Winter Forage Research Articles

Dietary composition, breadth, and overlap between seasonally sympatric Himalayan musk deer and livestock: Conservation implications

Livestock in high altitudes of Nepal and elsewhere, frequently and freely, use potential habitat of native wildlife for foraging. Such intrusion of ecologically similar domestic species is supposed to negatively impact the resident wildlife via ‘perceived’ and/or ‘real’ competitive interactions. Hence, assessment of dietary composition and overlap between herbivores is crucial to gain insight into the potential impacts via resource exploitation by foraging livestock. Also, evaluation of dietary composition of resident wildlife across seasons is important to decipher their seasonal resource needs. Within this context, microhistological technique, that makes use of fecal pellet for identification of plant species through comparison with reference slides of plant materials in the area, was used to assess dietary composition, breadth, and overlap between seasonally sympatric Himalayan musk deer and livestock in Nepal Himalaya. Musk deer and livestock were found to have significantly different dietary consumption and that partition was contributed by different species; meaning different plant species were associated to the diets of these two groups. Of notable, however, was a considerable ‘number’ of species (i.e., species richness) shared in diets by musk deer and livestock raising a concern of unchecked number of livestock with a potential to exploit and reduce the availability of shared plant species with musk deer. Also, seasonal dietary composition of musk deer significantly varied, with increased dietary breadth in winter, suggesting a potential for intraspecific competition for forage in winter because of limited availability of resources mediated by retarded growth and harsh conditions.

Effects of experimental night lighting on the daily timing of winter foraging in common European songbirds

The ecological effects of light pollution are becoming better understood, especially in birds. Recent studies have shown that several bird species can use street lighting to extend activity into the night during the breeding season. However, most of these studies are correlational and little is known about the effects of artificial night lighting on the timing of activities outside the breeding season. During winter, low temperatures and short days may limit foraging opportunities and can negatively affect survival of resident birds. However, night lighting may allow them to expand the time niche available for foraging. Here, we report on a study where we repeatedly manipulated the amount of night lighting during early winter at automated feeding stations in a natural forest. We used video‐recordings at the feeders to determine the time of the first (at dawn) and last (at dusk) foraging visits for six songbird species. We predicted that all species, and in particular the naturally early‐foraging species, would advance their daily onset of foraging during the mornings with night lighting, but would show minimal or no delays in their daily cessation of foraging during the lighted evenings. We found that two early‐foraging species, the blue tit and the great tit, started foraging earlier during the experimentally lighted mornings. However, in great tits, this effect was weak and restricted to nights with inclement weather. The light treatment did not have any effect on the start of foraging in the willow/marsh tit, the nuthatch, the European jay, and the blackbird. Artificial night lighting did not cause later foraging at dusk in any of the six species. Overall, our results suggest that artificial light during winter has only small effects on timing of foraging. We discuss these findings and the importance of temperature and winter weather in shaping the observed foraging patterns.

Within-pair similarity in migration route and female winter foraging effort predict pair breeding performance in a monogamous seabird

In long-lived monogamous animals, pair bond strength and durability are usually associated with higher fitness. However, whether pairs maximise fitness during the non-breeding season by maintaining contact during the winter or, instead, prioritise individual condition is unclear. Using geolocators recording spatial (light) and behavioural (immersion) data, we tracked pairs of the long-term monogamous Atlantic puffin Fratercula arctica during the non-breeding season to determine whether and how migratory strategies were related to future pair breeding performance and whether within-pair similarity in migratory movements or individual behaviour best predicted future fitness. While pair members migrated separately, their routes were similar in the first part of the non-breeding season but diverged later on; nonetheless, pairs showed synchrony in their return to the breeding colony in spring. Pairs following more similar routes bred earlier and had a higher breeding success the following spring. However, female (but not male) winter foraging effort was also a strong predictor of subsequent fitness, being associated with future timing of breeding and reproductive success. Overall, females had higher daily energy expenditure than males, especially in the late winter when their route diverged from their partner's and they foraged more than males. Our study reveals that female winter foraging, probably linked to pre-breeding condition, may be more critical for fitness than maintaining the pair bond outside of the breeding season. However, even without contact between mates, pairs can benefit from following similar migration routes and synchronise their returns, but the mechanisms linking these processes remain unclear.

