Ibiara Correia de Lima Almeida Paz

Desempenho e qualidade da carne de frangos de corte alimentados com diferentes níveis de sorgo em substituição ao milho

The effects of diets with graded levels of SAARA sorghum, a variety containing 0.49g/kg of tannin, on broiler performance and meat quality were evaluated. One-day-old, sexed Ross 308 chicks (n=2600) were randomly assigned within sex to one of five levels of sorghum (replacement of 0, 25, 50, 75 and 100% of corn in the diet). There were 65 birds per experimental unit in 4 replicates of the 5 sorghum level × 2 sex factorial design. Level of corn replacement by sorghum did not affect performance characteristics, carcass characteristics, main cut yield, muscle tissue chemical composition or sensory characteristics of the meat (P>0.05). Muscle tissue from males had higher pH values than that from females, and muscle pH decreased as sorghum replaced corn in the diet (P<0.05). Loin length, width and thickness were larger for males. Breast meat from males had higher cooking loss and required greater shear force than breast meat from females (P<0.05). With increasing level of sorghum in the diet, the L value (level of light) of breast and leg muscle increased, whereas a value (redness) and b value (yellowness) decreased (P<0.05). In summary, replacing corn in the diet with increasing levels of sorghum did not affect live performance, carcass or main cut yields or meat quality, but muscle pH and color were affected.

Assessing locomotion deficiency in broiler chicken

Locomotion deficiencies in broiler production cause poor welfare and lead to change in drinking and feeding behavior with consequent loss in weight gain. This research aimed to assess locomotion deficiencies in broiler chicken by analyzing the vertical peak force on both feet during walk. A chamber was built with an inlet ramp, a horizontal walkway in the middle and an outlet ramp. In the walkway a thin mat with piezoelectric crystal sensors was placed to record the step vertical peak force of the feet while walking on the force platform. The measurement system consisted of a mat with electronic sensors and software that allowed real time recording of the forces and the processing and analysis of data. Footage was taken from two digital video cameras and used for gait scoring. Forty male broilers were chosen at random, grown under similar rearing conditions and farms, with age varying from 49 to 28 days (ten birds of same age) to be used in the trial. Measurement consisted of inducing the bird to walk on the force platform which automatically registered the peak vertical force of the steps. Results showed that the gait score increased with the weight and age of the birds. Peak force asymmetry was found for each foot, independent of age or gait score. Although not identified visually in the broilers, the peak vertical force values differed in both right and left feet leading to slow and uneven walking. Walking deficiency was more severe in older birds.

Bone mineral density: review

Bone mineral density is one of the most important factors to measure bone quality. It is a biophysical parameter of critical experimental importance, and has...

Comparison of techniques for tibial dyschondroplasia assessment in broiler chickens

This study was carried out at Faculdade de Medicina VeterinAEria e Zootecnia, Universidade Estadual Paulista, Botucatu, SP, Brazil, with the objective of evaluating the efficacy of four techniques in the assessment of tibial dyschondroplasia lesions in broiler chickens. Four hundred Cobb male chicks were reared from 1 to 39 days of age. At 39 days, forty birds were selected and tibial dyschondroplasia status was assessed by four different techniques: evaluation using the lixiscope, macroscopic examination, histological examination and bone mineral density assessment using optical radiographic densitometry. The efficacy of each technique to assess dyschondroplasia lesions in the tibial growth plate was determined in comparison to histology, which was considered to be 100% efficient. The correlation results between lixiscope analysis and histology were poor. Macroscopic scores and densitometry readings were highly correlated with histology scores, and it is considered that these techniques reliably reproduce the status of the growth plate.

Ostrich (Struthio camellus) carcass yield and meat quality parameters

This article aimed at compiling recent studies on the main factors that influence ostrich meat quality and carcass yield. Few articles investigated the effect of subspecies, which generally are not even mentioned. There are important dietary effects, particularly those caused by dietary protein to energy ratio. Rigor mortis follow-up studies showed that there are no losses in meat quality when carcasses are hotdeboned. Age at slaughter influences some meat quality traits, such as tenderness and lipid content. Few effects of gender have been observed, and at the same age at slaughter, both male and female present the same meat quality traits.

Efeito da idade da matriz sobre o desempenho e rendimento de carcaça de frangos de corte

Avaliou-se efeito da idade da matriz sobre as caracteristicas de desempenho, rendimento de carcaca e partes de frangos de corte, criados ate 49 dias de idade. Foram utilizados 3600 pintos de um dia, oriundos de ovos de matrizes da linhagem Ross 308, distribuidos segundo um delineamento experimental inteiramente ao acaso, em esquema fatorial 5×2, com cinco idades de matrizes (29, 41, 58, 68 e 98 semanas) e dois sexos, com quatro repeticoes de 90 aves cada. Aos 21, 28, 35, 42 e 49 dias de idade, cinco frangos por parcela foram amostrados e abatidos apos jejum alimentar de oito horas, para avaliacao do rendimento de carcaca e partes. A idade da matriz influenciou (P 0,05) o rendimento de carcaca nas idades avaliadas. Os frangos oriundos de matrizes com 29 semanas apresentaram melhor rendimento de peito que aqueles de matrizes com 58 semanas. O sexo influenciou (P<0,05) tanto o desempenho quanto o rendimento de carcaca e partes dos frangos de corte.

