کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2420757 1552466 2008 21 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of grass regrowth interval on intake, rumen digestion and nutrient flow to the omasum in beef cattle
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم دامی و جانورشناسی
پیش نمایش صفحه اول مقاله
Effect of grass regrowth interval on intake, rumen digestion and nutrient flow to the omasum in beef cattle
چکیده انگلیسی

The effect of increasing grass regrowth interval (RI) (28 days vs. 38 days (d)) on zero-grazed intake, rumen fermentation, in situ degradability, rumen digesta kinetics and nutrient flow to the omasum, was determined in six ruminally cannulated Holstein-Friesian steers in a 2 × 2 cross-over design experiment. Digesta kinetics was determined using the rumen evacuation technique and omasal flow was estimated using Co-EDTA, Yb-acetate and indigestible neutral detergent fibre (INDF) as digesta flow markers and purine bases as microbial markers. Increasing RI had no effect (P>0.05) on dry matter intake (DMI), total volatile fatty acid (VFA) concentration or molar proportions of VFA in the rumen but reduced (P<0.05) rumen ammonia nitrogen (N) concentrations. Rumen digestion and flow to the omasum of organic matter (OM), neutral detergent fibre (NDFom) and N did not differ (P>0.05) between the RI treatments. A higher proportion (P<0.05) of NDFom digestion occurred in the rumen with the 28 d than the 38 d RI treatment. There was no effect (P>0.05) of RI on microbial N flow or on efficiency of microbial nitrogen synthesis but the flow of non-ammonia non-microbial N was reduced (P<0.05) with the 38 d compared to the 28 d RI treatment. The digestion rate (kd), derived from the rumen evacuation technique, of DM and OM (P<0.05), and NDFom and DNDFom (P<0.01) decreased with increased RI. These results indicate that increasing the RI of a perennial ryegrass-based sward by 10 d from 28 to 38 d in spring/early summer had relatively little or no adverse effects on DMI, rumen fermentation and rumen or total tract digestion of OM and NDFom of growing beef cattle but reduced ammonia N levels in the rumen, potentially reducing nitrogen excretion to the environment.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Animal Feed Science and Technology - Volume 146, Issues 1–2, 15 September 2008, Pages 21–41
نویسندگان
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