Effects of soil heterogeneity on the uncertainty in modelling the fate of urinary nitrogen deposited during winter forage grazing

Despite the importance of soil physical properties on loss pathways from high nitrogen (N) inputs quantitative information on the effect of soil heterogeneity on the fate of N is lacking. To quantify how changes in the physical description of soil layers, used as model inputs, affect various outputs of the biophysical APSIM model regarding the fate of urinary nitrogen (N) following winter grazing, a modelling sensitivity analysis was performed. APSIM was set up according to a field experiment on a poorly drained Flaxton soil in the Canterbury region of New Zealand. Soil profile descriptions were based on various measured datasets, with and without compacted soil surface layers due to treading during grazing of the winter forage crop. The effect of the inclusion of more permeable sandy layers within the subsoil, a common occurrence in the study region, was also examined. By systematically replacing soil layers with different physical properties, the effect of these layers on the N loss pathways was evaluated. The analysis identified that the bottom layer (1–1.5m depth) had the greatest impact. With a low-permeability bottom layer nitrate leaching was 20% lower, whereas pasture N uptake, denitrification and nitrous oxide emissions were greater (by 5%, 58% and 43%). This is due to the effect of the bottom layer on water movement and storage within the soil profile. This description of the bottom layer had a substantially greater effect than compaction of the top soil layers due to treading. These results highlight the need for accurate soil physical descriptions for adequate model parameterisation, when such models are used for assessing management practices aimed at reducing environmental impacts.

Winter habitat use by juvenile greater sage-grouse on Parker Mountain, Utah: implications for sagebrush management

Greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) are entirely dependent on sagebrush (Artemisia spp.) for food and cover during winter. Loss or fragmentation of important wintering areas could have a disproportionate affect on population size. We radio-marked and monitored 91 juvenile sage-grouse in south-central Utah from 2008 to 2010. Thirty-four individuals survived to winter (January to March) and were used to evaluate winter habitat use. Resource use was calculated using kernel density estimation of radio-marked individuals and compared to available habitat using a G-test. We found that juvenile sage-grouse used winter habitats characterized by 0 to 5% slopes regardless of aspect and slopes 5 to 15% with south-to-west facing aspects. The importance of high slope (5 to 15%) wintering habitats has not been previously documented in sage-grouse. Most winter use was on a small proportion (3%; 2,910 ha) of available habitat. Important wintering habitats may not be readily identifiable in typical years, and consequently, due to their elevation, may be more susceptible to land management treatments focused on increasing early season livestock or big game winter forage, rendering them unsuitable for winter use by sage-grouse. Prior to implementing land management treatments in lower elevation sagebrush sites with slopes ≤5% regardless of aspect and slopes 5 to 15% south to west in aspect, managers should consider the potential effects of such treatments on the availability of suitable winter habitat to mitigate against winters with above-normal snowfall.

