D. E. Rowe

Characterization of broiler cake and broiler litter, the by-products of two management practices

The application of broiler manure and bedding (litter) on land has been a long-used disposal method that benefits plant and soil. For proper manure management, factors such as nutrient content, house cleaning management, application methods, and many land, crop, and climatic factors must be considered. A study was undertaken to characterize broiler cake and broiler litter as the by-products of two management systems in Mississippi. Broiler cake and litter productions were quantified and analyzed for four flocks during 1999 and 2000. The overall means for broiler cake production were 12.50, 13.90, and 10.30 kg m(-2) for producers 1, 2, and 3, respectively. Significantly greater quantities of litter, 27.50, 29.0, and 28.30 kg m(-2) than cake were determined for the same producers. The cake and litter moisture averaged 455 and 277 g kg(-1), respectively. No significant differences were observed between cake and litter total N, NH4-N, total C, total P, and water-soluble P (WP). However, cake had significantly greater Ca, Mg, K, Cu, Fe, Mn, and Zn than litter. Approximately 16.8% of the broiler cake and 15.2% of the broiler litter total P were in the form of water-soluble P. The NH4-N content of the cake and the litter were 12.5% and 11.5% of the cake and litter total nitrogen, respectively. The results also showed the advantage of the decaking practice with respect to the quantity of the manure generated for land application. Approximately 57% of the litter remains in the poultry house with decaking practice after each growth cycle compared to the 0% for total cleanout practice.

