Kenneth P. Coffey

Hominy feed (HF) has been evaluated in feedlot and dairy rations but has not been evaluated as a supplemental energy source for lactating beef cows. The objective of this study was to determine the effect of level of HF supplementation on intake, digestibility, ruminal fermentation characteristics, and in situ dry matter (DM) disappearance of bermudagrass hay. Five ruminally cannulated lactating beef cows (body weight (BW) = 596 kg, SE = 13.9) were used in an experiment with a 5 × 5 Latin square design. Treatments were a bermudagrass hay-basal diet with low HF (LH; 0.25% BW), medium HF (MH; 0.50% BW), low ground corn (LC; 0.25% BW), medium ground corn (MC; 0.50% BW) and no supplement (CON). Cows were housed individually, and supplements were offered at 0800 daily. Hay was offered to maintain 10% refusal. Periods were 16–d, with 10 d for adaptation. Ruminal fluid was sampled on d 14 of each period for measurement of pH, volatile fatty acids, and rumen ammonia-N. An in situ degradation experiment for bermudagrass hay was completed for each diet. Hay dry-matter intake (DMI % BW) was not affected (p = 0.14) by supplement, but total DMI (DMI % BW) was greater (p ≤ 0.05) in MH and MC compared to LH and CON. Digestible DMI % BW was greater (p = 0.05) in MH compared to LC, MC was intermediate, and LH and CON were lesser (p ≤ 0.01) than all other diets. Dry-matter fill, passage rate, and retention time did not differ by diet (p ≥ 0.31). A diet × time interaction was observed for ammonia-N (p = 0.0002), and propionate (p = 0.02) time effects were observed for other parameters, but no diet effects. Bermudagrass hay’s potentially degradable fraction was greater (p ≤ 0.05) in LH than MH and CON, but effective DM degradability was not different (p = 0.39) among diets. Overall, no diets reduced hay intake or disappearance compared to CON; therefore, no negative associative effects were observed from any of the supplements at the levels offered in this study.

Tall fescue (Schedonorus arundinaceus (Shreb.) Dumort) is a cool-season forage grown in the mid-south United States of America that has the potential for spring silage. Ergovaline produced by the fungal endophyte Neotyphodium coenophialum is preserved in tall fescue silage and can induce tall fescue toxicosis in livestock. Condensed tannins, such as quebracho (Schinopsis quebracho-colorado (Schltdl.) F.A. Barkley and T. Meyer) extract, can bind to the nitrogenous components of ergovaline, rendering it ineffective in the ruminant. Quebracho tannin (QT) can also bind to crude protein, reducing its conversion to ammonia. Quebracho tannin was either not added (0QT) or added at 10 (10QT) or 20 (20QT) g/kg of dry matter (DM) of silage to chopped endophyte-infected tall fescue of 670 g/kg of moisture (high moisture, HM) and 440 g/kg of moisture (low moisture, LM). A moisture × QT interaction affected the final pH (p = 0.02), with the lowest pH observed in HM silages with 0QT and 10QT. The ergovaline concentrations were not significantly different (p = 0.19) among the post-ensiled forages. Ammonia concentrations (g/kg DM) were affected by a moisture × QT interaction (p = 0.05), with greater concentrations observed in HM 0QT compared with HM 10QT, HM 20QT, and LM 20QT. Lactic acid concentrations (g/kg DM) decreased (p = 0.05) with the addition of QT. The moisture × QT interaction (p = 0.02) resulted in higher concentrations of acetic acid in the HM silages with 0QT and 20QT compared to the LM silage with 20QT. The total acid concentrations (g/kg DM) were higher (p < 0.01) at HM but did not differ (p = 0.54) across the QT concentrations. Ensiling tall fescue with quebracho tannin did not reduce the ergovaline concentrations, although proteolysis was reduced at the inclusion of 10 g/kg of QT in the HM silages and 20 g/kg of QT in the LM silages. The results indicate that QT as a tall fescue silage additive showed promise for modifying silage characteristics but it did not reduce ergovaline concentrations at the low QT levels used in this study.

