Optimal harvest timing for brown midrib forage sorghum yield, nutritive value, and ration performance

Effect of acid detergent lignin concentration for diets formulated to be similar in neutral detergent fiber content on energy utilization in lactating Jersey cows

Lignin is a polyphenolic polymer that is an important factor in limiting fiber digestibility by ruminants. The objective of the current study was to evaluate lignin's effects on whole animal energy utilization in diets similar in NDF content. A low-lignin (LoLig) diet was formulated to contain 32.5% NDF (DM basis) and 9.59% lignin (NDF basis) and the high-lignin (HiLig) diet was formulated to contain 31.0% NDF (DM basis) and 13.3% lignin (NDF basis). These diets were randomly assigned and fed to 12 late-lactation (mean ± SD; 214 ± 14.9 DIM) multiparous Jersey cows (mean ± SD; 435 ± 13.9 kg) in a 2-period crossover design. Cows fed the LoLig treatment consumed more DM than cows on the HiLig diet (mean ± SD; 19.9 vs. 18.7 ± 0.645 kg/d) and the LoLig diet was concurrently of a greater gross energy concentration (mean ± SEM; 4.27 vs. 4.23 ± 0.03 Mcal/kg). As expected, increasing the concentration of lignin resulted in a reduction in total-tract NDF digestibility (45.5% vs. 40.4% ± 0.742%). Increasing lignin also resulted in a reduction in the digestibility of starch (97.7 vs. 96.3 ± 0.420) and CP (65.0 vs. 60.0 ± 0.829). Lignin also decreased the concentration of digestible energy (2.83 vs. 2.63 ± 0.04 Mcal/kg) and ME (2.52 vs. 2.36 ± 0.05 Mcal/kg), but the concentration of NEL was similar (1.81 vs. 1.75 ± 0.06 Mcal/kg). Increasing the concentration of lignin also reduced yields of ECM (33.7 vs. 30.0 ± 0.838 kg/d), milk protein (1.00 vs. 0.843 ± 0.027 kg/d), and milk fat (1.30 vs. 1.19 ± 0.058 kg/d). Decreasing the dietary lignin concentration did not affect daily methane emissions, averaging 391 ± 29.6 L/d. Results of this study indicate that feeding a diet greater in lignin decreases the digestibility of nutrients and provides less energy for production responses and that energy supplied from digestible NDF may be less than predicted by some nutrition models.

Unlocking growth potential: Synergistic potassium fertilization for enhanced yield, nutrient uptake, and energy fractions in Chinese cabbage

The implementation of integrated potassium management presents a viable approach for augmenting plant growth, yield, and nutrient uptake while enhancing soil nutrient availability. A field experiment was executed during the rabi season of 2020, employing a randomized complete block design encompassing eight treatments involving standard (100%) and reduced (75% and 50%) rates of the recommended dose of potassium (RDK) administered through muriate of potash (MOP). Treatments included variations in the incorporation/exclusion of plant growth-promoting rhizobacteria (PGPR), farmyard manure (FYM) at 25% of potassium recommendation, and foliar application of nano potash. The use of 100% RDK +25% K augmentation through FYM + PGPR and nano K fertilizer spray at 25 and 40 DAS (T8) exhibited significant enhancements in green fodder yield (64.0 ± 2.2 t ha-1) over control with no potassium application (47.3 ± 3.7 t ha-1) and found at par with and 75% RDK + 25% K augmentation through FYM + PGPR and nano K fertilizer spray at 25 and 40 DAS (T7). These treatments yielded maximum percent increase for plant height (34.9%), leaf count (38.5%), leaf dimensions (28.8-31.5%), stem girth (25.84%), root volume (27.0%), and root length (37.64%), observed at the harvest stage compared to control (T1-no potassium application). The treatment T8 was on par with T7 and recorded highest uptake of macro (N, P, and K) and micro (Zn, Fe, Cu, and Mn) nutrients. While soil parameters such as available nitrogen and potassium levels were notably increased through the application of treatment T7 across various treatment combinations and found significantly superiority over treatment T8. Multivariate analysis also highlighted treatment T7 is more efficient in maintaining sustainability. Hence, based on the present findings it can be concluded that application of 75% RDK +25% K augmentation through FYM + PGPR and nano K fertilizer spray at 25 and 40 DAS (T7) can be recommended for achieving enhanced productivity and soil fertility improvement within agricultural systems.

Effects of harvest stages and lactic acid bacteria additives on the nutritional quality of silage derived from triticale, rye, and oat on the Qinghai-Tibet Plateau

BACKGROUND

Triticale (×Triticosecale Wittmack L.), rye (Secale cereale L.), and oat (Avena sativa L.) are the main forage crops on the Qinghai-Tibet Plateau, but there has been relatively little research on the silage produced from these three species.

