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Varying the dietary supply of C and N to manipulate the manure composition of water buffalo heifers in Oman
No full textOptimizing the composition of manure has the potential to reduce nutrient losses to the environment and to increase crop yields. In this study the effect of dietary ratios of carbon (C) to nitrogen (N) and neutral detergent fibre (NDF) to soluble carbohydrates (SC) on faeces composition of water buffalo heifers was assessed. Two digestibility trials were conducted with 12 animals each, fed one control and four test diets composed to achieve (1) high C/N and high NDF/SC ratios (HH), (2) low C/N and low NDF/SC ratios (LL), (3) high C/N and low NDF/SC ratios (HL) and (4) low C/N and high NDF/SC (LH) ratios. Faecal C/N ratios were generally lower than dietary C/N ratios, but the reduction was especially large for high C/N ratio diets (HH=55 %, HL=51 %). Faecal N concentration was positively correlated (r(2) = 0.6; P < 0.001) with N intake, but the increase in faecal N was more pronounced for diets that supplied low amounts of N. Faecal NDF concentration was positively related to NDF intake (r(2) = 0.42; P < 0.001), as well as the faecal C/N ratio (r(2) = 0.3; P < 0.001). Results demonstrate that C/N ratio and NDF concentration of buffalo manure were affected by diet composition. Diets with high C/N ratio and low NDF/SC ratio are preferable with regard to manure quality, but may not satisfy the nutritional requirements of producing animals, since N concentration in these diets was low and fibre concentration simultaneously high
Particulate Rate of Passage and Faeces Quality of Water Buffalo Fed Diets Varying in Concentrations of Nitrogen and Structural and Non-structural Carbohydrates
No full textEffects of diet concentrations of carbon (C), nitrogen (N), neutral detergent fibre (NDF) and soluble carbohydrates (SC) on digesta passage and faeces quality were studied in water buffalo. Rhodes grass hay, soybean meal, wheat bran and maize were combined for a high C/N - high NDF/SC ratio (HH), low C/N - low NDF/SC ratio (LL), high C/N - low NDF/SC ratio (HL) and low C/N - high NDF/SC (LH) ratio. Diets were offered to four heifers each during 21 days adaptation and 7 days experimentation. When the experiment started animals received a pulse dose of ytterbium-marked fibre; particle passage was derived from a one-compartment age-dependent Gamma-2 model. Diet N concentration significantly affected faecal concentration of N (r= 0.82, P= 0.83, P<0.001). Ruminal particle passage (gimel) ranged from 0.033 h(-1) (HL) to 0.043 h(-1) (LL), and was significantly related to the N (r= -0.84, P<0.001) and C (r= -0.57, P<0.05) concentration of the diet. Total tract retention time was shortest (P <0.001) for diet LL. The results indicate that differences in diet quality entail significant quality differences in buffalo dung that are not annihilated by the species' very efficient digestion of fibrous feeds.Deutsche Forschungsgemeinschaf
Particulate Rate of Passage and Faeces Quality of Water Buffalo Fed Diets Varying in Concentrations of Nitrogen and Structural and Non-structural Carbohydrates
No full textEffects of diet concentrations of carbon (C), nitrogen (N), neutral detergent fibre (NDF) and soluble carbohydrates (SC) on digesta passage and faeces quality were studied in water buffalo. Rhodes grass hay, soybean meal, wheat bran and maize were combined for a high C/N - high NDF/SC ratio (HH), low C/N - low NDF/SC ratio (LL), high C/N - low NDF/SC ratio (HL) and low C/N - high NDF/SC (LH) ratio. Diets were offered to four heifers each during 21 days adaptation and 7 days experimentation. When the experiment started animals received a pulse dose of ytterbium-marked fibre; particle passage was derived from a one-compartment age-dependent Gamma-2 model. Diet N concentration significantly affected faecal concentration of N (r= 0.82, P= 0.83, P<0.001). Ruminal particle passage (gimel) ranged from 0.033 h(-1) (HL) to 0.043 h(-1) (LL), and was significantly related to the N (r= -0.84, P<0.001) and C (r= -0.57, P<0.05) concentration of the diet. Total tract retention time was shortest (P <0.001) for diet LL. The results indicate that differences in diet quality entail significant quality differences in buffalo dung that are not annihilated by the species' very efficient digestion of fibrous feeds.Deutsche Forschungsgemeinschaf
Varying the dietary supply of C and N to manipulate the manure composition of water buffalo heifers in Oman
