Green and sweet corn grown under different cover crops and phases of the no-tillage system

ABSTRACT Special corn is cultivated all year conventionally round; however, its productivity increases when grown under a no-tillage system (NTS). This study aimed to evaluate the agronomic performance of sweet and green corn cultivated under residues of different cover crops and the NTS implantation stages. Two experiments were carried out in the randomized block design, with four replications, in each of the three areas. The experiments consisted of evaluating the sweet and green corn, simultaneously, in three areas at different stages of development of NTS: initial (1 year), transition (7 years), and consolidation (19 years) with six types of cover crops: Signal grass (SG), Pearl millet (PM), Sunn hemp (SH), a mixture of SG + SH, SG + PM, and PM + SH. The dry matter (DM) production of the cover crops, the productivity of husked and unhusked ears, straw, and grain yield were evaluated. The SH had the highest dry mass production among the studied cover crops in all phases of the NTS. The phase of the NTS did not influence the productivity of ears with or without husk in green corn. The cultivation of sweet corn in transition and consolidation areas of the NTS showed better yields when compared to the initial phase of the system.

Combination of carbohydrases and essential oils improve dietary performance of feedlot steers on a high-energy diet

Essential oils and enzymes are alternatives to feed additives for ruminants that aim to replace the use of ionophores and improve animal performance, but their mechanisms of action are different. Therefore, the present study aimed to verify if there is a synergistic effect in the combined use of enzymes carbohydrates and essential oils on the performance, ingestive behavior and carcass traits of steers fed a high-energy diet. During the finishing period of 78 days, 40 steers were assigned to four treatments: CON- control; ENZ- enzymatic complex; EO- essential oil blend; ENZ+EO - enzymatic complex combined with essential oil blend. Regardless of the feedlot periods, the ENZ+EO treatment caused a reduction in the dry matter intake (12.48%) compared to the control. The ENZ+EO treatment resulted in the lowest mean fecal output and, consequently, the highest dry matter digestibility (DMD) and starch digestibility (SD), compared to the other treatments. Animals that received EO and ENZ+EO in the diet spent more time in feeding. As for the number of times animals visited the feeding trough, the highest values were presented by the animals in the EO, ENZ and ENZ+EO treatments. For the carcass parameters, only the subcutaneous fat thickness on the rib was significantly different between treatments, with the highest values obtained by adding EO and ENZ+EO (8.80 and 8.10 mm respectively). Thus, the combination of carbohydrate enzymes and essential oils proved to be synergistically beneficial in relation to better use of nutrients and productive performance of feedlot steers.

Diet of crab-eating fox (Cerdocyon thous) in two conservation units of the Amazon rainforest, Brazil

The present study aimed to evaluate the diet of the free-living crab-eating fox by identifying the stomach contents of the 17 crab-eating foxes (Cerdocyon thous) roadkilled in two conservation units, both located in the Amazon rainforest. The food items were quantified by frequency of occurrence (FO) and percentage of occurrence (PO). The stomach contents were analysed for dry matter (DM), crude protein (CP), crude fibre (CF), ether extract (EE), and mineral matter (MM). Nitrogen-free extractives (NFE), metabolisable energy (ME) values, as well as the energy need for maintenance were estimated. The composition of the diet for the crab-eating fox presented 29 food items from the different taxonomic groups, with a greater diversity of items of animal origin (n=22), although the highest frequency of occurrence was gramineae (Poaceae) (41.18%). Among the items of animal origin, 21% were mammals, 18% reptiles, 10% amphibians, 9% invertebrates and 3% birds. A high content of CF (62.76%) were determined. Nitrogen-free extractive and dry matter averages were 5.91% and 141.82 kcal/100g, respectively. The average maintenance energy was 447.01 kcal/day. These findings suggesting that the crab-eating foxes have a generalist diet with an omnivorous diet in the Amazon basin, feeding on gramineae, fruits, insects, snakes, amphibians, birds and small mammals and have the same feeding habit that present in other Brazilian biomes.

Predicting Metabolizable Energy from Digestible Energy for Growing and Finishing Beef Cattle and Relationships to Prediction of Methane

Reliable predictions of metabolizable energy (ME) from digestible energy (DE) are necessary to prescribe nutrient requirements of beef cattle accurately. A previously developed database that included 87 treatment means from 23 respiration calorimetry studies has been updated to evaluate the efficiency of converting DE to ME by adding 47 treatment means from 11 additional studies. Diets were fed to growing-finishing cattle under individual feeding conditions. A citation-adjusted linear regression equation was developed where dietary ME concentration (Mcal/kg of dry matter [DM]) was the dependent variable and dietary DE concentration (Mcal/kg) was the independent variable: ME = 1.0001 × DE – 0.3926; r 2 = 0.99, root mean square prediction error [RMSPE] = 0.04, P < 0.01 for the intercept and slope). The slope did not differ from unity (95% CI = 0.936 to 1.065); therefore, the intercept (95% CI = -0.567 to -0.218) defines the value of ME predicted from DE. For practical use, we recommend ME = DE – 0.39. Based on the relationship between DE and ME, we calculated the citation-adjusted loss of methane, which yielded a value of 0.2433 Mcal/kg of DMI (SE = 0.0134). This value was also adjusted for the effects of dry matter intake (DMI) above maintenance, yielding a citation-adjusted relationship: CH4, Mcal/kg = 0.3344 – 0.05639 × multiple of maintenance; r 2 = 0.536, RMSPE = 0.0245, P < 0.01 for the intercept and slope). Both the 0.2433 value and the result of the intake-adjusted equation can be multiplied by DMI to yield an estimate of methane production. These two approaches were evaluated using a second, independent database comprising 129 data points from 29 published studies. Four equations in the literature that used DMI or intake energy to predict methane production also were evaluated with the second database. The mean bias was substantially greater for the two new equations, but slope bias was substantially less than noted for the other DMI-based equations. Our results suggest that ME for growing and finishing cattle can be predicted from DE across a wide range of diets, cattle types, and intake levels by simply subtracting a constant from DE. Mean bias associated with our two new methane emission equations suggests that further research is needed to determine whether coefficients to predict methane from DMI could be developed for specific diet types, levels of DMI relative to body weight, or other variables that affect the emission of methane.