METHODS

Plants were harvested at the heading, flowering, grouting, milky, and dough stages and then used to produce silage with and without additives (Sila-Max and Sila-Mix). The nutritional quality of the resulting silages was analyzed.

RESULTS

Triticale was revealed to be more suitable than oat or rye for producing silage on the Qinghai-Tibet Plateau. On the basis of the dry matter yield (DMY), triticale and rye should be harvested at the milky stage to optimize silage quality, whereas oat should be harvested at the dough stage. The lactic acid bacteria additives Sila-Max and Sila-Mix had no significant effect on the nutritional quality of the three silages regardless of when the samples were harvested. Overall, triticale produced higher quality silage than oat or rye. More specifically, triticale variety 'Gannong No.2' harvested at the milky stage is ideal for silage production.

Effects of season, variety type, and trait on dry matter yield, nutrient composition, and predicted intake and milk yield of whole-plant sorghum forage

Sorghum forage is an important alternative to high-quality forage in regions where climatic and soil conditions are less desirable for corn production for silage and producing comparable nutritive value is challenging. The objective of this experiment was to assess the effects of season (spring vs. summer), sorghum variety type (forage sorghum vs. sorghum-sudangrass), and trait [brown midrib (BMR) vs. non-BMR] on dry matter (DM) yield, nutrient composition, and predicted intake and milk yield of whole-plant sorghum forage grown in Florida from 2008 to 2019. Whole-plant sorghum forage was harvested at a targeted 32% of DM, and each year, spring (April) and summer (July) trials were established. A total of 300 forage sorghum and 137 sorghum-sudangrass hybrids were tested for a total of 437 hybrids, of which 199 hybrids contained the BMR trait and 238 were non-BMR. An interaction between season and sorghum variety type was observed for DM yield. Dry matter yield was greater for the spring season than the summer season, with sorghum-sudangrass outperforming forage sorghum only during the spring season. In addition, BMR hybrids had a lower DM yield than non-BMR hybrids, regardless of season and variety type. An interaction between season and trait was observed for predicted neutral detergent fiber digestibility after 30 h of incubation in rumen fluid (NDFD_30h). Predicted NDFD_30h was greater for BMR sorghum in comparison to non-BMR sorghum, but BMR sorghum had slightly greater predicted NDFD_30h when grown in the spring than summer, whereas no seasonal differences were found for predicted NDFD_30h across non-BMR sorghum. An interaction between season, variety type, and trait was observed for predicted dry matter intake at 45 (DMI₄₅), 55 (DMI₅₅), and 65 (DMI₆₅) kg of milk/d. Predicted DMI₄₅ and DMI₅₅ were greater for spring BMR forage sorghum than for spring and summer non-BMR sorghum-sudangrass and were greater for spring BMR forage sorghum than for summer BMR sorghum-sudangrass. Predicted DMI₆₅ was greater for BMR forage sorghum in comparison to all non-BMR hybrids in the spring. Additionally, spring BMR forage sorghum was greater than summer sorghum-sudangrass regardless of trait. An interaction between season and sorghum variety type was observed for milk yield per megagram of forage. Milk yield per megagram of forage was greatest for spring forage sorghum. Sorghum variety type and trait selection are crucial to minimize differences in forage nutritive value of sorghum forage between seasons and improve the performance of high-producing dairy cows.

Nutritive value for ruminants of different fresh and ensiled sorghum (Sorghum bicolor (L.) Moench) varieties harvested at varying maturity stages

