Aerobic stability of heat and orchardgrass round-bale silage

In Arkansas, silage is typically stored as balage in long rows of round bales wrapped in plastic film. It is important to evaluate the aerobic stability of this fermented forage when it is exposed to air, especially during the winter months when most of it is fed to livestock or sold as a cash crop. Two types of forage, orchardgrass (Dactylis glomerata) and wheat (Triticum aestivum), were harvested in May 2002 and stored as balage. Twenty-one bales of each balage type were unwrapped and exposed to air on 10 Dec. 2002 for 0, 2, 4, 8, 16, 24, or 32 d to evaluate aerobic stability. For both orchardgrass and wheat balage, final bale weight, dry matter (DM) content, and pH were not affected (P \u3e 0.05) by exposure time. Across both balage types, DM recoveries were ≥97% for all bales, indicating that both types of balage were very stable when exposed to air. Concentrations of neutral detergent fiber (NDF) and 48-h ruminal in situ digestibility were not affected (P \u3e 0.05) by exposure time for either balage type. Concentrations of N were greater (P = 0.045) for orchardgrass balage exposed to air for 16 d or longer compared to balage sampled at exposure (d 0), but this response was not observed (P \u3e 0.05) for wheat balage. These results suggest that the balage evaluated in this trial was very stable after exposure to air for up to 32 d. This should allow for considerable flexibility with respect to feeding, transport, and marketing of balage during winter months without significant aerobic deterioration

Comparison of feeding diets diluted with sorghum-sudangrass silage or low-quality grass on nutrient intake and digestibility and growth performance of Holstein dairy heifers

This study was carried out to evaluate the nutrient intakes and growth of dairy heifers offered an alfalfa silage– corn silage diet (CON; 14.3% crude protein, 61.1% total digestible nutrients, 47.9% neutral detergent fiber) compared with diets containing 1 of 2 types of sorghumsudangrass (SS) silages: conventional or photoperiod sensitive. The objective of the study was to determine the potential to use SS to control dry matter (DM) and nutrient intakes and weight gain. Both diets were similar in nutrient composition, with approximately 13% crude protein, 60 to 61% total digestible nutrients, and 55% neutral detergent fiber. Seventy-two Holstein heifers (16–18 mo at study initiation) were blocked by initial body weight (light = 422 ± 12.8 kg; medium = 455 ± 14.8 kg; heavy = 489 ± 16.7 kg) with 3 pens assigned to each weight block (8 heifers/pen; 24 heifers/block). The 3 diets were randomly allocated to the pens within each block and offered for 12 wk. Heifers offered the CON diet had greater DM, protein, and energy intakes compared with those offered the SS silage-based diets due to the greater neutral detergent fiber concentration of the SS diets. With lower DM and nutrient intakes, average daily gain was in the recommended range (0.8– 1 kg/d for Holstein heifers) for heifers offered the SS silage-based diets (mean of 0.92 kg/d for both SS diets vs. 1.11 kg/d for CON). Sorting behaviors for heifers offered both SS diets were more aggressive against long, medium, and short particles compared with those of heifers offered the CON diet; however, heifers sorted large particles from photoperiod-sensitive silage more aggressively than those from conventional silage. Based on this study, SS silage-based diets can control the DM and energy intakes for heifers and maintain optimum growth rates, with harvesting at a shorter chop length likely helping to alleviate sorting issues

Effects of grain by-products as supplements for stocker cattle grazing bermudagrass

Two experiments were conducted to compare corn, dried distillers’ grains (DDG), and pelleted soybean hulls (SH) as supplements for cattle grazing bermudagrass. In Exp. 1, 66 crossbred steers (306 ± 3.2 kg) were stratified by weight and allotted randomly to six 2.4-ha bermudagrass pastures for a 107-d study. One of three supplement treatments (corn, DDG, or SH) was assigned randomly to each pasture group and was offered at 0.5% (as fed) of body weight. Calves were weighed at 28-d intervals and supplement was adjusted after each weigh period. In Exp. 2, five ruminally cannulated steers grazed bermudagrass pasture and were individually fed supplements (corn, DDG, or SH) at 0.5% of body weight in a 3 x 3 replicated, incomplete Latin-square design with a 14-d adaptation and a 5-d sampling period. In Exp. 1, supplementation with DDG and corn increased (P \u3c 0.04) the average daily gain compared to supplementation with SH (0.89, 0.87, and 0.74 kg for DDG, corn, and SH, respectively). In Exp. 2, in situ dry-matter-disappearance kinetic measures of bermudagrass were not affected by type of supplementation. The potential extent of digestion for DDG (93%) was lower than for corn (97%, P = 0.01) and SH (96%, P = 0.06). Supplementation with corn or DDG at 0.5% of body weight improved the gain of stocker cattle grazing bermudagrass compared to supplementation with SH, but these differences were not explained by differences in bermudagrass degradation kinetic

Research Report Winter Cereal Variety Evaluation at Maricopa, 2020

Winter cereals for forage are displacing durum for grain in many areas of Arizona due to the demands of the dairy and beef cattle industry. The University of Arizona has only sporadically tested winter cereals for forage. This tria was initiated at the request of the dairy industry and may be conducted in the future depending on demand for thi information and available funding

Research Report Winter Cereal Variety Evaluation at Maricopa, 2019

Winter cereals for forage are displacing durum for grain in many areas of Arizona due to the demands of the dairy and beef cattle industry. The University of Arizona has only sporadically tested winter cereals for forage. This trial was initiated at the request of the dairy industry and may be conducted annually depending on demand for this information and available funding