Bermudagrass Cultivar Response to Swine Effluent Application

Bermudagrass is the predominant forage grass grown in the region (Burton and Hanna, 1995), and hybrid Bermudagrass [Cynodon dactylon (L.) Pers.] has great potential bermudagrass responds readily to increasing N rates to recover nutrients due to its pronounced yield response to N. Our from either inorganic or organic sources (Overman et objective was to determine differences in forage dry matter (DM) al., 1993). When swine effluent was applied to Russell yield, nutrient concentration, and nutrient uptake among diverse berhybrid bermudagrass to provide 560, 1120, and 2240 kg mudagrass cultivars fertilized with swine effluent. ‘Alicia’, ‘Brazos’, N ha 1 yr 1, a yield response similar to that for inorganic ‘Coastal’, ‘Russell’, ‘Tifton 44’, and ‘Tifton 85’ hybrid bermudagrass N was observed, but efficiency of N and P recovery and common bermudagrass were grown on a Brooksville silty clay loam (fine, smectitic, thermic Aquic Hapludert) and fertilized with declined quickly with increasing effluent rate (Liu et effluent to provide 370 and 61 kg ha 1 yr 1 N and P, respectively al., 1997). Applying effluent at the two higher rates (mean of 3 yr), and on an Atwood silt loam (fine-silty, mixed, thermic resulted in large additions of N and P to the soil that Typic Paleudalf) and fertilized to provide 200 and 38 kg ha 1 yr 1 N were not recovered in the forage and were potential and P, respectively. Annual DM yields of Brazos, Coastal, Russell, contributors to ground and surface water pollution. In and Tifton 85 were similar on Brooksville (23.3–24.2 Mg ha 1) and North Carolina, Burns et al. (1985) reported that Atwood (12.3–14.1 Mg ha 1) soils. Annual N and P uptake ranged Coastal hybrid bermudagrass receiving 670 kg N ha 1 from 422 to 467 kg N ha 1 and 50 to 58 kg P ha 1 on the Brooksville and 153 kg P ha 1 from swine effluent removed an soil and from 181 to 230 kg N ha 1 and 32 to 40 kg P ha 1 on the average of 382 and 43 kg ha 1 yr 1 N and P, respectively. Atwood soil. Common bermudagrass uptake of N and P was similar Nutrient uptake by unimproved common bermudagrass, to or greater than all hybrids except Russell on Atwood soil due to prevalent throughout much of the southeastern USA, greater herbage N and P concentration. Hybrids generally recovered has not been compared with that of the hybrids when more K, Cu, and Zn than common bermudagrass. Relatively small manure served as the fertilizer source. differences in nutrient uptake among the bermudagrass cultivars sugBecause forage nutrient concentration tends to fluctugest that forage quality, winter hardiness, and establishment cost be ate little, nutrient removal is primarily a function of given equal consideration when choosing a cultivar. herbage yield (Robinson, 1996), which, among many factors, is strongly influenced by cultivar. Since the release of Coastal hybrid bermudagrass in 1943, several S production has traditionally been concenhybrid cultivars have become available to producers in trated in the Midwest (Hatfield et al., 1998), and the southeastern USA. Routine application of swine the manure has been applied primarily to soils that effluent to bermudagrass requires additional informaproduce row crops (Schmidt et al., 2001). The rapid tion about potential cultivar-dependent responses. Our growth of confined, contract swine production in the objective was to determine differences in forage DM southeastern USA (Welsh and Hubbell, 1999) has reyield and nutrient concentration and uptake among disulted in widespread application of swine effluent to verse bermudagrass varieties grown on contrasting soil forage crops. Forage crop uptake of nutrients applied types fertilized with swine effluent. with manure is often less than the quantity applied because the manure is applied at rates necessary to meet MATERIALS AND METHODS the N requirements of the forage (Sims, 1995) and the The study was conducted for 3 yr on two different confinedN/P ratio of manure does not match that of the crop feeding swine farms at Crawford, MS (33 17 N, 88 35 W), (Edwards, 1996). In addition, hay production may not on a Brooksville silty clay loam and at Houston, MS (34 0 prevent nutrient accumulation in the soil due to continN, 89 0 W), on an Atwood silt loam. At both locations, excreta ued manure application (Kingery et al., 1993). Hay prois washed from pits located below the barn floor into open duction, however, represents an important component lagoons and applied as effluent to adjacent fields using a center-pivot irrigation system (Crawford) or traveling spray gun of nutrient management. By exporting nutrients in the (Houston). Effluent had been applied to the soil at both locaform of hay from land receiving manure and by reducing tions at rates ranging from 10 to 15 cm ha 1 yr 1 (unknown runoff and soil loss, the rate of nutrient accumulation mineral concentration) for 2 to 5 yr before the experiment in the soil and the potential for ground and surface water started. Before forage yield measurements were made the first impairment may be reduced (Sims and Wolf, 1994). year, 20 soil samples were collected in the plot area at 0to 5-, 5to 15-, and 15to 30-cm depth and composited by depth. Selected soil chemical characteristics were determined using USDA-ARS, Waste Manage. and Forage Res. Unit, P.O. Box 5367, Mehlich-3 extractant (Mehlich, 1984; Table 1). Total soil N Mississippi State, MS 39762. G.E. Brink, current address: USDAconcentration was determined by the Dumas method (BremARS, U.S. Dairy Forage Res. Cent., 1925 Linden Drive West, Madiner, 1996). son, WI 53706-1108. Mississippi Agric. and Forestry Exp. Stn. Journal Alicia, Brazos, Coastal, Russell, Tifton 44, and Tifton 85 Article no. J10019. Received 7 Feb. 2002. *Corresponding author hybrid bermudagrass and common bermudagrass were estab(gebrink@wisc.edu). Abbreviations: DM, dry matter. Published in Agron. J. 95:597–601 (2003).

