Tall Fescue Hay Research Articles

The Effect of Rice Straw and Tall Fescue Hay for Holstein Dairy Heifers on Growth, Age at First Calving and Feed Cost

The Effect of Rice Straw and Tall Fescue Hay for Holstein Dairy Heifers on Growth, Age at First Calving and Feed Cost

Late gestational nutrient restriction in primiparous beef females: Performance and metabolic status of lactating dams and pre-weaning calves.

Fall-calving primiparous beef females [body weight (BW): 451 ± 28 (SD) kg; body condition score (BCS): 5.4 ± 0.7] were individually-fed 100% (control; CON; n = 13) or 70% (nutrient restricted; NR; n = 13) of estimated metabolizable energy and metabolizable protein requirements from day 160 of gestation to calving. Post-calving, all dams were individually-fed tall fescue hay supplemented to meet estimated nutrient requirements for maintenance, growth, and lactation in Calan gates until day 149 of lactation, which limited calves to milk only. From day 150 of lactation until weaning at day 243, dams and calves were group-fed in drylots. Dam BW and metabolic status were determined every 21 d, and BCS and backfat (BF) were determined every 42 d of lactation until weaning. Pre-weaning calf BW, size, and metabolic status were determined every 21 d. Data were analyzed with nutritional plane, calving date, and calf sex (when P < 0.25) as fixed effects. Circulating metabolites included day and nutritional plane × day as repeated measures. We previously reported that post-calving, NR dams were 64kg and 2.0 BCS less than CON, but calf BW and size at birth were not affected. During the first 147 d of lactation, NR dams gained more (P < 0.01) BW than CON and increased (P < 0.01) BCS, while CON decreased (P ≤ 0.01) BCS and BF. Previously, NR dams had lower (P < 0.01) circulating triglycerides on day 1 of lactation, tended to have lower (P = 0.08) triglycerides on day 21, and had lower (P ≤ 0.04) non-esterified fatty acids (NEFA) on days 21 and 243 than CON. Maternal glucose and urea N were not affected (P ≥ 0.73). At weaning, NR dams weighed 17kg less (P = 0.15), were 0.67 BCS lower (P < 0.01), and tended to have less (P = 0.06) BF. Calves born to NR dams weighed less (P = 0.02) than CON by day 42 of age and were 13% smaller (P < 0.01) at weaning. Calf girth measures diverged (P ≤ 0.05) by day 21 of age, and skeletal size measures were less (P ≤ 0.08) for calves born to NR dams at most timepoints after day 63 of age. Calves born to NR dams tended to have lower (P = 0.09) circulating urea N pre-weaning than CON, but glucose, triglycerides, and NEFA were not affected (P ≥ 0.16). In summary, first-parity beef females that were nutrient restricted during late gestation experienced compensatory growth and gained body condition during lactation but were still thinner at weaning. Nutrient restriction reduced pre-weaning calf growth, likely due to decreased milk production.

71 Effects of Late Gestational Nutrient Restriction on Calf pre-Weaning Growth, Backgrounding and Feedlot Performance, and Carcass Composition

Abstract Fall-calving Hereford-SimAngus heifers [single-sired; BW: 451 ± 28 (SD) kg; BCS: 5.4 ± 0.7] bred to a single sire were individually fed 100% (control; CON; n = 12) or 70% (nutrient restricted; NR; n = 13) of NASEM metabolizable energy and metabolizable protein requirements for maintenance, pregnancy, and growth from day 160 of gestation to calving. Post-calving, all females were fed chopped tall-fescue hay supplemented to meet lactational nutrient requirements in Calan gates to constrain diets of calves to milk only until day 147, then pen-fed in drylots until weaning at day 242 ± 3 (SD). Post-weaning, calves were fed a tall fescue hay-based backgrounding diet in the same large drylots for 53 ± 12 d, then moved to partially covered pens with GrowSafe feeding systems in 2 groups and fed a corn-based feedlot diet (formulated to be 18.3% CP, 1.21 Mcal NEg/kg, DM basis; 89% DM) for 255 ± 3 d (similar days on feed rather than carcass endpoint). Cattle were harvested in a commercial plant, and camera carcass grading was performed. Data were analyzed with maternal treatment, calving date, and calf sex (when P &amp;lt; 0.25) as fixed effects; feedlot group was included for feedlot and carcass measures. We previously reported that birth weight was not affected (P = 0.72), but NR decreased (P &amp;lt; 0.04) milk production by 15%. Calves born to NR dams had reduced ADG from birth to day 147 (P = 0.02), day 147 to weaning (P = 0.08), and birth to weaning (P = 0.003), resulting in NR calves having 13% lighter (P = 0.004) weaning weight. Backgrounding ADG was not affected (P = 0.80) by maternal treatment; thus, feedlot entry BW was 11% less (P = 0.009) in NR calves. On day 28, 56, 84, and 112 on feed, NR calves weighed less (P ≤ 0.09) than control. Final BW was not affected (P = 0.91) by maternal treatment. Feedlot ADG was greater for NR calves from day 168 to slaughter (P = 0.02) and the overall feeding period (P = 0.03), but not before day 168 on feed (P ≥ 0.22). Calves born to NR dams had less (P = 0.02) dressing percentage, but improved (P = 0.02) yield grade and backfat thickness. Hot carcass weight, ribeye area, marbling score, and KPH were not affected (P ≥ 0.26) by maternal treatment. Percent prime, yield grade ≤ 2, and yield grade ≥ 4 were not affected (P ≥ 0.29) by maternal treatment. Overall, late gestational nutrient restriction decreased growth pre-weaning but increased late finishing growth, without affecting backgrounding or early feedlot growth. These cattle had leaner carcasses after similar days on feed, suggesting that late gestational nutrient restriction altered growth patterns or body composition.

