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SUMMARY: The objective of this study was to determine the appropriate number of replicates to identify significant differences in carcass and cut yields in broiler chickens. At 42 d of age, a total of 480 broiler chickens were selected, weighed, and processed to obtain the hot carcass yield. Subsequently, after cooling, the cold carcass yield was determined. The cold carcass was dismembered into boneless and skinless breast, tenders, legs, and whole wings, which were individually weighed to obtain the cuts yield. The collected data underwent normality analysis and subsequent determination of descriptive statistics, as well as analysis of variance, in both cases to determine mean values, standard deviation, and coefficient of variation (CV). The required number of replicates to detect differences between means for different magnitudes was determined. The CVs obtained were stable, with the highest CV observed for tenders’ yield (11.34%) and the lowest for the hot carcass (2.35%). To achieve significant differences in both, cold and hot carcass, a minimum of 8 replicates is needed for 5% differences in 97% of experiments. For breast fillet characteristics, 10 replicates are required to detect a 10% difference in 99% of experiments. Due to higher variation, tenders yield necessitates at least 10 replicates to detect a 20% difference in 90% of cases. For wing yield, 8 replicates suffice for 94% accuracy when differences exceed 15%. Lastly, 10 replicates enable detection of 7.5% differences in leg variables in 95% of experiments. Effective experimental planning, based on the statistical power of the test, is essential for determining the requisite number of replicates. Researchers must prioritize the specific carcass characteristic relevant to their study and design the number of replicates, accordingly, ensuring more reliable and realistic results.

We determined the impacts of light intensity, blood fraction, fasting and storage time on glucose, cholesterol, triglycerides, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT) concentrations in 140 broiler chickens assigned to two light intensities (5 or 20 lux/m²) and seven fasting times (0, 2, 4, 6, 8, 10, and 12 h). The collected blood was fractionated into serum or plasma and stored at -20°C for 0, 15, 30, 60, and 120 days. Serum glucose concentrations declined linearly by 1.15 mg dL-1 every 2 h of fasting, whereas plasma glucose responded quadratically (minimum point at 8 h and 13 min of fasting). Serum ALT concentrations showed a quadratic effect, with a maximum point at 3 h and 46 min of fasting. Serum GGT concentrations were not influenced by fasting time, whereas plasma decreased by 1.60 IU L-1 at each 2 h of fasting. The AST concentrations were influenced by fasting. Storage times influenced the glucose concentrations in a quadratic manner, with maximum points in serum and plasma at 95 and 72 days, respectively. Serum cholesterol and triglyceride concentrations increased linearly with storage time. Storage time caused a quadratic response on serum ALT, with a maximum point at 32 days, whereas there was a minimum point at 93 days in plasma. Concentrations of GGT increased linearly with storage. Glucose, triglycerides, AST, and ALT concentrations were highest at 20 lux. Samples for AST analysis can be stored up to 120 days at -20°C. Serum glucose, cholesterol, triglyceride, ALT, and GGT analysis is indicated with a 6 h fasting time, without freezing. The light intensity should be specified.

ABSTRACT: The objective of this work was to evaluate the behavior of zeolite against different types of corn in broiler chickens’ diets. 1,200 male broiler chickens were assigned to 6 diets in a completely randomized design and a 2 × 3 factorial arrangement, consisting of 2 types of corn (higher or lower mycotoxin contamination) and the inclusion of zeolite (0; 5,000 and 10,000 g ton-1). In the period from d 1 to 21, there was an interaction (P = 0.0040) between types of corn and the inclusion of zeolite for feed conversion ratio (FCR). In the phase from 1 to 42 d, there was an interaction (P = 0.0322) on the serum levels of creatinine (CREA) and digestible gross energy (dGE); corn with lower mycotoxin level contamination (LMLC), caused a reduction in body weight gain (BWG) (P = 0.0046) and increase in the relative weight of abdominal fat (P = 0.0256). Inclusion rates of zeolite promoted an increase in the digestible CP (P = 0.0477) and digestible ash (P < 0.0001), as well as an increase (P < 0.0001) in hot carcass yield (P = 0.0433). The results indicate that the inclusion of zeolite, in the amounts used, did not alter the performance, serum levels, intestinal development and litter quality of the birds at 42 d of age. However, it was responsible for the improvement in the percentage of digestible nutrients (CP, GE, and MM).