EFFECT OF LONG-TERM SWINE EFFLUENT APPLICATION ON SELECTED SOIL PROPERTIES

Improving swine effluent management practices requires understanding of the fate of nutrients derived from swine effluent in soil quality. This study was conducted to evaluate the effects of long-term swine lagoon effluent application on nutrient distribution in an alkaline Okolona silty clay, an acidic Vaiden silty clay, and a Brooksville silty clay loam. Swine effluent has been applied using a center-pivot irrigation system at a total rate ranging from 10 to 15 cm ha−1 of effluent per year since 1990. In October 2005, soil samples were taken from the irrigated and nonirrigated sites at the following depths: 0 to 5, 5 to 15, 15 to 30, 30 to 60, and 60 to 90 cm. Soils were air-dried, ground to pass 2-mm sieve, and analyzed for selected chemical properties. Sorption isotherms were also performed on the soil samples to determine P sorption capacity and strength. Long-term application of swine effluent resulted in a decrease in soil pH and an increase in soil electrical conductivity in all three soils. Total soil C and microbial biomass C increased in irrigated sites for all soils. Soil ammonium, nitrate, acid-extractable P, water-soluble P, and Zn concentrations were elevated at the 0- to 5-cm and 5- to 15-cm depths, and their values were extremely lower in the alkaline Okolona soil than in the Brooksville and Vaiden soils. No clear effect was observed for P sorption strength and capacity. Low N and P accumulation in alkaline Okolona soil may prolong the capacity of this soil in receiving swine effluent particularly if threshold water-soluble P and soil test P levels are used as part of swine effluent management program.

Broiler Litter Application Effects On Selected Trace Elements Under Conventional And No-till Systems

This study was conducted on two separate commercial farms representing no-till at Coffeeville and conventional tillage system at Cruger in Mississippi to evaluate the dynamics of selected some trace elements in response to long-term broiler litter application to cotton. The soil at Cruger is a Dubbs silt loam (fine-silty, mixed, active, thermic Typic Hapludalfs) and at Coffeeville is an Ariel silt loam (coarse-silty, mixed, thermic Fluventic Dystrochreps). In each site, the experimental design was a randomized complete block with eight treatments replicated four times. Treatments included broiler litter rates of 0, 2.2, 4.5, and 6.7 Mg ha−1 in some combination with 0, 34, and 67 kg nitrogen ha−1. Commercial nitrogen, phosphorus, and potassium fertilizer at recommended rate was also included. At Coffeeville location at the end of third year, soil surface (0-15 cm) total C and total copper (Cu), zinc (Zn), and arsenic (As) significantly increased with increasing broiler litter applications. In Coffeeville under the no-till system, application of broiler litter at the highest rate (6.7 Mg ha−1) significantly increased soil surface (0-15 cm) total C, total Cu, Zn, and As by 28%, 67%, 51%, and 69%, respectively, as compared with unfertilized control. At Cruger location, changes in soil C and trace elements were less responsive to treatment applications. Downward movement of Cu and Zn was limited to 15 cm of soil depth, but As was detected at about 30 cm of soil depth at high broiler litter application rate. Despite elevated concentrations of trace metals at the soil surface, their concentrations in the soils were in the range considered normal with no potential threat to the ecosystems.

Foliar herbivory triggers local and long distance defense responses in maize

Many studies have documented the induction of belowground defenses in plants in response to aboveground herbivory and vice versa, but the genes and signaling molecules mediating systemic induction are not well understood. We performed comparative microarray analysis on maize whorl and root tissues from the insect resistant inbred Mp708 in response to foliar feeding by fall armyworm (Spodoptera frugiperda) caterpillars. Although Mp708 has elevated jasmonic acid (JA) levels prior to herbivory, genes involved in JA biosynthesis were up-regulated in whorls in response to fall armyworm feeding. Alternatively, genes possibly involved in regulating ethylene (ET) perception and signaling were up-regulated in roots following foliar herbivory. Transcript levels of genes encoding proteins involved in direct defenses against herbivores were enhanced both in roots and leaves, but transcriptional factors and genes involved in various biosynthetic pathways were selectively down-regulated in the whorl. The results indicate that foliar herbivory by fall armyworm changes root gene expression pathways suggesting profound long distance signaling. Tissue specific induction and suppression of JA and ET signaling pathway genes provides a clue to their possible roles in signaling between the two distant tissue types that eventually triggers defense responses in the roots in response to foliar herbivory.

