Improving efficiency of protein utilization is important for pregnant sows under restricted feed allowance and for lactating sows with limited feed intake. Sows have limited ability to support the growth of fetuses and mammary glands during late gestation and to support mammary growth and milk production, especially during first lactation period. A series of studies was conducted to characterize requirements and ideal ratios of AA for 1) fetal growth, 2) mammary gland growth of gestating sows, 3) maternal tissue gain of gestating sows, 4) mammary gland growth of lactating sows, and 5) maternal tissue gain of lactating sows. A total of 97 pregnant sows and their fetuses and a total of 174 lactating sows and their nursing piglets were used for these studies to collect fetal tissues, mammary tissues, and maternal tissues for AA analysis. Requirements and ideal ratios of AA for sows changed dynamically depending on stages of pregnancy. Suggested daily requirements for true ileal digestible Lys were 5.57 and 8.78 g, and relative ideal ratios for Lys:Thr:Val:Leu (on basis of AA weight) were 100:79:65:88 and 100:71:66:95 for d 0 to 60 and d 60 to 114 of gestation, respectively. Requirements and ideal ratios of AA for lactating sows changed dynamically depending on potential amounts of protein mobilization from maternal tissues, which are related to voluntary feed intake and milk production. Suggested ideal ratios for Lys:Thr:Val:Leu were 100:59:77:115 and 100:69:78:123 if BW losses of sows during 21 d of lactation are 0 and 33 to 45 kg, respectively. To optimize efficiency of dietary protein utilization by sows, the dietary AA content and ratios can be adjusted by stages of pregnancy (i.e., phase feeding) and by expected feed intakes or parities of sows during lactation (i.e., parity-split feeding) considering the dynamic changes in the requirements and ideal ratios of AA.

Tryptophan (Trp) as a precursor of serotonin (5-hydroxytryptamine, 5-HT) has long been used to extenuate aggressive behavior and control stress of humans as well as several farm animals. This study was conducted to determine the effect of supplemental L-Tryptophan (L-Trp) on growth, cerebral 5-HT concentration, stress hormone concentration, oxidative stress status, and behavior response of pigs under social stress, and also to determine an optimal daily total Trp intake that would benefit nursery pigs under social stress. Seventy two individually housed barrows at 6 wk of age were randomly allotted to 6 treatments with supplementation of 0, 2, 4, 6, 8, or 10 g L-Trp/kg to corn and soybean meal-based feedstuffs. Pigs were fed assigned feedstuffs for 15 d. Body weight was measured on d 0, 5, 10, and 15. Saliva and blood were collected on d 5, 10, and 15. On d 5 and 10, all 12 pigs in each treatment were paired in 6 new pens to record behavior for a 2-d period and returned to original individual pens. On d 15, pigs were euthanized to obtain hypothalamus. During the first 5 d, ADG and G:F increased (linear, P < 0.01) with increasing supplemental L-Trp. During the entire 15 d, ADG and G:F increased (linear, P = 0.01 and P < 0.01, respectively) with increasing supplemental L-Trp. Estimates of the daily total Trp intake based on ADG on d 15 were 10.8 g/d (P < 0.01; R(2) = 0.16) using a 1-slope broken-line analysis. Hypothalamic 5-HT and 5-hydroxyindoleacetic acid increased (linear, P < 0.01 and P = 0.03, respectively) with increasing supplemental L-Trp. Malonedialdehyde in plasma and hypothalamus, as well as salivary cortisol, on d 15 decreased (linear, P = 0.01, P < 0.01, and P < 0.01, respectively) with increasing supplemental L-Trp. Plasma urea nitrogen decreased (linear, P < 0.01) with increasing supplemental L-Trp. Increasing supplemental L-Trp affected pig behaviors during the first 2-d observation period by decreasing (quadratic, P = 0.04) lying, decreasing (linear, P = 0.04) sitting, and increasing (linear, P = 0.02) drinking. Overall, supplementation of L-Trp improved growth performance of 6 wk-old nursery pigs under social stress in association with increasing hypothalamic 5-HT production, reducing stress hormone concentrations, decreasing lipid peroxidation, increasing drinking, and reducing sitting and lying. Increase in BW gain of nursery pigs under social stress was maximal when daily total Trp intake was 10.8 g.