ABSTRACT: This study evaluated the level and length of time of vitamin A supplementation and its effects on carcass and cuts yield, meat quality, and myopathies in 42-day-old broilers. A total of 1,920 birds were divided into 6 groups, and each group received a different level of vitamin A: 0; 6,000; 16,000; 26,000; 36,000 and 46,000 IU/ kg. From d 1 to 21, the treatments were distributed among 16 replicates with 20 birds. From the 22nd d on, 8 repetitions remained with the initial treatment and the others received diets with no vitamin A supplementation. Twelve birds were slaughtered per treatment to evaluate carcass and cuts yield, shear force, cooking loss, water holding capacity, and the presence of substances reactive to thiobarbituric acid. The remaining birds were slaughtered and evaluated in loco for Wooden Breast (WB) and White Striping (WS). Wings weight was affected by vitamin A levels. The duration of the vitamin A supplementation process had effects on the weight of breast, legs with a dorsal portion, and meat color in the yellow intensity (b*). Incidence of WB had higher scores in birds supplemented until 42 d of age. WS showed a quadratic response and a lower response with supplementation of 29,700 IU/ kg. Even for WS, a higher occurrence of the normal score was found in birds supplemented until 21 d of age. Minimal quadratic responses were obtained for normal, moderate, and severe scores, in supplementations of 29,301; 29,959, and 29,827 IU/ kg, respectively. WB had lower occurrence rates in birds supplemented until 21 d of age. Consequently, the severe score was more frequent when supplementation was provided until 42 d of age. The level of vitamin A and the length of time during which this supplementation was provided had influence on cuts yield, meat color and the incidence of WB and WS of the 42-day-old birds.

ABSTRACT The objective of this study was to determine the chemical composition, non-starch polysaccharides (NSP) content, in vitro digestibility of starch, apparent metabolizable energy (AME), nitrogen-corrected AME (AMEn), and apparent and apparent nitrogen-corrected coefficient of metabolizable energy (ACME and ACMEn) of three corn hybrids dried at different temperatures in the diets of broiler chickens. The energetic values were determined by the total collection of excreta method, using broilers from 11 to 21 d, placed in a completely randomized design in a factorial scheme (three corn hybrids and two drying temperatures: 80 and 110 °C), totalizing six treatments, seven replicates, and four birds/replicate. The data were subjected to two-way ANOVA. There was an interaction between the two factors tested wherein the AME and AMEn were increased when using corn Hybrid 1 dried at 80 °C. As main effects, the use of corn Hybrid 3 increased ACME and ACMEn. The drying temperature of 110 °C increased amylose, resistant starch, and nitrogen bound to the fiber contents, and reduced soluble:total NSP ratio. These changes may be responsible for the differences in digestibility of nutrients. The mean values of AME and AMEn of corn dried at 80 and 110 °C were 14.03 and 13.84 MJ/kg, respectively, and 81.62 and 80.53% for ACME and ACMEn, respectively.

Chemical composition, energy values, digestibility coefficients and the values of true amino acid of eight different deactivated full-fat soybeans were determined. The total excreta collecting method was used to determine the energy values, where 180 broiler chicken, aging 21 days, were distributed in a completely randomized design, with nine treatments (eight soybeans and one reference diet), four replicates, and five birds per experimental unit. The method of “forced feeding” was used to determine the digestibility coefficients, where 40 cecectomized roosters were distributed in a completely randomized design, with eight treatments, five replicates and one rooster per experimental unit five cockerels were fasted to determine endogenous losses. The values for apparent metabolizable energy (AME), nitrogen corrected AME (AMEn), and coefficients of metab-olizability (CAME and CAMEn) for the soybean, ranged respectively, from 3.191 to 4.242 kcal/kg, 2.953 to 3.906 kcal/kg, 64.85 to 80.42% and 60.00 to 74.07%. The average values of true digestibility coefficients of essential and nonessential amino acids from soybeans evaluated ranged from 79.74 to 93.08% and from 78.33 to 91.85%, respectively. The soybean one (deactivated organic) showed the lowest digestible coefficients com-paring to the others (obtained commercially), probably due to a subprocess, confirmed by the urease activity of 0.32.

An experiment was conducted in the Department of Experimental Stations of the Universidade Tecnológica Federal do Parana - UTFPR campus Dois Vizinhos - PR, with the objective of determining the nutritional levels of threonine for laying hens aged 75 to 90 weeks. One hundred fifty laying Shaver Brown pullets were used in a completely randomized design (CRD) submitted to a basal diet containing 2.85 kcal ME/g and 148.7 g/kg CP, supplemented with 4.6; 4.9; 5.2; 5.5 or 5.8 g/kg of digestible Lthreonine (98 %), which provided 0.000, 0.027, 0.058, 0.089 or 0.120% threonine, respectively. The feed conversion, egg production, egg weight, egg mass and internal egg quality were not affected (P>0.05) by the threonine in the diet. The Haugh unit showed a linear effect with threonine consumption in that it increased levels of digestible amino acids in the diet. The variables percent albumin and shell showed quadratic effects, so the recommended dietary digestible threonine level was 5.20 g/kg, which corresponds to 0.648 g threonine/hen/day, and 5.25 g/kg, which is equivalent to 0.654 g threonine/hen/ day, respectively. The specific gravity was affected by the level of threonine; the indicated level is 5.22 g/kg, equivalent to 0.651 g of threonine/hen/day obtained by the quadratic effect.

