Effect of strain and nutritional density of the diet on the water-protein ratio, fat and collagen levels in the breast and legs of broilers slaughtered at different ages.

Many requirements are necessary to meet the European Union rules to export poultry, including the amount of physiological water and water-protein ratio (WPR) in carcasses. Therefore, the aim of this study was to identify if strain, nutrition, and age affect the amount of collagen and fat and the WPR in cuts and verify whether the latter meets the international export standards. A total of 3,240 male chicks were housed in a completely randomized design in a 3 × 3 × 5 factorial arrangement, which included 3 nutritional densities (regular, medium, and high), 3 strains (021 Embrapa and 2 commercial strains identified as A and B), and 5 ages. Twelve broilers from each treatment (totaling 540 birds) were slaughtered at 28, 35, 42, 49, and 56 D of age to determine collagen and fat levels and WPR (through the calculation of moisture and protein percentage) in broiler breasts and legs using the near-infrared spectroscopy method. The use of feeds with different nutritional densities presented in this study has no effect on the WPR in the breast and legs of broilers slaughtered between 28 and 56 D of age. However, nutritional density influences liveweight and percentage of fat in the breast and legs. Collagen percentage in the legs decreases with increasing nutritional density. The 021 Embrapa strain cuts present a lower WPR than those of other commercial strains. However, the values found for all strains studied are within the limits of the Europe Union and Brazilian legislations. The liveweight, breast weight, leg weight, and leg fat increases linearly with age. Quite the opposite, water protein ratio, breast fat level, and breast collagen level decrease linearly with age. Leg WPR and leg collagen level are not affected by age. Despite the differences found for strains, nutritional densities and age readers should be aware that these factors may interact with each other depending on the response variable studied.

Quantitative trait loci for morphometric and mineral composition traits of the tibia bone in a broiler × layer cross.

Many economic losses occur in the poultry industry due to leg fragility. Knowing the genomic regions that influence traits associated with the growth and composition of the leg's bone can help to improve the selection process leading to increased leg resistance to fracture. The present study aimed to map quantitative trait loci (QTL) for mineral composition and morphometric traits of the tibia in 478 animals from an F2 broiler × layer cross. The measurement of weight, length and width of Tibia was carried out at 42 days of age. Ash, dry matter, levels of calcium (Ca), phosphorus (P), magnesium (Mg), Zinc (Zn) and Calcium:Phosphorus (Ca:P) ratio were also recorded. The population was genotyped for 128 microsatellite markers and one single nucleotide polymorphism, covering 2630 cM of the chicken genome. A likelihood ratio test was performed to find QTLs. Additive and dominance effects of the QTLs were included in the model. In the chromosomes 2 (GGA2), 6 (GGA6), 8 (GGA8), 24 (GGA24) and 26 (GGA26) some suggestive QTLs (P<0.00276) were mapped for tibia weight (GGA2 and GGA26), ash percentage (GGA2 and GGA6), dry matter percentage (GGA2), Ca (GGA8 and GGA24) and Ca:P ratio (GGA8), many of which are close to genes already identified as good candidates for those traits. The suggestive QTL on GGA2 has a pleiotropic effect on ash percentage, dry matter and bone weight, whereas in the GGA8 there seems to be two QTLs, one for Ca and another for Ca:P ratio. Thus, this study identified at least five genomic regions, in different chromosomes, that can be targeted for further research to identify potential mutations influencing the development and composition of leg bones in Gallus gallus.

Growth performance, morphometric analysis of the intestinal mucosa and thyroid of broiler fed canola meal / Desempenho e análise morfométrica da mucosa intestinal e da tireoide de frangos de corte alimentados com farelo de canola

The aim of this study was to evaluate the effect of replacing soybean meal with canola meal in broiler diets on performance, liver histopathology, morphometry of the intestinal mucosa and thyroid. One-day-old Cobb chicks (n=300) were distributed in a completely randomized design, with increasing levels of replacement of soybean meal with canola meal (0, 25, 50, 75 and 100%) and 6 repetitions of 10 birds each. Weight gain decreased linearly (P< 0.05) with increasing levels of inclusion of canola meal, in all stages. Villus height in the duodenum and jejunum linearly decreased (P< 0.05). Follicle diameter and thyroid follicular epithelium height increased linearly with increasing levels of canola meal (P< 0.05). Similarly, there was an increase in relative weight of liver and heart, and liver steatosis in the highest levels of replacement. In conclusion, the replacement of soybean meal with canola meal can reduce performance, adversely affecting the thyroid, liver and the morphometric characteristics in the duodenum and jejunum.(AU)