Interrelationships Between Apoptosis and Fertility in Bull Sperm

Abstract Male fertility, the ability of sperm to fertilize and activate the egg and support early embryogenesis, is vital for mammalian reproduction. Despite producing adequate numbers of sperm with normal motility and morphology, some males suffer from low fertility whose molecular mechanisms are not known. The objective was to determine apoptosis in sperm from high and low fertility bulls and its relationship with male fertility. DNA damage, phosphatidylserine (PS) translocation, and expression of pro- and anti-apoptotic proteins (BAX and BCL-2) in the sperm were determined using TUNEL, Annexin V, and immunoblotting approaches, respectively. Amounts of apoptotic spermatozoa were 2.86 (± 1.31) and 3.00 (± 0.96) in high and low fertility bulls, respectively (P=0.548), and were not correlated with fertility. There was a negative correlation between early necrotic spermatozoa and viable spermatozoa (r = –0.99, P<0.0001). Fertility scores were correlated with live spermatozoa detected by eosin-nigrosin test and necrotic spermatozoa determined via flow cytometry (r = –0.49, P<0.006 and r = –0.266, P<0.0113, respectively). BAX level was higher in low fertile group than high fertile group; however, this difference was not statistically significant due to the variations of bull samples (Bull 1–3 vs. Bull 4–5) in low fertile group (P<0.283). BCL-2 was not detectable in any of the sperm samples. The results shed light onto molecular and cellular underpinnings of male fertility.

Broiler litter ammonia emissions near sidewalls, feeders, and waterers

Ammonia (NH3) volatilized from broiler litter diminishes indoor air quality, which can potentially decrease bird productivity. Emissions of NH3 exhausted from broiler houses pose environmental concerns for ecosystem biodiversity, aquatic nutrient enrichment, and particulate formation in the atmosphere. Research was conducted sampling litter (rice hull base) in 3 tunnel-ventilated commercial broiler houses during wk 3 (mid-growout) of 6 flocks. The purpose was to assess NH3 generated near the sidewalls, waterers, and feeders. Litter samples (100 g) were placed in chambers receiving constant air flow. Boric acid (H3BO3) titration each 24 h for 4 d was used to determine NH3 volatilized from the samples. Litter located near waterers emitted the most cumulative NH3 (approximately 12.3 mg of N•kg of litter(-1)•h(-1)) with less NH3 associated with feeders and sidewalls (2.9 to 7.6 mg of N•kg of litter(-1)•h(-1)). Moisture content of litter samples was greatest at waterers (45%) followed by sidewalls (26%) and feeders (20%). In addition, litter pH at the sidewalls and feeders could be predicted by linear equations associated with the number of flocks on the litter. At the waterers, litter pH was differentiated based on the half of house where higher litter pH existed in the nonbrood half (8.55 vs. 8.13). The results indicate that controlling NH3 near watering lines to a level consistent with feeding lines and near the house wall could reduce NH3 generated by 38 to 77%. These findings support efforts for NH3 control at mid-growout, especially considering zone litter treatments near waterers and appropriate attention to waterer management.

