Duration: 10/01/2003 to 09/30/2008

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Statement of Issues and Justification

Introduction:

Swine production is globally distributed. The U.S. is the world's second largest swine producing country behind China. In 2001, an estimated 98 million hogs were slaughtered in the U.S. for an estimated gross on-farm value of $12 billion. The average daily inventory was 59 million animals, of which 6.2 million were sows (USDA, 2002). Swine production is driven by the fact that pork continues to be one of the major high quality sources of protein in human diets. The average per capita consumption of pork in the U.S. is 21.6 kg (USDA, 2002).

Need as indicated by the stakeholders:

Swine enterprises constitute a major source of on-farm income in the Southern Region of the U.S., and production continues to increase. Swine production in the Southern Region represents 27% of U.S. production, up from 25% five years ago. The most rapidly growing component of swine production in the Southern Region is in sow farms producing feeder pigs that are shipped to the Midwest for finishing and market. This trend is attributed to favorable environmental conditions and the availability of labor and interest in contract swine production. The Southern Region has a more favorable climate during the winter months than many of the swine producing states of the Midwest; however, high environmental temperatures during the summer affect reproductive efficiency.

A primary factor affecting profitability of swine production is sow productivity, and optimum nutrition of the sow is essential to maximize sow productivity. An ideal nutrition program should provide adequate nutrients to maximize sow productivity while minimizing excreted nutrients and feed costs. The continuing trends to earlier weaning, confinement housing, and intensive production schedules place biological demands on the sow that make high performance difficult to obtain and maintain. An increase in the number of pigs marketed per sow per year, through improved sow nutrition, would result in increased profitability by allocating the fixed sow costs over more pigs.

Swine production in the Southern Region is concentrated in certain areas, much like swine production throughout the U.S. This concentrated production results in a concentration of waste applied to the land. The amount and nutrient composition of this waste may exceed the capacity of the land in these areas for its use as a fertilizer. Sows contribute approximately 16% of the total nitrogen from pig production enterprises, and nitrogen retention in sows averages 20 to 40% with 60 to 80% of nitrogen intake excreted to the environment. The potential impact of nutrient pollution of the environment is probably the major issue facing commercial swine producers in the U.S. Managing animal waste will be a much greater challenge in the future because of the volume produced for a given land mass.

The joint task force of Southern Agricultural Experiment Stations, USDA, and swine industry representatives (Swine Research Needs in the Southern Region, 1976) emphasized that sow research should have a high priority. This report stated that an important researchable area is to identify the optimum level of each nutrient for the gestating-lactating sow. Similarly, the research committee of the National Pork Producers Council identified improvements in sow nutrition as an area needing further research. The current S-288 committee has met with members of the American Feed Industry Association, the National Pork Board, and representatives from large feed companies to get their assessment of research needs by the industry. The research objectives that we have chosen result directly from those meetings. All segments of the industry recognize sow productivity and nutrition as an extremely important factor affecting profitability in swine production systems. Although progress has been made in sow nutrition in the last 30 years, there is still a dearth of information relative to specific nutrient requirements of sows during gestation and lactation, especially the high milk-producing sows used today. Further research is greatly needed to completely define the levels of various nutrients necessary for optimizing reproduction and lactation, and for minimizing nutrient excretion.

Importance of the work:

It is extremely important to conduct research to provide solutions to potential sow nutrition and production problems and the impact that concentrated production systems have on the environment. Social restrictions and governmental regulations place extreme pressures on our production systems. Solutions to these issues must be resolved so that swine production in the South, an extremely important component of agricultural productivity, will remain, and that it will continue to be an economically viable opportunity for our work force.

Technical feasibility of the research:

The original Southern Multi-State Research Group (S-145) and the current group (S-288) have made significant contributions in obtaining new knowledge and creating a better understanding of the nutritional needs of sows to improve reproductive efficiency. This Technical Committee has used the approach of (1) defining high priority research areas, (2) developing common protocols that are rigidly followed by all participating stations, (3) pooling the data, (4) drawing conclusions, and (5) publishing the pooled results in scientific journals. Since its inception, the Committee has published 13 refereed publications, 1 conference proceedings, and 17 abstracts. These publications are the direct result of the collaborative research effort of the Southern Multi-State Research Group. Also, in collaboration with the NCR-42 Committee, the Committee has published one book entitled Swine Nutrition and four book chapters. Over the last 20 years, participants in the Committee have clearly demonstrated that they can successfully collaborate in regional research. In addition, we meet with the NCR-42 Committee, which is an informational exchange group working on swine nutrition. We have opened our objectives to their participation.

Justification for a regional approach:

Sow research is well suited to a regional approach for two major reasons. First, in reproductive studies, large numbers of animals are required to generate meaningful data; individual experiment stations often do not have sufficient sow numbers to effectively conduct sow research. Second, pooled results from several experiments conducted with a common protocol but under different environments provides valuable information from which broad inferences can be drawn and more meaningful recommendations can be made. A further advantage of a regional approach is that the combined experience and expertise of several swine nutritionists can be focused on a few objectives. Also, a planned annual meeting provides opportunities to discuss new and old research findings.

