Effects of bedding type on compost quality of equine stall waste: implications for small horse farms.

Our objective in this study is to compare 4 of the most common bedding materials used by equine operations on the chemical and physical characteristics of composted equine stall waste. Twelve Standardbred horses were adapted to the barn and surrounding environment for 2 wk before the start of the study. Groups of 3 horses were bedded on 1 of 4 different bedding types (wood shavings, pelletized wood materials, long straw, and pelletized straw) for 16 h per day for 18 d. Stalls were cleaned by trained staff daily, and all contents removed were weighed and stored separately by bedding material on a level covered concrete pad for the duration of the study. Compost piles were constructed using 3 replicate piles of each bedding type in a randomized complete block design. Each pile was equipped with a temperature sensor and data logger. Water was added and piles were turned weekly throughout the 100-d compost process. Initial and final samples were taken, dried, and analyzed for DM mass, OM, inorganic nitrogen (nitrate-N and ammonium-N), electrical conductivity, and soluble (plant-available) nutrients. Data were analyzed using the GLM procedure, and means were separated using Fischer's protected LSD test (P < 0.05). No significant temperature differences were observed among the bedding materials. The composting process resulted in significant reductions (P < 0.05) in DM mass for each of the 4 bedding materials. The composting process resulted in significant reductions (P < 0.05) in OM and C:N ratio for all 4 bedding materials. The composted long straw material had greater concentrations of total Kjeldahl nitrogen (P < 0.05), nitrate-N (P < 0.05), and ammonium-N (P < 0.05) than the composted wood shavings. This study demonstrated that incorporating a simple aerobic composting system may greatly reduce the overall volume of manure and yield a material that is beneficial for land application in pasture-based systems. The straw-based materials may be better suited for composting and subsequent land application; however, factors such as suitability of the bedding material for equine use, material cost, labor, and availability must be considered when selecting a bedding material.

Ammoniation to reduce the toxicity of endophyte-infected tall fescue seed fed to rats.

To assess the efficacy of ammoniation in the detoxification of endophyte-infected tall fescue (Festuca arundinacea Schreb), 40 male Harlan Sprague-Dawley rats were randomly assigned to the following four treatments for 28 d: endophyte-free (E-), endophyte-infected (E+), ammoniated (2% dry matter basis, 7 d) endophyte-free (AE-), and ammoniated endophyte-infected (AE+) tall fescue seed. Total pyrrolizidine alkaloid (N-acetyl and N-formyl loline) and ergovaline contents of endophyte-infected fescue seed were reduced 24 and 54%, respectively, by ammoniation. Endophyte-infected treatment groups had lower (P < 0.01) daily feed intakes (DFI), daily weight gains (DWG), feed efficiencies, and primary serum hemagglutination titers to sheep red blood cell (SRBC) immunization than endophyte-free treatment groups. Performance parameters were higher (P < 0.01) for ammoniated diets in comparison to non-ammoniated diets; however, anti-SRBC titers were not significantly different. When compared to the E+ diet, the AE+ diet increased (P < 0.01) DFI (24%), DWG (41%) and feed efficiency (13%).

Ammoniation to reduce the toxicity of endophyte-infected tall fescue seed fed to rats.

To assess the efficacy of ammoniation in the detoxification of endophyte-infected tall fescue (Festuca arundinacea Schreb.), 40 male Harlan Sprague-Dawley rats were randomly assigned to the following four treatments for 28 d: endophyte-free (E-), endophyte-infected (E+), ammoniated (2% dry matter basis, 7 d) endophyte-free (AE-), and ammoniated endophyte-infected (AE+) tall fescue seed. Total pyrrolizidine alkaloid (N-acetyl and N-formyl loline) and ergovaline contents of endophyte-infected fescue seed were reduced 24 and 54%, respectively, by ammoniation. Endophyte-infected treatment groups had lower (P < 0.01) daily feed intakes (DFI), daily weight gains (DWG), feed effieiencies, and primary serum hemagglutination titers to sheep red blood cell (SRBC) immunization than endophyte-free treatment groups. Performance parameters were higher (P < 0.01) for ammoniated diets in comparison to non-ammoniated die [s; however, anti-SRBC titers were not significantly different. When compared to the E+ diet, the AIE+ diet increased (P < 0.01) DFI (24%), DWG (41%) and feed efficiency (13%).

Recycled cafeteria food waste as a feed for swine: nutrient content digestibility, growth, and meat quality.