Phosphorus Dynamics in Broiler Litter‐Amended Soils

Abstract Because land application of broiler litter is commonly made in the spring before cropping season and in the fall, it is essential to understand how environmental variations, such as temperature, affect the phosphorus (P) dynamics. A laboratory incubation study was conducted at Waste Management and Forage Research Unit, USDA‐ARS with the objective of determining the effects of temperature and soil properties on water‐soluble P (WSP), Mehlich 3 P, and P fractions in broiler litter‐amended soils. Broiler litter was mixed with three soils (Leeper silty clay, Grenada silt loam, and Ruston sandy loam) at the rate of 10 Mg ha−1. The mixtures were incubated at 18°C, 25°C, and 32°C for up to 90 days and repeated three times. Soil samples were taken at eight time intervals (2, 5, 10, 15, 30, 60, and 90 days) and analyzed for water‐soluble P and Mehlich 3‐extractable P (MEP). Phosphorus also was fractionated chemically into inorganic and organic components by sequential extraction for soil samples taken at the end of incubation period (90 days). Water‐soluble P decreased rapidly after a 15‐day incubation in all soils for all temperatures and followed to a steady state to the end of incubation period. Averaged across temperatures, broiler litter application resulted in a significant increase in all fractions compared with controls. However, the increase was greater for inorganic than for organic fractions. The concentration of calcium (Ca)‐P fraction was highest in calcareous Grenada soil, which suggests that the presence of carbonates influence the fate of P from applied broiler litter. The coarse textured Ruston contained a greater concentration of water‐soluble P (WSP) than the other soils. At 32°C, the concentration of plant‐available P fractions [bicarbonate inorganic P (IP) and hydroxide IP] significantly increased and WSP decreased. It is likely that the higher temperature (32°C) promotes higher biological activity and lower water‐soluble P than lower temperature. Contribution of the Mississippi Agricultural and Forestry Experiment Station, journal paper no. J10120.

Effects of drying method and rearing temperature on broiler manure nutrient content

There is no universally accepted method for preparing poultry manure samples prior to chemical analysis for nutrient content. Proper sample preparation and optimization of the techniques for manure chemical analyses are the keys to the determination of precise rates for land application to crops and pastures. This study was conducted to determine the effect of bird-rearing temperature (RT) and pre-analysis drying methods on broiler manure nutrient content. Four drying methods, air drying (AD), freeze drying (FD), oven drying at 65°C (OD65), and oven drying at 105°C (OD105) were evaluated on manure of birds grown at 16, 21, and 26°C. The results were compared with analysis of the fresh broiler manure with no drying (ND). All drying treatments resulted in highly significant nitrogen (N) loss (21%–27%) compared to ND at all rearing temperatures. However, there were no significant differences in total N loss among the four drying methods examined in this experiment. There was significant loss of NH4-N with OD105 for all RT, but no pattern was observed among other drying methods and RT with regard to NH4-N and organic N. The effect of drying methods on broiler manure nutrient content followed the same trend for all the rearing temperatures. The greatest loss of phosphorus (P), calcium (Ca), magnesium (Mg), potassium (K), iron (Fe), manganese (Mn), and zinc (Zn) were observed with freeze drying. We recommend fresh broiler manure analysis for the determination of total N and NH4-N after a proper mixing to obtain a homogeneous paste. For analyses of P, Ca, Mg, K, Fe, Mn, and Zn in the broiler manure, ND, AD, and OD65 generally resulted in lower reduction of these nutrients.

Comparison of Broiler Litter and Commercial Fertilizer at Equivalent N Rates on Soil Properties

A 3-year study was conducted to determine the effects of broiler litter relative to inorganic fertilizer on soil nutrient content and quality in an upland Loring silt loam soil. Treatments included annual broiler litter rates of 0, 2.2, 4.5, 5.6, 6.7, 10.1, and 13.4 Mg ha−1 y−1 and commercial fertilizer rates of 34, 68, 90, 112, 134, and 168 kg nitrogen (N) ha−1 y−1. Broiler litter application linearly increased soil total carbon (C), microbial biomass C, extractable soil phosphorus (P), potassium (K), soil cation exchange capacity (CEC), and the stability of soil aggregate. At the highest broiler litter rate, the stability of soil aggregate was 34% greater than inorganic fertilizer. Application of broiler litter or fertilizer N at rate greater than 6.7 Mg ha−1 or 90 kg N ha−1, respectively, exceeded plant N utilization potential as evidenced by higher end-of-season soil residual nitrate (NO3)-N. Broiler litter is more effective in improving soil physical, chemical, and biological components than conventional fertilizer.