Winter Forage Program Benefitted Small-Scale Goat Producers

Small and limited resource farmers are raising goats on pastures in the southeast USA. Nevertheless, many of these farms do not have productive and quality pastures to support the nutrient requirements of their animals. Information on forages that are suitable to improve goat pastures and sustainably grazing those pastures with goats is still lacking. Study objectives were to (1) find winter forages suitable for goats, (2) evaluate the productivity and quality of these forages and (3) assess the benefits farmers would receive from pasture improvement and grazing management. Two separate studies were conducted, one in Selma and another in Phenix City, Alabama, USA in 2012 and 2013 (September/October-April). Each study was designed as a randomized complete block with three replications. Five legumes: Arrowleaf clover (Trifolium vesiculosum Savi), berseem clover (Trifolium alexandrinum L.), crimson clover (Trifolium incarnatum L.), hairy vetch (Vicia villosa Roth) and winter peas (Pisum sativum L.) were grown with Marshall ryegrass (Lolium multiflorum Lam.) in 40:60 legume: Grass ratio on separate strips. A sole Marshall ryegrass strip was planted as a control. Goats’ preference for and productivity and quality of forages and benefits associated with winter pasture and grazing were evaluated. Goats readily grazed all forages but winter peas at the very first exposure; from the second exposure onwards, goats grazed winter peas well. The mixtures of crimson clover and Marshall ryegrass and hairy vetch and Marshall ryegrass produced the most. The cost of goat production was significantly reduced because of the development and management of winter pastures. Raising goats on pastures can be much more beneficial than raising them on purchased feeds.

Nitrous oxide emissions from cattle urine deposited onto soil supporting a winter forage kale crop

ABSTRACTWintering cows on forage crops leads to urine being excreted onto wet, compacted soils, which can result in significant emissions of nitrous oxide (N2O). A field trial was conducted to determine the N2O emission factor (EF3; proportion of urine-N lost as N2O-N) for dairy cows wintered on a kale forage crop on a poorly drained soil. Urine was collected from non-lactating dairy cows on a forage kale diet and applied at 550 kg N ha−1 to artificially compacted soil to simulate trampling and non-compacted soil in a kale field. Cumulative N2O losses over four months were 7.38 and 2.64 kg N2O-N ha−1 from urine applied to, respectively, compacted and non-compacted soil. The corresponding EF3 values 0.75% and 0.30%, respectively, differed (P = .003) due to compaction. Combining our results with previous studies, where brassica-fed livestock urine was applied to soils supporting a forage brassica crop, suggested a significant relationship between soil water-filled pore space (WFPS) and brassica-derived urine EF3 (P = .005).

Cratering behaviour and faecal C:N ratio in relation to seasonal snowpack characteristics in a High-Arctic ungulate

ABSTRACTSnow and ice determine winter forage availability for Arctic herbivores. Winter precipitation is anticipated to increase, and icing following warm spells and rain-on-snow (ROS) are likely to become more frequent. While this may reduce herbivore survival, fecundity and population growth, we can also expect behavioural and dietary responses. Here, we tested predictions from optimal foraging theory on how changing snowpack conditions influence choice of feeding craters and diet quality in a large generalist herbivore, the wild Svalbard reindeer. Snow and ice conditions over winter 2012/13 (a ‘normal’ winter with little ROS and icing) were measured in reindeer feeding craters, in paired controls one metre away and in fixed control sites. On average, feeding craters had less snow and integrated ram hardness (IRH, the force needed to reach the ground), but not less ice, than nearby controls. However, on this fine spatial scale, reindeer tended to select for microhabitat with worse snowpack conditions up...

Optimization of Analytical Methods for Ochratoxin A and Zearalenone by UHPLC in Rice Straw Silage and Winter Forage Crops

Optimization of Analytical Methods for Ochratoxin A and Zearalenone by UHPLC in Rice Straw Silage and Winter Forage Crops

Spatialization of the SNOWPACK snow model for the Canadian Arctic to assess Peary caribou winter grazing conditions

Peary caribou is the northernmost designatable unit for caribou species, and its population has declined by about 70% over the last three generations. The Committee on the Status of Endangered Wildlife in Canada identified difficult grazing conditions through the snow cover as being the most significant factor contributing to this decline. This study focuses on a spatially explicit assessment tool using snow model simulations (Swiss SNOWPACK model driven in an off-line mode by spatialized meteorological forcing data generated by the Canadian Regional Climate Model) to characterize snow conditions for Peary caribou grazing in the Canadian Arctic. The life cycle of Peary caribou has been subdivided into three critical periods: summer foraging and fall breeding (July–October), winter foraging (November–March), and spring calving (April–June). Winter snow conditions are analyzed and snow simulations compared to Peary caribou island counts to identify a snow parameter that could potentially act as a proxy for grazing conditions and explain fluctuations in Peary caribou numbers. This analysis concludes that caribou counts are affected by simulated snow density values >300 kg m−3. A software tool mapping possibly favorable and unfavorable grazing conditions based on snow is proposed at a regional scale across the Canadian Arctic Archipelago. Specific output examples are given to show the utility of the tool, mapping pixels with cumulative snow thickness above densities of 300 kg m−3, where cumulative seasonal thicknesses >7000 cm are considered unfavorable.

