Sources of omega-6 fatty acids do not alter the rumen degradation and transit of fibre from dairy cow diets
Journal Title: Journal of Animal and Feed Sciences - Year 2013, Vol 22, Issue 4
Abstract
The objective of this study was to evaluate the behaviour of fibre in the digestive tract on the basis of the passage kinetics of forage and concentrate particles in cows fed different omega-6 fatty-acid sources. The scientific hypothesis of this study was that omega-6 fatty acids do not interfere with the digestion of fibre in the diets of dairy cows. Five primiparous lactating Holstein cows were used in the experiment. The experimental diets were: control (C), ground soyabean (GS), cottonseed (CS), soyabean oil (SO), calcium salts of fatty acids (CSFA). The global mean estimates for the parameters of passage rate (γ) were 0.038 and 0.055 h–1 for forage and concentrate, respectively. The only significant effect with respect to the passage rate was a high negative correlation between the concentrate passage rate and dry matter intake. There was less undegradable neutral detergent fibre (NDF) in treatments without added lipid. Dietary supplementation with lipid sources does not alter the kinetic parameters of roughage and concentrate particle passage or in vitro NDF degradation. Sources of omega-6 fatty acids do not alter the rumen degradation and transit of fibre.
Authors and Affiliations
V. P. Bettero, J. R. Gandra, H. V. N. Nunes, J. E. Freitas Jr, R. V. Barletta, M. V. Carvalho, E. Detmann, J. C. Pereira
The nutritional value of narrow-leafed lupin (Lupinus angustifolius) for broilers
The nutritional value of four cultivars of Lupinus angustifolius L. seeds was investigated. The experiment was conducted on 50 male 16-day-old Ross 308 chickens. The birds were randomly allocated to five dietary treatmen...
Evaluation of methods used in vivo to estimate the transfer of amino acids and other substrates into the cells of mammary gland
mino acids and other substrates into the cell in vivo using arteriovenous concentration difference and volume blood flow data with their recalculation according to kinetic model of the system: capillary - interstitium -...
Postprandial oxidative losses of dietary leucine depend on the time interval between consecutive meals: a model study with rats
Postprandial oxidative losses of egg white-bound [1-13C]-leucine were studied as 13C recovery in the breath of rats in relation to different time intervals between two meals. Male Wistar rats (n = 48; 68.3 ± 5.9 g) divid...
Modelling of individual lactation curves of Tunisian Holstein-Friesian cows for milk yield, fat, and protein contents using parametric, orthogonal and spline models
Different equations were employed to directly model individual lactation curves of Tunisian Holstein-Friesian cows using 260 241 test day records for milk yield, fat, and protein contents. Eleven mathematical models were...
Effects of supplementing a mixed diet with echium (Echium plantagineum) oil on methanogenesis in a rumen simulation system
The rumen simulation technique (RUSITEC) was used to evaluate the effect of two levels of echium (Echium plantagineum) oil (EO) on methano-genesis. Treatments comprised: control (commercial total mixed ration for lactati...