Cool-season Grass Hay Research Articles

Influence of late gestation drylot rations differing in protein degradability and fat content on beef cow and subsequent calf performance.

Spring-calving, mature cows ( = 191 total) and their progeny were used to evaluate the effects of late gestation drylot rations differing in RUP and fat content on cow performance as well as performance and carcass characteristics of subsequent progeny. Cows were blocked by BW and anticipated calving date and assigned to 16 pens. Pens were randomly allotted to 1 of 2 treatments: limit-fed corn coproducts and ground cornstalks (COP; TDN = 64.4%, CP = 11.1%, RDP = 60.2% of CP, and fat = 5.1%) or limit-fed ground mixed, cool-season grass hay (HY; TDN = 55.7%, CP = 9.5%, RDP = 86.0% of CP, and fat = 2.3%). Treatments were limit fed as isocaloric, isonitrogenous rations from 88 ± 11 d prepartum to calving. All cows were fed a common diet postpartum. Cow BW and BCS were collected at the beginning of the feeding period, within 48 h after calving, and at breeding. Calf BW was collected at birth and at 64 ± 11 and 124 ± 11 d of age. Milk production was determined using the weigh-suckle-weigh technique at 64 ± 11 and 124 ± 11 d postpartum. At 124 ± 11 d of age, steers ( = 68) and nonreplacement heifer calves ( = 25) were weaned and placed on a common feedlot diet with individual feed intake monitored using GrowSafe. Feedlot calves were slaughtered at a commercial facility 35 ± 10 d after a minimum ultrasound 12-rib fat thickness estimation of 0.9 cm. After calving, cow BW was greater ( < 0.01) and BCS was greater ( < 0.01) for cows fed COP than for cows fed HY. Calf birth BW was greater ( = 0.04) for those born to cows fed COP with no difference ( = 0.43) in percentage of unassisted births across treatment. Cows fed HY were lighter ( < 0.01) at breeding with lower BCS ( = 0.03); nevertheless, overall pregnancy rate was not different ( = 0.80). No differences ( ≥ 0.22) in milk production were detected. For feedlot progeny, initial feedlot BW, final BW, and days on feed were not different ( ≥ 0.23), and as a result, no difference ( = 0.21) in feedlot ADG was detected. Feedlot DMI and G:F were not different ( ≥ 0.19) across treatments. Feedlot calf health was monitored with no differences ( ≥ 0.68) in morbidity and mortality observed. No differences ( ≥ 0.27) were detected for HCW, LM area, backfat, marbling score, yield grade, or KPH. Increased dietary RUP and fat content during late gestation increased cow BW and BCS but did not alter milk production, subsequent reproduction, or subsequent calf performance or carcass characteristics.

Characterization of the fecal bacteria communities of forage-fed horses by pyrosequencing of 16S rRNA V4 gene amplicons

The diversity of the equine fecal bacterial community was evaluated using pyrosequencing of 16S rRNA gene amplicons. Fecal samples were obtained from horses fed cool-season grass hay. Fecal bacteria were characterized by amplifying the V4 region of bacterial 16S rRNA gene. Of 5898 mean unique sequences, a mean of 1510 operational taxonomic units were identified in the four fecal samples. Equine fecal bacterial richness was higher than that reported in humans, but lower than that reported in either cattle feces or soil. Bacterial classified sequences were assigned to 16 phyla, of which 10 were present in all samples. The largest number of reads belonged to Firmicutes (43.7% of total bacterial sequences), Verrucomicrobia (4.1%), Proteobacteria (3.8%), and Bacteroidetes (3.7%). The less abundant Actinobacteria, Cyanobacteria, and TM7 phyla presented here have not been previously described in the gut contents or feces of horses. Unclassified sequences represented 38.1% of total bacterial sequences; therefore, the equine fecal microbiome diversity is likely greater than that described. This is the first study to characterize the fecal bacterial community in horses by the use of 16S rRNA gene amplicon pyrosequencing, expanding our knowledge of the fecal microbiota of forage-fed horses.

