Arginine is a common substrate for the synthesis of nitric oxide and polyamines that are crucial for placental angiogenesis and growth in mammals. This study was conducted to test the hypothesis that dietary l-arginine supplementation may improve reproductive performance of pregnant gilts. Fifty-two pregnant gilts with body weight (BW) of 166.3 +/- 1.8 kg were housed individually in gestation crates. At d 30 of gestation, gilts were assigned randomly to corn-soybean-based diets supplemented with 1.0% L-arginine-HCl or 1.7% L-alanine (isonitrogenous control). Both diets contained 13.0 MJ metabolizable energy/kg and 12.2% crude protein and were fed to gilts at 1 kg twice daily during gestation. Backfat thickness and BW were measured and blood samples were obtained on 30, 70, 90, and 110 d of gestation. At d 110 of gestation, gilts were transferred to individual farrowing crates. The numbers of total piglets born and born alive, as well as birth weights of piglets, were recorded immediately after farrowing. Throughout the gestation, BW or backfat thickness of gilts did not differ between treatment groups. Plasma urea concentrations were lower in arginine-supplemented than in control gilts at d 90 (P < 0.010) and d 110 (P < 0.001) of gestation. Compared with the control group, arginine supplementation increased the number of pigs born alive by 22% (11.40 vs. 9.37, P = 0.032) and live litter birth weight of piglets by 24% (16.38 vs. 13.19 kg, P = 0.016). This exciting finding provides the first evidence for a marked increase of live-born piglets by 2 per litter through nutritional intervention in gilts.

A 2 x 2 factorial arrangement of treatments in a randomized block design was used to determine the effects of dietary Arg supplementation during gestation and lactation on the lactation performance of 38 first-parity sows. At 30 d of gestation, pregnant gilts were allotted based on BW to 1 of 2 diets supplemented with 1% L-Arg.HCl or 1.7% L-Ala (isonitrogenous control). After farrowing, sows were further allotted based on BW within previous gestation treatment groups to 1 of 2 lactation diets supplemented with 1% L-Arg.HCl or 1.7% L-Ala (isonitrogenous control). All gestation diets contained 3.1 Mcal/kg and 12.2% CP (as is) and were fed 2 kg/d in 2 equally sized meals, whereas all lactation diets contained 3.2 Mcal/kg and 18.6% CP (as is) and were fed ad libitum. Litter size was standardized to 10 piglets by cross-fostering within 24 h postfarrowing. On a weekly basis, BW and backfat (BF) thickness of sows, as well as piglet BW were measured, and blood and milk samples were obtained from the sows. Number of days from weaning to estrus and ADFI were also recorded. There were no differences in BW, BF thickness, ADFI, or days until return to estrus among treatment groups. There was no effect of the gestation diet or a gestation x lactation diet interaction on any parameter measured. On d 7 of lactation, plasma concentrations of Arg and insulin in sows, as well as concentrations of most AA in milk, were greater (P < 0.05) in response to Arg supplementation during lactation compared with the control. Weight gain of piglets from sows fed the Arg-supplemented diet during lactation was greater between d 0 and 7 (P < 0.01) and between d 0 and 21 (P < 0.05) of lactation compared with piglets from sows fed the control diet. Collectively, results from this study indicate the potential beneficial effects of dietary Arg supplementation in improving the lactation performance of first-parity sows.

Four experiments were conducted using 671 nursery pigs to evaluate fermented soybean meal (FSBM) as a new vegetable protein source for nursery pigs. In Exp. 1, a total of 192 pigs weaned at 19.2 +/- 0.3 d of age were fed 3 diets (8 pens per treatment) for 2 wk: a control diet (without FSBM) and 2 diets with 3 and 6% FSBM replacing soybean meal, followed by a common diet for the next 2 wk. In Exp. 2, a total of 160 pigs weaned at 21.6 +/- 0.2 d of age were fed 4 diets (5 pens per treatment) for 2 wk: a control diet (without FSBM but with 25% dried skim milk; DSM) and 3 diets with 3, 6, and 9% FSBM replacing DSM based on CP. Concentrations of CP, Lys, Met, Thr, and Trp were kept consistent among diets in Exp. 1 and 2. In Exp. 3, a total of 144 pigs weaned at 22.1 +/- 0.2 d of age were fed 3 diets (6 pens per treatment) for 2 wk: a control diet (without FSBM but with 40% DSM) and 2 diets with 5 and 10% FSBM replacing DSM based on CP. Concentrations of CP, Lys, Met, Thr, Trp, and lactose were kept consistent among diets. In Exp. 4, a total of 175 pigs weaned at 20.7 +/- 0.4 d of age were fed 5 diets (5 pens per treatment) for 3 wk: a basal diet [15.5% CP without plasma protein (PP) and FSBM], 2 diets (18.4% CP) with 3.7% PP or 4.9% FSBM, and 2 diets (21.2% CP) with 7.3% PP or 9.8% FSBM. Concentrations of Lys, Met, Thr, and Trp were kept consistent among diets with the same CP concentrations. Pigs had access to feed and water ad libitum and their BW and feed intake were measured weekly for all experiments. Use of up to 6% FSBM replacing soybean meal improved (P < 0.05) G:F and diarrhea scores of nursery pigs (Exp. 1). Use of up to 9% FSBM replacing DSM reduced (P < 0.05) ADG and G:F (Exp. 2). When lactose concentrations were equal, FSBM could replace up to 10% DSM without adverse effects on ADG and G:F (Exp. 3). Relative bioavailability of protein in FSBM to PP was 99.1% (Exp. 4). Collectively, FSBM can serve as an alternative protein source for nursery pigs at 3 to 7 wk of age, possibly replacing the use of DSM and PP but excluding the first week postweaning for PP when balancing for AA and lactose.

