or organic acids had improved BW at 21 d (P = 0.05), but not thereafter. Cumulative feed conversion was better in birds fed Sangrovit alone or in combination with organic acids (P = 0.05). No differences were observed in villus height or crypt depth at 7, 14, 21 or 42 d. These results suggest that Sangrovit and the blend of organic acids used in this study were possibly beneficial additives for feeding programs designed without the addition of growth promoters.

Valine is likely the fourth limiting amino acid in most diets based on corn and soybean meal (C/SBM). However, the exact needs for Val are not well known, and information regarding it is sparse. A series of studies was conducted to validate the limitation of Val in all-vegetable diets fed to broilers, and subsequently to quantify an adequate ratio to Lys in high-yield late-developing broilers (Ross × Ross 708) from 21 to 42 d. A preliminary study was designed to evaluate the supplementation of different amino acids likely to be fourth limiting on a C/SBM-based diet, where Lys, TSAA, and Thr were supplemented but no other critical amino acids were given minimums in the formulation. Results obtained for BW gain, abdominal fat weight, and abdominal fat percentage showed that birds were more responsive (P < 0.05) to l-Val supplementation. A follow-up study using a corn-peanut meal (C/PM)-based diet formulated to be deficient in Val validated (P < 0.05) a Val deficiency based on poor growth performance and resulted in an immediate return to good performance when this amino acid was supplemented. Furthermore, the C/PM diet was compared with a nutritionally similar C/SBM diet, and no difference was observed in the performance of broilers fed these diets, thus validating the ability of the C/PM-based diet to support adequate growth of these broilers. This C/PM-based diet was used to feed gradual concentrations of Val, from levels that would be considered deficient (0.59% digestible) up to adequate (0.84% digestible Val). Results indicate that a ratio of Val to Lys of 78, or a minimum dietary value of 0.74% digestible Val (0.82% total Val), should be adequate for this high-yield broiler grown from 21 to 42 d of age.

Chicken feet (paws) are valuable products in the Asian market. Foot dermatitis, mostly caused by litter condition, can affect the foot skin tissue leading to downgrades and reduced market value. In this study, a diet having animal by-products was compared with 2 all-vegetable diets formulated with corn, soybean meal, and toasted soybean with or without corn gluten meal. A total of 1,200 birds were placed in 24 pens with new pine shavings as litter. Each treatment had 8 replications. Birds were fed the experimental diets up to 40 d of age. Starting at 21 d of age, 10 birds per replication were labeled and submitted to weekly evaluations of foot dermatitis. Litter samples were also collected weekly to determine percentage of moisture. In general, litter moisture and incidence and severity of foot dermatitis increased as broilers aged. Inclusion of corn gluten meal consistently reduced the incidence and severity of footpad dermatitis, which occurred in parallel with the reduction in litter moisture. Litter moisture from birds fed a diet with the inclusion of poultry by-product was similar to that obtained with corn gluten meal; however, benefits from reductions in foot dermatitis were not seen. It is concluded that feed formulation can affect litter moisture and the incidence and severity of foot dermatitis. Birds fed all-vegetable diets based exclusively on corn and soybean meal have an increased potential to develop footpad dermatitis as well as to produce excreta with greater percentages of moisture when compared with those fed diets with inclusions of poultry by-product or corn gluten meal.

There is an ongoing discussion regarding the relative effectiveness of the hydroxy analog of methionine (liquid MHA-FA) relative to DL-methionine (DLM). Five experiments were carried out under local conditions in 4 different countries to further test and determine the relative effectiveness of liquid MHA-FA. Additionally, multiexponential regression was used to determine if it is the proper mathematical model for estimation of Met relative effectiveness. The trials were carried out at the Research Center Foulum, Perdue Farms Inc., a major Mexican integrator, the University of Arkansas, and at the University of Rio Grande do Sul. Basal diets in all trials were formulated to be deficient in Met but adequate in all other nutrients and energy. Broilers performed well in each experiment; significant responses showed the Met deficiency of the basal diets. Relative effectiveness estimates of diluted DLM (65%) was 63% on average (n = 6, based on 3 trials), confirming that simultaneous regression analysis represents the proper mathematical model for comparative nutritional purposes. Relative effectiveness of liquid MHA-FA relative to DLM was 64% (n = 11, based on all 5 trials) on average for weight gain, feed conversion, and breast meat yield.

