Patrícia Emília Naves Givisiez

Milk adulteration: Detection of bovine milk in bulk goat milk produced by smallholders in northeastern Brazil by a duplex PCR assay.

The aim of this study was to investigate the adulteration of goat milk produced by smallholders in semiarid northeastern Brazil with bovine milk as an adulterant. The study was requested by the association of smallholder producers in the region to investigate and to inhibit adulteration practices as a need to ensure the quality and safety of goat milk. A duplex PCR assay has been developed and standardized. Further validation was performed in 160 fresh bulk goat milk samples. The detection limit of the duplex PCR was 0.5% bovine milk in goat milk and the results indicated that 41.2% of the goat milk presented to market was positive for bovine milk. Making the test available to the association of producers, together with extension activities, have been applied to reduce adulteration in goat milk sold to small-scale dairy plants and to ensure the species origin for goat milk in the state of Paraíba.

Exigência de lisina digestível para frangos de corte machos de 1 a 42 dias de idade

This study was carried out with the objective of estimating the nutritional requirements of digestible lysine for broiler from 1 to 42 days old. A total of 1,950 male Cobb chicks were used (750, 600 and 600 in pre-initial, initial and growing phase, respectively) with initial weight of 45.1 ± 0.6, 160.5 ± 2.4 g and 746.3 ± 10.7 g, respectively. The birds were distributed in a completely randomized design, using six treatments and five repetitions, with 25, 20, and 20 chicks per experimental unit in the pre-initial, initial and growing phases, respectively. The treatments consisted of a lysine-deficient basal diet that was supplement with L-lysine.HCl in order to contain six digestible lysine levels (1.10, 1.16, 1.22, 1.28, 1.34 and 1.40%; 0.92, 0.98, 1.04, 1.10, 1.16 and 1.22% and 0.815, 0.875, 0.935, 0.995, 1.055 and 1.115%, for the pre-initial, initial and growing phases, respectively). The characteristics evaluated were: feed intake, weight gain and feed conversion, weight and carcass yield and prime cuts, relative and absolute weight of edible viscera and abdominal fat. In all phases, there was a linear effect of digestible lysine levels on feed intake and quadratic effect on weight gain feed conversion. There was no effect of the digestible lysine levels on the absolute weights of carcass, heart, and abdominal fat, carcass yields, breast, thigh and drumsticks, and on the relative weights of the heart, liver, gizzard and abdominal fat. However, there was a quadratic effect on the absolute weights of the breast, drumstick, thigh and liver. Digestible lysine levels recommended for male broilers are 1.286; 1,057 and 0,998% in the pre-initial, initial and growing phases, respectively.

Effect of the levels of calcium and particle size of limestone on laying hens

This experiment was conducted to evaluate the effect of levels of calcium (Ca) and particle size of limestone (LS) for laying hens. It was used 216 Dekalb White laying hens at 25 to 49 weeks of age in a completely randomized design in a 3 × 2 factorial arrangement, composed of three levels of calcium (3.92, 4.02 and 4.12%) and two particle sizes of limestone (thin - 0.60 mm; and thick - 1.00 mm), resulting in 6 treatments with six replicates of six birds. There was no significant effect of levels of calcium and limestone particle size neither of the interaction calcium × particle size for feed intake, egg weight, specific gravity, shell thickness, shell percentage, Haugh unit, calcium and phosphorus digestibility and percentage of digestive tract. Production, mass, conversion by mass and conversion by egg dozen had their best results with 4.12% of calcium in the diet. Percentage of gizzard and feed intake observed at 3:00 p.m. improved as limestone granulometry improved from 0.60 to 1.00 mm. There was an interaction effect among calcium level and limestone granulometry for breaking strength of tibia, bone density, length of the small intestine and feed intake at 6:00 a.m.; 9:00 a.m., 12:00 p.m., 6:00 p.m. and 9:00 p.m., respectively. It is recommended the addition of 4.12% of calcium and limestone in the thick granulometry (1.00 mm) for a better performance of commercial laying hens. More studies are needed to elucidate the mechanisms involved in the alteration of nutritional behavior of laying hens in response to changes in the levels of calcium and in the granulometry of limestone in the rations.