Progress in sow nutrition and management research is hampered by the large variation among sows in the economically important reproductive traits (Aaron and Hays, 1991). In a summary of 2,346 farrowings in five herds, the coefficients of variation were 27% for total and live pigs farrowed and 32% for pigs weaned (Hays et al., 1969). In contrast, the coefficients of variation for growth rate and feed efficiency were 4 and 6%, respectively, for pens of growing and finishing pigs (Cromwell et al., 1984). The number of replications needed to detect a 10% difference in litter size at birth and at weaning, at an 80% success rate and a 5% probability level, is 114 and 161 sows per treatment, respectively. Thus, it is difficult for individual experiment stations to generate the number of observations needed to reach valid conclusions.

Goals and impacts of the current research:

The goals of this proposed project are to improve the reproductive performance of sows while reducing nutrient loss to the environment from urine and feces. This research will include a study to determine the concentration of nutrients currently excreted to the environment from urine and feces, and to investigate diets that increase the efficiency of production and reduce nutrient loss.

We plan to collect swine waste from sow production enterprises throughout the country to determine the nutrients that are lost to the environment from urine and feces. We plan to conduct research into particle size of diets for sows  a direct suggestion from our stakeholders. Feed intake in sows is a factor that limits production efficiency and reducing dietary particle size may increase nutrient digestibility, which in turn will increase nutrients available to the sow and decrease nutrient losses to the environment. There is very limited research to date on particle size of diets for sows. We plan to evaluate the inclusion of crystalline amino acids into sow diets. Low crude protein, amino acid supplemented diets have been extensively evaluated in growing pigs and are used widely in the industry. These low crude protein diets effectively reduce nitrogen loss to the environment. The efficiency of crystalline amino acid use depends on the number of times pigs eat per day. Growing pigs are offered feed continuously, but sows are fed only one to three times daily, which may decrease their efficiency of utilization. There is very little research into the area of crystalline amino acid use in sow diets. We also plan to evaluate the use of carnitine in sow diets. Carnitine is a dietary additive that has been shown to increase sow productivity, but the data are limited, controversial, and inconsistent. A large-scale study is absolutely necessary to evaluate the efficacy of this intermediary metabolite.

Related, Current and Previous Work

Literature searches were made in the CSREES index, the CRIS index, the CAB Index, the Index on Current Research in Pigs, and the Index of the Journal of Animal Science to locate past and current research in the four project areas.

The swine industry in the U. S. has shifted towards a highly specialized systems approach, which has resulted in the concentration of production in certain areas of the country. The amount and nutrient composition of the manure may exceed the capacity of the land in these areas for its application as a fertilizer and therefore, methods to reduce the excretion of nutrients from swine need to be sought. Currently, nitrogen and phosphorus are the nutrients of most concern, however, micro-minerals such as copper and zinc may become of concern in the future.

Growing-finishing pigs are responsible for approximately 76% of the nitrogen (Dourmad et al., 1992) and 67% of the phosphorus excretion (Poulsen et al., 1999). Sows excrete approximately 16% of the nitrogen (Dourmad et al., 1992) and 23% of the phosphorus (Poulsen et al., 1999). Although these levels are less than growing-finishing pigs, the impact of nutrient excretion by sows should not be underestimated. Many production units, especially in the Southeastern part of the U.S., have focused on the production of weanling pigs that are finished in other parts of the country. Thus, sows contribute a relatively large portion of nutrients that are excreted into the environment in these areas.

Objective 1: Survey of Nutrients Lost to the Environment from Urine and Feces of Lactating Sows

Kornegay and Harper (1997) estimated the retention of nitrogen to be 20 to 40% in lactating sows and 35 to 45% in gestating sows. Similarly, Dourmad et al. (1999) estimated an average retention of nitrogen of 23%. Conversely, nitrogen excretion can amount to levels of 55 to 80% of nitrogen intake. Retention of phosphorus has been estimated between 20 and 45% in gestating sows and approximately 20% in lactating sows (Kornegay and Harper, 1997; Poulsen et al., 1999). Therefore, excretion of phosphorus may vary from 55 to 86%. Limited information is available regarding the retention and excretion of micro-minerals in sows.

The large variation in nutrient excretion reported may be due to differences in production practices, sow reproductive performance, management, feed consumption, feed wastage, and feed composition. Spears (1996) reported that substantial variation in nutrient concentration of diets exist for sows. Diets from sow feeds on 26 farms in North Carolina had concentrations of calcium, phosphorus, copper, and zinc that ranged from 0.62 to 2.01%, 0.45 to 1.17%, 12 to 222 ppm, and 79 to 497 ppm, respectively, compared to suggested requirements (NRC, 1998) of 0.75%, 0.60%, 5 ppm, and 50 ppm, respectively. It is clear that this large variation in dietary concentrations of minerals greatly affects nutrient excretion in feces and urine. Poulsen et al. (1999) reported that sows excreted 27% of phosphorus in urine and contributed this to excessive levels in the diet. In addition, phosphorus excretion in feces was 52%, indicating low phosphorus digestibility of the diet (Poulsen et al., 1999). Therefore, nutrient intake of sows plays a critical part in the extent to which nutrients are excreted.

Estimates of nutrients in manure are required for proper manure planning purposes of swine production systems. Values for nutrient excretion are often based on average estimates published by the National Resource Conservation Service (NRCS), the American Society of Agricultural Engineers (ASAE), and the Midwest Planning Service (MWSP). These values do not account for production methods, feed intake, performance, diet composition, or methods to minimize excretion such as the use of alternative ingredients and enzymes.

Therefore, the objective of this project is to evaluate the average concentration of nutrients in feces and urine of sows and the variation that exists between herds. This information will provide a baseline of nutrient excretion values with associated variation in sows and will, together with feed composition data, provide an indication of the potential for reducing nutrient excretion from sows.