Dry Matter Intake and Digestion of Perennial and Annual Cool-Season Grasses by Sheep

Excess perennial cool-season grass production can be harvested as hay for feeding later. Thus, a series of experiments were conducted to estimate DMI and digestibility of perennial cool-season grasses relative to an annual cool-season grass hay. In Exp. 1, wheat (Triticum aestivum var. Pioneer 2174), tall wheatgrass (Thinopyrum ponticum var. Jose), smooth brome (Bromus inermis var. Lincoln), and intermediate wheatgrass (Thinopyrum intermedium var. Manska) were harvested in the spring as high-moisture hay and fed to lambs. At feeding, all 4 hays contained more (P < 0.05) ADF and less N than as standing forage. Apparent digestibility of the DM, NDF, and ADF fractions and DMI were not different (P > 0.10) among the hays used in this experiment. In Exp. 2, grasses were harvested as field-dried (DM >65%) hay from established stands of Jesup Max Q (Festuca arundinacea) and Nanyro (F. arundinacea) tall fescues, Harusakae meadow fescue (Festuca pratensis), and wheat (var. Pioneer 2174). Lambs fed wheat hay had greater (P < 0.05) DMI (69.3 g/kg BW0.75, respectively) compared with lambs fed Jessup or Nanyro (35.0 and 33.8 g/BW0.75), and lambs fed Harusakae hay had intermediate DMI (50.2 g/BW0.75). Digestibility of Jesup hay was greater (P < 0.05) than digestibility of the other 3 hays. Excess cool-season grasses can be harvested as high-moisture or field-dried hay, but harvested hays had greater concentrations of ADF and NDF and a lesser concentration of N than preharvest standing forage.

Dry Matter Recovery, Nutritive Value, and Economics of Cool-Season Grass Hay Stored for Seven or Fifteen Months in the Southern Appalachian Mountains

Forty 122 x 152-cm large round bales of mixed cool-season grasses were utilized in a study designed to determine the influence of storage system on spoilage and the changes in concentrations of nutrients during long term storage. Bales were randomly allocated to 1 of 5 treatments: 1) stored on the ground without cover; 2) stored on wooden pallets without cover; 3) stored on the ground and covered with a tarp; 4) stored on wooden pallets and covered with a tarp; and 5) stored in a barn on pallets. Bales were sampled after 7 or 15 mo of storage to determine the percentage of spoilage loss. Generally, losses were greater for bales stored without cover than for covered bales or bales stored in a barn. Concentrations of CP, ADF, and NDF increased with increasing time in storage for bales in most storage systems; however, concentrations of CP were not affected by sampling date in storage systems using wooden pallets without cover and wooden pallets in a barn. The economic analysis shows that the most cost effective system of hay storage depends on many factors, including the type of storage system, the length of the storage period, the initial cost of the hay, and the relative cost of alternative storage systems.

Effects of dam nutrition on growth and reproductive performance of heifer calves1

A 3-yr study was conducted with heifers (n = 170) whose dams were used in a 2 x 2 factorial arrangement of treatments to determine the effects of late gestation (LG) or early lactation (EL) dam nutrition on subsequent heifer growth and reproduction. In LG, cows received 0.45 kg/d of a 42% CP supplement (PS) or no supplement (NS) while grazing dormant Sandhills range. During EL, cows from each late gestational treatment were fed cool-season grass hay or grazed sub-irrigated meadow. Cows were managed as a single herd for the remainder of the year. Birth date and birth weight of heifer calves were not affected (P > 0.10) by dam nutrition. Meadow grazing and PS increased (P = 0.02; P = 0.07) heifer 205-d BW vs. feeding hay and NS, respectively. Weight at prebreeding and pregnancy diagnosis were greater (P < 0.04) for heifers from PS dams but were unaffected by EL nutrition (P > 0.10). There was no effect (P > 0.10) of LG or EL dam nutrition on age at puberty or the percentage of heifers cycling before breeding. There was no difference (P > 0.10) in pregnancy rates due to EL treatment. Pregnancy rates were greater (P = 0.05) for heifers from PS dams, and a greater proportion (P = 0.005) of heifers from PS dams calved in the first 21 d of the heifers' first calving season. Nutrition of the dams did not influence (P < 0.10) heifers' average calving date, calving difficulty, and calf birth weight during the initial calving season. Weight at the beginning of the second breeding season was greater (P = 0.005) for heifers from PS dams but was not affected by maternal nutrition during EL (P > 0.10). Dam nutrition did not affect (P > 0.10) heifer ADG or G:F ratio. Heifers from PS dams had greater DMI (P = 0.09) and residual feed intake (P = 0.07) than heifers from NS cows if their dams were fed hay during EL but not if their dams grazed meadows. Heifers born to PS cows were heavier at weaning, prebreeding, first pregnancy diagnosis, and before their second breeding season. Heifers from cows that grazed meadows during EL were heavier at weaning but not postweaning. Despite similar ages at puberty and similar proportions of heifers cycling before the breeding season, a greater proportion of heifers from PS dams calved in the first 21 d of the heifers' first calving season, and pregnancy rates were greater compared with heifers from NS dams. Collectively, these results provide evidence of a fetal programming effect on heifer postweaning BW and fertility.