The effects of forage removal on biomass and grain yield of intermediate and spring triticales

The dual-purpose use of cereals can be a convenient management option if grain yield (GY) is not significantly reduced. The effects of clipping at the terminal spikelet stage on biomass and grain production of an intermediate (‘Bienvenu’) and a spring (‘Oceania’) triticale cultivar grown at two sowing rates (300 and 600seedsperm2) were analysed in terms of the changes induced on radiation and water capture and use and biomass partitioning in five different Mediterranean environments with no additional N application following clipping. Clipped crops were able to recover completely in terms of the fraction of radiation interception (FIPAR) before anthesis, but the period in which plants exhibited a smaller leaf area resulted in a severe reduction − from 20 to 26% depending on the environment- in the total amount of radiation intercepted (IPAR, MJm−2), and consequently, in biomass at anthesis (from 14 to 30%). Radiation use efficiency (RUE) between clipping and anthesis ranged from 0.89 to 1.42gMJ−1, and only contributed to the decrease in biomass when leaf nitrogen levels were reduced as a consequence of clipping. Evaporation increased (by 13mm on average) and transpiration decreased (by 11mm on average) following clipping, with contrasting but quantitatively small effects on evapotranspiration. Transpiration efficiency decreased by about 20% following clipping in most environments because clipping decreased biomass production more than evapotranspiration in environments that did not allow the triticale crops to reach leaf area index values greater than 3–4. GY varied from about 300 to 850gm−2 and was only affected by clipping in the two environments with favourable post-anthesis conditions where unclipped crops showed a higher harvest index (HI, 0.38 unclipped vs 0.36 clipped crops on the average of the two environments). In the environments where a severe water stress (transpiration lower than 18% of reference evapotranspiration) following anthesis led to similar amounts of IPAR under the two treatment conditions, the lower biomass at anthesis of clipped crops lead to a higher HI and no reduction in GY. No interaction between clipping and cultivar was observed for FIPAR. Cultivar differences derived from their different phenologies and were mainly expressed before clipping; the longer duration of the phase prior to clipping (from 0 to 18days depending on the environment) resulted in the intermediate cultivar being superior in terms of winter forage production (193 vs 135gm−2 on average). On the other hand, the intermediate cultivar was less advantageous in terms of GY (270 vs 357gm−2) in the environments presenting the most severe terminal water stress. Sowing rate was only relevant in the pre-clipping period when the higher sowing rate produced, on average, 40% more biomass than the lower sowing density. Dual-purpose triticale can be a convenient management option in Mediterranean environments subjected to severe terminal water stress because GY is not affected and a variable amount of winter forage may be obtained.

Genetic Diversity of Great Plains Hard Winter Wheat Germplasm for Forage

Wheat (Triticum aestivum L.) has been widely grown for winter forage production across the world. However, improvement of forage yield and nutritive characteristics has not been a major goal of wheat breeding programs, and little is known about genetic diversity in the traits of winter wheat germplasm. A set of 299 hard winter wheat germplasm from the Great Plains was evaluated during two growing seasons in Oklahoma and 15 forage‐related traits were evaluated. There were significant (P < 0.0001) genetic variations in all the traits but effects of environment and germplasm × environment interaction were significant for seven and eight traits, respectively. A significant portion of the variation for forage traits was due to genetics, indicating an ability to breed for improved forage traits. Dry matter yield (DMY, kg ha−1) of the germplasm ranged from 1260 for Cheyenne to 4158 for Sturdy2K. Crude protein (CP, g kg−1) ranged from 161 for OK05108 to 268 for Nuplains. When crude protein yield (kg ha−1) was considered, Sturdy2K was the best germplasm, followed by 2180 and OK1068009. State of origin of the germplasm was also a significant source of variation for most of the traits. Heading date was positively and negatively associated with CP and DMY, respectively. This study identified significant genetic variations of the hard winter wheat germplasm for forage traits and the results of this study could provide useful guidelines for winter forage wheat breeding programs.