Chicken Meat Quality as a Function of Fasting Period and Water Spray

This study aimed at evaluating the effect of different fasting periods and water spray during lairage on the quality of chicken meat. A number of 300 male Ross broilers were reared up to 42 days of age, and submitted to four pre-slaughter fasting periods (4, 8, 12, and 16 hours) and sprayed with water or not during lairage. Deboned breast meat was submitted to the following analysis: pH, color, drip loss, water retention capacity, cooking loss, and shear force. There was a significant effect (p≤0.05) of fasting period on meat luminosity was significantly different, with the highest value obtained for 4-hour fasting, whereas no difference was found among the other fasting periods. Meat pH values were different among fasting periods when birds received water spray, with birds fasted for 4, 8, and 12 hours of fasting presenting lower meat pH values (5.87, 5.87, and 6.04, respectively). The interaction between fasting period and water spray influenced meat drip loss and cooking loss, with birds fasted for 16h and not receiving water spray presenting higher drip loss (4.88) and higher cooking loss (28.24) as compared to the other birds. Fasting period affects meat quality, and very short periods (4h) impair meat quality.

Litter materials and the incidence of carcass lesions in broilers chickens

The aim of this study was to evaluate the effects of different litter materials on litter compaction, broiler feathering and the incidence of carcass lesions. In the experiment, 3240 one-day-old Ross® chicks were selected by sex and distributed according to a completely randomized experimental design in a 2 x 6 factorial arrangement (two sex and six litter materials). The following litter materials were used: wood shavings, rice husks, chopped Napier grass, 50% sugar cane bagasse plus 50% wood shavings, 50% sugar cane bagasse plus 50% rice husks, and pure sugar cane bagasse. Litter compaction was weekly assessed using a penetrometer. On days 21, 35 and 42 of the experimental period, feathering on the back and legs was scored according to a 0 - 10 scale. On day 42, birds were slaughtered and the presence of bruises, scratches and footpad lesions was recorded. Litter material had no effect on bird feathering. Carcass lesions (scratches, bruises and footpad lesions) were influenced by the litter material evaluated. Birds reared on sugarcane bagasse and chopped Napier grass presented more scratches, bruises and footpad lesions than the others. Dermatitis was more evident in birds reared on sugarcane bagasse, chopped Napier grass and the combination of litter materials. It was found that males presented higher incidence of dermatitis and footpad lesions than females. Each litter material presented different compaction degrees, which increased along the experimental period. Sugarcane bagasse, chopped Napier grass and the combination of bedding materials presented the highest degree of compaction, compared with wood shavings and rice husks.

Qualidade físico-química e sensorial da carne de peito de matrizes pesadas de descarte

The aim of this research was evaluate the meat quality broiler breeder hens: pH, color, R value, drip loss, water holding capacity, water absorption capacity, emulsion capacity, cooking loss, shear force and sensorial analysis. The breast meat of broiler hens presents means values for pH, R value, drip loss and L* value parameter of 5.70, 1.43, 2.00 and 50.11, respectively. The means value for water retention capacity, water absorption capacity, cooking loss and shear force, were 77, 58, 18% e 4.94kgf cm-2 respectively. For sensory analysis, the meat of broiler hen present lower tenderness intensity (6.9), lower succulence (3.4), more elasticity, rubbery and swallowing difficulties. The meat of broiler hens presented good technology quality characteristics that make it possible to be used as meat for elaborated industry.

Tibial dyschondroplasia and bone mineral density

This study was carried out at Faculdade de Medicina VeterinAEria e Zootecnia, UNESP, Botucatu-SP, Brazil. The aim was to establish the normal values of bone mineral density (BMD) expressed in millimeters of aluminum in the tibia of broiler chickens using optical densitometry of radiographs. Four hundred Cobb male chicks were reared from 1 to 40 days of age, when 40 of them were selected and the right femurtibia articulation was radiographed. Radiographs were taken with the X-ray equipment calibrated for 45 kvp and 3.2 mAs and a focus-to-film distance of 90 cm. An aluminum phantom ASTM-6063 consisting of 20 ladder steps with graduate density was placed parallel to the area to be radiographed and used as a densitometry reference standard. Radiograph images were analyzed using the software ATHENA n SIA. The proximal growth plate of the right tibia epiphysis was used as the standard reading region. The inclination axis of the reading window was 0 and the window was 10 mm high and 40-45 mm wide, depending on the bone size. Optical densitometry values of the radiographs ranged from 1.46 to 1.77 mmAl, and the coefficient of variation was 9.93%. It was concluded that densitometry values beyond the range established in the present study might indicate the presence of bone alteration in the tibia of broilers.