The occurrence of the Western corn rootworm and increasing frequency of summer droughts have reduced forage maize yields and quality in Central Europe in recent years. Therefore, sorghum (Sorghum bicolor (L.) Moench) has been increasingly used as alternative forage in ruminant feeding, although information on the nutritive value of whole crop sorghum silage (WCSS) under Central European climate conditions is scarce. This research project aimed to study differences between sorghum varieties and harvest dates regarding dry matter (DM) yield, chemical composition of fresh panicle, fresh stover, fresh whole plant and WCSS as well as whole tract digestibility and energy content of WCSS. For this purpose, six sorghum varieties, classified by their predominant use (biomass, silage, grain), were cultivated and harvested at three maturity stages (late milk stage, dough stage, full maturity). Furthermore, WCSS quality was compared with feed value of fresh and ensiled forage maize. Dry matter yield was higher (p < 0.05) in biomass sorghum (24.9 t/ha) compared to other sorghum varieties (12.4 to 16.7 t/ha). However, panicle proportion was lowest in biomass sorghum (10.5%), highest in grain sorghum (59.1%) and intermediate in silage sorghum. Fibre content declined and starch content increased with rising panicle proportion in fresh panicle, fresh whole plant and WCSS. Therefore, whole tract organic matter digestibility (66.8%) and metabolisable energy (ME) content (9.49 MJ/kg DM) were highest in grain sorghum silage. Especially low ME content was found in the biomass sorghum silage (7.43 MJ/kg DM). Dry matter yield of sorghum increased between late milk and dough stage of maturity, while it remained constant afterwards. Furthermore, ME content of WCSS rose tendentially (0.05 < p < 0.10) between late milk and dough stage of maturity and dropped again between dough stage and full maturity. Highest nutritive value of WCSS is achieved if grain sorghum varieties are used and both nutritive value and DM yield are optimised if harvest is carried out at dough stage of maturity. However, compared to forage maize, grain sorghum varieties have disadvantages both in DM yield and in nutritive value under common Central European climate conditions.

Evaluation of warm season annual forages for forage yield and quality in the north-central United States

Grazing-based dairy operations require productive, high-quality forages capable of supporting the nutritional needs of mid-lactation dairy cows. Our objectives were to evaluate primary and regrowth harvests of two cultivars of sudangrass (SU), sorghum-sudangrass (S×SU), and pearl millet (PM) forages for growth and nutritive characteristics within the specific context of suitability for grazing by dairy cows. Three harvest cycles, including primary and regrowth cycles in 2016, and a single harvest cycle of primary growth in 2017, were evaluated at two locations (Prairie du Sac and Marshfield, WI). Within each cycle, sampling was initiated when canopy height was about 41 cm and continued thereafter on weekly intervals for 5 weeks, resulting in six equally spaced sampling dates per harvest cycle. Data were analyzed as a split-plot design with cultivars (6) as whole-plots arranged in randomized complete blocks and weekly harvest dates (6) as subplots. Yields of dry matter (DM) were less consistent at the more northern location (Marshfield), which is known for its heavier, poorly drained soils. Despite locational differences, the taller-growing cultivar within each forage type frequently exhibited yield advantages over dwarf or shorter-growing cultivars; this occurred for 7 of 9 intra-forage-type comparisons (P ≤ 0.021) across three harvest cycles at Prairie du Sac, and for 6 of 9 similar comparisons (P ≤ 0.032) at Marshfield. In 2016, shorter-growing cultivars had greater percentages of leaf in 4 of 6 intra-forage-type comparisons at both locations (P ≤ 0.004), which is especially relevant for grazing. Similarly, PM cultivars exhibited shorter canopy heights (P ≤ 0.002), but greater percentages of leaf (P < 0.001), than all other cultivars during all harvest cycles at both locations. However, the greater leaf percentages exhibited by PM cultivars did not translate into reduced percentages of structural plant fiber (asNDFom) on a whole-plant basis during any harvest cycle at either location; furthermore, asNDFom concentrations for PM cultivars were greater (P ≤ 0.047) than observed for other cultivars within 3 of 6 harvest cycles across both locations. Ruminal in-situ degradation of asNDFom for whole-plant forages based on a 48-h incubation was significantly greater (P ≤ 0.006) for PM compared with other cultivars in 4 of 6 harvest cycles. Pearl millet cultivars generally exhibited more suitable characteristics for grazing livestock than SU or S×SU cultivars.

Graduate Student Literature Review: Current perspectives on whole-plant sorghum silage production and utilization by lactating dairy cows

The purpose of this literature review is to evaluate current research into and understanding of whole-plant sorghum silage production and the effect of feeding whole-plant sorghum silage on lactation performance of dairy cows. Sorghum's drought tolerance, water efficiency, and low cost of production make it an intriguing crop in areas where whole-plant corn silage production may be limited. Currently, urban land encroachment and reduced water availability have increased social and economic pressures on farms to improve crop production efficiency. As these challenges become more prevalent, greater reliance on sorghum can be expected because of its ability to produce high dry matter yields while maintaining nutritive value, even under less-than-ideal growing conditions. Moreover, whole-plant sorghum silage provides both physically effective fiber and energy through fiber and grain fractions. Advancements in sorghum genetics and mechanical processing have the potential to alleviate common challenges associated with whole-plant sorghum silage supplementation, such as increased neutral detergent fiber and decreased neutral detergent fiber digestibility, starch concentration, and starch digestibility. These nutritive challenges must be overcome for whole-plant sorghum silage to be a viable alternative to whole-plant corn silage.