Early pair housing increases solid feed intake and weight gains in dairy calves

Dairy calves have traditionally been kept in individual pens throughout the milk-feeding period. Social rearing is associated with increased solid feed intake and hence higher weight gains before and after weaning. Little is known about the effect of the age at which social housing begins. The aim of this study was to assess the effects of early versus late pairing on feeding behavior and weight gain before and after weaning. Holstein bull calves were reared individually (n=8 calves), or paired with another calf at 6 ± 3 d (n=8 pairs) or 43 ± 3 d of age (n=8 pairs). All calves were fed 8 L of milk/d for 4 wk, 6 L/d from 4 to 7 wk and then milk was reduced by 20%/d until calves were completely weaned at 8 wk of age. Calves were provided ad libitum access to calf starter and a total mixed ration (TMR). Body weight and feed intake were measured weekly from 3 to 10 wk of age. Intake of calf starter was significantly higher for the early-paired calves than for individually-reared and late-paired calves throughout the experimental period. At 10 wk of age, starter dry matter intake (DMI) averaged 2.20 ± 0.22 kg/d, 1.09 ± 0.25 kg/d and 1.26 ± 0.33 kg/d for early pair, late pair and individually housed calves, respectively. Intake of TMR did not differ among treatments, TMR dry matter intake (averaged 3.27 ± 0.72 kg/d, 3.08 ± 0.46 kg/d, and 2.89 ± 0.54 kg/d for the same three treatments). Calves in the early pair treatment also showed significantly higher average daily gain (ADG) over the experimental period (0.89 ± 0.04 kg/d versus 0.76 ± 0.04 kg/d and 0.73 ± 0.04 kg/d for the early paired, individual and late-paired calves, respectively). These results indicate that social housing soon after birth can increase weight gains and intake of solid feed

Fish diversity decline in the lower Gangetic plains: a victim of multiple stressors

Analysis of long-term data provides a valuable approach to determining the extent of biodiversity decline and likely causes, but such approaches are rare in large tropical rivers. We investigated the response of the fish fauna to hydrological, climate and anthropogenic factors over the period 1982–2017 in the lower Ganges (Padma) River, Bangladesh. Systematic effort-based sampling of fish between 2007 and 2017 from a 70-km reach showed a decreasing trend in abundance and diversity. Compared to 1982 data for the same sites and fishing methods, 28 fish species, including 16 nationally threatened ones, were absent in recent catches, suggesting local extinction of these. Fish community diversity was negatively affected by fishing pressure (71 fishermen in 1980, 2616 in 2019, 37.8-fold increase) and non-native species abundance (6.8-fold increase in abundance between 2007 and 2017). Permanent water area has reduced by ~ 50% since 1984. Annual mean rainfall, Ganges water depth and river discharge at the study location decreased significantly since 1980 (by 19.2%, 17.8% and 27.6% respectively, while annual air temperature increased (25.1 °C in 1981 to 26.2 °C in 2019). Water diversion at the Farakka Barrage, ~ 70 km upstream, is partially responsible for reductions in permanent water area in the study reach. Potential sources of biological invasion and water pollution have been identified. Widespread ecological consequences on fish diversity and productivity, resulting from multiple factors, are occurring in the lower Ganges. Reduction of fisheries impacts and improved prevention of accidental aquaculture releases of non-native fishes are identified as conservation priorities for arresting the decline of native fishes in the lower Ganges

Increased Accumulation of Medium-Chain Fatty Acids by Dynamic Degradation of Long-Chain Fatty Acids in Mucor circinelloides

21 pags., 8 figs., 2 tabs.Concerns about global warming, fossil-fuel depletion, food security, and human health have promoted metabolic engineers to develop tools/strategies to overproduce microbial functional oils directly from renewable resources. Medium-chain fatty acids (MCFAs, C8-C12) have been shown to be important sources due to their diverse biotechnological importance, providing benefits ranging from functional lipids to uses in bio-fuel production. However, oleaginous microbes do not carry native pathways for the production of MCFAs, and therefore, diverse approaches have been adapted to compensate for the requirements of industrial demand. Mucor circinelloides is a promising organism for lipid production (15-36% cell dry weight; CDW) and the investigation of mechanisms of lipid accumulation; however, it mostly produces long-chain fatty acids (LCFAs). To address this challenge, we genetically modified strain M. circinelloides MU758, first by integrating heterologous acyl-ACP thioesterase (TE) into fatty acid synthase (FAS) complex and subsequently by modifying the β-oxidation pathway by disrupting the acyl-CoA oxidase (ACOX) and/or acyl-CoA thioesterase (ACOT) genes with a preference for medium-chain acyl-CoAs, to elevate the yield of MCFAs. The resultant mutant strains (M-1, M-2, and M-3, respectively) showed a significant increase in lipid production in comparison to the wild-type strain (WT). MCFAs in M-1 (47.45%) was sharply increased compared to the wild type strain (2.25%), and it was further increased in M-2 (60.09%) suggesting a negative role of ACOX in MCFAs production. However, MCFAs in M-3 were much decreased compared to M-1,suggesting a positive role of ACOT in MCFAs production. The M-2 strain showed maximum lipid productivity (~1800 milligram per liter per day or mg/L.d) and MCFAs productivity (~1100 mg/L.d). Taken together, this study elaborates on how the combination of two multidimensional approaches, TE gene over-expression and modification of the β-oxidation pathway via substantial knockout of specific ACOX gene, significantly increased the production of MCFAs. This synergistic approach ultimately offers a novel opportunity for synthetic/industrial biologists to increase the content of MCFAs.This work was supported by the National Natural Science Foundation of China (31670064, 31972851), the TaiShan Industrial Experts Program (tscy 20160101), the Chinese Government Scholarship Council (CSC) to Y.S., and the National Institutes of Health/National Institute of Allergy and Infectious Diseases (NIH/NIAID) Grant R03 AI11917 and the University of Texas at San Antonio research funds to S.C.L

Widespread evolution of molecular resistance to snake venom ?-neurotoxins in vertebrates

10.3390/toxins12100638Toxins121063