91Ex Vivo Fermentation of Corn and hay by Rumen Bacteria from Sheep and Cattle

Abstract Data from cattle and sheep studies are often utilized interchangeably to make inferences regarding ruminant nutrition and physiology, but few studies have directly compared rumen microbiological responses. The objective of this study was to evaluate species differences in ex vivo fermentation of concentrates and forages. Rumen fluid was obtained via oral intubation from Holstein steers (n = 3; age: 212 ± 8 d) and Polypay ram lambs (n = 3; age; 34 ± d) fed a 100% tall fescue (TF) hay diet ad libitum. Mixed bacterial cell suspensions in buffered media contained the following feed substrate treatments (3% wt/vol): TF hay (HY), 2:1 TF hay-to-corn (HC), 2:1 corn-to-TF hay (CH), and corn (CN). Samples were collected after 2, 4, 8, and 24 h of incubation (39°C) for analysis of pH and lactate. Data were analyzed by PROC MIXED in SAS (v. 9.4, SAS Inst. Inc., Cary, NC). The pH differed by species (P = 0.004), treatment (P = 0.005), and time (P &amp;lt; 0.001), with a species by treatment by time interaction (P = 0.001). The pH at 2 h was 6.61 ± 0.02 regardless of species or treatment, and pH declined by 24 h for both steer and ram rumen cell suspensions in all treatments (P &amp;lt; 0.001). Final pH at 24 h did not differ between species for HY (6.15 ± 0.03), but for all treatments including corn, pH was lower in steer rumen cell suspensions (HC: steer – 5.86, ram – 6.06; CH: steer – 5.59, ram – 5.98; CN: steer – 5.26, ram – 5.91 ± 0.05; P ≤ 0.004). Lactate accumulation differed by species (P = 0.038), treatment (P = 0.048), and time (P &amp;lt; 0.0001), with a species by treatment by time interaction (P &amp;lt; 0.001). Lactate at 8 h did not differ between species for HY (steer:3.06, ram: 9.22 ±.84 mmolּ L-1), but was greater in steer than in ram cell suspensions fermenting HC (steer: 12.64; ram: 6.39 ±.84 mmolּ L-1), CH (steer: 13.44; ram: 3.21 ±.84 mmolּ L-1), and CN (steer:3.63; ram:.10 ±.84 mmolּ L-1; P ≤ 0.023). By 24 h, lactate accumulation was minimal for HY, HC, and CH (≤ 1.50 mmolּ L-1) and did not differ between species (P ≥ 0.657). However, lactate at 24 h was greater in steer rumen cell suspensions fermenting CN (steer: 25.78; ram: 182 ± 1.84 mmolּ L-1; P &amp;lt; 0.001). These results indicate that the rumen microbial community of sheep and cattle may differ both in composition and function resulting in different capacities to utilize common dietary feed ingredients.

PSXV-15 Effect of Supplemental Garlic on the Incidence of Heinz Body Anemia in non-Working Horses

Abstract Garlic (Allium sativum) has been historically used as a fly and pest control for horses, a practice that continues today. Recent research has shown garlic supplementation may cause Heinz body anemia in horses. The purpose of this study was to evaluate the incidence of Heinz body anemia in horses supplemented with incremental amounts of powdered garlic. The study included 12 horses divided into 4 groups (n=3), with horse serving as the experimental unit. Supplementation groups included: Control (0.0 g garlic/kg BW and 14.3 g molasses) and 3 supplementation rates: Low (0.0625 g garlic/kg BW and 14.3 g molasses), Medium (0.125 g garlic/kg BW and 14.3 g molasses), and High (0.1875 g garlic/kg BW and 14.3 g molasses) that were fed daily for 74 days. Horses were maintained on dormant tall fescue pasture and had ad libitum access to medium quality tall fescue hay throughout the study. Blood samples (jugular venipuncture) and weights were taken on day 0, 25, 50, and 74. Data were analyzed using Proc Mixed (SAS 9.4) for a completely randomized design, α = 0.05. Garlic supplementation reduced red blood cell count (P = 0.028) compared with Control and lymphocyte count (P = 0.046) showed a quadratic response to supplementation rate, with Low having the greatest lymphocyte count. A trend was noted for white blood cell count (P = 0.090) and hemoglobin count (P = 0.074) with garlic supplementation. Heinz body count (P = 0.406) was not affected by garlic supplementation. Results are interpreted to mean that garlic supplementation did not induce Heinz body anemia in horses; however, other blood constituents, including red blood cell and lymphocyte counts, were affected. Horses in the study were non-working, further research would be needed to evaluate any potential health impacts these variations in blood constituent concentrations would have in working horses.

79 Effects of Nutrient Restriction During Late Gestation of the First Parity on cow and Calf Performance During the Second Lactation

Abstract Fall-calving Herford-SimAngus heifers were individually fed either 100% (control; CON, n = 10) or 70% (nutrient restricted; NR, n = 12) of NASEM metabolizable energy and metabolizable protein requirements from d 160 of gestation to calving. Postpartum cows were individually fed 100% of energy and protein requirements until d 149 of lactation, then fed tall fescue hay or pasture as a single group through parity 2. Second parity cow performance and calf size were measured at birth, d 30, and d 60 post-calving. Single-quarter colostrum yield was collected pre-suckling. At d 30 and 60 of lactation, 4-hour milk yield was collected. Data were analyzed with the fixed effect of first parity nutritional plane, and calving or breeding date, calf sex, and calf sire (calf measures) were covariates. Milk yield included day and day x treatment (repeated measures). We previously reported that in parity 1, NR reduced (P ≤ 0.04) colostrum and milk yield, calf weaning weight, and dam weaning BCS. From calving to d 60 of parity 2, CON cows had greater (P ≤ 0.008) BCS and greater (P = 0.003) backfat on d 30. Additionally, CON cows had greater (P ≤ 0.002) BW compared with NR at d 30 and 60 of lactation. Calf size was not affected (P ≥ 0.17) by first parity nutritional plane except that cannon length at birth and d 60 tended (P ≤ 0.08) to be longer in CON calves. Colostrum and milk volume and weight were not affected (P ≥ 0.37) by first parity nutritional plane. Milk yield was greater (P ≤ 0.001) at d 30 than d 60. These data indicate that cow BW and energy reserves remained less in parity 2 when heifers experienced late gestational nutrient restriction, but calf size, colostrum yield, and milk yield were unaffected in the second parity.

