Effect of low-glucosinolate crambe meal in diet on lactational performance, efficiency of nutrient utilization, and hepatic function of crossbred Holstein × Zebu and Jersey cows.

Crambe meal (CM) is a potential dietary protein source for ruminant, but its effects in diets for lactating dairy cows remains unknown. We evaluated the effects of inclusion of the low-glucosinolates (GIs) CM (450 mg GIs/kg DM) in partial total mixed ration (pTMR) on performance, efficiency of nutrient utilization, and hepatic function of crossbred Holstein × Zebu and Jersey cows. Eight crossbred Holstein × Zebu cows and four Jersey cows were blocked by breed and days in milk, and randomly assigned in a replicated 4 × 4 Latin square design, and distributed in one of four isonitrogenous TMRs (130 g CP/kg DM): 0, 45, 90, and 135 g CM/kg DM pTMR. Crambe meal was included in pTMR replacing soybean meal (SBM) and ground corn grain (GCG). The pTMRs were offered ad libitum between 7:00 a.m. and 5:00 p.m. Cows were kept on pasture of Panicum maximum cv. Mombaça (90.4 g CP/kg DM) between 6:00 p.m. and 6:30 a.m. Pasture intake was measured from external and internal fecal excretion marker. Inclusion of CM did not affect (P ≤ 0.05) the DM intakes of pTMR and pasture, apparent total-tract digestibilities of organic matter, CP and NDF, ruminal outflow microbial protein, milk yield, milk composition, urinary N excretion, milk N efficiency, and level of plasm hepatic enzymes. The effects of CM inclusion in pTMR were independent of breed. Low-glucosinolates CM can be incorporated up to 135 g/kg DM in pTMR in replacement of SBM and GCG without affecting performance, efficiency of nutrient utilization, and hepatic function of crossbred Holstein × Zebu and Jersey cows.

Performance of an integrated system combining microalgae and vertical flow constructed wetlands for urban wastewater treatment.

The present study investigated the performance of an integrated system, combining the sequential use of microalgae (MA) and vertical flow constructed wetland (VFCW) for the treatment of wastewaters produced at a university campus. Ecotoxicity and phytotoxicity assays were performed using respectively Daphnia magna and Lactuca sativa, whereas the genotoxicity of the wastewaters was assessed by using D. magna and Allium cepa. The results revealed that the major environmental impacts of the studied wastewaters are associated with the high eutrophication potential, due to high N-NH3 (68.8 ± 25.7 mg L-1), total P (7.71 ± 2.5 mg L-1), and BOD5 (526.4 ± 177 mg L-1) values, pathogenic load, and genototoxicity (p < 0.0001). The results also showed that the integrated system (MA + VFCW) was not able to satisfactory reduce the total p values (only 4%). Nevertheless, the MA + VFCW system achieved very promising results for the nitrogen removal, with emphasis on N-NH3 removal (100%) and the highest BOD5 removal (57%). Neither the raw wastewaters nor the treated wastewaters were phytotoxic. The integrated system completely eliminated the ecotoxicity (100%) and genotoxicity (n.s.) of the raw wastewater and showed decontamination potential. Thus, the integrated system emerges as an innovative environmental technology and, with minor adjustments, might be efficiently used in large scale and eventually replace conventional wastewater treatment systems.