Farinha de algas marinhas (schizochytrium sp.) na alimentação de cordeiros confinados: desempenho, digestibilidade e qualidade da carcaça e da carne
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2018-03-06
Autores
Borghi, Thiago Henrique [UNESP]
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Universidade Estadual Paulista (Unesp)
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Objetivou-se avaliar o desempenho, a digestibilidade dos nutrientes, os parâmetros quantitativos da carcaça e os qualitativos e sensoriais da carne de cordeiros Ile de France terminados em confinamento, recebendo dietas com crescentes inclusões de farinha de algas marinhas. Foram utilizados 32 cordeiros não castrados com aproximadamente 60 dias de idade e 20 ± 0,2 kg de peso corporal, alojados em baias individuais e abatidos aos 35,0 ± 0,2 kg. Os tratamentos foram compostos por quatro dietas: D0- silagem de milho + concentrado sem farinha de algas; D2- silagem de milho + concentrado + 2% de farinha de algas; D4- silagem de milho + concentrado + 4% de farinha de algas e D6- silagem de milho + concentrado + 6% de farinha de algas. A relação volumoso:concentrado foi 40:60, compondo dietas com semelhantes teores proteicos (15%) e energéticos (3,3 Mcal de energia digestível/kg de matéria seca). Os dados foram avaliados num delineamento experimental inteiramente casualizado, com quatro tratamentos e oito repetições. Os resultados foram submetidos à análise de variância e regressão, com os graus de liberdade desdobrados em efeitos linear, quadrático e cúbico. As inclusões de farinha de algas marinhas influenciaram (P<0,05) o consumo de nutrientes, com efeito linear decrescente para matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), fibra insolúvel em detergente neutro (FDN), fibra insolúvel em detergente ácido (FDA) e energia bruta (EB), e crescente para a fração EE (extrato etéreo). Da mesma forma, a digestibilidade dos nutrientes foi influenciada (P<0,05) pelas inclusões de farinha de algas marinhas, com efeito linear decrescente para as variáveis MS, MO, FDN, FDA, CHOT e CNF. A digestibilidade da fração EE apresentou efeito (P<0,05) linear crescente e a PB, efeito (P<0,05) quadrático. O peso do fígado dos animais aumentou (P<0,05) linearmente. As medidas das papilas ruminais dos cordeiros diminuíram (P<0,05) com as inclusões de farinha de algas marinhas nas dietas. Na avaliação do desempenho, foram observados efeitos (P<0,05) lineares crescente para dias de confinamento (DC) e decrescente para ingestão de matéria seca (IMS) e ganho médio diário de peso (GMDP). A conversão alimentar (CA) dos cordeiros não foi alterada (P>0,05). Os rendimentos da carcaça e dos cortes comerciais, as perdas por resfriamento e as medidas do músculo longissimus não foram alteradas (P>0,05). Não foram observadas diferenças significativas para as características físico-químicas da carne dos cordeiros. Na análise sensorial, houve efeito (P<0,05) linear decrescente para os atributos odor, sabor e na intenção de compra dos consumidores. As inclusões de farinha de algas marinhas nas dietas não alteraram (P>0,05) a composição centesimal da carne dos cordeiros. Foram observados efeitos (P<0,05) lineares decrescente no teor de colesterol e crescente para a oxidação lipídica da carne dos animais. No perfil de ácidos graxos houve aumento (P<0,05) na concentração dos ácidos 16:0, 17:0, 18:1 n-7, 18:2 c9t11, 20:5 n-3 e 22:6 n-3 e redução dos ácidos graxos 18:0, 18:1 n-9 e 18:2 n-6. As concentrações de ácidos graxos monoinsaturados (AGMI), ácidos graxos poli-insaturados (AGPI) e as relações AGMI:AGS e AGPI:AGS apresentaram efeito (P<0,05) quadrático. Houve efeitos (P<0,05) linear decrescente no total de ácidos graxos n-6 e quadrático para os da família n-3 e na relação n-6:n-3. A atividade das enzimas dessaturase 16 diminuiu (P<0,05) linearmente. Foi observado efeito quadrático (P<0,05) para a atividade da enzima elongase, nos índices de aterogenicidade e trombogenicidade, nas concentrações de ácidos graxos hiper e hipocolesterolêmicos e na relação h:H. A farinha de algas marinhas não se mostrou uma alternativa interessante, uma vez que consumo e a digestibilidade dos nutrientes é prejudicada, acarretando em menor desempenho dos animais. O incremento de ácido palmítico na carne dos cordeiros sobrepõem todos os benefícios inerentes aos ácidos graxos da família n-3.