A study was carried out to investigate the sodium requirements of broiler chicks in the first week post-hatching using diets with two dietary electrolyte balances (DEB). During the first week, birds were given feeds with four levels of total sodium (0.12, 0.24, 0.36, and 0.48%) and two DEB (Na+ + K+ - Cl- = 160 or 240 mEq/kg). Feeds given thereafter to 42 d had common formulation. Both sodium and DEB affected live performance of chicks. Increasing sodium in the feed led to improvements in BW and feed conversion through the first week. Birds fed increased sodium had up to 25% increased water consumption and had corresponding reductions of 12 and 13% in carcass and excreta DM in the seventh day of age. Water consumed remained 6% higher in birds fed increased sodium through the second week of age. Regression analysis were run for BW gain and feed conversion, which estimated sodium requirements between 0.38 and 0.40% in the first week post-hatching. Since responses to increased sodium did not remain with broilers marketed at 6 wk of age, the use of this study’s estimated requirements will depend on the need to improve the performance immediately after hatching. There was an increased mortality at 4 d of age when the levels of sodium were maximized (0.48%). Increasing DEB from 160 to 240 mEq/kg demonstrated benefits on weight gain and feed conversion, but only limited to the first 4 d of age.

Programs that limit early growth of broilers are widely used to reduce mortality and culling and to improve feed conversion. Skip-a-day feed removal is a technique for limiting early growth and has not been extensively examined for broilers. This technique may be more easily implemented than other commonly used programs. Broilers were subjected to one of the following regimens: provided feed ad libitum to 54 d of age (AL); ad libitum except for 24-h removal periods at 8 and 10 d of age (R2); 24-h removal periods at 8, 10, 12, and 14 d of age (R4); or 24-h removal periods at 8, 10, 12, 14, 16, and 18 d of age (R6). Body weights at the end of feed removal were reduced 29, 35, and 41% by R2, R4 and R6 treatments, respectively, when compared with the AL treatment for the same periods. Average daily gains on R4 and R6 treatments were greater upon resumption of feeding ad libitum. Feed removal for a total of 2 or 4 d did not decrease final body weight, feed consumption, or carcass weight; however, removal for a total of 6 d decreased these variables. Cumulative feed conversion, BW, uniformity, mortality, carcass yield, carcass weight, abdominal fat pad, and feed costs per pound of body and carcass weights were not affected by feed removal. These results indicate subjecting broilers to 4 d of feed removal significantly reduced early growth without compromising final weight or meat recovery.

Male broiler chicks having either immediate or a 24-hr delayed access to feed and water after transportation from the hatchery were placed in floor pens having new or used pine shaving. All birds received common feeds not containing antimicrobials other than coccidiostats to 7 wk. Chicks experiencing delayed access had a 50% reduction in yolk sac contents compared to those placed earlier, reduced weight gain at 3 wk which was never recovered, and additional mortality Employing used litter also led to reductions in weight gain at 3 wk, but birds subsequently compensate. Broilers delayed in placement had reduced carcass weight and a decreased percentage of grade A’s, but proportion of parts after cone deboning was unaffected. Although birds reared on used litter had carcass weight similar to those on new litter, bruised drumsticks were more apparent and the proportion of breast fillets increased at the expense of rib cage and frame, particularly with delayed placement. For the most part, the adverse effects of delayed placement were independent of those resulting from used litter.

Three consecutive grow-outs of broilers fed nicarbazin were conducted to assess the presence of nicarbazin residues in muscle tissue and liver and in the litter. The anticoccidial was added to starter and grower feeds given to mixed sex broilers to 35 days. Finisher feeds without nicarbazin were given in the last week. Very few samples of tissue from breasts and leg quarters retained nicarbazin residue, but residues always remained in the litter and reflected the level present in the feed. Residues of nicarbazin persisted in the litter to the end of the third grow-out even in pens were birds received diets with nicarbazin only in the first grow-out. Residues occurred in livers more frequently than in muscle tissue, but still in a concentration considered safe for human consumption. Commercial use of nicarbazin following current applications by the industry is considered safe since residues found in tissue are far below the limits established by law.