Pre-Partum Supplementation with Polyunsaturated Fatty Acids on Colostrum Characteristics and Lamb Immunity and Behavior after a Mild Post-Weaning Aversive Handling Period.

Simple SummaryLivestock farming faces the necessity of reducing the use of medicines, particularly antimicrobials, without compromising animal welfare as one main challenge. A strategy to improve animal health, specifically in breeding stock, relies on improved nutrition of the mothers during late pregnancy and on management factors during early life. These could affect mother and offspring physiological functions (calostrogenesis, fetal development or maturation of lamb’s immune system) and potentially modulate their stress-response capabilities. We studied the effect of pre-partum omega-3 (n-3) polyunsaturated fatty acids supplementation on ewe colostrum composition and immunological quality and whether changes resulted in any advantage on lambs’ passive immunization and on their physiological, behavioral, and inflammatory responses when subjected to a post-weaning stressor to confer stress resilience. Gestational supplementation with nutrients rich in essential fatty acids was effective to enhance colostrum quality related to biologically active molecules, such as conjugated linoleic acid, which plays a role in the regulation of the immune response. Stress resilience was studied by assessing lamb’s behavioral response after exposing lambs to a combination of stressors and by measuring plasma cortisol concentrations and immunological responses to specific circulating cytokines. This work highlights the complex relationship between late pregnancy nutrition in the mothers and immune system development in the offspring and explores the potential for programming nutrition interventions to develop more resilient livestock and to tackle the need for a reduction in the use of antibiotics.We studied the effect of pre-natal supplementation with n-3 α-linolenic acid (ALA) combined with a tannin-rich forage on colostrum composition and immunological quality and whether these changes had advantageous effects on lambs’ survival and stress reaction to a post-weaning stressor. Forty-eight Latxa ewes were fed during the last five weeks of pregnancy with two experimental diets: a control diet based on a neutral concentrate and forage (tall fescue hay; CO-FES), and a supplemented diet based on polyunsaturated (PUFA)-rich concentrate and tanniferous forage (sainfoin; ALA-SAIN). After parturition, twenty ewes had their blood and colostrum sampled, and their lambs were monitored until post-weaning. Lambs were afterwards subjected to (i) an aversive handling period (AHP) followed by a behavioral assessment and (ii) inflammatory and lymphocyte proliferation challenge. Feeding ALA-SAIN resulted in changes in colostrum fatty acid composition, specifically higher α-linoleic acid (p < 0.001), conjugate linoleic acid (p = 0.005), vaccenic acid (p = 0.006) and long-chain n-3 PUFA (p = 0.004). Pre-partum nutrition did not affect lamb immunoglobulin (Ig) G apparent efficacy absorption, but circulating IgG tended to be higher (p = 0.054) in ALA-SAIN lambs. ALA-SAIN lambs interacted more frequently with other lambs (p = 0.002), whereas ALA-SAIN females spent more time closer to other lambs (p < 0.001). Plasma cortisol was higher (p = 0.047) and plasma interleukin (IL)-2 lower (p = 0.003) in CO-FES lambs. This research highlights the importance of prenatal nutrition on the immune system stimulation and lambs’ behavior as a strategy to improve lambs’ health and welfare during early life.

68 Late Gestational Nutrient Restriction Decreases Blood Flow to the Mammary Gland in Lactating Primiparous Beef Females

Abstract To determine the effects of late gestational nutrient restriction on mammary blood flow during lactation, fall-calving Hereford-SimAngus heifers (single-sired; BW: 451 ± 28 [SD] kg; BCS: 5.4 ± 0.7) bred to a single sire were individually-fed 100% (control; CON; n = 10) or 70% (NR; n = 13) of NASEM net energy and metabolizable protein requirements for maintenance, pregnancy, and growth from d 160 of gestation to calving. Post-calving, all females were individually fed chopped tall fescue hay supplemented to meet lactational nutrient requirements in Calan gates. Transrectal color Doppler ultrasonography of both external pudendal arteries was conducted every 21 d from d 23 to 107 of lactation. Total mammary blood flow was calculated and hemodynamics from both sides averaged. Data were analyzed with fixed effects of nutritional plane, day of lactation, and their interaction, using repeated measures. Calving date and calf sex (if P &amp;lt; 0.25) were fixed effects, and Doppler angle of insonation was included in the model for flow-related variables. We have previously reported that CON cows had greater (P ≤ 0.003) BW, BCS, and backfat from calving to d 147 of lactation, and NR cows had 15% less (P &amp;lt; 0.04) milk yield. External pudendal artery pulsatility index tended to be greater (P = 0.06) and resistance index, peak systolic velocity, and cross-sectional area were greater (P ≤ 0.04) in CON cows. Heart rate was greater (P = 0.008), yet mammary blood flow was 19% less (P = 0.004) in NR cows. Mammary blood flow/cow BW and blood flow/milk yield were not affected (P ≥ 0.13) by nutritional plane. All hemodynamic variables were affected by day (P ≤ 0.04) except resistance index (P = 0.11). In summary, late gestational nutrient restriction decreased mammary blood flow similarly to the reduction observed in milk yield.