Objective 2: Low-Crude Protein, Amino Acid-Supplemented Diets for Lactating Sows

Recently, swine producers and nutritionists have implemented nutrition and feeding strategies to reduce nutrient excretion. An established method to reduce nitrogen excretion by pigs is to reduce dietary crude protein with supplementation of crystalline amino acids to achieve a more ideal pattern of amino acids (Kerr and Easter, 1995). To date, most of the research conducted in this area has been with growing-finishing pigs, with limited studies with sows. Research is required with low crude protein, amino acid-supplemented, corn-soybean meal-based diets for lactating sows.

Kerr and Easter (1995) suggested that each 1% reduction in dietary protein (when accompanied by appropriate amino acid supplementation) results in an 8% reduction in nitrogen excretion for growing pigs. Cromwell (1996) and Tuitoek et al. (1997) also reported that reductions of 2 or 3% dietary protein for growing pig diets could be done with no reduction in average daily gain or feed efficiency when amino acids are supplemented. However, in some experiments where protein reduction was greater than 3%, pig performance was negatively affected (Hansen et al., 1993; Gomez et al., 2002).

Low protein intake during lactation increases body protein loss (Jones and Stahly, 1999) and reduces reproductive performance (King and Williams, 1984; Brendemuhl et al., 1987; Yang et al., 2000). These reductions in performance are attributed to an inadequate intake of essential amino acids to meet both the demands of lactation and maintenance of sow body protein. It is the aim of this study to reduce dietary protein (total nitrogen intake) but supplement the diets with amino acids to meet the true digestible amino acid requirements (NRC, 1998) of lactating sows.

Few studies have been conducted with low protein, amino acid-supplemented diets for sows. Gestating sows fed either a 14.8% crude protein diet or a diet with 12.0% crude protein with added lysine and threonine for three parities had similar body weights at breeding, backfat during gestation, and litter size and weight (Mohn et al., 2002). However, sows on the low protein, amino acid-supplemented diet excreted 19.4% less nitrogen than sows consuming the 14.8% crude protein diet (Mohn et al., 2002).

Atakora et al. (2002) using the same gestation diets as Mohn et al. (2002) and a reduced protein diet during lactation, concluded that low protein, amino acid-supplemented diets for sows in gestation and lactation significantly reduced carbon dioxide production and thus reduced greenhouse gas. The reduced heat production observed is indicative of an improved nutrient utilization, which would also lead to less waste. McMillan et al. (2002), using barley-based diets and 80 second parity sows, compared the effects of a low protein, amino acid-supplemented diet (LP, 16.3%, supplemented with lysine and threonine) to a high protein (HP, 19.3%) conventional diet fed during lactation. The authors concluded that sows fed the LP diet had similar performance as sows fed the HP diet during lactation but they excreted significantly less nitrogen.

Limited research suggests that low protein, amino acid-supplemented diets can be fed to sows during lactation, but to our knowledge, no research has been published using corn-soybean meal diets, which would be the standard diets used for typical U.S. production facilities. Furthermore, our study would reduce crude protein by 2 and 4 percentage units, and diets would include not only lysine and threonine, but also tryptophan, methionine and valine additions. We hypothesize that the low protein, amino acid-supplemented diet will result in sow performance equal to that of a high protein diet, while greatly reducing the nitrogen excretion in urine and feces.

Objective 3: Effect of Dietary Carnitine Supplementation on Sow Productivity

Carnitine is a naturally synthesized, vitamin-like compound found in most tissues throughout the body. It plays an important role in fat metabolism. Long-chain fatty acids that have entered the cell must be transported across the mitochondrial membrane in order to be utilized for energy. Carnitine is a vital component of the trans-membrane transport, converting the fatty acid to a transferable form capable of passing through the membrane.

Serum carnitine concentrations in reproducing pigs are relatively low compared with other species (Wittek et al., 1999), which suggests that dietary supplementation may be beneficial. Musser et al. (1999a,b) recently reported that both serum and milk carnitine levels were increased by carnitine supplementation. Gestation weight gain and backfat gain also were increased along with increases in both total litter and individual pig birth weight (Musser et al., 1999a), but there was no effect on litter size. However, supplementation of the carnitine did not occur before breeding so there would have been no opportunity to affect ovulation rate, which is one of the factors controlling litter size. An interesting observation, however, was that litter size in the subsequent parity was improved from the supplementation of carnitine in either gestation or lactation. Sows fed carnitine in gestation remained 10 kg heavier, which may suggest a better body condition, resulting in better rebreeding performance. Subsequently, Musser et al. (1999b) reported that dietary carnitine supplementation beginning from day 107 to 112 of gestation and continuing through lactation at rates of 50 to 200 ppm did not affect current litter performance or subsequent litter size, although in one of three studies a numerical increase (12.3 vs. 10.8) was observed in subsequent litter size that was comparable to the response in the initial report (Musser et al., 1999a). A series of three trials (Newton and Cera, 2000) in commercial settings involving about 4,500 test litters from sows supplemented at a rate of 50 ppm failed to see increases in litter size.

The field studies that failed to see a response in litter size (Newton and Cera, 2000) did not mandate similar gestational feed allowances, but sows were fed to a similar body condition per standard farm procedures. If carnitine did have the effect of increasing backfat and weight gain in these field studies in a manner similar to that observed in the controlled studies by Musser et al. (1999a), feed allowance of the carnitine-supplemented sows would have been decreased because of that improved body condition; potentially masking a response to carnitine.