Forage management and environmental conditions affect water soluble carbohydrate (WSC) storage, and, in turn, influence ruminant forage utilization in silvopastoral systems. The objective was to determine effects of four dependent variables: forage species [(non-native, C₃ (orchardgrass (Dactylis glomerata L.)) and native C₄ mix (8:1:1 big bluestem (Andropogon gerardii Vitman), little bluestem (Schizachyrium scoparium Michx. Nash) and indiangrass (Sorghastrum nutans L.))]; fertility (poultry litter and an unfertilized control); forage sampling date (mid-May, late-May, early-June, mid-June, and late-June); and hour of day (0800, 1100, 1400, and 1700 h) on WSC accumulation in a silvopasture. Concentrations of WSC (g kg DM⁻¹) were greater (p ≤ 0.05) for C₃ forages, with poultry litter not impacting WSC accumulation. Overall, WSC was greatest in mid-June, with the lowest WSC concentration observed at 0800 compared to 1100, 1400, and 1700 h (p ≤ 0.05). Therefore, harvesting forages later in the day resulted in greater WSC. A stepwise regression model indicated acid detergent fiber, ash, and forage P concentration were the best predictors (R₂ = 0.85, p ≤ 0.05) of forage WSC. These results may be useful in future studies aimed at explaining diurnal cattle grazing preference and optimum forage harvest timing in silvopastoral systems.

Dairy slurry is used commonly as an animal-sourced fertilizer in agronomic production. However, residual effects of slurry application on intake and digestibility of alfalfa (Medicago sativa L.) silage from subsequent harvests are not well known. The objective of this study was to determine if moisture concentration of alfalfa silage and timing of dairy slurry application relative to subsequent harvest affected intake and digestibility by sheep. Katahdin crossbred ewes (n = 18; 48 ± 5.3 kg) in mid-gestation were stratified by BW and allocated randomly in each of 2 periods to 1 of 6 treatments arranged in a 2 × 3 factorial arrangement. Treatments consisted of recommended (RM; 46.8%) or low (LM; 39.7%) moisture at baling after either no slurry application (NS), slurry application to stubble immediately after removal of the previous cutting (S0), or slurry application 14 d after removal of the previous cutting (S14). Silages were chopped through a commercial straw chopper, packed into plastic trash cans, and then offered to ewes within 4 d of chopping. Period 1 of the intake and digestion study consisted of a 14-d adaptation followed by a 7-d fecal collection period. Period 2 followed period 1 after a 4-d rest and consisted of an 11-d adaptation followed by 7 d of fecal collection. Ewes were housed individually in 1.4 × 4.3-m pens equipped with rubber mat flooring. Feces were swept from the floor twice daily, weighed, and dried at 50°C. Ewes had ad libitum access to water and were offered chopped silage for a minimum of 10% refusal (DM). Blood samples were collected immediately prior to feeding, and 4 and 8 h after feeding on the day prior to the end of each period. Organic matter intake (g/kg BW) and OM digestibility tended (P < 0.10) to be, and digestible OMI (g/kg BW) was reduced by slurry application. Lymphocytes (% of total white blood cells) were greater (P < 0.05) from LM vs. RM and from NS vs. S0 and S14. Red blood cell concentrations were greater (P < 0.05) from S14 vs. S0 and from S0 and S14 vs. NS. Serum urea N concentrations did not differ (P > 0.17) across treatments. Therefore, moisture concentration of alfalfa silage within the range used in this study may not affect voluntary intake or digestibility, but slurry application may have an effect on digestible OM intake. Also, moisture concentration of alfalfa silage and time of dairy slurry application may affect specific blood hemograms.