The effect of increasing glucose to broilers has been demonstrated with the use of gluconeogenic compounds, such as propionate, as well as with high carbohydrate diets. These are thought to facilitate the utilization of the high fat reserves present in the yolk sac, thereby enhancing the chick’s ability to progress from yolk sac nutrition to independent feeding. Ground corn and a standard starter feed either with or without 2.4% calcium propionate supplementation were given to broilers for the first 3 days. Feeds thereafter were common to all treatments. The effects of corn and propionate were independent. Early feeding of corn reduced body weight gain until 42 days, whereas alterations attributable to propionate were not apparent. Early mortality was relieved when corn was fed but no advantage occurred with supplemental propionate. Early feeding of corn led to increased abdominal fat and reduced carcass yield; however, defects capable of downgrading were minor and proportions of deboned parts were similar. Propionate did not alter the whole carcass nor deboned parts. Integrity of femurs after cone deboning of thighs was similar among the treatments.

Events following the hatching of chicks have lately gained increased interest by the poultry industry. Research evaluating composition of eggs and yolk sacs of chicks from different sources and their effect on early chick development is scarce. In this research broiler hatching eggs were obtained from breeder flocks of four diverse strains, then categorized as “heavy” or “light” to represent the top and bottom one-third weights from each population. Heavy eggs typically had a greater proportion of albumen and less yolk than small eggs., and these differences were similarly expressed among strains. Influence of the egg source on hatched chicks differed with the carcass and yolk sac. Egg weight and strain affected chick weight but not its composition, whereas the yolk sac was consistent in proportion to the chick but varied in composition. Overall differences in weight, proximate analysis, amino acid, and mineral compositions of eggs and chicks appear to be small, and possible nutrient accommodation in the first feed to improve performance seems unnecessary.

Eggs and broiler chicks originating from breeder flocks having extremes in age (27 vs. 62 wk old) wee examined. Eggs from the older flock were heavier and had a greater proportion of yolk and smaller proportions o albumen and shell than those from 27 wk old birds. Yolks of eggs from young breeders and albumen of eggs from old breeders had greater percentage of moisture. Chick and yolk sac weights from old breeders were greater, but yolk sac proportions were not different. Analyses for crude protein and amino acids, as well as ash and minerals of eggs, chicks, and yolk sacs, did not reveal obvious differences in concentrations. Phosphorus in the yolk sac of chicks from young breeders appeared to be low, indicating that additional supplementation in the first feed may be appropriate.

Hatching eggs were obtained from four commercial breeder flocks of different strains. Eggs were categorized as “heavy” and “light”, to represent the top and bottom thirds by weight from each flock. Chicks from heavy eggs had better overall live performance through 49 days than those from light eggs. Differences in live performance among the strains exceeded that between heavy and light eggs, yet responses by each strain to egg weight were similar. Relative incidence of carcass defects that would influence grade and bone-out yields varied among the strains, but alterations due to extremes in hatching egg weight were negligible.

Chicks originating from 27- and 62-wk-old breeder flocks were evaluated beyond live performance to carcass characteristics. One half of each source and sex received 3% ammonium propionate in the first week’s feed; thereafter, a common regimen was given to 7 wk of age. Birds from the older breeders showed superior live gain and survival, but birds from younger breeders had better feed conversion. Supplemental propionate decreased live gain wile it was being fed but improved ultimate feed conversion for all birds and survival in birds from the young breeder flock. Proportion of abdominal fat was similar, regardless of breeder age and supplemental propionate; however, additional carcass yield with broilers from the old breeders provided further advantage in chilled weight. Few differences in carcass defects associated with downgrading were detected. Proportions of cone deboned parts were similar among treatments.

A variety of corn having higher oil content (5.7%) than the common yellow dent corn (3.8%) was introduced experimentally in Brazil. Several questions about the nutritional characteristics of this newly developed corn arose from poultry nutritionists, especially regarding its energy utilization by broilers. This study attempted to compare the high oil corn (HOC) with the yellow dent corn (YDC) commonly used in broiler feeds in Brazil. Broiler field performance was evaluated with two groups of broilers fed diets containing HOC or YDC and high or low energy levels from 1 to 21 or from 21 to 42 days. Dry matter digestibility (DMD), ether extract digestibility (EED), and Amen were also determined with the two types of corn. Similar values of DMD and EED were found for both types of corn, but AMEn was higher for HOC (3478 kcal/kg) than for YDC (3280 kcal/kg). Results suggest a better utilization of YDC than HOC with young chicks when supplemental oil is added.

The nutritional value of a variety of triticale (CP, 12.90%; CF, 1.50%; EE, 1.40 moisture, 13.20%) was investigated in two experiments. The first experiment included triticale in broiler diets to a level of 40%. The second experiment determined the apparent metabolizable energy (AMEn) of the grain. Triticale inclusion at the levels tested did not negatively affect the performance of the broilers. The average AMEn was 3246 kcal/kg.