The objective of this study was to determine the requirement of digestible methionine + cystine of brown-eggs laying hens from 50 to 66 weeks age at the end of the first production cycle. The design was completely randomized, with 150 Brown Shaver hens, which were distributed in five treatments with six replications of five birds each. Birds received a basal diet with 2857 kcal/kg metabolizable energy and 15.97% crude protein, supplemented with 0.132; 0.174, 0.215, 0.256 and 0.298% DL-methionine (98%), in order to provide 0.572, 0.613, 0.653, 0.693 and 0.734% digestible methionine + cystine. The levels of digestible methionine + digestible cystine followed, respectively, the relations of 67, 72, 77, 81 and 86% with lysine fixed at 0.851%. Feed intake, methionine + cystine intake, feed conversion per dozen eggs, egg weigth and mass, percentage of egg components, internal egg quality and weight gain were evaluated. Methionine + cystine levels showed a quadratic effect on feed conversion per dozen eggs and egg weight, a linear effect on feed conversion per kilogram of eggs and percentage of albumen. There was also a positive linear effect on yolk percentage. The methionine + cystine requirement was estimated at 0.572%, corresponding to 682 mg of digestible methionine + cystine/bird/day.

This work aimed to evaluate the microbiological, sensory and centesimal characterization of four kinds of fishburgers elaborated with tilapia mechanically separated meat. The microbiological analyses showed that both raw material and fishburgers met the microbiological standards for products derived from fish and certified that the use of byproducts derived from fish processing is a form of aggregating value to a final product, with good acceptance by the consumer, assisting quality standards. It was not verified significant differences for the averages attributed for taste, aroma, softness, global appearance and purchase intention that ranged, respectively, from 7.14 to 7.44; 7.14 to 7.46; 7.30 to 7.42; 7.21 to 7.35; 3.86 to 3.98. All fish burgers were moderately and very accepted and did not have a preferred specific one. The results of purchase intention oscillated between “maybe would buy”/”wouldn’t buy” and “possibly would buy the product”. The physical-chemical analysis presented the following results: 15.50 to 16.14; 1.73 to 10.28 and 1.12 to 2.44 g/100 g for crude protein, ethereal extract and mineral matter, respectively. The unit cost ranged from R$ 0.36 to R$ 0.37 with yield of 12 units/kg, that denote the production viability.Objetivou-se com este trabalho avaliar as características microbiológicas, sensorial e centesimal de quatro tipos de fishburgers elaborados à base de carne de tilápia mecanicamente separada (CMS). As análises microbiológicas demonstraram que tanto a matéria-prima quanto os fishburgers atenderam aos padrões microbiológicos para derivados de pescado, constatando-se que a utilização de subprodutos de processamento do pescado é uma forma de agregar valor a um produto final, com boa aceitação pelo consumidor e atendendo aos padrões de qualidade. Não foram observadas diferenças significativas para as médias atribuídas aos parâmetros sabor, aroma, maciez, aparência global e intenção de compra, que oscilaram, respectivamente, entre 7,14 e 7,44; 7,14 e 7,46; 7,30 e 7,42; 7,21 e 7,35; 3,86 e 3,98. Todos os fishburgers estiveram entre moderadamente e muito aceitos, não havendo preferência por um específico. Os resultados referentes à intenção de compra variaram entre “talvez comprasse”/”não comprasse” e “possivelmente compraria o produto”. A análise físico-química indicou resultados de 15,50 a 16,14; 1,73 a 10,28 e 1,12 a 2,44 g/100 g para proteína bruta, extrato etéreo e matéria mineral, respectivamente. O custo unitário variou de R$0,36 a R$ 0,37, com rendimento de 12 unidades/kg, o que denota a viabilidade da produção.

The dietary requirement of threonine was determined for brown laying hens in the period 50-66 weeks of age, based on performance parameters and quality of eggs. For this we used 150 laying Shaver Brown hens distributed in a completely randomized design with five treatments (0.460; 0.490; 0.520; 0.550 and 0.580%) of digestible threonine, six replications and five birds each. The digestible threonine levels did not affect (p>0.05) feed intake, egg production, egg weight, egg mass or feed conversion kg kg-1, but presented a quadratic effect (p0.05) on the yolk and albumen index, specific gravity, yolk percentage, thickness or shell weight per surface area, since the variable Haugh unit displayed linear behavior (p