Effects of harvest date and growth stage on triticale forages in the southwest USA: Kinetics of in vitro disappearance of fiber and dry matter

Recently, there has been interest in including triticale (X Triticosecale Wittmack) within forage programs in the southwest USA. Our objectives were to evaluate in vitro disappearance kinetics of neutral detergent fiber (NDF) and dry matter (DM) for cultivars identified during 2019 as positively or negatively deviant from typical cultivars, based specifically on regressions of 48-h in vitro disappearance of NDF on growth stage (GRST). All NDF analyses included the use of heat-stable α-amylase and sodium sulfite, as well as correction for residual ash (asNDFom). Seven triticale cultivars were established on December 18, 2019 at the University of Arizona Maricopa Agricultural Center, located near Maricopa, AZ. Forage plots were arranged in a randomized complete block design with three complete blocks (replications), and then harvested on seven dates the following late-winter and spring (February 26, March 17, April 1, April 14, April 28, May 12, and May 26). Based on a linear model, GRST was highly variable among cultivars on March 17 (44 ± 10.6), April 1 (57 ± 12.1), April 14 (67 ± 8.9), and April 28 (79 ± 7.2) compared with other harvest dates (SD ≤ 1.7). For concentrations of asNDFom, all cultivars exhibited linear (P ≤ 0.042) and quadratic (P < 0.001) polynomial contrasts in response to harvest date, and all cultivars except Merlin Max (P ≥ 0.063) exhibited at least one additional cubic or quartic effect (P ≤ 0.015). A contributing factor to the unique response by Merlin Max was the numerically greater maximum canopy height (145 ± 9.8 cm) compared with the mean of all cultivars (107 ± 17.7 cm), which also was associated with greater percentages of stem, as well as reduced percentages of DM partitioned within the grain head. Regressions of asNDFom disappearance after 30- or 48-h incubations on GRST indicated this was an effective independent variable (R2 ≥ 0.927), and responses were most often linear in nature. Generally, relationships for DM disappearance were quadratic, ostensibly due to the complicating effect of grain fill, but GRST was again an effective predictor variable with R2 statistics ≥ 0.852 for 12 of 14 combinations of cultivar and incubation time. Predicted percentages of digestible DM attributed to asNDFom disappearance were ≥50.3% through the fully flowered stage of growth, but digestible contributions from nonfiber components following the onset of grain fill profoundly affected overall DM digestibility among cultivars harvested at later GRST. Published by Oxford University Press on behalf of the American Society of Animal Science 2022.Recently, there has been increased interest in including triticale within forage programs throughout the southwest USA. Unless there is an urgency for removing the triticale crop, such as those created by a feed shortage or need to establish a secondary crop, harvest management decisions should be based on plant growth stage, and not calendar date. Assuming a common growth stage, this work suggests that most triticale cultivars will differ only modestly with respect to digestibility before the onset of grain fill. However, producers should be cautious of cultivars with unique or atypical phenotypic traits, such as exceptional canopy height, which may cause exceptions to the previous generalization. If yield is a critical management objective, harvest should most likely be delayed until after the onset of grain fill, but cultivar selection can become more complicated at that time because varying contributions from the filling grain head can radically affect overall digestibility of dry matter (DM). In this respect, producers should carefully evaluate their nutritional and production goals to assess whether their needs prioritize digestible fiber or overall DM digestibility, the latter of which can have limited contributions from digestible fiber.Public domain articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Comparison of feeding diets diluted with sorghum-sudangrass silage or low-quality grass on nutrient intake and digestibility and growth performance of Holstein dairy heifers

This study was carried out to evaluate the nutrient intakes and growth of dairy heifers offered an alfalfa silage– corn silage diet (CON; 14.3% crude protein, 61.1% total digestible nutrients, 47.9% neutral detergent fiber) compared with diets containing 1 of 2 types of sorghumsudangrass (SS) silages: conventional or photoperiod sensitive. The objective of the study was to determine the potential to use SS to control dry matter (DM) and nutrient intakes and weight gain. Both diets were similar in nutrient composition, with approximately 13% crude protein, 60 to 61% total digestible nutrients, and 55% neutral detergent fiber. Seventy-two Holstein heifers (16–18 mo at study initiation) were blocked by initial body weight (light = 422 ± 12.8 kg; medium = 455 ± 14.8 kg; heavy = 489 ± 16.7 kg) with 3 pens assigned to each weight block (8 heifers/pen; 24 heifers/block). The 3 diets were randomly allocated to the pens within each block and offered for 12 wk. Heifers offered the CON diet had greater DM, protein, and energy intakes compared with those offered the SS silage-based diets due to the greater neutral detergent fiber concentration of the SS diets. With lower DM and nutrient intakes, average daily gain was in the recommended range (0.8– 1 kg/d for Holstein heifers) for heifers offered the SS silage-based diets (mean of 0.92 kg/d for both SS diets vs. 1.11 kg/d for CON). Sorting behaviors for heifers offered both SS diets were more aggressive against long, medium, and short particles compared with those of heifers offered the CON diet; however, heifers sorted large particles from photoperiod-sensitive silage more aggressively than those from conventional silage. Based on this study, SS silage-based diets can control the DM and energy intakes for heifers and maintain optimum growth rates, with harvesting at a shorter chop length likely helping to alleviate sorting issues