Temporal profiles of vegetation indices for characterizing grazing intensity on natural grasslands in Pampa biome

The Pampa biome is an important ecosystem in Brazil that is highly relevant to livestock production. The objective of this study was to analyze the potential use of vegetation indices to discriminate grazing intensities on natural grasslands in the Pampa biome. Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) images from Jan to Dec, 2000 to 2013 series, were analyzed for natural grassland experimental units managed under high (forage allowance of 5 ± 2 % live weight – LW), moderate (13 ± 5 % LW) and low grazing intensity (19 ± 7 % LW). Regardless of intensity, the temporal profiles showed lower NDVI and EVI during winter, increased values in spring because of summer species regrowth, slightly decreased values in summer, especially in years when there is a water deficit, and increased values in the fall associated with the beginning of winter forage development. The average temporal profiles of moderate grazing intensity exhibited greater vegetation index values compared with low and high grazing intensities. The temporal profiles of less vegetation index were associated with lower green biomass accumulation caused by the negative impact of stocking rates on the leaf area index under high grazing intensity and a floristic composition with a predominance of tussocks under low grazing intensity. Vegetation indices can be used for distinguishing moderate grazing intensity from low and high intensities. The average EVI values can discriminate moderate grazing intensity during any season, and the NDVI values can discriminate moderate grazing intensity during spring and winter.

Simulated animal trampling of a free‐draining stony soil stimulated denitrifier growth and increased nitrous oxide emissions

AbstractWinter forage grazing systems in New Zealand cause compaction of soil by grazing animals, especially when the soil is wet. However, there is little information on the effects of animal trampling on denitrifiers in soil, despite their importance for N2O production. Here, we report a field study of the abundance of the denitrifying genes nirS, nirK, and nosZ and N2O emissions following the application of dairy cow urine in a free‐draining stony soil. Importantly, we found that simulated animal trampling altered some of the denitrifying microbial communities, thus leading to increased N2O emissions. Over the 111 day measurement period, the abundance of nitrite (NO2−)‐reducing nirS gene copy numbers increased significantly by 87% in the trampled soil with urine (P < 0.01) and increased by 40% in the trampled soil without urine (P < 0.05), but the nirS gene abundance did not change significantly in the nontrampled soil. The abundance of NO2− reducing nirK gene copy numbers was not affected by trampling, but increased significantly following urine application. The abundance of N2O‐reducing nosZ clade I and nosZ clade II gene copy numbers increased significantly in the trampled soil, but did not change significantly in the nontrampled soil. N2O emissions from the trampled soil were about twice that from the nontrampled soil without urine (1.20 and 0.62 kg N2O‐N per ha, respectively) and about eight times greater (6.24 kg N2O‐N per ha) than from nontrampled soil (0.80 kg N2O‐N per ha) when urine was applied. These results strongly suggest that animal trampling during winter forage grazing can have a major impact on denitrifying communities in soil, which in turn stimulate greater denitrification with increased N2O emissions.

