The predictability of the spring emergence period of kochia is a potentially exploitable attribute that may be applied to weed management. The emergence timing of kochia was monitored, during the spring and summer of 2005 and 2006, in 12 farmed fields in the northern region of the Northern Great Plains (NGP) of North America. Kochia emergence began at 50 cumulative growing-degree days (GDD Tbase 0 C, starting January 1) and continued into late summer. The onset of kochia emergence occurred well before the emergence onset of other weed species common to this region. Fall soil samples revealed few kochia seeds remained in the seedbank. In growth room studies, kochia seed placed at the soil surface had greater emergence compared with seed burial to a 10 mm or greater depth. Kochia did not emerge from seed planted 80 mm deep; however, radical emergence was evident indicating fatal germination. Kochia should be controlled early in the growing season, and burying seed will greatly reduce future kochia ...

Peat moss has been a standard carrier of inoculum for experimentation and in agriculture. Peat moss is, however, a non-renewable resource. Alternatively, biochar could serve as an inoculum carrier. Here, we tested the effect of biochar-based seed coatings as a carrier for the phosphorous-solubilizing Pseudomonas libanensis inoculum, on corn growth after soluble and insoluble P addition. The survival of P. libanensis was determined based on the measure of colony-forming units from samples of four inoculated guar gum-based biochar coatings and was compared to peat. Storage experiments were performed on inoculated biochars for 22 weeks at 25 °C and on coated corn seeds for 16 weeks at 4 °C. Seed coatings were prepared with inoculated and uninoculated biochars (100 seeds treatment⁻¹), and effects of these treatments are reported on indices of seed germination after 7 days. A greenhouse experiment investigated the effects of the inoculated and uninoculated biochar seed coating on corn plants. The parameters measured from the greenhouse-grown corn plants were germination, fresh weight, dry weight, height, root length, basal stem diameter, leaf area, chlorophyll content, and tissue phosphorous. Our results show that corn plants grown from seeds coated with a biochar from hardwood feedstock are 2 to 10 g heavier than controls and that controls are 4 to 26 % shorter than the plants grown from biochar-coated seeds, where soluble phosphorous is applied. Moreover, corn seeds that were coated with a biochar produced from softwood feedstock germinated more quickly, based on the speed of germination index. Overall, we show that a biochar-based seed coating can benefit sustainable agriculture by carrying P. libanensis and enhancing the growth of corn, but according to parametric statistical tests, it does so without increasing the phosphorous content of the plants.

In the present study, we evaluated whether the nasopharyngeal, ruminal, and vaginal microbiota would diverge (1) in virgin yearling beef heifers (9 months old) due to the maternal restricted gain during the first trimester of gestation; and (2) in pregnant beef heifers in response to the vitamin and mineral (VTM) supplementation during the first 6 months of pregnancy. As a secondary objective, using the microbiota data obtained from these two cohorts of beef heifers managed at the same location and sampled at the same time, we performed a holistic assessment of the microbial ecology residing within the respiratory, gastrointestinal, and reproductive tract of cattle. Our 16S rRNA gene sequencing results revealed that both α and β-diversity of the nasopharyngeal, ruminal and vaginal microbiota did not differ between virgin heifers raised from dams exposed to either a low gain (targeted average daily gain of 0.28 kg/d, n = 22) or a moderate gain treatment (0.79 kg/d, n = 23) during the first 84 days of gestation. Only in the vaginal microbiota were there relatively abundant genera that were affected by maternal rate of gain during early gestation. Whilst there was no significant difference in community structure and diversity in any of the three microbiota between pregnant heifers received no VTM (n = 15) and VTM supplemented (n = 17) diets, the VTM supplementation resulted in subtle compositional alterations in the nasopharyngeal and ruminal microbiota. Although the nasopharyngeal, ruminal, and vaginal microbiota were clearly distinct, a total of 41 OTUs, including methanogenic archaea, were identified as core taxa shared across the respiratory, gastrointestinal, and reproductive tracts of both virgin and pregnant heifers.

The effects of providing rest on physiological and behavioural indicators of welfare of cattle being transported by road has not been well studied in North America. New revisions to Canada’s Health of Animals Regulations Part XII: Transportation of Animals indicate un-weaned and weaned calves can be transported a maximum of 12 and 36 h, respectively, before an 8 h rest is required. Therefore, the aim of this study was to assess the effects of rest duration, after 12 and 36 h of transport, on physiological and behavioural indicators of welfare in 7–8 mo-old beef calves. Three hundred and twenty conditioned calves (258 ± 23.9 kg BW) were randomly assigned to a 2 × 4 factorial design where the main factors included transport duration: 12 h (12; n = 160) and 36 h (36; n = 160) and rest stop duration: 0 h (R0; n = 80), 4 h (R4; n = 80), 8 h (R8; n = 80) and 12 h (R12; n = 80). After the resting period, animals were transported for an additional 4 h. Blood and hair samples were taken from 12 animals per treatment prior to and after the first and the 4 h transport; and then 7 h, 2 d and 28 d after the 4 h transport. The concentrations of haptoglobin, creatine kinase, non-esterified fatty acids (NEFA), lactate, and serum and hair cortisol were determined. Standing and lying behaviour was assessed for 14 d after transport, while feeding behaviour of calves in one pen per treatment were assessed for 28 d after transportation using an electronic feed bunk monitoring system. Body weight (BW), average daily gain (ADG) and shrink (%) was assessed for all calves. The data was modeled using generalized linear mixed methods (SAS PROC GLIMMIX), where transport and time (nested in rest) were considered fixed effects and animal and pen were considered random effects. Statistically significant (p < 0.05) effects of transport were observed on BW and shrink, where 36 h-transported calves had lower (p < 0.01) BW and greater (p < 0.01) shrink than 12 h-transported calves. A transport × time (nested in rest) interaction (p < 0.01) was observed for lying percentage where, 36-R8 calves had greater (p < 0.01) lying percentage than 12-R8 calves on d 1 after transportation. The area under the curve (AUC) for NEFA was greater (p < 0.01) for 36-R0 calves than 12-R0, 36-R4, and 36-R8 calves, and greater (p < 0.01) in 36-R12 calves than 12-R12 calves. Haptoglobin AUC was greater (p = 0.05) in 36-R12 than 12-R12 calves. Overall, physiological indicators of reduced welfare were greater in calves transported for 36 than 12 h, while no clear differences were observed between rest stop groups with the exception of NEFA. Based on these results, conditioned calves benefit from shorter transport durations but there was no clear evidence that calves rested 4, 8, and 12 h following transportation experienced reduced transport related stress compared to those that were not rested (0h).