Recently, Eder et al. (2002) reported that carnitine supplementation of 125 mg/d in gestation and 250 mg/d in lactation increased the number of viable pigs at weaning by 0.4 to 0.6. This litter size was the actual litter size minus those pigs with low body weight or in other ways considered unfit for rearing. There also was a consistent increase in birth weight of about 70 to 80 g/pig. It was also reported that weight gain during the suckling period was greater in pigs nursing sows fed carnitine.

Additional research is required to clearly establish the role of carnitine for improving the reproductive efficiency of high producing sows.

Objective 4: Effect of Dietary Particle Size on Performance and Diet Digestibility in Gestating and Lactating Sows

Reducing dietary particle size increases the surface area of the grain particles, which allows for a greater interaction with digestive enzymes (Cline and Richert, 2001). Hedde et al. (1985) reported an 8% increase in rate of gain for finishing pigs fed corn-based diets when the particle size was reduced from a coarse grind to a fine grind. Similar results have been reported in studies where the geometric mean particle size (ASAE, 1983) was measured (Hale and Thompson, 1986; Wondra et al., 1995a). Wondra et al. (1995a), Giesemann et al. (1990), and Hancock and Behnke (2001) also reported improvements in feed efficiency when particle size was reduced.

Experiments to evaluate the effect of particle size on performance in gestating sows have not been conducted and data in lactating sows is limited. Limited data in lactating sows is surprising because it is recognized that high-producing, lactating sows have nutrient requirements that are not met by traditional dietary regimens. Increasing nutrient intake of sows has been shown to improve performance (Brooks and Cole, 1972; Reese et al., 1982; King and Williams, 1984). Lactating sows fed diets with greater energy and(or) protein concentrations lose less body fat and muscle mass (Brendemuhl et al., 1987), return to estrus sooner (Reese et al., 1982; Nelssen et al., 1985), and have improved pig weight gain (Nelssen et al., 1985; King et al., 1993). The methods most often used to increase nutrient intake is to increase dietary nutrient density by adding more protein or fat, both of which increase diet cost.

Wondra et al. (1995b) fed 100 primiparous sows diets with corn milled to four particle sizes (1,200, 900, 600, and 400 5m). Decreasing particle size from 1,200 to 400 5m increased feed intake, energy digestibility, and litter weight gain but decreased fecal excretion of dry matter by 21% and nitrogen excretion by 31%. Improved performance in lactating sows seems to be due to improved nutrient digestibility, which is consistent with numerous observations made in growing-finishing pigs (Hancock and Behnke, 2001; Wondra et al. 1995c). Metabolizable energy digestibility was increased from 3,399 to 3,745 kcal/kg as particle size of corn was reduced. Hancock and Behnke (2001) estimated that a 9% addition of fat would be required to achieve the same increase in energy density.

Gastric ulcers have been associated with decreasing dietary particle size in diets for growing-finishing pigs (Maxwell et al., 1970, 1972; Wondra et al., 1995a). Wondra et al. (1995a,b) observed that decreasing particle size from 1,200 to 400 5m increased incidence of ulcers and increased keratinization, although no detrimental effects on performance due to the increased incidence of ulcers were observed.

Studies are needed to determine if the improvement in digestibility observed in the lactating sow are observed in gestation where limit feeding may reduce the impact that the effect of particle size reduction has on digestibility. Additionally, studies with a larger number of sows over more than one parity are needed to determine if benefits in digestibility observed with decreasing particle size in lactating sows can be obtained without decreasing longevity as a result of increased ulcer problems.

Objectives

1. To survey nutrient losses to the environment from urine and feces of lactating sows.
   
2. Determine the effect of low-crude protein, amino acid-supplemented diets for lactating sows.
   
3. Determine the effect of dietary carnitine supplementation on sow productivity.
   
4. Determine the effect of dietary particle size on performance and diet digestibility in gestating and lactating sows.
   
5. 
   

