Four experiments were conducted with 120 pregnant Sprague-Dawley rats to determine effects of dietary arginine supplementation on embryonic survival. Rats were fed a nonpurified diet supplemented with 1.3% (wt:wt) l-arginine-HCl or 2.2% (wt:wt) l-alanine (isonitrogenous control) throughout pregnancy (Expt. 1), between d 1 and 7 of gestation and then the nonpurified diet until parturition (Expt. 2), between d 1 and 7 of gestation for determining the number of surviving embryos on d 7 (Expt. 3), or between d 1 and 4 of pregnancy for blood sampling on d 5 after overnight food deprivation (Expt. 4). Litter size increased (P < 0.01) in response to arginine supplementation throughout pregnancy (14.5 ± 0.62 vs. 11.3 ± 0.61) or during the first 7 d of pregnancy (14.7 ± 0.33 vs. 11.3 ± 0.37). The number of surviving embryos was greater (P < 0.01) when arginine was supplemented between d 1 and 7 of pregnancy (14.7 ± 0.39 vs. 11.4 ± 0.66). Concentrations of nitric-oxide metabolites, arginine, proline, glutamine, and ornithine were higher (P < 0.05), but urea levels were lower (P < 0.05) in the serum of arginine-supplemented rats compared with the control group. The arginine treatment increased (P < 0.05) protein levels for inducible and constitutive nitric-oxide synthase at implantation sites by 35–37%. These results indicate that dietary arginine supplementation enhances embryonic survival, therefore increasing litter size by 30% at term birth. This novel finding has important implications for preventing early pregnancy loss and enhancing reproductive performance in mammals.

Fatty acids are not only widely known as energy sources, but also play important roles in many metabolic pathways. The significance of fatty acids in modulating the reproductive potential of livestock has received greater recognition in recent years. Functional fatty acids and their metabolites improve follicular development, oocyte maturation and embryo development, as well as endometrial receptivity and placental vascular development, through enhancing energy supply and precursors for the synthesis of their productive hormones, such as steroid hormones and prostaglandins. However, many studies are focused on the impacts of individual functional fatty acids in the reproductive cycle, lacking studies involved in deeper mechanisms and optimal fatty acid requirements for specific physiological stages. Therefore, an overall consideration of the combination and synergy of functional fatty acids and the establishment of optimal fatty acid requirement for specific stages is needed to improve reproductive potential in livestock.

This experiment was conducted to investigate the effects of dietary ratios of n-6:n-3 polyunsaturated fatty acids (PUFA) on the performance of lactating sows and their piglets. Thirty pregnant Landrace sows were assigned to one of three treatments from d 108 of gestation until weaning (26–29 d) and were fed diets containing different ratios of n-6:n-3 PUFA including 3:1, 9:1 and 13:1. The effects on sow and litter production traits were examined together with an assessment of sow body condition. No differences were detected among the treatments for the daily feed intake of sows or changes in sow weight and back-fat levels during lactation (P > 0.05). Litter size at d 14 and d 21 were tended to increase in 3:1 treatment compared with 9:1 and 13:1 treatments (P < 0.10). Litter weight gain (1.77 kg/d) from d 0 to d 14 was tended to increase in 9:1 groups compared with the other two treatments (P < 0.10). A significant difference was observed for the content of α -linolenic acid, total n-3 PUFA, and the ratio of n-6:n-3 PUFA in the colostrum, milk, and piglets plasma (P < 0.01). The effects of different ratios of n-6:n-3 PUFA in sow diets on colostrum, milk, and piglet plasma immunoglobulin concentrations are studied. No difference was observed among treatments in the concentrations of IgM, and IgA in colostrum (P > 0.05). A great significant difference for IgG concentration was observed among 3 group in colostrum. A great significant difference for IgA, and IgM (P < 0.01) concentrations in piglet plasma at d14 and a significant difference for IgG(P < 0.05) was observed at d14. Furthermore, at d 21 of lactation, piglet plasma IgG and IgA concentration were greater in 3:1 compared with 13:1 group (P < 0.01).In summary, the current study demonstrated that altering the ratio of n-6:n-3 PUFA in lactating sow diet had an effect on the immune component including immunoglobulin and cytokines, and it tended to increase the litter average daily gain and improve the immune status of piglets when dietary ratio of n-6:n-3 PUFA was 9:1.

