Potential of coffee straw biochal as a substrate conditioner in seed lettuce and sorghum germination and vigority.

The use of residues from coffee production to obtain biochar is a sustainable approach, which aims to minimize the environmental impact of these materials. In this study, the effect of adding coffee straw biochar on the physiological quality of lettuce and sorghum seeds was investigated. Thus, the objective of this work was to study the effect of adding different concentrations of coffee biochar in the substrate composition on the physiological quality of lettuce (Lactuca sativa) and sorghum (Sorghum bicolor) seeds. The experimental design used was completely randomized, with five concentrations of biochar (0; 7.5; 15; 30 and 60%), conducted with four replications of 25 seeds. The use of biochar in the concentrations studied does not provide an increase in the average germination percentage and vigor of lettuce and sorghum seeds. The increase in the concentration of biochar caused less seed vigor, suggesting a toxic effect. For seed germination, there was no significant difference between lettuce and sorghum species, regardless of treatment. For the germination speed index, sorghum seeds have higher means, except for the treatment with the addition of 15% coffee straw biochar. Lettuce seeds have higher shoot length averages, except for treatment with 100% commercial substrate. The sorghum seeds have higher mean root length and dry mass than lettuce, regardless of the treatment.

Culturable bacterial diversity from a feed water of a reverse osmosis system, evaluation of biofilm formation and biocontrol using phages.

Biofilm formation on reverse osmosis (RO) systems represents a drawback in the application of this technology by different industries, including oil refineries. In RO systems the feed water maybe a source of microbial contamination and thus contributes for the formation of biofilm and consequent biofouling. In this study the planktonic culturable bacterial community was characterized from a feed water of a RO system and their capacities were evaluated to form biofilm in vitro. Bacterial motility and biofilm control were also analysed using phages. As results, diverse Protobacteria, Actinobacteria and Bacteroidetes were identified. Alphaproteobacteria was the predominant group and Brevundimonas, Pseudomonas and Mycobacterium the most abundant genera. Among the 30 isolates, 11 showed at least one type of motility and 11 were classified as good biofilm formers. Additionally, the influence of non-specific bacteriophage in the bacterial biofilms formed in vitro was investigated by action of phages enzymes or phage infection. The vB_AspP-UFV1 (Podoviridae) interfered in biofilm formation of most tested bacteria and may represent a good alternative in biofilm control. These findings provide important information about the bacterial community from the feed water of a RO system that may be used for the development of strategies for biofilm prevention and control in such systems.

A meta-analysis of the effects of dietary copper, molybdenum, and sulfur on plasma and liver copper, weight gain, and feed conversion in growing-finishing cattle.

The minerals Cu, Mo, and S are essential for metabolic functions related to cattle health and performance. The interaction between Cu, Mo, and S can determine the utilization of each mineral, in particular Cu, by ruminants. A meta-analysis was performed to evaluate the effects of dietary Cu, Mo, and S and their interactions on plasma and liver Cu, ADG, and G:F in growing-finishing cattle. Data were collated from 12 published studies. The model with the best fit to data indicated plasma Cu was positively affected by dietary Cu (P < 0.01) and negatively affected by both dietary Mo (P < 0.01) and S (P < 0.01). Another model also indicated that plasma Cu concentration is positively related to Cu:Mo ratio in the diet (P < 0.01). Dietary Cu had a positive effect on liver Cu (P < 0.01), whereas Mo showed a negative effect (P < 0.05), and no effect of dietary S on liver Cu was observed (P > 0.05). Average daily gain was negatively affected by dietary Mo (P < 0.05) and S (P < 0.01) and positively affected by Cu:Mo ratio (P < 0.01), likely because an increased Cu:Mo ratio minimizes the antagonistic effect of Mo on Cu. The feed conversion ratio was negatively affected by Mo (P < 0.05) and S (P < 0.01), whereas effects of the Cu:Mo ratio and dietary Cu were not significant (P > 0.05). The interaction between S and Mo affected (P < 0.01) G:F, which was likely related to a positive response with the proper balance between these minerals. In conclusion, dietary Cu, Mo, and S and the Cu:Mo ratio caused changes in plasma Cu. Only dietary Mo and S led to a negative response in the performance of growing-finishing cattle, whereas the diet Cu:Mo ratio has a linear and quadratic effect on ADG. Nutritionists and producers need to consider with caution the supplementation of growing-finishing cattle diets with Mo and S because of their potentially adverse effects on animal performance. An appropriate Cu:Mo ratio is desirable to minimize the effects of an impaired supply of Mo on Cu metabolism and ADG.

An extended model of phosphorus metabolism in growing ruminants.