Methods

Each objective will have a coordinator whose responsibility will be to prepare the detailed protocol for the collection of the data, for the statistical analysis of the data submitted by the other collaborators, and for abstract and manuscript preparation. Objective 1: Survey of nutrient losses to the environment from lactating sows. Coordinator, Dr. Eric van Heugten. Commercial and University sow herds for this project will be identified and information will be gathered through a questionnaire. Information requested will include size of the swine operation, number of sows in the facility, reproductive performance of sows (from the most recent records to provide average performance data for the farm; including number of pigs born, number born alive, birth weight, number of pigs weaned, weaning weight, weaning age, and average sow parity), and feed intake. Additional information on management procedures and diet composition will be collected, including physical diet form (pellet vs. meal, particle size, addition of enzymes [particularly phytase]), and the use of byproducts. A representative feed sample will be obtained from both gestation and lactation diets. Feed samples will be analyzed for neutral detergent fiber, nitrogen, calcium, phosphorus, potassium, copper, and zinc. Fecal and urine samples will be obtained from multiple sows (at least ten to provide a representative sample for each farm) and composited for each facility. Samples will be collected at 60 (+/- 10) days of gestation and at 14 (+/- 6) days of lactation. Fecal samples will be collected by palpation or from the floor when the sample has not been contaminated with urine. Urine will be collected from the females in the morning as they are evacuating, and samples will be acidified using 6 M HCl (1% of urine volume) to limit nitrogen loss, and both urine and fecal samples will be frozen at 20 0C until they are analyzed. Participation of at least 10 stations is anticipated and therefore, samples collected will provide a representative measure of nutrient excretion in feces and urine in sows throughout the U.S. Each station is expected to provide samples and information from at least three facilities (depending on the number of facilities present in the state). Samples will be analyzed for nitrogen, calcium, phosphorus, potassium, copper, and zinc. In addition, urine will be analyzed for creatinine to correct for variation in urine volume and subsequent dilution effects. Analysis of calcium, phosphorus, potassium, copper, and zinc in feces and urine will be conducted using an inductively coupled plasma optical emission spectrometry instrument (ICP-OES; Vista-MPX, Varian, Inc., Palo Alto, CA) following digestion using nitric acid and hydrochloric acid. Nitrogen will be analyzed following flash combustion using a Flash EA 1112 NC analyzer (Thermo Finnigan, San Jose, CA). Neutral detergent fiber will be analyzed according to the method of van Soest et al. (1991). Analysis of creatinine will be conducted using a commercial kit (555-A, Sigma-Aldrich Co., St. Louis, MO). Data will be analyzed to obtain ranges, means, median values, and coefficients of variation. Partial least squares regression will be performed to investigate relationships between feeding practices, diet composition, management, and nutrient excretion. General methods for objectives 2, 3, and 4. Low-crude protein, amino acid-supplemented diets for lactating sows, dietary carnitine supplementation on sow productivity, and effect of dietary particle size on performance and diet digestibility in gestating and lactating sows. All stations participating in the project will follow the same protocol for each objective. Faculty participants at each station will have the responsibility to allot sows to the treatments per standard procedures regarding respect to breed and parity that will allow appropriate pooling and analysis of the collected data. Each station will allot a minimum of 10 sows per treatment. Corn will be used as the grain source and soybean meal will be used as the protein source in all gestation and lactation diets. The gestation diets will be identical for objectives 2, 3, and 4. The lactation diets will be identical for objectives 3 and 4, and the positive control diet for objective 2 (Appendix 1, Table 1). A common source of trace minerals and vitamins will be used. During gestation, sows will be fed 1.82 kg/day during the months of March to November, and 2.27 kg/day during the months of December to February (for those stations that house sows outside and that increase the feeding level due to low ambient temperatures). Feed will be provided at least two to three times per day during lactation. Samples of diets at each mixing will be collected by each participating station, and samples composited by diet on a quarterly basis will be sent to the coordinator of the specific objective. Appropriate chemical analysis will be conducted at a common laboratory site. Animals will be on a standard deworming and vaccination schedule common for the individual stations. Pigs will be processed according to standard procedures at each station. Sows or gilts can be started on each objective. Data collected for each objective will include parity, sow weights at farrowing (within 24 hours postpartum), at 17 days postpartum, and at weaning. Feed consumption will be recorded during lactation from farrowing to weaning. Number and weights of pigs at birth (total and live), after cross-fostering, and at weaning will be recorded. After weaning, the number of days to first estrus will be determined. When a sow is removed from the study for any reason, the exact reason will be recorded. Additional data collected for each objective will be indicated in the specific protocols that follow. Cross-fostering should be kept to a minimum and within treatment if at all possible. Litter size should be standardized to 10 pigs per sow by day three postfarrowing. Data will be collected and submitted on standardized forms and pooled with data from the other stations that participate. Data will be analyzed as a randomized block design with the litter serving as the experimental unit. The model will include terms for station, treatment, parity on study, and all possible interactions; biological parity may serve as a covariate on some objectives. Objective 2. Determine the effect of low-crude protein, amino acid-supplemented diets for lactating sows. Coordinator, Dr. J. H. Brendemuhl. The standard gestation diet will be fed from breeding until sows enter the farrowing house at approximately day 110 of gestation. Lactation treatments. A lactation diet containing 0.90% true digestible lysine (TDL) will be formulated using corn and soybean meal. This level of lysine assumes sows are nursing 10 pigs for 21 days with a daily weight gain of 250 g/pig, and a sow lactation weight change of minus 10 kg (NRC, 1998). True digestible amino acid values for dietary requirements and feed composition were obtained from Nutrient Requirements of Swine (NRC, 1998). The 0.90% TDL diet will serve as the positive control (PC) diet (18.87% CP). Two additional lactation treatment diets will be formulated to contain 2 and 4 percentage units lower crude protein compared with the PC. The reduced protein diets will be supplemented with the appropriate crystalline amino acids (lysine, threonine, tryptophan, methionine, or valine) as necessary to meet the true digestible amino acid requirements for sows (NRC, 1998). Gilts or sows will be allotted to dietary treatment upon entering the farrowing house at day 110 of gestation with attention given to balancing the allotment relative to parity, weight, and genetic background. Samples of feces and urine will be collected from each sow on day 10 (+/- 3) postpartum and analyzed for nitrogen, and the urine will be analyzed for creatinine. Blood samples will be collected on day 10 (+/- 3) postpartum and 3 to 4 hours after the morning feeding for determination of plasma urea nitrogen. Objective 3. Determine the effect of dietary carnitine supplementation on sow productivity. Coordinator, Dr. C. R. Dove. Supplemental carnitine concentrations of 0 or 50 ppm will be evaluated in gestation and lactation diets in a 2 x 2 factorial arrangement of treatments. The treatments will be: 1) Control diet, 0 ppm carnitine in gestation and lactation, 2) 50 ppm carnitine in gestation only; 3) 50 ppm carnitine in lactation only; and 4) 50 ppm carnitine in gestation and lactation. The gestation diets will start on day 1 after breeding, and the lactation diets will start on day 110 of gestation when the sows are placed into the farrowing house. At day 60 (+/- 10) of gestation and on day 10 (+/-3) of lactation a blood sample (plasma) may be collected following a 6 to 8 hour fast for NEFA (non-esterified fatty acids) analysis by those stations wishing to do so. Blood samples should be frozen (-20 0C) and forwarded for analysis at the completion of the study. Objective 4. Determine the effect of dietary particle size on performance and diet digestibility in gestating and lactating sows, and to determine the variation in particle size of corn ground through the same screen size at different research stations. Coordinator, Dr. C. V. Maxwell. The initial allotment to the two treatments will be on day 1 after breeding. Sows rebred in this study should remain on the same treatment. Gestation diets will be fed at the initiation of breeding and continued through day 110 of gestation. Starting on day 110, all sows will be fed the lactation diets. The treatments will be: 1) 900 5m corn-soybean meal diet. Corn will be ground with a hammer mill through a screen with a 9.5-mm (No. 24, 3/8 screen) opening. This opening will produce a geometric mean particle size of 900 5m. 2) 400 5m corn-soybean meal diet. Corn will be ground with a hammer mill through a screen with a 1.2-mm (No. 3, 3/64 screen) opening. This opening will produce a geometric mean particle size of 400 5m. Treatment diets will contain chromic oxide for determination of energy, nitrogen, calcium, phosphorus, and potassium digestibility. Fecal samples will be collected on day 60 (+/- 10) during gestation and between day 7 and 14 of lactation. Ground corn samples and complete diet samples before pelleting will be obtained each time feed is mixed and a 200 g composite sample obtained for determining geometric mean particle size, particle size uniformity (log normal standard deviation), and surface area of corn and the complete diet. Procedures will follow ASAE (1983) guidelines using a Ro-Tap sieve shaker (W. S. Tyler, Mentor, OH).

