Effect of increasing doses of chitosan to grazing beef steers on the relative population and transcript abundance of Archaea and cellulolytic and amylolytic bacterias.

This paper aims to investigate the influence of increasing chitosan doses on the relative proportion and abundance of cellulotytic, amylolytic bacteria, and Archaea transcripts for grazing cattle. Five rumen cannulated crossbread steers [3.6 months and 300 ± 25 kg body LW (live weight), mean ± standard deviation] were used in a 5 × 5 latin square design, randomly assigned to treatment sequence containing chitosan added to 0, 400, 800, 1200, or 1600 mg/kg concentrate. There was the effect of chitosan on the population of Fibrobacter succinogenes, Ruminococcus albus, and Archaea. The lowest population of these bacteria of 576.60 mg/kg DM (dry matter), 1010.40 mg/kg DM, and 634.80 mg/kg DM were noted when chitosan was added at levels of 3.87, 4.16, and 3.52. Except for Ruminococcus albus, which was not affected by increasing chitosan doses, supplementation of this additive in the concentrate quadratically increased the relative abundance of Fibrobacter succinogenes and Archaea Supplemental 740 mg CHI/kg concentrate for grazing steers receiving concentrate at 150 grams/100 kg LW is recommended to promote minimal effect on the relative population and abundance of cellulolytics and amylomatics and to restrict Archaea growth.

Degradability, in vitro fermentation parameters, and kinetic degradation of diets with increasing levels of forage and chitosan.

Chitosan is the second most important natural biopolymer in the world, extracted from crustaceans, shrimps, and crabs and can modulate rumen fermentation. Our hypothesis is that the addition of chitosan alters the fermentation patterns of different diets for ruminants. This study aimed to evaluate the effects of different levels of chitosan and forage on in vitro dry degradation kinetics and fermentation in a gas production system. The chitosan levels (0, 1625, 3,500, or 7,500 mg/kg of dry matter [DM]) were arranged in a completely randomized block design, and for in vitro ruminal fermentation assay, we used a split splot arrangement. Into the incubator, all chitosan levels were distributed in the four jars, and the forage levels varying on 100, 65, 50, 35, and 20 on DM basis. There was an interaction effect for chitosan and forage levels (P ≤ 0.05) on IVDMD; IVOMD. IVDCP and IVDNDF. Chitosan negatively affected IVDMD in all roughage levels evaluated. The pH and ammonia concentration present effect only for roughage levels and incubation hours. The chitosan did not change (P = 0.3631) the total short-chain fatty acid concentration (overall mean = 21.19 mmol/L) and the C2:C3 ratio (overall mean = 5.85). The IVDCP showed the same decreasing quadratic behavior (P < 0.0001). The increasing chitosan addition increases (P < 0.0001) the gas production and decreases (P < 0.0001) the lag time (parameter C) of diets with greater concentrate participation, characterizing greater efficiency in the degradability of the diet, confirming its potential use in diets for ruminants. Chitosan changes in vitro dry degradation kinetics and fermentation at the minimum dose of 1,722 mg/kg DM for all diets. The roughage level influenced the in vitro nutrients degradability and cumulative gas production.

Fatty acids profile, atherogenic and thrombogenic health lipid indices in the meat of lambs that received canola grain / Perfil de ácidos graxos, índices de lipídios aterogênicos e trombogênicos em carne de cordeiros alimentados com grãos de canola

This study evaluated the fatty acid composition and qualitative characteristics of meat from lambs feed in feedlot with increasing levels of canola grain. Meat obtained from 27 lambs fed 0, 8 and 16% inclusion of canola grain were analyzed. There was a reduction in the content of saturated fatty acids (SFA): lauric, heptadecanoic, and stearic; and unsaturated fatty acids (UFA): palmitoleic, oleic, and eicosatrienoic, with the increasing levels of canola grain. There was a linear reduction for the ω3 acid and the ω3: ω6 ratio, while the ω6: ω3 ratio increased. But the values observed for this ratio (ω6: ω3) were lower than 4, which is considered a satisfactory value. There was a slight increase (~2%) for the thrombogenicity index and atherogenicity index with the inclusion of canola grain. There was a reduction in the hypocholesterolemic: hypercholesterolemic ratio, with mean values of 2.09 for the diet with 0% inclusion, and 2.06 for 8 and 16% inclusion of canola. Although the inclusion of canola grain for lambs decreased the content of some UFA, reflecting alterations in the correlated nutritional properties, there is a reduction of SFA. The results for instrumental analysis, proximate composition, and sensory acceptance of the lamb meat were similar among the treatments.(AU)

Objetivou-se avaliar a composição dos ácidos graxos e as características qualitativas da carne de cordeiros terminados com níveis crescentes de canola grão na dieta. Foram estudadas amostras de carne provenientes de 27 cordeiros, confinados por 45 dias e alimentados com 00, 08 e 16% de inclusão de canola grão. Houve efeito para os ácidos graxos saturados (AGS): laurico, heptadecanoico e esteárico; ácidos graxos monoinsaturados (AGMI): palmitoleico e oleico; e ácidos graxos polinsaturados (AGPI): eicosatrienoico. Estes ácidos reduziram à medida que os níveis da canola grão aumentaram. Para os AGMI, houve efeito com maior concentração no músculo dos cordeiros alimentados sem a canola grão (49,80%). Houve uma redução linear para o ácido ω3 e para a relação ω3:ω6, enquanto que a relação ω6:ω3 aumentou. A canola grão influenciou o índice de aterogenicidade, com média de 0,57 para o tratamento com 0% de inclusão e 0,58 para os tratamentos com 8% e 16% de inclusão. Observou-se aumento linear para o índice de trombogenicidade com a inclusão da canola grão, cujas médias foram, respectivamente, 0,16, 0,17 e 0,18 para os tratamentos 0%, 8% e 16% de inclusão. Houve redução para a relação hipocolesterolêmicos-hipercolesterolêmicos, com médias de 2,09 para a dieta com 0% de inclusão, e 2,06 para 8% e 16% de inclusão da canola em grão na dieta. A canola grão não influenciou a análise instrumental, composição centesimal e atributos sensoriais da carne.(AU)