Sowing a winter catch crop can reduce nitrate leaching losses from winter‐applied urine under simulated forage grazing: a lysimeter study

AbstractGrazing of winter forage crops is a common management option used in the dairy industry of New Zealand, particularly in the South Island, where they are used to feed nonlactating, pregnant dairy cows prior to calving. However, there is concern that the large crop yields per hectare grazed, combined with a high stocking density of cows, lead to large amounts of urinary nitrogen (N) deposited on bare, wet soil that, in turn, could lead to large nitrate leaching losses. We report the results of a simulated winter forage grazing event using field lysimeters planted with a kale (Brassica oleracea L.) crop. The effect of sowing a ‘catch crop’ of oat (Avena sativa L.) following the simulated winter forage grazing on nitrate leaching losses from urine applied at different times throughout the winter was measured. A catch crop sown between 1 and 63 days after the urine deposition in early winter reduced N leaching losses from urine patches by ~34% on average (range: 19–49%) over the winter–spring period compared with no catch crop. Generally, the sooner the catch crop was sown following the crop harvest, the greater the uptake of N by the catch crop and the greater the reduction in nitrate leaching losses. The results indicate that sowing of a catch crop following winter crop grazing could be an effective management strategy to reduce nitrate leaching as well as increase the N‐use efficiency of dairy winter forage grazing systems.

Evaluating old and novel proxies for in vitro digestion assays in wild ruminants

In vitro digestion assays provide useful data for wild ruminant ecologists. It remains highly constraining, however, to conduct these assays in the field. We evaluated various proxies for in vitro digestion assays that use ruminal liquor from wild ruminants. The ruminal liquor of freshly killed white-tailed deer (Odocoileus virginianus) was used to measure in vitro true digestibility (IVTD), total gas, and volatile fatty acids (VFA) production of dominant summer and winter forage. We evaluated the ability of 4 proxies to predict these digestibility variables: 1) IVTD, total gas, and VFA produced with cow ruminal liquor; 2) acid detergent fiber (ADF) concentration; 3) CO2 production from soil–forage mixtures; and 4) predictive models based on near infrared spectra (NIRS) of forages. Predictions using NIRS were best correlated with all deer digestibility variables (each r2 > 0.93) with limited bias across forage species. Forage ADF and CO2 production from soil–forage mixtures were related with all digestibility variables (r2 = 0.62–0.95). Digestion assays using cow ruminal liquor was relatively good for predicting IVTD (r2 = 0.94) from deer ruminal liquor, but the weakest for predicting total gas (r2 = 0.63) and VFA production (r2 = 0.44). Calibrated NIRS models could substantially improve the prediction of in vitro digestibility variables. If access to NIRS technology or the ability to collect reference data with deer inocula for NIRS calibrations is impractical, forage ADF or CO2 production from soil–forage mixtures remain acceptable alternatives. Comparing the digestion kinetics and VFA production of wild and domestic ruminants is an innovative avenue for better understanding the adaptive ecophysiology of digestion by different herbivores. © 2016 The Wildlife Society.

Livestock grazing limits beaver restoration in northern New Mexico

The North American beaver (Castor canadensis) builds dams that pond water on streams, which provide crucial ecological services to aquatic and riparian ecosystems and enhance biodiversity. Consequently, there is increasing interest in restoring beavers to locations where they historically occurred, particularly in the arid western United States. However, despite often intensive efforts to reintroduce beavers into areas where they were severely reduced in numbers or eliminated due to overharvesting in the eighteenth and nineteenth centuries, beavers remain sparse or missing from many stream reaches. Reasons for this failure have not been well studied. Our goal was to evaluate certain biotic factors that may limit the occurrence of dam‐building beavers in northern New Mexico, including competitors and availability of summer and winter forage. We compared these factors at primary active dams and at control sites located in stream reaches that were physically suitable for dam‐building beavers but where none occurred. Beaver dams mostly occurred at sites that were not grazed or where there was some alternative grazing management, but were mostly absent at sites within Forest Service cattle allotments. Results indicated that cattle grazing influenced the relation between vegetation variables and beaver presence. The availability of willows (Salix spp.) was the most important plant variable for the presence of beaver dams. We conclude that grazing by cattle as currently practiced on Forest Service allotments disrupts the beaver‐willow mutualism, rendering stream reaches unsuitable for dam‐building beavers. We recommend that beaver restoration will require changes to current livestock management practices.