Measurement of Progress and Results

Outputs

• Objective 1. Data collected will be ranges, means, median values, and coefficients of variation for neutral detergent fiber, nitrogen, calcium, phosphorus, potassium, copper, and zinc in feed, and for nitrogen, calcium, phosphorus, potassium, copper, and zinc in feces and urine samples from sows. Data collected will be from swine producers and research stations throughout the U.S.
• Objective 2. Data collected will include parity, sow weights at farrowing (within 24 hours postpartum), at 17 days postpartum, and at weaning; feed consumption during lactation from farrowing to weaning; number and weights of pigs at birth (total and live), after cross-fostering, and at weaning; the number of days to first estrus after weaning; nitrogen content of feces and urine; and urea nitrogen in plasma.
• Objective 3. Data collected will include parity, sow weights at farrowing (within 24 hours postpartum), at 17 days postpartum, and at weaning; feed consumption during lactation from farrowing to weaning; number and weights of pigs at birth (total and live), after cross-fostering, and at weaning; the number of days to first estrus after weaning; and plasma non-esterified fatty acids during gestation and lactation.
• Objective 4. Data collected will include parity, sow weights at farrowing (within 24 hours postpartum), at 17 days postpartum, and at weaning; feed consumption during lactation from farrowing to weaning; number and weights of pigs at birth (total and live), after cross-fostering, and at weaning; the number of days to first estrus after weaning; energy, nitrogen, calcium, phosphorus and potassium digestibility; and geometric mean particle size, particle size uniformity (log normal standard deviation), and surface area of corn and the complete diet.

Outcomes or Projected Impacts

• Objective 1. The outcome of this objective will be the determination of the mean and variability of nutrient content of diets and of nutrient losses to the environment from swine farms throughout the U.S. The emphasis will be on the contribution from urine and feces of sows. This information will provide a baseline of nutrient excretion values with associated variation in sows and will, together with feed composition data, provide an indication of the potential for reducing nutrient excretion in sows.
• Objective 2. From this objective, we will know whether sow reproductive efficiency will be affected if sows are fed low crude protein, amino acid-supplemented diets. If the results are positive, production costs may be decreased and the amount of nitrogen lost to the environment will be dramatically reduced. The participating agricultural economist will provide an assessment of the economic feasibility of the application of this research.
• Objective 3. From this objective, we will know whether sow reproductive efficiency will be improved by the addition of supplemental carnitine. The participating agricultural economist will provide an assessment of the economic feasibility of the application of this research.
• Objective 4. From this objective, we will know whether sow reproductive efficiency will be affected by the particle size of the diets. The participating agricultural economist will provide an assessment of the economic feasibility of the application of this research.

Milestones

(0):re are no time-linked accomplishments that must be made before any of the objectives can be initiated.

(0):0

Projected Participation

View Appendix E: Participation

Outreach Plan

Data from each objective will be published first in abstract form by the coordinator of the objective, and he/she will present the data orally or in poster form at a national or regional scientific conference. Next, a manuscript will be prepared and submitted to a refereed journal, probably the Journal of Animal Science. Each participant of the objectives may choose to publish their contribution to the objective in producer field days, university publications, or in a graduate students thesis or dissertation. In addition, some members of the committee hold extension appointments, and all members of the committee interact with their extension colleagues or participate in extension functions.