Coproduct feedstuffs offer a unique and potentially profitable avenue for cattle feeding strategies. However, research is lacking in the evaluation of varying coproducts on ruminal fermentation and digestive characteristics when included as the major component of the diet of cows. Our objective was to determine the effect of coproduct feedstuffs as a forage replacement on digestive and fermentative characteristics of cows. Eight ruminally fistulated cows (672 ± 32.0 kg initial BW and approximately 9 yr of age) were stratified by BW and randomly allocated to 1 of 4 diets (2 cows∙diet⁻¹∙period⁻¹) in a 2-period study: soybean hulls (SH), distillers’ dried grains with solubles (DG), an isoenergetic mixture of soybean hulls and distillers’ dried grains with solubles (MX), or ad libitum hay plus 0.9 kg/d of an isoenergetic mixture of soybean hulls and distillers’ dried grains with solubles (HY). Diets were formulated to meet the ME requirements of a similar, companion study. Coproduct amounts were increased over a 14-d period. This was followed by a 14-d adaptation to diet and facilities and 5 d of total fecal collections. On the final day of fecal collections, rumen fluid was sampled immediately prior to feeding and 2, 4, 6, 8, 10 and 12 h after feeding for measurement of rumen VFA and ammonia concentrations. Intake of DM and OM was not different (P ≥ 0.28) among treatments, but digestibilities of DM, OM, NDF, and ADF were improved (P < 0.05) by coproduct feeding and by MX vs. the mean of SH and DG. Ruminal DM and OM fill were greater (P < 0.05) for cows offered HY than for cows offered the coproduct diets, greater for cows offered SH than for cows offered DG, and for the mean of SH and DG vs. MX. Ruminal retention time was greater (P < 0.05) for HY vs. the coproduct diets and for SH vs. DG. Apparent N absorption tended (P < 0.10) to be greater for cows offered the coproduct diets than for cows offered HY and greater for cows offered DG than for cows offered SH. Total VFA averaged across sampling times were greatest (P < 0.05) for cows offered SH, and ruminal ammonia N was greatest (P < 0.05) for cows offered either DG or MX at all sampling times. Based on these data, coproduct feedstuffs may be fed to meet the energy requirement of cows without negative effects on digestion or ruminal fermentation. Copyright © 2017. American Society of Animal Science .

Coproduct feedstuffs offer a unique and potentially profitable avenue for cattle feeding strategies. However, research is lacking in the evaluation of varying coproducts on ruminal fermentation and digestive characteristics when included as the major component of the diet of cows. Our objective was to determine the effect of coproduct feedstuffs as a forage replacement on digestive and fermentative characteristics of cows. Eight ruminally fistulated cows (672 ± 32.0 kg initial BW and approximately 9 yr of age) were stratified by BW and randomly allocated to 1 of 4 diets (2 cows∙diet⁻¹∙period⁻¹) in a 2-period study: soybean hulls (SH), distillers’ dried grains with solubles (DG), an isoenergetic mixture of soybean hulls and distillers’ dried grains with solubles (MX), or ad libitum hay plus 0.9 kg/d of an isoenergetic mixture of soybean hulls and distillers’ dried grains with solubles (HY). Diets were formulated to meet the ME requirements of a similar, companion study. Coproduct amounts were increased over a 14-d period. This was followed by a 14-d adaptation to diet and facilities and 5 d of total fecal collections. On the final day of fecal collections, rumen fluid was sampled immediately prior to feeding and 2, 4, 6, 8, 10 and 12 h after feeding for measurement of rumen VFA and ammonia concentrations. Intake of DM and OM was not different (P ≥ 0.28) among treatments, but digestibilities of DM, OM, NDF, and ADF were improved (P < 0.05) by coproduct feeding and by MX vs. the mean of SH and DG. Ruminal DM and OM fill were greater (P < 0.05) for cows offered HY than for cows offered the coproduct diets, greater for cows offered SH than for cows offered DG, and for the mean of SH and DG vs. MX. Ruminal retention time was greater (P < 0.05) for HY vs. the coproduct diets and for SH vs. DG. Apparent N absorption tended (P < 0.10) to be greater for cows offered the coproduct diets than for cows offered HY and greater for cows offered DG than for cows offered SH. Total VFA averaged across sampling times were greatest (P < 0.05) for cows offered SH, and ruminal ammonia N was greatest (P < 0.05) for cows offered either DG or MX at all sampling times. Based on these data, coproduct feedstuffs may be fed to meet the energy requirement of cows without negative effects on digestion or ruminal fermentation. Copyright © 2017. American Society of Animal Science .