No full textOptimizing the composition of manure has the potential to reduce nutrient losses to the environment and to increase crop yields. In this study the effect of dietary ratios of carbon (C) to nitrogen (N) and neutral detergent fibre (NDF) to soluble carbohydrates (SC) on faeces composition of water buffalo heifers was assessed. Two digestibility trials were conducted with 12 animals each, fed one control and four test diets composed to achieve (1) high C/N and high NDF/SC ratios (HH), (2) low C/N and low NDF/SC ratios (LL), (3) high C/N and low NDF/SC ratios (HL) and (4) low C/N and high NDF/SC (LH) ratios. Faecal C/N ratios were generally lower than dietary C/N ratios, but the reduction was especially large for high C/N ratio diets (HH=55 %, HL=51 %). Faecal N concentration was positively correlated (r(2) = 0.6; P < 0.001) with N intake, but the increase in faecal N was more pronounced for diets that supplied low amounts of N. Faecal NDF concentration was positively related to NDF intake (r(2) = 0.42; P < 0.001), as well as the faecal C/N ratio (r(2) = 0.3; P < 0.001). Results demonstrate that C/N ratio and NDF concentration of buffalo manure were affected by diet composition. Diets with high C/N ratio and low NDF/SC ratio are preferable with regard to manure quality, but may not satisfy the nutritional requirements of producing animals, since N concentration in these diets was low and fibre concentration simultaneously high
Effects of quebracho tannin extract (Schinopsis balansae Engl.) and activated charcoal on nitrogen balance, rumen microbial protein synthesis and faecal composition of growing Boer goats
No full textUnder irrigated arid conditions, organic fertiliser rich in slowly decomposable nitrogen (N) and carbon (C) is needed for soil fertility maintenance. Feeding ruminants with condensed tannins will lower ruminal protein degradation, reduce urinary N excretion and might increase the faecal fraction of slowly decomposable N. Supplementation with activated charcoal (AC) might enrich manure with slowly degrading C. Therefore, we investigated the effects of feeding quebracho tannin extract (QTE) and AC on the N balance of goats, the efficiency of microbial protein synthesis in the rumen (EMPS) and the composition of faeces. The feeding trial comprised three periods; in each period, 12 male Boer goats (28 +/- 3.9kg live weight) were assigned to six treatments: a Control diet (per kg diet 500g grass hay and 500g concentrate) and to further five treatments the Control diet was supplemented with QTE (20g and 40g/kg; diets QTE2 and QTE4, respectively), with AC (15g and 30g/kg, diets AC1.5 and AC3.0, respectively) and a mixture of QTE (20g/kg) plus AC (15g/kg) (diet QTEAC). In addition to the N balance, EMPS was calculated from daily excretions of purine derivatives, and the composition of faecal N was determined. There was no effect of QTE and AC supplementation on the intake of organic matter (OM), N and fibre, but apparent total tract digestibility of OM was reduced (p=0.035). Feeding QTE induced a shift in N excretion from urine to faeces (p0.001) without altering N retention. Total N excretion tended to decrease with QTE treatments (p=0.053), but EMPS was not different between treatments. Faecal C excretion was higher in QTE and AC treatments (p=0.001) compared with the Control, while the composition of faecal N differed only in concentration of undigested dietary N (p=0.001). The results demonstrate that QTE can be included into diets of goats up to 40g/kg, without affecting N utilisation, but simultaneously increasing the excretion of slowly decomposable N and C fractions. Feeding AC up to 30g/kg of the diet increases slowly degradable faecal C concentration, without negative effects on N metabolism of goats
Relationships between feeding and microbial faeces indices in dairy cows at different milk yield levels.
No full textA study was carried out to gain quantitative information on the diet-dependent faecal microbial biomass of dairy cows, especially on the biomass fractions of fungi, Gram-positive (G+) and Gram-negative (G-) bacteria. Groups of high-yield, low-yield and non-lactating cows were investigated at four different farms. A mean faecal microbial biomass C (MBC) concentration of 33.5 mg g-1 DM was obtained by the chloroform fumigation extraction method. This is similar to a mean microbial C concentration of 31.8 mg g-1 DM, which is the sum of bacterial C and fungal C, estimated by cell-wall derived muramic acid (MurN) and fungal glucosamine (GlcN), respectively. However, the response of these two approaches to the feeding regime was contradictory, due to feeding effects on the conversion values. The higher neutral detergent fibre (NDF) and acid detergent fibre (ADF) concentrations in the non-lactating group led to higher (P < 0.05) concentrations of cellulose and lignin in their faeces in comparison with the lactating cows. This change in faecal chemical composition in the non-lactating group was accompanied by usually higher ratios of G+/G- phospholipid fatty acids (PLFA), ergosterol/MBC and fungal C/bacterial C. Although bacteria dominate the faecal microbial biomass, fungi contribute a considerable mean percentage of roughly 20% to the faecal microbiome, according to PLFA and amino sugar data, which requires more attention in the future. Near-infra red spectroscopic estimates of organic N and C fractions of cow faeces were able to model microbial biomarkers successfully, which might be useful in the future to predict its N2O emission potential and fertilizer value
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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