525 Late-Breaking: Late Gestational Nutrient Restriction of Primiparous Beef Heifers Decreases Milk Yield and Pre-weaning Calf Growth

Abstract Fall-calving Hereford-SimAngus heifers (single-sired; BW: 451 ± 28 [SD] kg; BCS: 5.4 ± 0.7) bred to a single sire were individually-fed 100% (control; CON; n = 12) or 70% (nutrient restricted; NR; n = 13) of NASEM net energy and metabolizable protein requirements for maintenance, pregnancy, and growth from d 160 of gestation to calving. Post-calving, all females were limit-fed chopped tall-fescue hay supplemented to meet lactational nutrient requirements in Calan gates to constrain calves’ diets to milk only until d 147. Four-hour milk yields were measured 5 times; calf size was determined every 21 d. Data were analyzed with treatment, calving date, and calf sex (when P &amp;lt; 0.25) as fixed effects; day and day x treatment were included for milk yield. From calving to d 147, CON cows had greater (P ≤ 0.003) BW, BCS, and backfat, but NR cows gained more (P ≤ 0.004) BW, BCS, and backfat. Milk weight and volume was 15% less (main effect; P &amp;lt; 0.04) for NR cows. Calf size did not differ at birth (P ≥ 0.27). From d 42 to 147, calves born to NR dams had lower (P ≤ 0.02) BW. Heart, abdominal, and flank girths were less (P ≤ 0.07) for NR calves through d 147. Calf ribeye area tended to be less (P ≤ 0.11) in NR calves at d 42, 84, and 126. Nutrient restricted calves had less shoulder to rump length (d 63 to 147; P ≤ 0.08), shoulder height (d 63 to 126; P ≤ 0.02), cannon length (d 42 to 105 and 147; P ≤ 0.09), and cannon circumference (d 63 and 105 to 147; P ≤ 0.06). These data indicate that even when dams are fed to meet lactational requirements, milk yield and calf growth are reduced by late gestational nutrient restriction.

Comparison of injectable trace minerals vs. adjuvant on measures of innate and humoral immune responses of beef heifers

• Injectable trace minerals (ITM), adjuvant (ADJ) and saline did not impact calf growth • Haptoglobin and ceruloplasmin were greatest for ADJ but similar between SAL and ITM • ITM enhanced calf antibody titers but not to the extent as ADJ injection Previous studies reported heightened innate and humoral immune responses among cattle administered injectable trace minerals (ITM) concurrent to immunogen challenge, thus suggesting a potential adjuvant-like activity of ITM. To pursue this concept further, a two-year study was conducted at the Mountain Research Station (North Carolina State University, Waynesville) to evaluate immunological responses of Angus heifers (n = 22, 235 ± 18 kg of BW and 225 ± 4 d of age in yr 1; n = 36, 237 ± 6 kg of BW and 247 ± 5 d of age in yr 2). On d 0 (30 days after weaning), heifers were administered two 5-mL i.m. injections of porcine red blood cells (PRBC; Lampire Biological Laboratories, Pipersville, PA) solution (25% PRBC and 75% sterile PBS; Amresco, Solon, OH), concurrent to either a single 2.5-mL s.c. injection of sterile saline (SAL; 0.9% NaCl), a squalene-based oil-in-water adjuvant (ADJ; AddaVax; InvivoGen, Inc. San Diego, CA) that specifically induces a humoral immune response, or injectable trace minerals (ITM; MultiMin 90; MultiMin USA, Inc. Fort Collins, CO; 60, 10, 15 and 5 mg/mL of Zn, Mn, Cu and Se). During the 28-d study, heifers were offered tall fescue hay ( Lolium arundinacea ) and concentrate at 1.2 and 1.0% of BW (DM basis), respectively, blended with 114 g daily of a complete mineral mix. Shrunk BW was recorded on d 0 and 28 following 12 h of feed and water withdrawal. Blood samples were collected on d 0, 2, 7, 15, and 21 for determination of antibody titers against PRBC and plasma concentrations of ceruloplasmin and haptoglobin. Liver biopsy samples were collected 1 mo prior to weaning and on d 15 after weaning for determination of trace mineral status. No differences were detected ( P ≥ 0.13) for BW change, ADG, G:F, or DMI. Liver Se concentrations on d 15 were greater ( P ≤ 0.01) for heifers receiving ITM compared to SAL and ADJ treatments. Plasma haptoglobin concentrations on d 2 were greatest for ADJ ( P < 0.0001) and did not differ between SAL and ITM heifers ( P ≥ 0.46). Plasma ceruloplasmin concentrations on d 2 were greatest for ADJ ( P ≤ 0.04) and did not differ between SAL and ITM heifers ( P = 0.39). On d 7, plasma concentrations of ceruloplasmin did not differ ( P = 0.37) between ADJ and ITM, were less for SAL vs. ADJ ( P = 0.005), and tended to differ ( P = 0.064) between ITM and SAL heifers. Serum PRBC titers were greatest for ADJ ( P ≤ 0.03) vs. SAL on d 7, 15, and 21 and ITM on d 7 ( P < 0.001). Serum PRBC titers did not differ between SAL and ITM on d 7 and 15 ( P ≥ 0.23), but were greater in ITM vs. SAL on d 21 ( P = 0.03). In summary, ITM prolonged the antibody titers against PRBC on d 21 compared to saline injection in mineral-adequate beef calves, but not as quickly or to the extent of ADJ injection.