Cropping capacity of winter rye cultivated for fodder

Realization of the yield potential depends on the biological characteristics of the variety, cultivation technology and weather conditions. The article presents the results of studies carried out in 2018-2021. on the productivity of various varieties of winter rye in dryland conditions of the central zone of the Republic of Kalmykia. The fresh yield of winter rye harvested for fodder depended on the variety. Its highest index was obtained for the Saratovskaya 4 variety and amounted to 17.7 ... 26.9 t / ha. The analysis of the productivity of winter rye harvested for green fodder showed that the studied varieties provided the yield of dry matter at the level of 5.4 ... 7.1 t / ha on average for three years. All varieties have good winter hardiness. Keywords: WINTER RYE, VARIETY, NAKED FALLOW, PLANT HEIGHT, GREEN MASS, FRESH YIELD, CROP PRODUCTIVITY, DRY MATTER

Effect of variety and cutting interval on yield and proximate composition of alfalfa (Medicago sativa L.) under irrigation in Central Gondar zone, Ethiopia

Background Understanding the relationship between dry matter yield production and forage quality throughout the growing season will help to optimize the cutting intervals between harvests in different Alfalfa (Medicago sativa L.) varieties. An experiment was conducted to assess the effects of harvest frequency on forage yield and quality of 2 improved cultivars (ILRI-6984 and var. DzF-552) of alfalfa (Medicago sativa L.) in Western Dembia district over 20 months during 2017 and 2018. Four harvest frequencies (every 30, 40, 50 and 60 days) were compared in a randomized complete block design (RCBD) with 4 replications. The experiment was laid down in a randomized complete block design (RCBD) in factorial arrangement with four replications. To assess their production potential plant height (cm), number of branches per plant, fresh biomass yield (t ha−1) and dry matter yield (t ha−1) of the forge and its nutrient content were recorded. The data collected was subjected to analysis of variance (ANOVA) by using the general linear model (GLM) procedure in Statistical Analysis System (SAS) (2003) version 9.1. Results The results revealed that highest forage dry matter yield was recorded for variety ILRI-6984 harvested every 40 days (26.8 t DM ha−1) and for var. DzF-552 when harvested every 60 days (24.1 t DM ha−1) (P<0.001). While crude protein concentration tended to decline as age at harvest increased, there was little consistency in the pattern. Crude protein yields were also inconsistent across treatments but ILRI-6984 harvested every 40 days produced the highest yields (6.5 t ha−1) (P<0.001). Conclusion These preliminary findings need to be confirmed under field conditions on a large scale along with longer-term studies to examine the longevity of the stands at these harvest frequencies. Irregular harvesting based on stage of maturity should be compared with fixed inter-harvest intervals.

Fermentation of liquid feed with lactic acid bacteria reduces dry matter losses, lysine breakdown, formation of biogenic amines and phytate-phosphorus

ABSTACT This study investigated the fermentation of liquid feed for pigs and the effect of lactic acid bacteria (LAB) supplementation on fermentation rate, dry matter losses (DML), formation of biogenic amines and degradation of phytate-P. The basal substrate in all three in-vitro batch experiments consisted of 50% canola meal, 25% wheat, and 25% barley. The mixed substrates were adjusted to a dry matter (DM) content of 28.4% and fermented in 1L-vessels at 37° C for 24 h. Experiment 1 focused on changes in pH profiles over time. Treatments were: (1) liquid feed without additive (control) and (2) liquid feed supplemented with a mixture of Lactobacillus plantarum, Pediococcus pentosaceus, and Lactobacillus lactis (adLAB) at 2.0 × 10 5 CFU/g liquid feed (wet wt.; n = 8). Substrate pH was measured every 2 h. Experiment 2 focused on DML and the impact of fermentation on phytate-P. Treatments were identical to experiment 1 (control and adLAB; n = 8). Measured parameters included concentration of lactic acid, acetic acid, ethanol, and phytate-P, and DML after 24 h of fermentation. Counts of molds, Enterobobacteriaceae, yeasts and LAB were determined in one combined sample of all replicates. Dry matter losses were lower in LAB supplemented fermentations (5.89%) compared to the control (11.8%; P &lt; 0.001). Supplementation with LAB reduced the phytate-P content (2.66 g/kg DM) compared to the control (3.07 g/kg DM; P = 0.002). Experiment 3 evaluated DML and the impact of fermentation on formation of biogenic amines. Treatments were: (1) control, (2) adLAB (2.0 × 10 5 CFU LAB/g liquid feed), (3) adLys (0.60% DM supplemented lysine) and (4) adLAB+Lys (combination of adLAB and adLys; n = 8). The fermentation of adLys resulted in a nearly complete breakdown of supplemented lysine, while only 10% of supplemented lysine was lost in adLAB+Lys. Furthermore, all adLys samples tested positive for cadaverine (mean concentration 0.89% DM), while no adLAB samples contained cadaverine above the detection limit (P &lt; 0.001). Results indicate that DML is reduced in fermentations supplemented with homofermentative LAB. Fermentation of liquid feed with homofermentative LAB can effectively reduce the degradation of supplemental lysine, and has the potential to further improve P availability.