Organization/Governance

The Multi-state research conference committee includes the regional Administrative Advisor (nonvoting); a technical representative of each cooperating experiment station, appointed by the respective Director; and a non-voting, consulting member representing CSREES. The Committee will elect a Chair, Vice-Chair, and Recorder. The Recorder position will be elected each year; the Vice-Chair will move into the position of Chair, the Recorder will move to the position of Vice-Chair. Administrative guidance will be provided by an assigned Administrative Advisor and a CSREES Representative.

Literature Cited

Aaron, D. K., and V. W. Hays. 1991. Statistical techniques for the design and analysis of swine nutrition experiments. In: (Eds.) E. R. Miller, D. E. Ullrey, and A. J. Lewis, Swine Nutrition, pp. 605-622, Butterworth-Heinemann, Stoneham, MA 02180.

Atakora, J. K. A., D. J. McMillan, S. Mohn, and R. O. Ball. 2002. Low protein diet for sows reduce carbon dioxide and heat production. J. Anim. Sci. 80(Suppl. 1):131 (Abstr.).

ASAE. 1983. Method of determining and expressing fineness of feed materials by sieving. American Society for Agricultural Engineers, Standard S319, Yearbook of Standards, 325.

Brendemuhl, J. H., A. J. Lewis, and E. R. Peo, Jr. 1987. Effect of protein and energy intake by primiparous sows during lactation on sow and litter performance and sow serum thyroxine and urea concentrations. J. Anim. Sci. 64:1060.

Brooks, P. H., and D. J. A. Cole. 1972. Studies in sow reproduction. 1. The effect of nutrition between weaning and remating on the reproductive performance of primiparous sows. Anim. Prod. 15:259.

Cline, T. R., and B. T. Richert. 2001. Feeding growing-finishing pigs. In: A. J. Lewis and L. L. Southern (Ed) Swine Nutrition. pp 721.CRC Press, Boca Raton, FL.

Cromwell, G. L. 1996. Synthetic amino acids may improve performance, reduce nitrogen excretion. Feedstuffs 68(49):12-31.

Cromwell, G. L., L. F. Tribble, and R. H. Hines. 1984. Efficacy of furazolidone in grower diets on subsequent performance of swine - A cooperative study. J. Anim. Sci. 59:863-868.

Dourmad, J. Y., D. Guillou, and J. Noblet. 1992. Development of a calculation model for predicting the amount of N excreted by the pig: effect of feeding, physiological stage and performance. Livest. Prod. Sci. 311:95-107.

Dourmad, J. Y., B. Seve, P. Latimier, S. Boisen, J. Fernandez, C. van der Peet-Schwering, and A. W. Jongbloed. 1999. Nitrogen consumption, utilisation and losses in pig production in France, The Netherlands and Denmark. Liv. Prod. Sci. 58:261-264.

Eder, K., A. Ramanau, and H. Kluge. 2002. Effect of dietary L-carnitine supplementation on the performance of sows. Lohmann Information No. 26, pp. 1-4.

Giesemann, M. A., A. J. Lewis, J. D. Hancock, and E. R. Peo, Jr. 1990. Effect of particle size of corn and grain sorghum on growth and digestibility of growing pigs. J. Anim. Sci. 68(Suppl. 1):104 (Abstr.).

Gomez, R. S., A. J. Lewis, P. S. Miller, and H.-Y. Chen. 2002. Growth performance, diet apparent digestibility, and plasma metabolite concentrations of barrows fed corn-soybean meal diets or low-protein, amino acid-supplemented diets at different feeding levels. J. Anim. Sci. 80:644-653.

Hale, O. M., and L. M. Thompson. 1986. Influence of particle size of wheat on performance of finishing swine. Nutr. Rep. Int., 33:307.

Hancock, J. D., and K. C. Behnke. 2001. Use of ingredient and diet processing technologies (grinding, mixing, pelleting and extruding) to produce quality feed for pigs. In: A. J Lewis and L. L. Southern (Ed) Swine Nutrition. pp. 672-673. CRC Press, Boca Raton, FL.

Hansen, J. A., D. A. Knabe, and K. G. Burgoon. 1993. Amino acid supplementation of low-protein sorghum-soybean meal diets for 20- to 50-kilogram swine. J. Anim. Sci. 71:442-451.

Hays, V. W., D. D. Kratzer, V. C. Speer, R. J. Bunch, and G. L. Cromwell. 1969. Variability in litter size and birth weight of pigs as it relates to needed replication. J. Anim. Sci. 29:136 (Abstr.).

Hedde, R. D., L. F. T. O. Lindsey, R. C. Parish, H. D. Daniels, E. A. Morgenthien, and H. B. Lewis. 1985. Effect of diet particle size and H2-receptor antagonist on gastric ulcers in swine. J. Anim. Sci. 61:179.

Jones, D. B., and T. S. Stahly. 1999. Impact of amino acid nutrition during lactation on body nutrient mobilization and milk nutrient output in primiparous sows. J. Anim. Sci. 77:1513-1522.

Kerr, B. J., and R. A. Easter. 1995. Effect of feeding reduced protein, amino acid-supplemented diets on nitrogen and energy balance in grower pigs. J. Anim. Sci. 73:3000-3008.

King, R. H., and I. H. Williams. 1984. The effect of nutrition on the reproductive performance of first-litter sows. 2. Protein and energy intakes during lactation. Anim. Prod. 38:249.

King, R. H., M. S. Toner, H. Dove, C. S. Atwood, and W. G. Brown. 1993. The response of first-litter sows to dietary protein level during lactation. J. Anim. Sci. 71:2457.