Evaluation of annual ryegrass straw:corn juice silage with cattle and water buffalo: digestibility in cattle vs. buffalo, and growth performance and subsequent lactational performance of Holstein heifers

Two experiments were undertaken to evaluate ryegrass straw:corn juice silage (35:65 wt. wt. ) as a basal feed for Holstein heifers and to determine digestibility of this silage in water buffaloes and Hereford cows. In experiment 1, (143 d) 48 pregnant heifers (16 animals; 3 pens per treatment) were fed (1) mixed cool season grass hay (GH), (2) straw:corn juice silage (S), and (3) S + 125 g fishmeal d −1 (SF). All animals were also fed 2.27 kg concentrate per day. Average daily gain (kg) was 1.00, 0.82 and 1.02 for GH, S and SF groups, respectively. ADG in the SF group was higher ( P < 0.05) than in the S group. Roughage DM intake was 7.77, 6.45 and 6.02 (kg d −1) for the GH, S and SF treatments, respectively. Roughage intakes were lower ( P < 0.05) for S and SF than for GH and lower ( P < 0.05) for SF than F. Feed efficiency was 12.91, 14.31 and 10.96 for H, S and SF, respectively. Feed efficiency was better in SF vs. S ( P < 0.05). Subsequent milk yields and composition data were obtained for 300 days post-partum after the completion of the feeding trial. Milk, milk fat and SNF yields (kg d −1) were 30.91, 1.13, 1.03; 31.5, 1.19, 1.05; and 32.06, 1.19 and 1.07 for H, S, and SF, respectively. None of the milk production parameters differed ( P > 0.05) among animals from the different pre-partum treatments. In experiment 2, six water buffaloes and six Hereford cows were fed the same silage as fed to experiment 1 animals. The silage was mixed with 0.39% chromic oxide and fed for 15 days. Fecal grab samples were obtained over several days. Digestibility (percent) of DM, CP, NDF and ADF was calculated by determination of the chromic oxide concentration in feed and feces. Respective apparent digestibility values for buffaloes and cows were: dry matter, 47 and 40%; crude protein, 47 and 34%; neutral detergent fiber, 47 and 41%; and acid detergent fiber, 43 and 35%. All digestibility parameters were significantly higher ( P < 0.05) in buffaloes than in cows. In conclusion, straw:corn juice silage was equivalent to grass hay in supporting weight gain and feed efficiency of Holstein heifers, and FM supplementation of the silage significantly improved performance. There was no effect of pre-partum feeding of grass straw:corn juice silage on subsequent lactational performance of Holstein heifers as compared to the control diet containing grass hay.