Determining the Rate of Ergot-alkaloid Degradation in Toxic Endophyte-infected Tall Fescue Hay and Haylage During Long Term Storage

Abstract The objectives of this experiment were to determine changes in the nutritive value and ergot alkaloid concentrations of endophyte-infected tall fescue hay and haylage during a 180-d storage period. Forage from a single field of Kentucky-31 tall fescue was cut for hay in late June and allowed to dry in the field. The dry matter (DM) of the windrow of cut forage was measured every 2 h after clipping. Forage was sampled from the windrow in 6 location blocks once forage DM reached target levels for haylage and hay treatments. Haylage and hay samples were taken when the DM of the windrow reached 50% and 80%, respectively. Seven subsamples of each treatment within block were chopped to 1.91 cm in length with a lettuce chopper and vacuum sealed in oxygen-excluding bags. Sample bags were stored indoors and opened at 30 d intervals over the 180-d storage period. Samples were analyzed for pH, nutritive value, and individual ergot alkaloid concentrations using high-performance liquid chromatography. Within each storage day, treatment within block was considered the experimental unit. Data were analyzed in SAS using the MIXED procedure with fixed effects of treatment, day, and the treatment by day interaction. Location block was considered a random effect. As expected, pH was decreased for haylage compared to hay at all time points (P &amp;lt; 0.01) and DM was greater (P &amp;lt; 0.01) for hay compared to haylage. Neutral detergent fiber values were greater (P &amp;lt; 0.01) for hay compared to haylage and declined during storage (P &amp;lt; 0.01). Total ergot alkaloid concentrations did not differ by treatment (P = 0.61), but ergovaline concentrations declined (P &amp;lt; 0.01) during storage. Collectively, these results indicate minimal differences in nutritive value and ergot alkaloid concentrations between hay and haylage during storage, and that ergovaline concentrations decline during storage.

Effects of cold temperature and fat supplementation on growth performance and rumen and blood parameters in early fattening stage of Korean cattle steers

We investigated the effects of cold ambient temperatures and the supplementation of rumen-protected fat (RPF) on the growth performance, rumen fermentation parameters, and blood metabolic parameters of Korean cattle steers during the early fattening stage. Twenty Korean cattle steers (body weight = 356.5 ± 3.72 kg, age = 16.8 ± 0.34 months) were divided into two groups: 10 steers were fed a conventional concentrate (control), and 10 steers were fed a concentrate supplemented with 8 g/kg RPF (treatment). Steers were fed a concentrate at 1.6% body weight and 3 kg tall fescue hay daily for 12 weeks in 2016: January 8 to February 2 (P1), February 3 to March 3 (P2), and March 4 to April 1 (P3). Body weight was measured, and blood and rumen fluid were collected four times from each steer: at the start of the experiment, and then at 4-week intervals. The mean indoor temperatures during P1 (−7.37 ℃) and P2 (–2.96℃) were lower (P < 0.001) than the mean P3 temperature (6.22 ℃). These lower temperatures were within the range that causes mild to moderate cold stress (CS) in other cattle breeds. By contrast, the mean indoor temperature during P3 is considered thermoneutral. The average daily gain (P = 0.39 and P = 0.16) and gain-to-feed ratio (P = 0.26 and P = 0.57) were not affected by RPF supplementation or time-period. Total dry matter, crude protein, ether extract, neutral detergent fiber, and acid detergent fiber intakes per body weight were higher (all P < 0.001) in colder P1 or P2 compared to other time periods, but these variables were not affected (P ≥ 0.31) by RPF supplementation, except ether extract intake. Ruminal total VFA concentrations were higher (P = 0.001) in a colder January than in other months, but these were not affected (P = 0.26) by RPF supplementation. The ruminal propionate proportion was higher (P < 0.001) in a colder January than in other months, whereas the butyrate proportion was lower (P = 0.01). Serum triglyceride (P = 0.007), total cholesterol (P = 0.001), and high-density lipoprotein (P = 0.03) concentrations were lower during colder months. RPF supplementation increased (P = 0.008) serum cholesterol concentrations. Our results indicate that mild to moderate CS may not affect Korean cattle, as cattle growth performance was not affected by colder temperatures, although concentrate and forage intakes were increased, and some changes in blood metabolic and ruminal parameters were observed. The 8 g/kg RPF supplementation did not improve growth performance under cold conditions, although it did not decrease intake and ruminal total VFA concentration.

Fermentative Quality and Animal Acceptability of Ensiled Persimmon Skin with Absorbents for Practical Use in Ruminant Feed.

Simple SummaryAlthough persimmon skin (PS) has a high nutrition content, it loses much of its nutrient value through effluent, which hampers its use as a feed. To reduce effluent production during ensiling, we tested three kinds of moisture absorbents (kraft pulp, wheat bran, and beet pulp). We evaluated five types of table scale silages: persimmon skin only, persimmon skin plus Lactobacillus buchneri inoculum, and persimmon skin plus L. buchneri plus each absorbent in turn. We observed low effluent and gas loss in absorbent-treated groups, implying a positive contribution of these absorbents to fermentation quality. Further, we performed an in vitro culture test of PS silage supplemented with an absorbent mixture. The proportion of methane to total gas decreased in the ensiled group compared with that in the other groups. Finally, we conducted a preliminary feeding experiment on dry ewes to assess the palatability of PS with a partial substitution of up to 20% dry matter, and found no adverse effect on feed intake and acceptability. Our results highlight the potential use of PS as a part of ruminant feed.Persimmon skin (PS), while representing an attractive feed source, requires an appropriate preservation procedure to increase its shelf life. We assessed the fermentation quality, in vitro ruminal incubation, and intake of persimmon skin silage ensiled with different dry absorbents. We prepared the silage on a table scale (Experiment 1) and evaluated five different mixtures: PS without an additive, PS plus Lactobacillus buchneri inoculum (LB), and PS plus LB plus each of the absorbents kraft pulp, wheat bran, or beet pulp. We opened the laboratory bags, kept at 25 °C, at 0, 14, 28, and 60 days for fermentation quality and chemical analysis (n = 3 for each measurement). Further, with an in vitro rumen simulated cultivation study (Experiment 2), we evaluated the fermentation pattern of PS with a mixture of two absorbents (kraft pulp and wheat bran) either raw (no fermentation) or ensiled (n = 4 for each treatment). Finally, we conducted an in vivo experiment using six dry ewes assigned based on their body weight to two experimental groups in a crossover design of two periods (Experiment 3). We fed a control group a 100% basal diet (tall fescue hay and concentrate mixture) and ensiled PS (PSS) group, a 20% dry matter substitution of tall fescue with PS silage mixed with kraft pulp as the sole absorbent. The results of Experiment 1 show, regardless of the absorbents used, the effluent volume of the lab bags was lower in absorbent-treated groups (p < 0.001). In Experiment 2, the condition of the PS with absorbents (raw or ensiled) did not affect the total gas production (p > 0.05), but we observed an increased propionate proportion in PSS with absorbents compared to basal diet (p = 0.019). The proportion of methane to the total gas in PSS group was considerably reduced compared with that in the other groups (p < 0.001). As we did this incubation study with a single run, a more detailed evaluation in the future would verify these observations. In the animal trial (Experiment 3), dry matter intake was similar between groups (p > 0.05), but ewes spent a shorter time eating in the PSS-fed group (p = 0.011). Here we present the practical use of PSS as part of ruminant feed in which dry absorbents prevented dry matter loss.