This project was undertaken to compare growth, meat quality, and diet digestibility when pigs were fed cafeteria food waste (FW) or a corn/soybean meal (CSM) diet. Cafeteria food waste (36 samples) fed in the growing and finishing experiment averaged 22.4% DM, 21.4% CP, 14.1% ADF, 27.2% ether extract, and 3.2% ash. The first experiment used 50 crossbred pigs randomly assigned to four diets. During the growing phase, pigs fed a CSM diet gained faster (P < .05) than pigs fed FW or FW plus energy supplements. However, the two groups fed FW plus energy supplements (at 25 or 50% of the intake of the CSM diet) gained faster (P < .05) than pigs fed FW alone (.61 and .65 kg/d, respectively, vs .46 kg/d). In the finishing phase, FW plus an energy supplement fed at 50% of the level of CSM intake resulted in gains that did not differ from those of pigs fed the CSM diet (.90 vs .99 kg/d; P > .05). A nutrient digestibility and nitrogen balance trial using eight growing barrows compared FW with the same CSM growing diet fed earlier. Dry matter digestibility was similar for the two diets (P > .05). However, CP digestibility was higher (P < .05) in the FW diet than in the CSM diet (88.2 vs 84.3%). Although the percentage of nitrogen retained was not different between FW and CSM diets (56.0 vs 55.2%; P > .05), the amount of nitrogen retained was greater for pigs fed the CSM diet (29.3 vs. 24.5 g/d; P < .05) because DMI was greater (1.7 vs 1.4 kg/d) for pigs fed CSM compared with FW. At the completion of the finishing experiment, six pigs were selected from both the CSM and FW diets and fed to finishing weight. The pigs were slaughtered, and the pork loins were removed for flavor and texture analysis. A consumer panel rated the meat quality from FW pigs as acceptable and overall flavor comparable to CSM pigs (P > .05). These results indicate that food waste has nutritive value and may be useful in swine diets.

Science and agriculture policy at Land-Grant Institutions.

United States Department of Agriculture (USDA) funding of science and education at Land-Grant College institutions is in transition. The traditional "science pipeline" model linking basic science funding with the application of technology is in question as some policymakers dispute the premise that non-directed science results in benefits to society. Historically, research at USDA and Land-Grant institutions is much more directed than that funded by the National Science Foundation (NSF), National Institutes of Health (NIH), or Department of Energy (DOE). Nevertheless, there are calls for change at the USDA as well. An approach that both the Congress and the Executive branch are taking seeks to direct research dollars according to predetermined goals. This is being emphasized in part due to budget pressures and may force the system to struggle maintaining funding in constant dollars. Deficit cutters are first considering cutting "earmarked grants" for research and facilities at USDA and Land Grant Institutions. Savings in these categories may help to support modest increases in formula funding and competitive grants. Earmarked grants for research and facilities at the Cooperative State Research Service (CSRS) for Fiscal Year 1993 were approximately 26% of total appropriations and distributed to well over 100 specific line items. This level has increased from approximately 15% of CSRS appropriations in 1985. At the same time formula funding has remained static and competitive grants, although increasing, are below authorized levels. As state and federal budgets face pressure and as concerns from consumer and environmental groups are encountered, balancing the percentage of research dollars devoted to research intended to increase production efficiency and the percentage devoted to meeting concerns about food safety, pesticides, water quality, sustainability, animal welfare, and so on will be a challenge. Linking research priorities with producer and consumer needs will be essential in the 1990s. Food Animal Integrated Research 1995, or FAIR '95, was a good start to a process involving multiple stakeholders and relating research goals to societal benefits from animal agriculture. Maintenance of research relevance and fiscal accountability is essential to avoid becoming non-contributors.

In vitro and in vivo ruminal and physiological responses to endophyte-infected tall fescue.

Relationships between alkaloid compounds in endophyte-infected tall fescue and ruminal metabolism were studied in two experiments. In the first experiment, different combinations of the pyrrolizidine alkaloids, N-formyl and N-acetyl loline, were incubated with ruminal fluid for 0, 24, or 48 h. Rate of disappearance of N-formyl and N-acetyl loline increased over time. After 48 h, disappearance of N-formyl loline and combinations of N-formyl and N-acetyl loline was greater than N-acetyl loline. Significant amounts of N-formyl and N-acetyl loline were metabolized and converted to loline. In the second experiment, abomasally cannulated sheep were fed increasing amounts of endophyte-infected feed to compare diet digestibility, alkaloid metabolism, and physiological responses. Total tract DM digestibility was greatest for the endophyte-free diet, as were ruminal and total tract ADF, ruminal NDF, and total tract CP digestibilities. N-Formyl and N-acetyl loline recoveries averaged 5% from abomasal contents and 0% in feces. Sixty-eight percent of the pyrrolizidine alkaloids recovered in abomasal contents had been metabolizable to loline. Ergot alkaloids administered in the diet were recovered (50 to 60%) in the abomasal contents, but recovery was only 5% in fecal collections. No significant differences occurred in the physiological parameters measured. Results indicate that response to endophyte-infected tall fescue may be influenced by ruminal metabolism.

Bovine plasma vitamin A responses to selected nutrients, monensin, and endophytic fescue.

