Voluntary intake and digestibility by sheep of alfalfa ensiled at different moisture concentrations following fertilization with dairy slurry.

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 two periods to one of six treatments arranged in a two × three 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 OM intake (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.

Feeding distillers' grains, soybean hulls, or a mixture of both to cows as a forage replacement: Effects on intake, digestibility, and ruminal fermentation characteristics.

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∙period) 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 ( ≥ 0.28) among treatments, but digestibilities of DM, OM, NDF, and ADF were improved ( < 0.05) by coproduct feeding and by MX vs. the mean of SH and DG. Ruminal DM and OM fill were greater ( < 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 ( < 0.05) for HY vs. the coproduct diets and for SH vs. DG. Apparent N absorption tended ( < 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 ( < 0.05) for cows offered SH, and ruminal ammonia N was greatest ( < 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.

Effects of forage species and poultry litter application timing on forage preference by horses.

Bermudagrass ( L.) is a familiar forage in the equine industry and teff () is gaining popularity as well. However, it is unclear if the application of poultry litter as a fertilizer affects palatability of these forages in horses. Therefore, the objective of this study was to determine if forage species and timing of litter application as a fertilizer has an effect on preference by horses. Hay treatments were arranged in a 2 × 3 factorial treatment arrangement consisting of teff and bermudagrass harvested after no poultry litter application (NL), poultry litter applied to stubble immediately after removal of the previous cutting (L0), or poultry litter applied 14 d after the previous cutting (L14). Mature, stock-type geldings ( = 5; 480 ± 52.9 kg) were used in this study arranged as a balanced incomplete block design. Horses were offered different combinations of 4 of the 6 total forages daily for 3 d in each of 3 evaluation periods that immediately followed a 10-d adaptation period. Each forage was offered at half of the total daily DMI as measured during the last 5 d of the 10-d adaptation period to encourage selection among the 4 forages. Each hay offered was randomly allocated to a corner and suspended in hay nets over muck buckets in the corners of each stall. Horses were individually housed in 3.6- by 3.6-m indoor stalls with sand bedding and access to 3.6- by 7.6-m outdoor runs. Along with hay, horses were offered oats twice daily at 0.125% of BW at each feeding. Dry matter intake was greater ( < 0.01) for bermudagrass than for teff and for NL and L0 treatments compared with L14 treatments. Horses spent more ( < 0.01) time consuming bermudagrass compared with teff. However, there were no differences ( ≥ 0.25) in time spent consuming hay across litter treatments. Therefore, horses may prefer bermudagrass to teff and later application of poultry litter may affect voluntary intake by horses. However, all forages were mature, which may have impacted total intake and preference.

Aerobic stability of wheat and orchardgrass round-bale silages during winter.

Using recently developed technology, balage is often stored in large (1.2 x 1.2 m) round bales that are wrapped in plastic film with an in-line wrapper. The aerobic stability of this fermented forage is important, particularly during winter months when it is fed to livestock or sold as a cash crop. Two types of forage, orchardgrass [Dactylis glomerata L.; 54.4% dry matter (DM)] and wheat (Triticum aestivum L.; 62.4% DM), were packaged in large round bales and wrapped with an in-line wrapper during May 2002. Twenty-one bales of each balage type were unwrapped and exposed to air on Dec. 10, 2002 for 0, 2, 4, 8, 16, 24, or 32 d (ambient temperature range = 0.6 to 19.4 degrees C) to evaluate aerobic stability. For both orchardgrass and wheat balage, final bale weight, concentration of DM, and pH were not affected by exposure time. Across both balage types, DM recoveries were > or = 97% for all bales, indicating that both balage types were very stable when exposed to air. For orchardgrass balage, exposure time had no effect on concentrations of NDF, ADF, hemicellulose, cellulose, or lignin, thereby indicating that little deterioration occurred. Similarly, no contrast relating any fiber component with exposure time was significant for wheat balage. Concentrations of crude protein (CP) were not affected by exposure time for wheat balage, but there was a tendency for exposed orchardgrass bales to have greater concentrations of CP than bales sampled on d 0. Exposure time had no effect on 48-h in situ digestibility of DM for wheat balage, but there was a tendency for a linear increase with exposure time for orchardgrass balage. However, the overall range (78.2 to 80.5%) over the 32-d exposure period was very narrow, and this response is probably of limited biological significance. Generally, concentrations of fermentation acids were low, primarily because of the high concentration of DM within these balages, and only minimal changes in these acids were observed over the exposure interval. These results suggest that the balage evaluated in this trial during winter conditions 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.