Efeito do tempo de jejum pós-eclosão, valores energéticos e inclusão do ovo desidratado em dietas pré-iniciais e iniciais de pintos de corte

Two experiments were carried out to determine the nutritional value of the dried egg (DEGG), and the effect of the post-starvation hatching time (PSHT) and the inclusion of dried egg powder in the diet of broiler chicks. In experiment 1, 120 male Ross-308 broiler chicks were housed according to a completely randomized design into three treatments and five repetitions of eight birds each. Excreta collection was daily performed from 24 to 29 days of age in the morning and afternoon. In experiment 2, a sex-mixed batch of 810 Cobb-500 chicks was used. Initial weight was 33.41 ± 0.53 g, and the chicks were housed in pens measuring 1.0 × 1.5 m. A completely randomized experimental design was used with nine treatments and six repetitions of 15 birds each, according to a 3 × 3 factorial of three DEGG levels (0, 2 and 4%) and three PSHT (28, 40 and 52 hours), corresponding to: 0, 12 and 24 hours of starvation after housing, respectively. DEGG showed 51.54% of CP and 4,278 kcal AMEn/kg. From 1 to 7 days of age, the birds submitted to starvation for 40 and 52 hours showed lower live weight, weight gain and feed intake when compared to birds fed sooner (at 28 hours PSHT). The poorest performance was shown by birds fasted for 52 hours (24 hours of starvation after being housed). DEGG levels of 4% in the pre-initial diet improved the live weight in the second and third days of age. In conclusion, DEGG might be used from 1 to 21 days of age in broiler diets without impairing the bird performance.

Enterotoxin-Encoding Genes in Staphylococcus spp. from Bulk Goat Milk

Although Staphylococcus aureus has been implicated as the main Staphylococcus species causing human food poisoning, recent studies have shown that coagulase-negative Staphylococcus could also harbor enterotoxin-encoding genes. Such organisms are often present in goat milk and are the most important mastitis-causing agents. Therefore, this study aimed to investigate the occurrence of enterotoxin-encoding genes among coagulase-positive (CoPS) and coagulase-negative (CoNS) staphylococci isolated from raw goat milk produced in the semi-arid region of Paraiba, the most important region for goat milk production in Brazil. Enterotoxin-encoding genes were screened in 74 staphylococci isolates (30 CoPS and 44 CoNS) by polymerase chain reaction targeting the genes sea, seb, sec, sed, see, seg, seh, and sei. Enterotoxin-encoding genes were found in nine (12.2%) isolates, and four different genes (sea, sec, seg, and sei) were identified amongst the isolates. The most frequent genes were seg and sei, which were often found simultaneously in 44.5% of the isolates. The gene sec was the most frequent among the classical genes, and sea was found only in one isolate. All CoPS isolates (n=7) harboring enterotoxigenic genes were identified as S. aureus. The two coagulase-negative isolates were S. haemolyticus and S. hominis subsp. hominis and they harbored sei and sec genes, respectively. A higher frequency of enterotoxin-encoding genes was observed amongst CoPS (23.3%) than CoNS (4.5%) isolates (p<0.05), reinforcing the importance of S. aureus as a potential foodborne agent. However, the potential risk posed by CoNS in goat milk should not be ignored because it has a higher occurrence in goat milk and enterotoxin-encoding genes were detected in some isolates.

Substituição de minerais inorgânicos por orgânicos na alimentação de poedeiras semipesadas

This study evaluated the effect of the supplementation with organic microminerals on performance and egg quality of semi-heavy layers. Dekalk Brown layers (n=216) were distributed according to a completely randomized design into four treatments, nine repetitions and six birds per repetition. The experiment lasted 140 days and was comprised of five 28 day cycles. The basal diet was formulated to fulfill the nutritional requirements and was supplemented with organic or inorganic minerals, resulting in four treatments: T1 - basal + 100% inorganic minerals; T2 - basal + 100% organic minerals; T3 - basal + 66% organic minerals; T4 - basal + 33% organic minerals. Egg production, egg weight, egg mass, feed conversion for dozen and mass, albumen percentage, specific gravity, shell thickness and relative gross margin have better results when the inorganic minerals are replaced with 66% organic.

Exigência de sódio para poedeiras no final do primeiro ciclo e durante o segundo ciclo de postura

Two experiments were carried out to estimate sodium requirements for brown-eggs laying hens in the late first and during second egg-production cycle. A completely randomized design was used, with seven sodium levels (0.08, 0.13, 0.18, 0.23, 0.28, 0.33 and 0.38%), six replications of six birds in the late first egg-production cycle and five replications of six birds in the second egg-production cycle. In the late first egg-production cycle, sodium levels (SL) had no effect on feed intake (FI), egg weight (EW), egg dozen feed conversion (EDC) and egg-shell specific gravity (SG). The SL showed quadratic effect on egg production (EP), egg mass (EM) and egg mass feed conversion (EMC), that resulting in sodium requirements (SR) of 0.21, 0.22 and 0.21%, respectively. In the second egg-production cycle, SL had no effect on EW and SG. However, EP, EM, EMC and EDC improved when the levels of sodium were 0.20, 0.19, 0.18 and 0.19%, respectively. Considering the estimates of sodium requirements to egg production and egg mass feed conversion, could be suggests 0.22% e 0.20% as maximum sodium levels, respectively, to late first and second egg-production cycle.