PSIII-29 Effects of late gestational tall fescue forage system on spring-calving beef cow performance, circulating metabolites, and colostrum quality

Abstract Multiparous cows [n = 56; 639 ± 73 (SD) kg initial BW; 5.3 ± 0.4 initial BCS; 5.9 ± 3.0 yr of age; February 16, 2016 average calving date] were allocated by BW, BCS, age, and expected calving date to strip-graze endophyte-infected stockpiled tall fescue (STF; n = 4 pastures; 12.5% CP, 59.5% NDF; DM basis) or consume ad libitum endophyte-infected tall fescue hay (n = 4 uncovered drylots; 7.5% CP, 65.3% NDF; DM basis) for the last 75.0 ± 11.9 d of gestation. At 13.5 ± 1.6 d pre-calving, STF cows were moved to drylots and fed tall fescue haylage (12.6% CP, 61.7% NDF; DM basis). Effects of forage system were included in the model with pen as experimental unit. For gestational metabolites, effects of forage system, day, and their interaction were included with day as a repeated measure. Forage system did not affect (P ≥ 0.35) cow BW. Cows fed STF had greater (P ≤ 0.06) BCS than hay-fed cows at d 32 and 62 of study. Forage system did not affect (P ≥ 0.12) gestational plasma glucose or triglycerides. Serum non-esterified fatty acids (NEFA) were greater (P ≤ 0.005) in hay-fed cows at d 32 and 82 of study and less (P = 0.02) at d 62 of study. After study initiation, serum urea N was greater (P ≤ 0.002) in STF-fed cows than hay-fed cows. At colostrum sampling (6.8 ± 0.9 h postpartum), forage system did not affect (P ≥ 0.10) circulating NEFA, glucose, or triglycerides. Cows fed STF had greater (P ≤ 0.002) serum and colostrum urea N than hay-fed cows. Forage system did not affect (P ≥ 0.17) colostrum protein, lactose, triglyceride, or immunoglobulin concentrations. In conclusion, grazing STF improved cow BCS and altered cow metabolic status but did not affect colostrum quality.

The interplay between exposure and preference for unpalatable foods by lambs

Herbivores satiate on single foods ingested too frequently or in excess. We hypothesized that exposure to the same unpalatable food too frequently or in excess causes satiety, which in turn would reduce subsequent use and preference for this food when alternatives become available. In each of three experiments, twenty-four lambs were randomly assigned to three treatment groups (8 lambs/group), where they received high (Ad libitum), intermediate (100–200 g/d) or low exposure (20–40 g/d) to three unpalatable foods: The invasive weed medusahead (Experiment 1), an alfalfa:quebracho tannin ration (70:30; QT) (Experiment 2), or wheat straw (Experiment 3). After exposure, all groups in Experiments 1 and 3 received a simultaneous offer of the unpalatable food and a novel food that changed across four consecutive preference tests: Grape pomace (Test 1), barley straw (Test 2), tall fescue hay (Test 3), and beet pulp (Test 4). Lambs in Experiment 2 received a simultaneous offer of each of these novel foods and the same novel food containing 30% quebracho tannins. During exposure, lambs in Experiment 1 showed a low and cyclic pattern of medusahead intake, and the group with intermediate level of medusahead exposure showed greater intake values than the Ad libitum group, followed by the group with the lowest level of exposure (P < 0.05). For the rest of the experiments, intake was Ad libitum > intermediate > low level of exposure (P < 0.05). During preference tests, lambs with the least level of exposure to the unpalatable foods tended to consume more medusahead (35% to 37%; P = 0.11) or wheat straw (15 to 30%; P = 0.10) than lambs that received greater levels of exposure. In contrast, differential exposure to QT did not influence subsequent preference for tannin-containing foods (P = 0.33), but animals with the greatest level of exposure to QT consumed 24% more alternatives (i.e., non-tannin containing foods) than lambs that had received the lowest level of QT exposure (P < 0.05). Intake of alternative novel foods during preference tests increased with increments in nutritional quality from grape pomace and barley straw to tall fescue hay and beet pulp (P < 0.05), suggesting that lambs discriminated the nutritional value of the novel foods. In conclusion, repeated exposure to unpalatable foods has the potential to further reduce their utilization when alternatives –even when novel– become available. This effect appeared to be influenced by the chemical characteristics of the unpalatable food and it has implications for the coexistence of plant species in grazed communities.

Effects of heat stress and rumen-protected fat supplementation on growth performance, rumen characteristics, and blood parameters in growing Korean cattle steers.

