1,721,018 research outputs found
Equipment for the separate collection of faeces and urine from lactating cows: description and variability of experimental data
No full textIn vitro rumen fermentation of feed substrates added with chestnut tannins or an extract from Stevia rebaudiana Bertoni
Full text linkRumen fermentation parameters and microbiota were evaluated in 3 in vitro rumen fermentation experiments after addition of chestnut tannins (CT) or an extract from Stevia rebaudiana Bertoni (SB) to substrates. A control (CTR) substrate was fermented alone or added with 1.5% of CT or SB extracts in a batch culture system (Exp. 1, fermentation in 500 mL for 24 h) and in a subsequent continuous culture system (Exp. 2, fermentation in 2 L bottles for 9 d). Experiment 3 used the fermentation system of Exp. 1 and tested 7 doses of each extract added to CTR (additions of 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2% and 1.4% for 48 h). The addition of CT lowered (P < 0.01) the in vitro rumen ammonia concentration in all experiments and reduced the protozoa counts in Exp. 1 (P < 0.05). In contrast, the SB extract did not modify the ammonia concentrations, but significantly lowered the protozoa counts in all 3 experiments (reduction of 47% and 20% in Exp. 1 and 2, P < 0.05; and a quadratic reduction in Exp. 3, R2 = 0.63, P < 0.01). Neither extract affected the fermentation in terms of gas production (Exp. 1 and 3) nor volatile fatty acids (VFA) yield (Exp. 1 and 2), if we exclude a reduction at the highest CT concentration in Exp. 3. Changes in VFA profile were induced by CT and were limited to reductions in the iso-valerate (P < 0.01, in Exp. 2) and iso-butyrate levels (P < 0.01, Exp. 2). The CT increased the abundance of Prevotella ruminicola and Selenomonas ruminantium and decreased that of Ruminobacter amylophilus (P < 0.01, P < 0.05 and P < 0.05, respectively). The SB extract increased the relative abundance of Treponema saccarophylum (P < 0.05). Both of the studied substances had an impact on rumen metabolism, with SB reducing protozoa counts and CT lowering the rumen ammonia concentration. The effects of both extracts on the rumen were appreciable at low dietary doses, and the negative impacts on fermentation were limited to the reduction in protein degradation with the addition of CT
Income over feed cost as a selection index of performance tested Charolais and Limousin young bulls
No full textImpacts of rumen fluid, refrigerated or reconstituted from a refrigerated pellet, on gas production measured at 24h of fermentation
Full text linkRumen fluid is used as fresh inoculum for gas production fermentations to predict the nutritional value of feeds and rations for ruminants. However, collection of rumen fluid from animal donors is invasive, expensive, time consuming and results in fluids of variable quality. The general aim was to identify a procedure to manipulate rumen inoculum in order to facilitate its storage and transfer between laboratories. This strategy would also limit fluid collections from animals. Two experiments were completed based on gas production from graduated 100 mL glass syringe with five feeds as substrates. In experiment 1, the gas production and some fermentation parameters of fresh rumen fluids were compared with those preserved at 4 °C for 24, 48, 72 and 96 h. Refrigeration did not modify concentration of volatile fatty acids and pH, but ammonia in liquids refrigerated for 48–96 h was higher (P < 0.05) compared to fresh. In contrast, rumen fluid refrigeration for 24, 48 or 72 h did not depress gas production at 24 h, but it was lower at 96 h. In experiment 2, the rumen fluid was centrifugated at 13,000 x g and sedimented material (i.e., pellet) was refrigerated for 48 h at 4 °C. The asymptote of gas production kinetics from rumen fluid regenerated from the pellet was 8 % lower (P < 0.05) than that from fresh. However for 24 h gas production, the correlation between fresh liquid and pellet inoculum, calculated for five ingredients, was high (R2 = 0.94). Results support the use of rumen fluid preserved by refrigeration for up to 72 h, and rumen fluid reconstituted from refrigerated pellet, as an alternative to fresh. This would reduce the need for laboratories to maintain animal donors and/or frequently collect rumen fluid
Ereditabilità di alcune variabili ematochimiche e correlazioni fenotipiche e genetiche con l'attitudine alla produzione della carne nei bovini Pezzati Rossi
No full textEffetto del grado di frantumazione della granella di mais ceroso sulla degradabilità in vitro della sostanza organica
No full textEffetti associativi delle buccette d'uva e del silomais sul consumo alimentare e sull'utilizzazione digestiva
No full textRisultati del quinto e sesto ciclo di prove di progenie per l'attitudine alla produzione della carne dei tori Pezzati Rossi.
No full textFatty acid profile of table eggs from laying hens fed hempseed products: A meta-analysis
No full textAbstract
The type of dietary lipids consumed by laying hens affects the fatty acid (FA) profile of the eggs. This work analyzed the available scientific publications that examined the use of hempseed products (Cannabis sativa L. varieties with low concentration of tetrahydrocannabinol) on the fatty acid profiles of eggs produced by laying hens. The literature search was performed to identify publications that reported experiments, in which laying hens were fed hemp products (seeds, cakes, or oils). Fourteen eligible publications (49 dietary treatments) were identified that were published in international journals from 2005 to 2019. Most of the experimental diets (24 treatments) used whole hempseeds, about one-third of the diets examined low levels of hempseed oils, and 3 studies (7 treatments) examined hempseed cakes and meal. To summarize the results of the different experiments, the inclusions of hempseed products were converted into hempseed equivalents based on total fat concentration. The inclusion of hempseed products in the diet did not affect the total saturated FA concentration of the eggs, but it did decrease the monounsaturated FA content (R2 = 0.47) by about 115 mg/yolk for each 10% inclusion in the diet of hempseed products. Dietary hempseed also increased several polyunsaturated FA (PUFA) content of yolk. A 10% increase in the dietary hempseeds led to eggs that had 46 mg/yolk of α-linolenic acid (ALA, R2 = 0.86), 25% greater than the control diet (36 mg/yolk). The same inclusion rate of dietary hempseeds increased the γ-linolenic acid content by 1.7 mg/yolk (+28% relative to the basal level, R2 = 0.85), and increased the linoleic acid (LA) content by about 6%. The other ω-3 PUFA also increased (docosahexaenoic acid, R2 = 0.62, +33%; docosapentaenoic acid, R2 = 0.81, +51%; eicosapentaenoic acid, R2 = 0.60, +41%). For each 10% increase in the diet of hempseeds, the egg yolks had greater increases of ALA than LA, leading to a reduction in the ω-6:ω-3 (R2 = 0.66). In conclusion, diets for laying hens containing hemp products led to eggs that had increased PUFA and a reduction in the ω-6:ω-3
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