Kornegay, E. T., and A. F. Harper. 1997. Environmental nutrition: Nutrient management strategies to reduce nutrient excretion of swine. Prof. Anim. Sci. 13:99-111.

Maxwell, C. V., E. M. Reimann, W. G. Hoekstra, T. Kowalczysk, N. J. Benevenga, and R. H. Grummer. 1970. Effect of dietary particle size on lesion development and on the contents of various regions of the stomach. J. Anim. Sci. 25:1019.

Maxwell, C. V., E. M. Reimann, W. G. Hoekstra, T. Kowalczysk, N. J. Benevenga, and R. H. Grummer. 1972. Use of tritiated water to assess, in vivo, the effect of particle size on the mixing of stomach contents of swine. J. Anim. Sci. 34:212.

McMillan, D. J., S. Mohn, and R. O. Ball. 2002. Low protein diets can be fed to lactating sows with few adverse effects. J. Anim. Sci. 80(Suppl. 1):14 (Abstr.).

Mohn, S., D. J. McMillan, and R. O. Ball. 2002. Low protein diets can be fed to gestating sows without adverse effects. J. Anim. Sci. 80(Suppl. 1):130 (Abstr.).

Musser, R. E., R. D. Goodband, M. D. Tokach, K. Q. Owen, J. L. Nelssen, S.A . Blum, S. S. Dritz, and C. A. Civis. 1999a. Effects of L-carnitine fed during gestation and lactation on sow and litter performance. J. Anim. Sci. 77:3289.

Musser, R. E., R. D. Goodband, M. D. Tokach, K. Q. Owen, J. L. Nelssen, S. A. Blum, R. G. Campbell, R. Smits, S. S. Dritz, and C. A. Civis. 1999b. Effects of L-carnitine fed during lactation on sow and litter performance. J. Anim. Sci. 77:3296.

Nelssen, J. L., A. J. Lewis, E. R. Peo, Jr., and J. D. Crenshaw. 1985. Effect of dietary energy intake during lactation on performance of primiparous sows and their litters. J. Anim. Sci. 61:1164.

Newton, E. A., and Cera, K. R. 2000. Akeys field trial experience with L-carnitine supplementation of sow diets. Akey Swine Newsletter, April 2000.

NRC. 1998. Nutrient requirements of swine. 10th ed. National Academy Press, Washington, DC.

Poulsen, H. D., A. W. Jongbloed, P. Latimier, and J. A. Fernandez. 1999. Phosphorus consumption, utilisation and losses in pig production in France, The Netherlands and Denmark. Liv. Prod. Sci. 58:251-259.

Reese, D. E. , B. D. Moser, E. R. Peo, Jr., A. J. Lewis, D. R. Zimmerman, J. E. Kinder, and W. W. Stroup. 1982. Influence of energy intake during lactation on the interval from weaning to first estrus in sows. J. Anim. Sci. 55:590.

Spears, J. W. 1996. Optimizing mineral levels and sources for farm animals. In: Nutrient Management of Food Animals to Enhance and Protect the Environment (Ed. E. T. Kornegay): pp. 259-275.

Swine Research Needs in the Southern Region. 1976. Joint Task Force of S. Agr. Exp. Sta., United States Department of Agriculture and Swine Industry.

Tuitoek, K., L. G. Young, C. F. M. de Lange, and B. J. Kerr. 1997. The effect of reducing excess dietary amino acids on growing-finishing pig performance: An evaluation of the ideal protein concept. J. Anim. Sci. 75:1575-1583.

USDA. 2002. Agricultural Statistics. United States Department of Agriculture, Washington, DC.

USDA. 1992. National Swine Survey: Morbidity/Mortality and Health Management of Swine in the United States. Animal and Plant Health Inspection Service: Veterinary Services. Washington, DC.

Van Soest, J. B. Robertson, and B. A. Lewis. 1991. Methods of dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74:3583-3597.

Wittek, T., K. Elze, S. Scharfe, and H. Seim. 1999. Carnitine concentration in blood serum of pig in relation to reproduction. Zuchtungskunde 71:219-228.

Wondra, K. J., J. D. Hancock, K. C. Behnke, R. H. Hines, and C. R. Stark. 1995a. Effects of particle size and pelleting on growth performance, nutrient digestibility and stomach morphology in finishing pigs. J. Anim. Sci. 73:414.

Wondra, K. J., J. D. Hancock, G. A. Kennedy, R. H. Hines, and K. C. Behnke. 1995b. Effects of reducing particle size of corn in lactation diets from 1,200 to 400 micrometers improves sow and litter performance. J. Anim. Sci. 73:421.

Wondra, K. J., J. D. Hancock, G. A. Kennedy, K. C. Behnke, and K. R. Wondra. 1995c. Effects of reducing particle size of corn in lactation diets on energy and nitrogen metabolism in second-parity sows. J. Anim. Sci. 73:427.

Yang, H., J. E. Pettigrew, L. J. Johnston, G. C. Shurson, and R. D. Walker. 2000. Lactational and subsequent reproductive responses of lactating sows to dietary lysine (protein) concentration. J. Anim. Sci. 78:348-357.

Attachments

Land Grant Participating States/Institutions

AL, AR, FL, GA, KY, LA, MN, NC, OK, TX, VA

Non Land Grant Participating States/Institutions

INIFAP, Campo Experimental Sierra de Chihuahua, Cd. Cuauhtimoc, Chih., Mixico, Hidalgo 1213, 31500, Universidad Autonoma De Baja