Alpha-ketoglutarate (AKG) is an important cellular metabolite that participates in energy production and amino acid metabolism. However, the protective effects and mechanism of AKG on mucosal lesions have not been well understood. This study was conducted to investigate the effects of dietary AKG supplementation on epithelial restitution in early-weaning piglets under Escherichia coli lipopolysaccharide (LPS) induction. A total of 32 weaned piglets were used in a 2 × 2 factorial design; the major factors were dietary treatment (basal diet or AKG diet) and inflammatory challenge (LPS or saline). The results showed that AKG supplementation improved the growth performance and intestinal morphology in the LPS-induced early-weaning piglets. Compared with the basal diet, the AKG diet remarkably decreased the concentration and mRNA expression of intestinal inflammatory cytokines (IL-1β, IL-6, and IL-12) in the LPS-induced piglets. Moreover, AKG administration upregulated the mRNA expression of nutrient-sensing transporters (GLUT-2, SGLT-1, PEPT-1, I-FABP2) in the small intestine of both saline-and LPS-treated piglets, and improved the distribution and expression of tight-junction genes andproteins (ZO-1, Occludin, Claudins, E-cadherin). Collectively, our findings indicate that AKG has the potential to alleviate intestinal inflammatory response and improve epithelial restitution and nutrient-sensing ability under stress injury in early-weaning piglets, and it also provides an experimental basis for enteral use of AKG in swine production and clinical application to prevent intestinal epithelial damage. www.impactjournals.com/oncotarget/

The experiment investigated the effects of a supplemental candy coproduct (Chocolate Candy Feed [CCF]; International Ingredient Corp., St. Louis, MO), an alternative carbohydrate source to dietary lactose, on growth performance and on health status of nursery pigs. Crossbred pigs ( = 1,408; 21 d of age and 7.1 ± 0.3 kg BW; Smithfield Premium Genetics, Rose Hill, NC) were randomly assigned to 4 treatments (16 pens/treatment and 22 pigs/pen) in a randomized complete block design: 0, 15, 30, and 45% of lactose replaced by CCF based on equal amounts of total sugars. The experimental period was divided into 3 phases: phase I (1.8 kg diet/pig for 11 ± 1 d), phase II (6.8 kg diet/pig for 17 ± 2 d), and phase III (until 49 d after weaning). Pigs received a common phase III diet. The levels of lactose, supplied by whey permeate (79.3 ± 0.8% lactose), were 20, 8, and 0% in phase I, II, and III, respectively. All experimental diets contained the same levels of essential AA and energy (ME) for each phase. Fecal scores were observed on d 5, 7, and 9 after weaning. Blood samples were taken at the end of phase I and II to measure blood urea N. The duration of phase I tended to linearly decrease ( = 0.063) with increasing CCF. In phase I, the ADFI increased ( < 0.05) with increasing CCF whereas ADG and G:F did not change. In phase II, the duration and ADFI did not change whereas ADG linearly decreased ( < 0.05) with increasing CCF. However, the G:F was not changed as CCF increased. During phase I and II together, the duration was linearly decreased ( < 0.05) as CCF increased, whereas no difference in growth performance was observed. Overall, ADFI, ADG, and G:F were not affected by replacing whey permeate with CCF in diets, indicating no adverse effects of a candy coproduct as a carbohydrate substitute to lactose on growth performance of nursery pigs. Blood urea N did not change in phase I but tended to linearly increase ( = 0.088) in phase II as CCF increased. There were no differences in fecal scores and mortality as CCF increased. However, increasing CCF tended to linearly decrease ( = 0.083) morbidity, which implies no adverse effects of a candy coproduct replacement on health status of nursery pigs. In conclusion, a candy coproduct can be used to replace up to 45% of dietary lactose for nursery pigs without negative effects on growth performance or health status. A candy coproduct could be an economical alternative to partly replace the use of lactose in swine production.