Prediction of rabbit caecal fermentation characteristics from faeces by in vitro gas production technique: roughages

To find equations able to estimate the fermentation characteristics of the caecum from that of faeces, caecal content and faeces of 10 hybrid Hyla rabbits were used as inocula for an in vitro gas production trial. About 1 g of 12 roughages, 11 hays (ryegrass, alfalfa, sulla, oat, vetch, sulla-lolium, vetch-oat, sulla-oat, clover, ryegrass-clover, sulla-vetch-oat) and a wheat straw, was weighed, in triplicate per inoculum, in 120-ml flasks; 75 ml of anaerobic medium and 4 ml of reducing solution were added and the flasks were placed at 39 degrees C. Caecal content and faeces were diluted respectively 1:2 (CI) and 1:8 (FI) with anaerobic medium and were introduced into their respective flasks (10 ml). Gas production was recorded 20 times at 2-24 h intervals throughout fermentation (120 h). The fermentation characteristics (i.e. degraded organic matter, OMd; potential gas production, A; maximum fermentation rate, R(max); volatile fatty acid, VFA; ammonia, NH(3)) were studied by inocula and substrates. The two inocula did not differ in OMd but CI produced significantly higher gas (A, 213.1 vs. 199.4 ml/g, respectively, for CI and FI, p < 0.01) in less time (R(max), 3.08 vs. 2.24 ml/h, respectively, for CI and FI, p < 0.01). CI also produced higher levels of total VFA (57.86 vs. 46.70 mmol/g OM, respectively, for CI and FI, p < 0.01) and showed a higher branched chain proportion (0.023 vs. 0.018, respectively, for CI and FI, p < 0.01). For some parameters (as OMd pH and propionate) the equations for the estimation of caecal fermentation characteristics from that of faeces were accurate (R(2) > 0.8828) and reliable (CV < 10.78%) suggesting that faeces can be successfully used for the estimation of these parameters.     

Effects of monensin on growth performance of beef heifers consuming warm-season perennial grass and supplemented with sugarcane molasses

Tropical Animal Health and Production - The objective of this study was to evaluate the effects of monensin on performance of beef heifers fed warm-season forages. Brangus heifers...     

Multivariate analysis of CPMAS 13C-NMR spectra of soils and humic matter as a tool to evaluate organic carbon quality in natural systems

A series of humic and fulvic acids isolated from different sources, size‐fractions separated from a humic acid, and three soils of different origin were subjected to CPMAS ¹³C‐NMR spectroscopy to obtain the distribution of their carbon contents. The relative areas of chemical shift regions in NMR spectra were used to apply a principal component analysis (PCA) to the three sets of samples. The multivariate analysis was successful in efficiently differentiating samples on the basis of the quality of their organic carbon content. The PC biplots based on two principal components distinguished objectively among samples as accurately as it was possible to do by subjective qualitative evaluation of the original spectra. In the case of the soils, a discriminant analysis (DA) was applied to build a classification model that allowed the validation of the three soils according to their origin. Percentage of validation in the classification model is expected to increase when a large number of NMR spectra are accumulated and/or the concentration of organic carbon in samples is enhanced. The multivariate analyses described are likely to become a useful tool to increase the importance of CPMAS ¹³C‐NMR spectra in the appraisal of natural organic matter variations in heterogeneous natural systems.     

Preslaughter Anesthesia with Lippia alba Essential Oil Delays the Spoilage of Chilled Rhamdia quelen

This study evaluated whether anesthesia with essential oil (EO) of Lippia alba (300 mg L^?1 for 4 min) prior to electronarcosis (128 V m^?1 × 300 Hz for 5 s) or hypothermia (ice/water slurry) could delay fish spoilage during chilled storage of whole fish. Silver catfish (Rhamdia quelen) were subjected to two different pre-stunning treatments (water or anesthesia with EO of L. alba) followed by two different stunning procedures (hypothermia or electrical stunning), yielding four groups (n = 32/group): water (control) + hypothermia, water (control) + electrical stunning, EO of L. alba + hypothermia, and EO of L. alba + electrical stunning. After stunning, fish were slaughtered by percussion and stored in ice. Preslaughter anesthesia with the EO of L. alba extended fish shelf life by delaying the loss of freshness (nucleotide degradation), growth of Enterobacteriaceae, and fish deterioration (sensory evaluation). Such preservative effect was most remarkable for fish that were subsequently submitted to electrical stunning, as they had the lowest demerit scores and greatest shelf life in the sensory evaluation. Our results showed that preslaughter anesthesia with EO of L. alba followed by electrical stunning can delay the loss of freshness and extend fish shelf life during chilled storage.     

Influence of Electronarcosis on Behavioral Responses,Blood Markers,and Fillet Properties of Silver Catfish (Rhamdia quelen)

Behavioral responses, blood markers, and fillet properties were investigated after silver catfish exposure to different electric field strengths, frequency, and duration of electric current in the preslaughter stunning. All combinations of electric fields and frequencies were able to stun fish. Longer apparent stun was obtained at the intermediate electrical frequencies. High electric field strength detracted the texture of fillets. At least 5 s was required to stun fish, and longer exposure to electrical current did not prolong the apparent stun or damage fillet properties. Results indicate that silver catfish are relatively resistant to electronarcosis.     

In vitro fermentation patterns and methane production of sainfoin (Onobrychis viciifolia Scop.) hay with different condensed tannin contents

Sainfoin (Onobrychis viciifolia Scop.) is a perennial legume recently reappraised for some positive characteristics leading to highly satisfactory animal performance. Sainfoin’s characteristics may be partly explained by the presence of moderate levels of condensed tannins (CTs) able to protect dietary protein from microbial degradation in the rumen. Decreased CH₄ emissions have been reported for ruminants consuming CT‐containing forage. The aim of this study was to evaluate the effects of CT content on the in vitro fermentation characteristics and kinetics and methane production of four samples of O. viciifolia cut at different phenological stages. Sainfoin hays and one sample of alfalfa hay were incubated at 39°C in anaerobiosis using the in vitro gas production technique. The chemical composition, tannin content and fermentation characteristics and kinetics of sainfoin samples were significantly affected by phenological stage. After 48 h, the CH₄ production in sainfoin hays showed a tendency to increase with the advancement of phenological stage [from 38·6 to 49·8 mL g⁻¹ of degraded organic matter (OM)]. The best period to cut sainfoin for hay making is between early and late flowering, when the forage combines high OM digestibility, low CH₄ production and more efficient microbial fermentation.