Identifying Major Crop Types in Eastern Canada Using a Fuzzy Decision Tree Classifier and Phenological Indicators Derived from Time Series MODIS Data

. This article presents a methodology that uses a fuzzy decision tree classifier and phenological indicators derived from remote sensing data for identifying major crop types in southwestern Ontario in eastern Canada. Phenological indicators were derived from time series Normalized Difference Vegetation Index (NDVI) calculated from 250-m surface reflectance data of the Moderate Resolution Imaging Spectroradiometer (MODIS). Training and testing samples were derived from crop classification maps at 30-m resolution for 2011, 2012, and 2013. Training samples for 2013 were used for discrimination rule development, and the classifier was then applied to all 3 years. Results showed that the classifier was able to discriminate major crop types such as winter wheat, corn, soybean, and forage crops with an overall accuracy of 75.3 % for 2013 and comparable accuracy for 2011 and 2012. Confusion exists mainly between corn and soybean, and between winter wheat and forage crops. This indicates that phenological indicators derived from optical remote sensing data are intrinsic to a crop and might be more indicative than the commonly used remote sensing features that are susceptible to environmental and management impacts. This methodology provides an opportunity for discriminating general crop types without requiring a year-specific training sample set.

Variations of Forage Yield and Nutritive Value in Winter Rye Germplasm

There has been an increasing use of rye (Secale cereale L.) for winter forage production in the United States because of its good forage yield, nutritive value, and winter hardiness. However, limited information on forage rye is available. To identify variations and germplasm with superior forage yield and/or nutritive value, winter rye germplasm, including elite cultivars and advanced breeding lines, were evaluated during two growing seasons. Effects of germplasm, clipping date, and germplasm by clipping date interactions were significant for dry matter yield (DMY). Clipping date and germplasm by clipping date interactions were significant for crude protein (CP), minerals, and nutritive value, but germplasm effect was not significant. Across the environments, seasonal DMY ranged from 789 kg ha−1 for ThunderGreen at the first clipping to 3733 kg ha−1 for NF97352 at the first clipping. Crude protein concentration varied from 17.7 to 27.9% for ThunderGreen at the third and first clipping, respectively. Cumulative DMY ranged from 5301 kg ha−1 for ThunderGreen to 8114 kg ha−1 for NF95319B. The results of this study identified significant variations in DMY and nutritive value among the rye germplasm, which may provide useful information for rye breeding programs for winter forage production and livestock producers.

Effect of Planting Date on Distribution of Seasonal Forage Yields in Dual‐Purpose Wheat, Oats, and Ryegrass Crops

Planting date is a key factor for determining the forage yields in different seasons to meet grazing requirements for various winter annual crops. The main objective of this study was to evaluate the effect of planting date on seasonal forage yield distribution for different grazing systems in dual‐purpose winter wheat (Triticum aestivum L.), oats (Avena sativa L.), and ryegrass (Lolium multiflorum L.). The research was conducted in two consecutive growing seasons (2003–2004 and 2004–2005) at the Texas A&M University Agriculture Research and Extension Center, McGregor, TX. Treatments were six planting dates (September through November with 2‐week interval between consecutive planting dates) for all three crops designed in randomized complete block with three replications. Three harvests of forage (fall, winter, and spring) were conducted each year for all three winter annuals. The results indicated that early planting (early September) favored the higher forage yields in fall season for both years in all three crops. For all three crops, under below‐average precipitation (2003–2004), planting date had no significant effect (P < 0.05) on both winter and spring forage yields. In the year 2004–2005, with above‐normal precipitation, late‐mid planting (late October) was optimum for both winter and spring seasons in wheat and oats. For ryegrass, late‐early (late September) planting produced significantly greater yields in fall and spring seasons. Planting date had no significant effect on winter forage yields for ryegrass. These research findings may be utilized in making planting decisions for the farmers with different grazing requirements in south and central Texas.