Estudo comparativo da proteína do feno de maniçoba em relação à proteína do feno de alfafa na ração de coelhos

O presente experimento foi conduzido com o objetivo de avaliar a substituicao parcial da proteina bruta (PB) do feno da alfafa (FA) pela PB do feno de manicoba (FM) na alimentacao de coelhos em crescimento, bem como o valor nutricional da proteina bruta do feno de manicoba. Foram estudados os parâmetros de desempenho, digestibilidade, rendimento de carcaca e dos cortes nobres submetidos as dietas experimentais. Os tratamentos consistiram em quatro niveis de substituicao (0, 25, 50 e 75%) da proteina do feno de alfafa pelo feno de manicoba. A substituicao crescente dos niveis de feno manicoba resultou em um aumento linear no consumo de racao e no ganho de peso de forma quadratica aos 83 dias, mostrando que esse ingrediente pode ser utilizado como substituto ao feno de alfafa na dieta de coelhos. A proteina do feno da alfafa pode ser substituida parcialmente pela proteina do feno de manicoba.

Electrolyte balance in diets with reduced protein for semi-weighted laying hens in the second production cycle

The objective was to evaluate the effect of electrolyte balance in diets with reduced protein for semi-weighted Bovans Goldline laying hens in the second production cycle. The design was completely randomized with five treatments and seven replicates of six birds per experimental unit. Treatment 1 consisted of a control diet containing 165.0 g/kg crude protein (CP), formulated with the addition of DL-methionine to meet birds requirements during the experimental period. To compose the treatments 2-5 (BE149, BE167, BE185 and BE203), a basal diet with reduced protein (135.0 g/kg CP) supplemented with synthetic amino acids DL-methionine, L-lysine, L- threonine, L-valine and L-tryptophan was formulated. This basal diet was supplemented with potassium carbonate, to replace the inert, so as to provide four levels of potassium (5.86, 6.56, 7.26 and 7.96 g/kg) corresponding to the electrolyte balance of 171, 149, 167, 185 and 203 meq/kg, respectively. There was increased linear effect for feed intake and decreasing linear effect for albumen weight and yolk percentage and quadratic effect for conversion per dozen and per egg mass. Crude protein is recommended at 135.0g/kg with 6.77 g/kg potassium and electrolyte balance of 172.51meq/kg in the diet of semi-weighted laying hens in the second production cycle.

POEDEIRAS ALIMENTADAS COM DIFERENTES NÍVEIS DE ENERGIA E OLEO DE SOJA NA RAÇÃO

EnglishThe aim of this work was to evaluate increasing levels of energy and soybean oil on performance and internal and external egg quality. Three hundred and sixty semi-heavy laying hens Bovans Goldline, 29 week-old, were used, during five periods of 28 days each. It was used a completely randomized design, in a double factorial (3 x 3), totaling nine treatments, with five replicates of eight birds each. Studied factors were soybean oil (1, 2 and 3%) and energy (2600, 2750 and 2900 kcal EMkg-1) levels on diet. No interaction was observed among soybean oil and metabolizable energy. Soybean oil did not promote effect over none of the evaluated parameters. No effect was observed for energy levels on egg production, feed conversion, egg mass, yolk and shell weight, yolk and albumen percentage and specific gravity. Differences were observed for feed conversion, egg and albumen weight and shell percentage, given that the highest weights were observed at the lowest energy level and the highest percentage was observed at the highest energy level. Providing 2600 kcal EMkg-1 was more suitable in order to keep production and body weight and also to promote improvement on energetic conversion and an increase on egg weight. portuguesObjetivou-se avaliar os efeitos de niveis crescentes de energia e de oleo de soja sobre o desempenho e a qualidade interna e externa dos ovos de poedeiras semipesadas. Foram utilizadas 360 poedeiras comerciais da linhagem Bovans Goldline, com 29 semanas de idade, durante cinco periodos de 28 dias, distribuidas num delineamento inteiramente casualizado, em esquema fatorial 3 x 3, totalizando 9 tratamentos com 5 repeticoes de oito aves cada. Os fatores estudados foram niveis de oleo de soja (1, 2 e 3%) e niveis de energia metabolizavel na racao (2600, 2750 e 2900 kcal/kg). Nao foi observada interacao entre os niveis do oleo de soja e a energia metabolizavel da dieta. Os niveis de oleo de soja nao promoveram efeito para nenhum dos parâmetros avaliados. Os niveis de energia metabolizavel nao influenciaram a producao de ovos, conversao alimentar, massa de ovos, peso de gema e de casca, percentagem de gema e de clara e gravidade especifica. Foram observadas diferencas para conversao energetica, peso do ovo e de clara, e percentagem de casca, sendo os maiores pesos observados no menor nivel de energia e a maior percentagem observada no maior nivel de energia. O fornecimento de 2600 kcal de EM/kg foi mais adequado para manter a producao e o peso corporal e para promover melhoria na conversao energetica e aumento no peso do ovo.