ObjectiveThis study was performed to evaluate whether hot temperature and rumen-protected fat (RPF) supplementation affect growth performance, rumen characteristics, and serum metabolites in growing stage of Korean cattle steers.MethodsTwenty Korean cattle steers (230.4±4.09 kg of body weight [BW], 10.7±0.09 months of age) were divided into a conventional control diet group (n = 10) and a 0.8% RPF supplementation group (n = 10). Steers were fed 1.5% BW of a concentrate diet and 4 kg of tall fescue hay for 16 weeks (July 10 to August 6 [P1], August 7 to September 3 [P2], September 4 to October 1 [P3], October 2 to 30 [P4], of 2015).ResultsThe mean temperature-humidity index (THI) was higher (p<0.001) in P1 (76.8), P2 (76.3), and P3 (75.9) than in P4 (50.9). The mean THI of P1–3 were within the alert heat stress (HS) category range according to previously reported categories for feedlot cattle, and the mean THI of P4 was under the thermo-neutral range. Neither month nor RPF supplementation affected (p>0.05) average daily gain and gain to feed ratio. Month and RPF supplementation affected concentrations of glucose, albumin, and high-density lipoprotein (HDL); those of albumin and glucose tended to decrease (p<0.10), but HDL concentration increased (p<0.01) by RPF supplementation. Neither month nor RPF affected (p>0.05) ruminal pH, NH3-N, and volatile fatty acid concentrations, whereas the C2:C3 ratio was affected (p<0.05) by month.ConclusionKorean cattle may not have been significantly affected by alert HS during the growing stage. Growth performance was higher during hotter months, although some changes in blood metabolites were observed. The RPF supplementation affected some blood lipids and carbohydrate metabolites but did not affect growth performance.

Effects of feeding stockpiled tall fescue versus summer-baled tall fescue-based hay to late gestation beef cows: I. Cow performance, maternal metabolic status, and fetal growth.

We hypothesized that cows grazing stockpiled tall fescue (STF) during late gestation would have increased nutrient intake, resulting in improved metabolic status and fetal growth compared with cows consuming summer-baled tall fescue hay. Multiparous, spring-calving, crossbred beef cows (year 1: n = 48, year 2: n = 56) were allocated by body weight (BW), body condition score (BCS), age, service sire, and expected calving date to 1 of 2 forage systems (4 rep/system) in mid-November on day 188 of gestation: strip-graze endophyte-infected STF in 4.05 ha pastures or consume ad libitum endophyte-infected summer-baled tall fescue-based hay in uncovered dry lots. Treatments were terminated 1 wk postpartum, and cow-calf pairs were managed together until weaning. Data were analyzed with forage system, year, and their interaction as fixed effects. Sampling day was a repeated effect for cow metabolites and hormones. Calf date of birth was in the model when P < 0.25; pasture or pen was the experimental unit. Cow prepartum BW was not affected (P ≥ 0.424) by forage system, but cows grazing STF tended (P = 0.09) to have greater BCS at day 35 and had greater (P = 0.03) final precalving BCS than hay-fed cows. Additionally, final precalving 12th rib fat thickness tended (P = 0.09) to be greater for STF than hay-fed cows. Calves born to cows fed hay only weighed 10.2% less (P = 0.03) at birth than calves born to cows consuming STF, indicating reduced fetal growth. Postpartum cow BW, BCS, first service conception rate, and overall pregnancy rate were not affected (P ≥ 0.15) by late gestational forage system. After day 0, serum urea N was greater (P < 0.001) in cows consuming STF on all days measured. Cows grazing STF also tended (P = 0.08) to have greater plasma glucose than cows consuming hay. Serum nonesterified fatty acids (NEFA) were greater (P < 0.001) in cows grazing STF on day 56 in year 1 and on day 77 and 99 in year 2. Serum triiodothyronine was less (P = 0.03) on day 0, but greater (P = 0.004) on day 99, in cows grazing STF. Cows grazing STF tended (P = 0.06) to have greater thyroxine on day 77 in year 1. Serum cortisol was greater (P = 0.003) on day 35 and tended (P = 0.10) to be greater on day 99 in cows grazing STF. Calf birth weight was positively correlated with prepartum maternal serum urea N (r = 0.31, P = 0.002) and NEFA (r = 0.12, P = 0.005). In this study, cows grazing STF had increased nutrient intake during late gestation, resulting in greater fetal growth.

Effects of source and level of dietary energy supplementation on in vitro digestibility and methane production from tall fescue-based diets

There is a lack of information about the effect of different sources, levels, and the mixtures of energy supplements commonly fed to cattle grazing tall fescue. Therefore, the objective of this study was to evaluate different common energy sources for beef cattle grazing tall fescue using an in vitro fermentation system. Four ruminally cannulated Holstein steers (571 ± 16.1 kg BW) were fed tall fescue hay once daily and served as donors of rumen contents for an in vitro fermentation experiment. Treatments were tall fescue hay (CON), soybean hulls (SBH), corn gluten feed (CGF), corn (CORN), or combinations (SBH + CGF, SBH + CORN, CGF + CORN, SBH + CGF + CORN) of these. Flasks were incubated for 48 h and then assessed for digestion by measuring true DM digestibility, VFA and ammonia concentrations, and total gas and methane production. Supplemental energy sources did not affect total VFA concentration, ammonia concentration, valerate proportion, isobutyrate proportion, isovalerate proportion, or acetate:propionate ratio. True digestibility and digestible energy were generally greater than CON (Table 3; P < 0.001) in all CORN containing treatments. The CORN (P < 0.001) and CGF + CORN (P = 0.023) treatments had a lower acetate proportion than CON. Propionate proportion was reduced by CORN (P < 0.001). Corn grain supplementation increased butyrate proportion in all corn-containing treatments (P < 0.035). All treatments containing energy supplements increased methane production and CH4-E (P < 0.027). The DE loss from CH4-E was increased in CORN, SBH + CGF, SBH + CORN, CGF + CORN, and SBH + CGF + CORN (P < 0.01). Corn grain supplementation at low levels (≤0.20 diet DM) can improve diet utilization by increasing digestibility and energetic efficiency to improve beef cattle production.