Two experiments were conducted to estimate the net energy (NE) of corn, soybean meal, expeller-pressed rapeseed meal (EP-RSM) and solvent-extracted rapeseed meal (SE-RSM) using indirect calorimetry and to validate the NE of these four ingredients using pig growth performance. In Exp.1, 24 barrows (initial BW = 36.4 ± 1.6 kg) were allotted to 1 of 4 diets which included a corn basal diet, a corn-soybean meal basal diet and two rapeseed meal diets containing 20% EP-RSM (9.5% ether extract) or SE-RSM (1.1% ether extract) substituted for corn and soybean meal. The design allowed the calculation of NE values of corn, soybean meal and rapeseed meals according to the difference method. In Exp.2, 175 growing pigs (initial BW = 36.0 ± 5.2 kg) were fed 1 of 5 diets for 28 d, with five pigs per pen and seven replications (pens) per treatment in order to validate the measured energy values. Diets were a corn-soybean meal diet and four diets including 10% or 20% EP-RSM and 10% or 20% SE-RSM. The NE of corn, soybean meal, EP-RSM and SE-RSM were 12.46, 11.34, 11.71 and 8.83 MJ/kg DM, respectively. The NE to ME ratio of corn (78%) was similar to tabular values, however, the NE to ME ratios of soybean meal (70%) and rapeseed meal (76%) were greater than tabular values. The greater NE value in EP-RSM than in SE-RSM is consistent with its higher EE content. Increasing EP-RSM or SE-RSM did not affect the growth performance of pigs and the caloric efficiency of NE was comparable for all diets. The NE of EP-RSM was similar to soybean meal, and both were greater than SE-RSM. The DE, ME and NE values measured in Exp.1 are confirmed by results of Exp. 2 with comparable caloric efficiencies of DE, ME or NE for all diets.

Ulcerative colitis (UC), which affects millions of people worldwide, is characterized by extensive colonic injury involving mucosal and submucosal layers of the colon. Nuclear factor E2-related factor 2 (Nrf2) plays a critical role in cellular protection against oxidant-induced stress. Antioxidant response element (ARE) is the binding site recognized by Nrf2 and leads to the expression of phase II detoxifying enzymes and antioxidant proteins. The Nrf2/ARE system is a key factor for preventing and resolving tissue injury and inflammation in disease conditions such as UC. Researchers have proposed that both Keap1-dependent and Keap1-independent cascades contribute positive effects on activation of the Nrf2/ARE pathway. In this review, we summarize the present knowledge on mechanisms controlling the activation process. We will further review nutritional compounds that can modulate activation of the Nrf2/ARE pathway and may be used as potential therapeutic application of UC. These comprehensive data will help us to better understand the Nrf2/ARE signaling pathway and promote its effective application in response to common diseases induced by oxidative stress and inflammation.

The aim of the three experiments was to evaluated methods to predict fasting heat production (FHP) and to compare methods to determine the net energy (NE) of corn and soybean meal (SBM) fed to growing pigs. To estimate heat production (HP), pigs were housed in respiratory chambers for all experiments. In Experiment 1, six barrows (43.0 ±1.4 kg body weight [BW]) were fed a Corn–SBM diet for 20 d. The experimental design consisted of following periods: 7 d adaptation, 5 d ad libitum feeding, 3 d feeding at 2 × metabolisable energy (ME) for maintenance (ME_m), 3 d feeding at 1 × ME_m and 2 d fasting. The FHP was calculated by extrapolating HP measured at the different feeding levels to zero ME intake. The daily FHP [per kg BW^0.6] determined directly after fasting for 24 h and using the regression method was 774 kJ and 694 kJ, respectively. In Experiment 2, 18 barrows (34.3 ± 1.1 kg BW) were randomly allotted to three diets: Diet 1 contained 97.5% corn (direct NE determination of corn); diets 2 and 3 contained 25 % and 15% SBM at the expense of corn, respectively, and were used to calculate the NE of corn by difference. The NE of corn determined directly (13.21 MJ/kg DM) and by difference (13.69 MJ/kg DM) was not different. In Experiment 3, 24 barrows (36.2 ± 1.4 kg BW) were randomly allotted to four diets to determine the effects of different basal diets on the NE content of SBM. The diets were: Basal diet 1 (97.5% corn), Test diet 1 (15% SBM at the expense of corn), Basal diet 2 (contained 72.5% corn and 25% SBM) and Test diet 2 (58% corn and 39.5% SBM). These diets were used to determine the NE of SBM using the Corn–basal diet or the Corn–SBM–basal diet, respectively. It was shown that the estimated NE of SBM did not depend on the used diet (10.04 MJ/kg and 10.62 MJ/kg DM for Basal diet 1 and 2, respectively). In summary, using the regression method to determine FHP results in lower FHP than the fasting method. There was no difference observed in the NE of corn determined directly or by difference, and different basal diets did not affect the NE of SBM.