Concentrates

The effect of biosolids on hydrophobic properties of sulfides ores was studied. The principal components of biosolids are humic substances, mainly humic acid, and phosphorus compounds. The feasibility of using biosolids as collector for copper sulfide ores (CSO) was performed through zetapotential measurements, FT-IR analysis and film flotation tests. Addition of different dosages of biosolids, a commercial humic acid (CHA), and an industrial collector makes the zeta potential of a copper sulfide ore more electronegative in the entire pH range studied. FT-IR spectra show that CHA can interact with mineral surfaces through outer-sphere linkages. CHA can adsorb physically on chalcopyrite and pyrite through hydrogen bonds or Van der Waals forces. Orthophosphate, however, adsorbs chemically on the surfaces of these mineralogical species through inner-sphere linkages. Therefore, biosolids that contains both humic acid and phosphorus compounds can interact with CSO surfaces through a complex mechanism involving both inner and outer-sphere linkages. Further, film flotation tests – in accordance with zeta potential results – show that biosolids adsorb on the surface of the sulfide ores investigated, changing their hydrophobicity. Biosolids show greater affinity for pyrite while commercial humic acid show similar behavior to industrial collectors. Therefore, both biosolids and humic acids can change the hydrophobic properties of sulfide ores and can be used as collectors in froth flotation processes. Further research will be needed in order to scale-up laboratory results to industrial mineral operations.► The effect of biosolids on hydrophobic properties of sulfides ores was studied. ► Addition of different dosages of biosolids, commercial humic acids and an industrial collector makes the zeta potential of sulfide ores more electronegative. ► Biosolids can interact with sulfide ores surfaces through a complex mechanism involving both inner and outer-sphere linkages. ► Biosolids show greater affinity for pyrite while humic acids show similar behavior to industrial collectors. ► Biosolids and humic acids can change the hydrophobic properties of sulfide ores and can be used as collectors in froth flotation processes.

A study was conducted to evaluate the efficiency of compensatory feeding. Twenty-five Arsi bulls (32±4 months) were blocked by weight and randomly allocated to the following feed restriction treatments: ad libitum feeding for the entire period (control), maintenance feeding level (maintenance), 15% body weight loss (−15%), 20% body weight loss (−20%) and 25% body weight loss (−25%). A 91-day period of feed restriction was followed by a 105-day re-alimentation period. No treatment effects was observed on average daily gain (ADG) or feed conversion efficiency (FCE) during the compensatory period, both between control and maintenance feeding levels, and within the restricted treatment groups. Recovery index differed (P<0.01) both between the control and maintenance groups as well as within restricted treatments. Compensation was not complete, perhaps due to the low energy diet or insufficient time for compensation. No treatment effects on any carcass traits were observed between the ad libitum (control) and maintenance level feeding except ingesta (P<0.01) and among (P<0.05) restricted groups ( Table 4). Effects of feeding levels linearly decreased slaughter weight (Wt2) and ingesta weight (P<0.05), as well as carcass and lean meat yield (P<0.01). Proportions of lean meat, fat and bone to total carcass and slaughter weight differed (P>0.05) between control and maintenance groups as well as among restricted treatments. Although statistically not significant, compensatory gains, FCE, and lean meat yield for treatments −15, −20 and −25% had increasing tendencies with increasing levels of feed restriction. Therefore, Arsi bulls need longer than 105 days of compensatory feeding for complete recovery of LW losses caused by different levels of restriction in a period of 91 days. The appropriate time of feeding and change in the energy density of the diet by manipulating the roughage and concentrate ratios for complete compensation following different levels of retarded growth along with cost–benefit relationship requires further investigation.

Animal husbandry is an integral component of Indian agriculture supporting livelihood of more than two-thirds of the rural population. Reduction in agricultural production during drought affects livestock and the livelihood of farmers. Karnataka is second state next only to Rajasthan in terms of total geographic area which is drought prone. Fodder mitigating plan in place for Karnataka is must to sustain livestock. An assessment was made based on the availability and requirement of fodder as dry matter (DM) in each district. Secondary data of crop production, land utilization and livestock census data were used along with the primary data collected through pre-tested interview schedule. Out of 29 districts of Karnataka, 6 districts belonged to adequate DM available category with the mean availability of 87.51%. Five districts belonged to moderately adequate and 10 districts belonged to deficient DM available categories. However, 1 in every 4 districts belonged to severely DM deficie...

Two levels of concentrate (20 and 40% dry matter) and presence or absence of propolis ethanolic extract (PEE) in the diet at 30% w/v were evaluated in this study. The intake and apparent digestibility of nutrients, milk production and composition, live weight, feed efficiency and concentrate use for milk production were evaluated. Eight Holstein cows were distributed in two 4 × 4 Latin squares. The experiment was carried out in four 21-day periods, the first fourteen days were for the animals to adapt to the diets and the last seven days were for data collection. The experimental diets consisted of corn silage in the proportion of 80 or 60%, and concentrates based on corn and soybean meal, in addition to 34 mL PEE per day in the treatments that required this additive. The animals were housed in individual pens, fed ad libitum and milked twice a day. There was no interaction between concentrate levels and propolis, and there was no PEE effect for the evaluated parameters. The diets w...

The porphyry Cu–Mo deposits in the southern Siberian craton and Northern Mongolia including subduction-, collision-, and rift-related igneous series of early Paleozoic to Mesozoic age, are all characterized by varying crustal contribution to their parent magmas and the presence ...