Liveweight gain by beef calves grazing cool-season annual grass in the spring and supplemented with grass hays

Supplementing beef calves grazing cool-season annual grass with warm- or cool-season grass hay (0.4% liveweight), differing in cell wall content, depressed weight gain more by heifers than steers. Adding supplemental corn (0.8% liveweight) to hay only improved gain by heifers, though gain was not greater than controls for either gender. Key words: Cattle, beef, supplements, pasture, corn, hay

Feed intake and digestion by Holstein steer calves consuming bermudagrass or ryegrass-wheat hay and supplemented with alfalfa, corn or monensin

Effects of supplementing with legume and/or grain or monensin on intake and digestion by Holstein steer calves fed warm or cool season grass hay (bermudagrass or ryegrass-wheat) were determined. In Experiment 1, eight steers (140 kg body weight (BW)), in two simultaneous 4 × 4 Latin squares, were fed bermudagrass (72% neutral detergent fiber, NDF) or ryegrass-wheat hay (59% NDF) ad libitum and no supplement (BG and RIV treatments) or approximately 0.5% BW of ground alfalfa hay (BG-A and RW-A treatments), 1.0% BW of ground corn (BG-C and RW-C treatments) or both once daily (BG-AC and RW-AC treatments). Supplement treatments affected organic matter (OM) intake differently with each forage (2.97 kg day −1, 3.35 kg day −1, 4.05 kg day −1, 4.07 kg day −1, 4.07 kg day −1, 4.28 kg day −1 and 4.54 kg day −1 for BG, BG-A, BG-C, BG-AC, RW, RW-A, RW-C and RW-AC, respectively; SE = 0.11). Total tract NDF digestibility was 63.2%, 62.3%, 61.1%, 59.7%, 68.9%, 67.3%, 60.9% and 54.2% (SE = 3.0) for BG, BG-A, BG-C, BG-AC, RW, RW-A, RW-C and RW-AC, respectively (greater with than without supplementation and for alfalfa and corn given together vs. alone; P < 0.05). Supplementation with alfalfa or corn alone increased digestible OM intake with bermudagrass but not with ryegrass-wheat; offering alfalfa and corn together increased digestible OM intake with both forages as compared with corn alone (1.72 kg day −1, 2.01 kg day −1, 2.57 kg day −1, 2.74 kg day −1, 2.71 kg day −1, 2.71 kg day −1, 2.77 kg day −1 and 3.02 kg day −1 for BG, BG-A, BG-C, BG-AC, RW, RW-A, RW-C and RW-AC, respectively; SE = 0.13). In another experiment (4 × 4 Latin square), four steers (228 kg BW) were fed bermudagrass (75% NDF) or orchardgrass (64% NDF) hay ad libitum with 0.5% BW of ground corn and 0 or 200 mg of monensin. Neither intake nor digestibility were significantly affected by monensin, but monensin tended to depress both measures with bermudagrass. Characteristics of forages such as those unique to cool and warm season grasses can affect changes in feed intake and digestion with supplementation.

Intake and digestion in cattle fed warm- or cool-season grass hay with or without supplemental grain.

Intake and digestion in cattle fed warm- or cool-season grass hay with or without low-level grain supplementation were studied with a 2 x 2 factorial arrangement of treatments in two 4 x 4 Latin square experiments. In Exp. 1, four cannulated beef cows (396 kg) were given Bermuda grass (B) or orchard grass (OG) hay at 1.5% body weight (BW) with 0 or .3% BW of ground corn (C; dry matter). Bermuda grass contained 12.1% crude protein, 79.3% neutral detergent fiber (NDF) and 5.5% acid detergent lignin (ADL); OG contained 10.6% crude protein, 82.4% NDF and 8.1% ADL. An interaction (P less than .07) between forage type and C supplementation was noted for microbial N entering the duodenum; C supplementation had a positive effect with B (30% increase) and little effect with OG. Corn supplementation did not affect ruminal NDF digestion with B, but it elicited an increase with OG (interaction, P less than .05; means were 60.7, 60.1, 61.5 and 66.3%). In the second experiment, growing dairy steers (196 kg) were given ad libitum access to similar B or OG hays and were fed 0 or .5% BW of C. Dry matter (DM) intake was lower for OG than for B (P less than .05) and was lower with than without C (P less than .06; means were 2.76, 2.56, 2.53 and 2.30% BW for B, BC, OG and OGC, respectively). Total tract organic matter digestion (%) was higher for OG than for B (P less than .10) and was higher with than without C (means were 54.7, 61.5, 60.4 and 65.3%). In conclusion, chemical constituents such as NDF may govern differences in intake between warm- and cool-season grasses, but physical attributes of the forages appear more important to digestion.