O objetivo deste estudo foi avaliar o efeito da substituição do farelo de soja pelo farelo de canola na dieta de frangos de corte sobre o desempenho, a histopatologia hepática, a morfometria da mucosa intestinal e da tiroide. Foram distribuídos 300 pintos com um dia de idade em um delineamento inteiramente causualizado, com níveis crescentes de substituição do farelo de soja pelo farelo de canola (0, 25, 50, 75 e 100%), 6 repetições com 10 aves cada. O ganho de peso diminuiu linearmente (P< 0,05) com níveis crescentes da substituição, em todas as fases. Assim como, a altura das vilosidades no duodeno e jejuno diminuiu linearmente (P< 0,05) em todas as idades avaliadas. O diâmetro do folículo e a altura do epitélio da tireoide aumentaram linearmente conforme aumentou os níveis de farelo de canola (P< 0,05). Da mesma forma, houve um aumento do peso relativo do fígado e do coração, e aparecimento de esteatose hepática nos níveis mais altos de substituição. Em conclusão, a substituição do farelo de soja pelo farelo de canola pode reduzir o desempenho, afetando negativamente a tireoide, o fígado e as características morfométricas no duodeno e jejuno.(AU)

Meat quality and cut yield of pigs slaughtered over 100kg live weight / Qualidade de carne e rendimento de cortes de suínos abatidos acima de 100kg de peso vivo

Meat quality and cut yield of pigs slaughtered between 100 and 150kg live weight were evaluated. Pigs (417 Agroceres PIC barrows and gilts) were fed a daily allowance of 2.8kg per head from 80kg until 100.71±0.85, 118.58±0.99, 134.07±1.18 or 143.90±1.24kg live weight. Seventy-one pigs were used for the evaluation of primal and subprimal cuts. There was no interaction between sex and slaughter weight for any of the evaluated parameters. Ham, shoulder, and loin weights linearly increased (P<0.01; R2: 84.3-93.2%) with increasing slaughter weight, which, however, had little effect on primal cuts meat yield. Increasing slaughter weight promoted a linear (P<0.05) and a quadratic (P<0.01) increase of red/green coordinate (a* value) of the loin and ham, respectively. Shear force showed a quadratic response (P<0.05), with minimum value estimated at 122kg slaughter weight. It was concluded that, under the applied management, increasing slaughter weight increased the volume of meat, but had little effect on meat yield. The meat of pigs slaughtered at heavier weights showed more intense red color and the same intramuscular fat content as lighter pigs, while tenderness was slightly affected.

Foi avaliada a qualidade da carne e os cortes de suínos abatidos entre 100 e 145kg de peso vivo. Os suínos (417 machos castrados e fêmeas, linhagem Agroceres PIC) foram mantidos sob fornecimento programado de 2,8kg de ração por animal por dia a partir de 80kg até o abate aos: 100,71±0,85, 118,58±0,99, 134,07±1,18 ou 143,90±1,24kg de peso vivo. Destes, 71 suínos foram usados para avaliação dos cortes primários e secundários. Não foi observada interação entre sexo e peso de abate em nenhuma das variáveis avaliadas. Os pesos do pernil, da paleta e do carré aumentaram linearmente (P<0,01; R2entre 84,3 e 93,2%) com o peso de abate, com pouco efeito sobre o rendimento da carne. A coordenada vermelho/verde (valor de a*) aumentou linearmente (P<0,05) no lombo e de forma quadrática (P<0,01) no pernil com o aumento do peso de abate. A força de cisalhamento apresentou resposta quadrática (P<0,05), com redução até o valor mínimo estimado para os 122kg de peso vivo. Conclui-se que, com o manejo utilizado neste estudo, a elevação do peso de abate resulta em aumento na quantidade de carne produzida, com pouco efeito sobre o rendimento de carne. A carne de suínos abatidos em pesos elevados apresenta cor vermelha mais intensa e mesmo nível de gordura intramuscular que a carne de suínos mais leves, enquanto a maciez é alterada apenas de maneira discreta.

Effects of genotype and dietary oil supplementation on performance, carcass traits, pork quality and fatty acid composition of backfat and intramuscular fat.

A 42-day study was conducted to evaluate the effect of genotype: terminal sire line Duroc×F1 (DC×F1); terminal sire line Embrapa MS-115×F1 (MS-115×F1); and MS-115×Moura (MS-115×MO) and three dietary oil sources: soybean; canola; and canola+flax, on performance, carcass traits, pork quality, and fatty acid composition. Genotype affected the technological quality of pork and fatty acid profile. MS-115-sired pigs had better meat color and Duroc-sired pigs had higher intramuscular fat content, more saturated fat and better omega-6/omega-3 ratio. Moura breed influenced positively meat tenderness and intramuscular fat. Diet did not affect the technological quality of the meat. Canola or canola+flax oil diet supplementations increased monounsaturated and C18:3 and decreased C18:2 fatty acids, reducing the omega-6/omega-3 ratio. The best omega-6/omega-3 ratio was obtained through supplementation with canola+flax.