A major objective of this study was to extend the Vitti-Dias model used to describe P metabolism in ruminants, by adding 2 new pools to the original model to represent the rumen and saliva. An experiment was carried out using 24 male sheep, initial BW of 34.5 kg, aged 8 mo, fed a basal diet supplied with increasing amounts of dicalcium phosphate to provide 0.14, 0.32, 0.49, and 0.65% P in the diet. Sheep were individually housed indoors in metabolic cages and injected with a single dose of 7.4 MBq of (32)P into a jugular vein. Feed intake and total fecal and urinary outputs were recorded and sampled daily for 1 wk, and blood samples were obtained at 5 min, and 1, 2, 4, 6, 24, 48, 72, 96, 120, 144, and 168 h after (32)P injection. Saliva and rumen fluid samples were taken on d 6, 7, and 8. Then, animals were slaughtered and samples from liver, kidney, testicle, muscle, and heart (soft tissue) and bone were collected. Specific radioactivity and inorganic P were then determined in bone, soft tissue, plasma, rumen, saliva, and feces, and used to calculate flows between pools. Increased P intake positively affected total P (r = 0.97, P < 0.01) and endogenous P excretion in feces (r = 0.85, P < 0.01), P flow from plasma to saliva (r = 0.73, P < 0.01), from saliva to rumen (r = 0.73, P < 0.01), and from lower gastrointestinal tract to plasma (r = 0.72, P < 0.01). Urinary P excretion was similar for all treatments (P = 0.35). It was, however, related to plasma P (r = 0.63, P < 0.01) and to net P flow to bone (accretion - resorption; r = -0.64, P < 0.01). Phosphorus intake affected net P flow to soft tissue (P = 0.04) but not net P flow to bone (P = 0.46). Phosphorus mobilized from bone was directed toward soft tissue, as suggested by the correlations between P flow from bone to plasma and net P flow to soft tissue (r = 0.89, P < 0.01), and P flow from plasma to soft tissue and net P flow to bone (r = -0.76, P < 0.01). The lack of effect of dietary P on net P accretion in bone suggests that P demand for bone formation was low and surplus P was partially used by soft tissue. In conclusion, the model resulted in appropriate biological description of P metabolism in sheep and added knowledge of the effects of surplus dietary P on P metabolism. Additionally, the model can be used as a tool to assess feeding strategies aiming to mitigate P excretion into the environment.

Cinética do fósforo em tecidos de ovinos em crescimento alimentados com diferentes fontes de cálcio / Kinetics of phosphorus in tissues of lambs fed different sources of calcium

Foram utilizados 12 cordeiros machos, inteiros, com peso médio de 31,6kg. Os cordeiros foram alimentados com dietas à base de milho e farelo de soja, suplementadas com diferentes fontes de cálcio: calcário calcítico (CC), feno de alfafa (FA), polpa cítrica (PC) e farinha de conchas de ostras (FCO). Os animais receberam injeção de 7,4 MBq do radiofósforo (32P) e após sete dias foram abatidos para posteriores análises. Utilizou-se o delineamento em blocos ao acaso, com quatro tratamentos e três repetições. A taxa de retenção de 32P, as atividades específicas relativas e padronizadas, e a quantidade de P inorgânico nos tecidos foram iguais para todos os tratamentos (P>0,05). A comparação entre os tecidos mostrou que a concentração de P inorgânico e a taxa de retenção de 32P (P<0,01) foram mais altas nos ossos em relação aos tecidos moles (P<0,01). A retenção de 32P apresentou a seguinte ordem decrescente: rins, fígado, coração, músculos e ossos (P<0,01). A reabsorção óssea de P foi maior que a deposição de P, levando ao balanço negativo do elemento para a maioria dos animais. Concluiu-se que as diferentes fontes de cálcio não interferiram na cinética do P e que a quantidade de P ingerida não atendeu às exigências de P dos animais.

Sixteen growing rams, averaging 31.6kg were studied. They were fed diets based on corn and soya meal, supplemented with different sources of calcium: limestone (CC), alfalfa hay (FA), citrus pulp (PC) and oyster shell meal (OSM). The animals received an injection of 7.4 MBq of radioactive P (32P) and after 7 days they were slaughtered for further analyses. Experimental measurements were analyzed as a completely randomized design with four treatments and three repetitions. The rate of 32P retention, the relative specific activity, the standardized specific activity and the inorganic P in tissue were similar for all treatments (P>0.05). The comparison between tissues showed that the concentration of inorganic P and rate of 32P retention was greater in bone (P<0.01) than in soft tissue. The 32P retention presented the following decreasing order: kidney, liver, heart, muscle and bone (P<0.01). P resorption in bone was higher than P accreted in bone, leading to a negative balance of P in bone for the majority of animals. The means for P accreted in bone were 1.56, 3.29, 2.74 and 2.06g/animal and the means for P resorption in bone were 2.82, 4.51, 4.09 and 3.05g/animal for limestone (CC), alfalfa hay (FA), citrus pulp (PC) and oyster shell meal (OSM), respectively. P resorption values were higher than P accretion in bone leading to a negative balance of P for the majority of animals. It was concluded that the different sources of calcium did not interfere in the kinetics of phosphorus and the amount of P absorbed did not attend P demands of the animals.

A revised model for studying phosphorus and calcium kinetics in growing sheep.

The objective of the study was to revise a model of P kinetics proposed by Vitti et al. (2000) and extend its use to study Ca flows in growing sheep. Twelve Santa Ines male sheep, 8 mo of age, with average BW of 31.6 kg were injected with 32P and 45Ca to trace the movement of P and Ca in the body. The original model had 4 pools representing the gut, plasma, soft tissues, and bone. In the revised model, instantaneous values rather than averages for pool derivatives were incorporated, and the model was extended to represent absorption and excretion of phytate P explicitly. The amendments improved the model, resulting in higher flows between plasma and bone than between plasma and tissue and, therefore, a more accurate representation of P metabolism. Phosphorus and Ca metabolism were then assessed conjointly using the revised model. The results showed that P and Ca metabolism are closely related as evidenced by the ratio of these minerals in the bidirectional flows between plasma and bone and between plasma and tissue. Phytate P digestibility was 47%, and P retention was negative (-1.4 g/d), suggesting that a feed characteristic impaired P utilization and led to P deficiency. The revised model provides an improved prediction of P and Ca metabolism that can be used to assess mineral requirements and to estimate losses to the environment.