Calcium addition is necessary to balance the high phosphorus concentrations in high-concentrate diets. However, calcium sources differ in their bioavailability. The objective of this study was to determine apparent Ca and Mg absorption and retention in goats offered diets containing different sources of Ca. Spanish-Boar goats (n = 16; 19.6 ± 1.88 kg) were stratified by weight and randomized to dietary treatments consisting of Purina Antlermax^® 16 containing either calcium carbonate (CC), Calmin^® (CM) or Milk Cal^® (MC). Goats were offered their respective diets at a total of 2% of BW in equal feedings at 0830 and 1800 h while housed in 1.0 × 1.5 m pens with plastic-coated expanded metal floors. Goats were offered increasing amounts of a control corn-based high-concentrate diet on mixed bermudagrass (Cynodon dactylon) pasture until they were consuming the diet at 2% of BW. They were then moved to individual pens and adjusted to their respective diets along with removal of hay from the diet over a 7-d period. Goats were then offered their respective diets for an additional 14-d adaption period to diet and facilities. Total urine and feces were then collected for 7 d and analyzed for Ca and Mg by inductively coupled plasma emission spectroscopy. Data were analyzed using PROC MIXED of SAS. Calcium and Mg intake were not different (P ≥ 0.12) among diets. Calcium apparent absorption and retention (g/d and % of Ca intake) were greatest (P < 0.05) in goats offered CC and did not differ (P ≥ 0.20) between goats offered the CM and MC diets. Magnesium apparent absorption and retention (g/d and % of Mg intake) were greatest (P < 0.05) in goats offered CC and did not differ (P ≥ 0.69) between goats offered the CM and MC diets. Therefore, calcium and magnesium were more available for goats from the diet containing calcium carbonate compared with diets containing Calmin and Milk Cal. Copyright © 2016. American Society of Animal Science .

Delays often occur between baling and wrapping during production of baled silage that increases exposure time of the forage to oxygen. This study was conducted to investigate the effect of 2 different wrapping sources and time intervals between baling and wrapping on intake and digestibility of alfalfa silage by gestating sheep. Alfalfa silage was baled in large round bales, and then wrapped with plastic either with or without an oxygen-limiting barrier; wrapping occurred either the day of baling, or 1, 2 or 3 d after baling. Beginning in January, silages were chopped and packed into plastic-lined trash containers, and then offered randomly for ad libitum consumption to 16 gestating ewes (n = 16; 63.5 ± 1.71 kg BW) to provide 2 ewes per treatment for 3 experimental periods. Each period consisted of a 10-d dietary adaptation period followed by 7 d of total fecal and urine collection. Ewes were housed in individual 1 × 1.5-m pens with plastic coated expanded metal flooring and were re-randomized to different treatments each period such that ewes were not offered the same treatment in any subsequent period. Data were analyzed using PROC MIXED of SAS for a 2 × 4 factorial treatment arrangement and orthogonal polynomial trend analyses were used to assess effects of time delay for wrapping after baling. Intakes of DM responded with linear, quadratic, and cubic effects (P < 0.05), while OM responded with linear and quadratic effects (P < 0.05) as wrapping was delayed after baling. Digestibility of DM and OM responded cubically (P < 0.05), that of NDF increased linearly (P < 0.05), and digestible DM and OM intake (g/kg BW) responded linearly, quadratically, and cubically (P < 0.05) with time delay between baling and wrapping. In general, intake and digestibility were greatest in silage wrapped the day following baling. Type of wrap tended (P = 0.10) to affect DM digestibility, and digestible OM intake was affected (P < 0.05) by the wrap type × wrapping time after baling interaction, but other intake and digestibility measurements were not affected (P ≥ 0.15) by wrap type and the interaction of wrap and wrapping time after baling. Therefore, delaying wrapping alfalfa silage bales beyond 1 d after baling may have detrimental effects on energy status in gestating ewes. The study was supported in part by USDA-ARS specific cooperative agreement 58–3655–4-052. Copyright © 2016. American Society of Animal Science .