Forty-two sows were used to determine the effects of adding a Saccharomyces cerevisiae fermentation product (SCFP) to the gestation and lactation diets on the performance of sows and their progeny. At 5 d before breeding, sows were allotted to 2 dietary treatments representing 1) sows fed a diet with 12.0 g of fermentation product/d through gestation and 15.0 g of fermentation product/d through lactation (SCFP treatment, n=22), and 2) sows fed a diet with equal amounts of a mixture of corn and soybean meal instead of the SCFP (CON treatment, n=20). Sow BW and backfat thickness were recorded. Blood was collected from sows, as well as piglets, for the measurement of cell numbers, plasma urea nitrogen (PUN), and IgG. Fecal samples from d 7 to 9 of lactation were collected to determine apparent total tract nutrient digestibility. The composition of colostrum and milk was also measured. No difference (P > 0.10) in reproductive performance was observed between treatments. However, sows in the SCFP treatment tended to have increased total litter weaning weight (P=0.068) and litter BW gain (P=0.084) compared with sows in the CON treatment. Neutrophil count was decreased (P < 0.05) by adding the fermentation product on d 110 of gestation and d 17 of lactation, whereas a decreased (P < 0.05) white blood cell count was observed only on d 110 of gestation. Concentration of PUN tended to be greater (P=0.069) for sows in the CON treatment compared with sows in the SCFP treatment on d 110 of gestation. Apparent total tract nutrient digestibility values of ash, CP, DM, and ether extract were not affected (P > 0.10) by adding the fermentation product. Protein and fat contents in colostrum and milk did not differ (P > 0.10) between treatments. Colostrum from sows in the SCFP treatment contained a greater (P < 0.05) amount of ash than colostrum from sows in the CON treatment. Immunoglobulin G measured in the colostrum, milk, and plasma of piglets did not differ (P > 0.10) between sows in the CON and SCFP treatments. This study indicates that adding the SCFP in the gestation and lactation diets has the potential to 1) improve litter BW gain during lactation, possibly by improving maternal protein utilization, as shown in a tendency to reduce PUN; 2) improve the maternal health status, as shown by the reduced neutrophil cell count; and 3) increase milk production, as shown in a tendency to improve litter BW gain without affecting nutrient composition of the colostrum and milk.

A study was conducted to determine the efficacy of organic (Se-yeast, SelenoSource AF, Diamond V Mills Inc., Cedar Rapids, IA) and inorganic sources of Se on growth performance, tissue Se accretion, and carcass characteristics of growing-finishing pigs fed diets with high endogenous Se content. A total of 180 pigs at 34.4 +/- 0.06 kg of BW were allotted to 1 of 5 dietary treatments: a negative control without added Se (NC); 3 treatment diets with 0.1, 0.2, or 0.3 mg/kg of added Se from an organic source; and a diet with 0.3 mg/kg of added Se as sodium selenite. Each treatment had 6 pens, with 6 pigs per pen-replicate. Experimental diets were changed twice at 66.1 +/- 0.5 kg and 99.0 +/- 0.9 kg of BW, and were fed until the pigs reached market weight. Growth performance was measured at the end of each phase. Upon reaching 129.9 +/- 1.4 kg of BW, the pigs were transported to a local abattoir (Seaboard Foods, Guymon, OK), where carcass, loin, and liver samples were obtained. Hair and blood samples were obtained at the beginning and end of the study for Se analysis. Growth performance did not differ (P > 0.05) among treatments. Percent drip loss of the NC pigs was greater (2.41 vs. 1.75, P = 0.011) compared with pigs supplemented with Se. Pigs fed diets with added Se had greater Se concentrations in the liver (0.397 vs. 0.323 ppm, P = 0.015), loin (0.236 vs. 0.132 ppm, P < 0.001), serum (0.087 vs. 0.062 ppm, P = 0.047), and hair (0.377 vs. 0.247 ppm, P = 0.003) compared with the NC pigs. Percentage drip loss was linearly reduced [percent drip loss = 2.305 - (2.398 x Se), r2 = 0.29, P = 0.007] as dietary organic Se concentration increased. The Se concentration (ppm) in the liver [liver Se = 0.323 + (0.291 x Se), r2 = 0.33, P = 0.003], loin [loin Se = 0.122 + (0.511 x Se), r2 = 0.57, P < 0.001], serum [serum Se = 0.060 + (0.113 x Se), r2 = 0.33, P = 0.004] and hair [hair Se = 0.237 + (0.638 x Se), r2 = 0.56, P < 0.001] increased linearly as dietary organic Se concentration increased. Slope ratio analysis indicated that the relative bioavailability of organic Se for percent drip loss and loin and hair Se response was 306, 192, and 197% of that for inorganic Se, respectively. The results of the study show a potential advantage of organic Se supplementation in reducing drip loss even when the basal diet contains an endogenously high Se concentration of 0.181 ppm.