Previous research at this station adapted a maximal dose response (MDR) method of evaluating vitamin A status and utilization for use in beef cattle. This method was used in two experiments. In this first experiment, forty-eight crossbred steers (average weight, 284 kg) were fed diets supplemented with salt, monensin or both, and injected with vitamin E, zinc or selenium. Steers receiving monensin had higher (38.5 micrograms/dl, monensin; 31.0 micrograms/dl, controls) initial plasma concentrations of vitamin A (P = .14). However, monensin did not affect post-dosing (MDR) vitamin A concentrations. None of the other dietary treatments or injections affected either pre- or post-dosing concentrations of vitamin A in the plasma. In a second experiment 23 lactating multiparous beef cows (average weight, 500 kg) grazing either fungal endophyte-infected or endophyte-free tall fescue were used to assess possible influences of infected fescue upon vitamin A metabolism. Fungal endophyte infection did not affect either pre- (44.9 micrograms/dl, end-noninf.; 47.7 micrograms/dl, end-inf.) or post-dosing (57.2 micrograms/dl, end-noninf.; 59.3 micrograms/dl, end-inf.) vitamin A concentrations.

Influence of rumen fermentation on response to endophyte-infected tall fescue seed measured by a rat bioassay.

Possible alteration of toxicity of endophyte-infected tall fescue by ruminal fermentation was studied using 28 Harlan Sprague-Dawley rats (avg. initial wt., 141 g). These were assigned randomly to one of four treatments in a 2*2 factorial consisting of a 14-day growth period with weights and feed consumption data determined on days 0, 5, 10 and 14. Treatments were: endophyte-infected Kentucky-31 tall fescue seed (E+) or endophyte free Johnstone tall fescue seed (E-) that was incubated for 0 (NON) or 24 hours (INC) with rumen fluid collected from a 290-kg cannulated steer fed a diet containing 37% endophyte-infected tall fescue hay. Diets consisted of 50% lab chow, 39% fescue seed and 11% rumen contents (air-dry basis). Alkaloid content (N-acetyl plus N-formyl loline) for the four diets were 2540, 2680, 0, and 0 micrograms/g for E+NON, E+INC, E-NON, and E-INC diets, respectively. E- treatments gained faster, consumed more feed and converted feed more efficiently (P < .05) than did E+ fed groups. No difference in feed intake was observed within E+ treatments, however, the E+INC diet gained faster (P < .05) and converted feed more efficiently (P < .05) than did E+NON fed rats (2.56 vs 1.96 g/d and 5.94 vs 7.51 g of feed/g of gain for gain and feed conversion, respectively). Including endophyte-infected seed in rat diets depressed performance (ie. intake, gain and feed efficiency). This depression was partially alleviated by a 24-hour incubation with rumen fluid contents suggesting that toxicity of endophyte-infected tall fescue is lessened due to rumen microbial action.

Plasma vitamin A levels in cattle in response to large doses of vitamin A.

A dose response procedure was developed for evaluating vitamin A status and utilization in cattle. This could be useful for evaluating diets, vitamin A stores and homeostatic control of vitamin A. Three experiments were designed to determine: 1) size of vitamin A dose required to increase plasma vitamin A concentrations; 2) time after dosing when plasma vitamin A concentrations peak, and 3) if changes in plasma vitamin A concentrations are useful in assessing dietary vitamin A utilization. Using twenty-four steers and heifers, the first two experiments showed that 30X or 40X daily vitamin A requirement (daily requirement calculated as X = body weight in kilograms times 55 International Units of vitamin A) given orally was sufficient to cause plasma vitamin A concentrations to rise 20 hours after dosing. Plasma vitamin A concentrations increased (P less than .01) from 57 to 81 micrograms/dl and 64 to 84 micrograms/dl after a 30X or 40X treatment, respectively. Twenty-X daily requirement resulted in a slight increase after 20 hours (P greater than .05). Seventy-two feedlot steers were used in experiment three to determine if diet affects vitamin A dose response. Variations in feed intake, monensin in the diet or a single dose of vitamin E did not cause significant changes in plasma vitamin A response to vitamin A dosage. Steers receiving monensin had higher initial plasma vitamin A concentrations, but no differences were observed after dosing. Results indicate that dose responses may be useful in assessing dietary vitamin A utilization.

Metabolism of decoquinate in chickens and Japanese quail.

Thirty mature chicken hens and 40 mature Japanese quail hens were used in an experiment to compare pathways of decoquinate (DQ) excretion. Labelled DQ was injected into chickens (.5 microCi via wing vein puncture) and quail (.25 microCi via cardiac puncture) on Day 0. Blood was sampled at 0, 1.5, 3, 6, 9, 12, 24, and 48 h postinjection. Eggs and excreta of chickens and quail were collected for 28 and 14 days, respectively, and analyzed for 14C. Six chickens and eight quail were sacrificed prior to 14C-DQ injection and also on Days 1, 7, 14, and 34 or 32 postinjection. Samples of liver, heart, kidney, bile, skin, fat, and muscle were analyzed for 14C. Blood rapidly cleared 14C in both species, and the half-time of 14C excretion via excreta was more rapid in quail (.37 day) than in chickens (.92 day). Little 14C was found in the eggs of quail (.32% of dose) and chickens (.17% of dose). Quail appeared to excrete peak amounts of detectable 14C 1 day earlier (Day 4) than chickens (Day 5). Liver contained the greatest concentration of 14C on Day 1 in both species. By the end of the experiment, less than 1% of the dose remained in liver or other organs. Results indicate that chickens and quail metabolize 14C-DQ at comparable rates and by similar pathways.