This study was undertaken to evaluate the performance, nutrient digestibility, quantitative parameters of carcass, and qualitative and sensory parameters of meat in feedlot-finished lambs fed diets with increasing levels of marine algae meal inclusion. Thirty-two newly weaned 60-day-old uncastrated Ile de France lambs weighing 20.0 ± 0.2 kg body weight were used. The animals were housed in invidual pens and slaughtered at 35.0 ± 0.2 kg. The treatments were composed of four diets: D0- corn silage + concentrate without algae meal; D2- corn silage + concentrate + 2% algae meal; D4- corn silage + concentrate + 4% algae meal; and D6- corn silage + concentrate + 6% algae meal. The roughage:concentrate ratio was 40:60, and diets were formulated with similar protein (15%) and energy (3.3 Mcal digestible energy/kg DM) contents. The data were evaluated in a completely randomized experimental design, with four treatments and eight replications. The results were submitted to analysis of variance and regression. The algae meal contente were broken down into linear, quadratic and cubic effects. Marine algae meal levels influenced (P<0.05) nutrient intake, with a linear decrease seen in DM, OM, CP, NDF, ADF and GE; the opposite effect was found on EE, which increased linearly. Likewise, nutrient digestibility was influenced (P<0.05) by the algae meal levels, which linearly reduced the digestibilities of DM, OM, NDF, ADF, TC, and NFC. The digestibility of the EE fraction rose linearly (P<0.05), whereas that of CP responded (P<0.05) quadratically. Liver weight increased (P<0.05) linearly. Rumen papillary measurements in the lambs decreased (P<0.05) as the meal was included in the diet. In the performance trial, a linear increase (P<0.05) was observed for days in the feedlot, while dry matter intake and average daily weight gain decreased linearly. Feed conversion did not change (P>0.05). The yields of carcass and primal cuts, chilling losses, and longissimus muscle measurements did not differ (P>0.05). Likewise, no significant differences were observed for the lamb meat physicochemical traits. Sensory analysis revealed a linear (P<0.05) decrease in the attributes aroma, taste, and consumers’ purchase intention. Dietary inclusion of marine algae meal did not influence (P>0.05) the centesimal composition of lamb meat. The meat cholesterol content decreased linearly (P<0.05) and lipid oxidation responded in the opposite direction, increasing linearly. In the fatty acid profile, increasing linear (P<0.05) effects were found for the concentrations of 16:0, 17:0, 18:1 n-7, 18:2 c9t11, 20:5 n-3, and 22:6 n-3 fatty acids, while 18:0, 18:1 n-9, and 18:2 n-6 decreased linearly. Concentrations of MUFA and PUFA and MUFA:SFA and PUFA:SFA ratios had a quadratic response (P<0.05). The treatments elicited a linear decrease (P<0.05) in total n6 fatty acids, while fatty acids of the n-3 family and n-6:n-3 ratio responded quadratically. The desaturase-16 enzyme activity declined linearly (P<0.05). Elongase activity, atherogenicity and thrombogenicity indices, hyper- and hypo-cholesterolemic fatty acid concentrations, and h:H ratio responded quadratically (P<0.05). The marine algae meal did not show an interesting alternative, since consumption and the digestibility of the nutrients is impaired, leading to lower performance of the animals. The increase of palmitic acid in the lamb meat overlies all the benefits inherent to the n-3 family of fatty acids.
This study was undertaken to evaluate the performance, nutrient digestibility, quantitative parameters of carcass, and qualitative and sensory parameters of meat in feedlot-finished lambs fed diets with increasing levels of marine algae meal inclusion. Thirty-two newly weaned 60-day-old uncastrated Ile de France lambs weighing 20.0 ± 0.2 kg body weight were used. The animals were housed in invidual pens and slaughtered at 35.0 ± 0.2 kg. The treatments were composed of four diets: D0- corn silage + concentrate without algae meal; D2- corn silage + concentrate + 2% algae meal; D4- corn silage + concentrate + 4% algae meal; and D6- corn silage + concentrate + 6% algae meal. The roughage:concentrate ratio was 40:60, and diets were formulated with similar protein (15%) and energy (3.3 Mcal digestible energy/kg DM) contents. The data were evaluated in a completely randomized experimental design, with four treatments and eight replications. The results were submitted to analysis of variance and regression. The algae meal contente were broken down into linear, quadratic and cubic effects. Marine algae meal levels influenced (P<0.05) nutrient intake, with a linear decrease seen in DM, OM, CP, NDF, ADF and GE; the opposite effect was found on EE, which increased linearly. Likewise, nutrient digestibility was influenced (P<0.05) by the algae meal levels, which linearly reduced the digestibilities of DM, OM, NDF, ADF, TC, and NFC. The digestibility of the EE fraction rose linearly (P<0.05), whereas that of CP responded (P<0.05) quadratically. Liver weight increased (P<0.05) linearly. Rumen papillary measurements in the lambs decreased (P<0.05) as the meal was included in the diet. In the performance trial, a linear increase (P<0.05) was observed for days in the feedlot, while dry matter intake and average daily weight gain decreased linearly. Feed conversion did not change (P>0.05). The yields of carcass and primal cuts, chilling losses, and longissimus muscle measurements did not differ (P>0.05). Likewise, no significant differences were observed for the lamb meat physicochemical traits. Sensory analysis revealed a linear (P<0.05) decrease in the attributes aroma, taste, and consumers’ purchase intention. Dietary inclusion of marine algae meal did not influence (P>0.05) the centesimal composition of lamb meat. The meat cholesterol content decreased linearly (P<0.05) and lipid oxidation responded in the opposite direction, increasing linearly. In the fatty acid profile, increasing linear (P<0.05) effects were found for the concentrations of 16:0, 17:0, 18:1 n-7, 18:2 c9t11, 20:5 n-3, and 22:6 n-3 fatty acids, while 18:0, 18:1 n-9, and 18:2 n-6 decreased linearly. Concentrations of MUFA and PUFA and MUFA:SFA and PUFA:SFA ratios had a quadratic response (P<0.05). The treatments elicited a linear decrease (P<0.05) in total n6 fatty acids, while fatty acids of the n-3 family and n-6:n-3 ratio responded quadratically. The desaturase-16 enzyme activity declined linearly (P<0.05). Elongase activity, atherogenicity and thrombogenicity indices, hyper- and hypo-cholesterolemic fatty acid concentrations, and h:H ratio responded quadratically (P<0.05). The marine algae meal did not show an interesting alternative, since consumption and the digestibility of the nutrients is impaired, leading to lower performance of the animals. The increase of palmitic acid in the lamb meat overlies all the benefits inherent to the n-3 family of fatty acids.
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Palavras-chave
ácidos graxos, alimento alternativo, ômega-3, alternative feed, fatty acids, Ile de France, n-3