Effects of gradual reduction in frequency of energy supplementation on growth and immunity of beef steers.

This study evaluated the effects of gradual reduction in frequency of energy supplementation following vaccination on growth and measurements of innate and humoral immunity of beef steers. At 14-d postweaning (d 0), Angus steers (n = 42; 200 ± 5 kg of BW; 175 ± 4 d of age) were stratified by BW and age, and randomly assigned into 1 of 14 drylot pens (three steers/pen). From d 0 to 42, steers were provided ad libitum ground tall fescue hay (57% TDN, 13% CP of DM basis) and supplemented with concentrate at 1% of BW (50:50 soybean hulls and corn gluten feed; 71% TDN, 15% CP of DM basis). Treatments were randomly assigned to pens, and consisted of similar weekly concentrate DM supplementation (1% of BW multiplied by 7 d) that was divided and offered daily from d 0 to 42 (7X; 4 pens), 3 times weekly from d 0 to 42 (3X; Monday, Wednesday, and Friday; 5 pens), or daily from d 0 to 15 and then 3 times weekly from d 16 to 42 (7-3X; 5 pens). Steers were vaccinated against infectious bovine rhinotracheitis (IBR), bovine viral diarrhea virus (BVDV), parainfluenza-3 (PI-3), Mannheimia haemolytica, and Clostridium on d 0 and 15. Individual shrunk BW was collected on d 0 and 42, following 12 h of feed and water withdrawal. Blood samples were collected via jugular venipuncture 4 h after concentrate supplementation on d 0, 1, 2, 3, 7, 15, 16, 17, 18, 22, and 42. Mean BW, ADG, G:F, hay DMI, and total DMI over the 42-d period did not differ among treatments (P ≥ 0.26). Plasma concentrations of cortisol and mean serum BVDV-1a titers also did not differ among treatments (P ≥ 0.35), but overall plasma haptoglobin concentrations were greater for 3X vs. 7-3X and 7X steers (P ≤ 0.05; 0.44, 0.37, and 0.33 ± 0.026 mg/mL, respectively). Also, 3X steers had less mean serum IBR titers (P ≤ 0.05; 0.29 vs. 0.88 and 0.79 ± 0.179 log2, respectively) and less seroconversion to PI-3 virus on d 15 than 7-3X and 7X steers (P ≤ 0.05; 36.0 vs. 76.6 and 57.8 ± 8.24%, respectively). In summary, a gradual reduction in frequency of energy supplementation during a 42-d preconditioning period did not negatively impact growth, but alleviated indices of inflammation and prevented reductions in vaccine response against BVDV-1a and PI-3 viruses compared to steers offered concentrate 3 times weekly during the entire study.

Effects of timing of vaccination relative to weaning and post-weaning frequency of energy supplementation on growth and immunity of beef calves.

A 2 × 2 factorial design study evaluated the impact of pre- vs. post-weaning vaccination and different post-weaning frequency of energy supplementation (daily vs. 3X weekly) on growth and immunity of beef calves. At 14 d before weaning (d -14), 48 Angus calves (24 steers and 24 heifers; 244 ± 33 kg; 196 ± 20 d) were stratified by BW and age, and randomly assigned to receive vaccinations against bovine viral diarrhea virus 1a (BVDV-1a) and parainfluenza-3 (PI-3) on d -14 and 0 (PRE) or 7 and 21 (POS), relative to weaning. Calves were weaned on d 0 and offered daily concentrate DM supplementation (50:50 soybean hulls and corn gluten feed; 71% TDN, 15% CP of DM) at 0.5% of BW for 7 d. On d 7, calves were stratified by vaccination scheme and assigned into 1 of 16 drylot pens (3 calves of same sex/pen; 4 pens/treatment). Pens were randomly assigned to receive similar weekly concentrate DM supplementation (1% of BW multiplied by 7 d) that was divided and offered daily (7X) or three times weekly (3X; Mondays, Wednesdays, and Fridays) from d 7 to 43. From d 0 to 43, calves were provided ad libitum ground tall fescue hay (57% TDN, 13% CP of DM). Blood samples were collected from jugular vein on d 0, 1, 3, 7, and 14, relative to the respective first vaccination, and on d 43 of the study. Effects of timing of vaccination × frequency of supplementation were not detected for any variable in this study (P ≥ 0.12), except for overall ADG from d -14 to 43 (P = 0.04), which was less for PRE-3X vs. PRE-7X, POS-3X, and POS-7X calves (0.60, 0.70, 0.70, and 0.77 ± 0.04 kg/d, respectively; P ≤ 0.08). Post-weaning total DMI and G:F did not differ among treatments (P ≥ 0.11). Pre-weaning vaccination increased plasma concentrations of cortisol and haptoglobin from d 0 to 3, relative to first vaccination (P ≤ 0.03), and decreased serum PI-3 titers on d 43 compared with post-weaning vaccination (P < 0.0001). Decreasing the supplementation frequency tended (P = 0.10) to increase overall plasma cortisol concentrations and reduce overall serum BVDV-1a titers. Hence, pre-weaning vaccination associated with reduced post-weaning frequency of energy supplementation caused the greatest reduction on calf growth performance. Post-weaning vaccination and daily energy supplementation alleviated inflammation and improved humoral immunity compared with pre-weaning vaccination and reduced post-weaning frequency of energy supplementation of recently weaned beef calves.