Effect of optimizing dietary valine-to-lysine ratio in late gestation or lactation on biochemical indices and performance of lactating primiparous sows

Effects of Macleaya Cordata Extract on Performance, Nutrient Apparent Digestibilities, Milk Composition, and Plasma Metabolites of Dairy Goats

In this study, we aimed to investigate the effects of Macleaya cordata extract (MCE) supplementation on performance, nutrient apparent digestibilities, plasma metabolites, and milk quality in dairy goats. Twenty-four lactating Guanzhong dairy goats (n = 24) were randomly divided into two groups (each containing 12 goats) in a 52-day trial: the CON group was fed a basal diet; the MCE group was fed a basal diet supplemented with 400 mg/kg MCE. The results indicated that the 4% fat corrected milk yield (4% FCM); uncorrected milk yield; milk-fat concentration; content of C4:0, C18:0, and C18:1n9c fatty acids in milk; and apparent digestibility of neutral detergent fiber (NDF) and acid detergent fiber (ADF) in the MCE group were significantly higher (p < 0.05). Furthermore, the lactoferrin (LTF), alpha-lactalbumin (α-La), and beta-lactoglobulin (β-Lg) of the milk and feed conversion rate (FCR) of the goats were significantly greater (p < 0.01) in the MCE group than in the CON group. In contrast, the somatic cell count (SCC) (p < 0.01), content of C14:0 fatty acids (p < 0.01) of milk, and blood urea nitrogen (BUN) concentrations (p < 0.05) were significantly lower in the in the MCE goats. These results show that the feeding of MCE can increase the performance and apparent nutrient digestibility of fiber in dairy goats, improving the quality of goat milk.

Determination of Free Amino Acids in Milk, Colostrum and Plasma of Swine via Liquid Chromatography with Fluorescence and UV Detection

Amino acids are ubiquitous components of mammalian milk and greatly contribute to its nutritional value. The compositional analysis of free amino acids is poorly reported in the literature even though their determination in the biological fluids of livestock animals is necessary to establish possible nutritional interventions. In the present study, the free amino acid profiles in mature swine milk, colostrum and plasma were assessed using a targeted metabolomics approach. In particular, 20 amino acids were identified and quantified via two alternative and complementary reversed-phase HPLC methods, involving two stationary phases based on core-shell technology, i.e., Kinetex C18 and Kinetex F5, and two detection systems, i.e., a diode array detector (DAD) and a fluorescence detector (FLD). The sample preparation involved a de-proteinization step, followed by pre-chromatographic derivatization with 9-fluorenylmethylchloroformate (FMOC-Cl). The two optimized methods were validated for specificity, linearity, sensitivity, matrix effect, accuracy and precision and the analytical performances were compared. The analytical methods proved to be suitable for free amino acid profiling in different matrices with high sensitivity and specificity. The correlations among amino acid levels in different biological fluids can be useful for the evaluation of physio-pathological status and to monitor the effects of therapeutic or nutritional interventions in humans and animals.

A meta-regression analysis to evaluate the influence of branched-chain amino acids in lactation diets on sow and litter growth performance

The branched-chain amino acids (BCAA) Ile, Leu, and Val are three dietary essential amino acids for lactating sows; however, effects of dietary BCAA on sow and litter growth performance in the literature are equivocal. Thus, a meta-regression analysis was conducted to evaluate the effects of BCAA and their interactions in lactating sow diets to predict litter growth performance, sow bodyweight change, and sow feed intake. Thirty-four publications that represented 43 trials from 1997 to 2020 were used to develop a database that contained 167 observations. Diets for each trial were reformulated using NRC. 2012. Nutrient requirements of swine. 11th ed. Washington, DC: National Academies Press nutrient loading values in an Excel-based spreadsheet. Amino acids were expressed on a standardized ileal digestible (SID) basis. Regression model equations were developed with the MIXED procedure of SAS (Version 9.4, SAS Institute, Cary, NC) and utilized the inverse of reported squared SEM with the WEIGHT statement to account for heterogeneous errors across studies. Predictor variables were assessed with a step-wise manual forward selection for model inclusion. Additionally, statistically significant (P < 0.05) predictor variables were required to provide an improvement of at least 2 Bayesian information criterion units to be included in the final model. Significant predictor variables within three optimum equations developed for litter ADG included the count of weaned pigs per litter, NE, SID Lys, CP, sow ADFI, Val:Lys, Ile:Lys, and Leu:Val. For sow BW change, significant predictor variables within two developed models included litter size at 24 h, sow ADFI, Leu:Lys, and Ile + Val:Leu. The optimum equation for sow ADFI included Leu:Trp, SID Lys, NE, CP, and Leu:Lys as significant predictor variables. Overall, the prediction equations suggest that BCAA play an important role in litter growth, sow BW change, and feed intake during lactation; however, the influence of BCAA on these criteria is much smaller than that of other dietary components such as NE, SID Lys, sow ADFI, and CP.

Effect of dietary arginine-to-lysine ratio in lactation on biochemical indices and performance of lactating sows

The present study investigated the effect of optimizing the total dietary arginine (Arg)-to-lysine (Lys) ratios on the metabolism of lactating sows and piglet performance by supplementation with l- Arg during lactation. A total of 200 multiparous sows (three to six parities, Yorkshire × Landrace) were selected and randomly and equally assigned to five groups in lactation, and finally, 36, 34, 35, 36, and 33 dams completed the study in the dietary treatments, respectively, where the diets consisted of five step-up Arg-to-Lys ratios (0.9, 1.0, 1.1, 1.2, and 1.3) by the addition of 0%, 0.10%, 0.20%, 0.30%, and 0.40% Arg. The diets contained 3.37 to 3.38 Mcal of digestible energy/kg energy, 17.73% to 17.75% crude protein, and 0.98% to 1.01% Lys and were fed ad libitum during lactation. The performance of sows and suckling piglets was measured, and plasma and milk samples were collected for analysis. The feed intake of sows as well as litter weight gain during lactation increased linearly (P ≤ 0.05), while maternal backfat and milk composition were not affected (P > 0.05) as the dietary Arg-to-Lys ratios increased. Analyzed plasma biochemical indices, including concentrations of free Arg, Orn, and Glu, and prolactin, insulin, and follicle-stimulating hormone, responded linearly (P ≤ 0.05) to increases in dietary Arg-to-Lys ratios. The dietary Arg-to-Lys ratios of 1.01 and 1.02 were optimal for maternal feed intake and litter weight gain, based on broken-line models. Collectively, the results of this study indicate that increasing total dietary Arg-to-Lys ratios in lactation was beneficial for the performance of lactating sows and suckling piglets, and dietary Arg-to-Lys ratios of 1.01 and 1.02 were optimal, from regression analyses, for the practical feeding of lactating sows.

Effects of Dietary Lysine Levels on Production Performance and Milk Composition of High-Producing Sows during Lactation

Modern genotype sows require enhanced nutrition because of their larger body size and higher reproductive performance than 20 years ago. This study aimed to evaluate the effect of dietary Lys on the lactating of primiparous sows and the second lactating period to minimize sow body weight (BW) loss and maximize the survival rate of piglets and litter gain. A total of 160 primiparous Yorkshire sows were randomly allotted to one of four experimental lactation diets. Formulated to contain 0.84%, 0.94%, 1.04%, and 1.14% standardized ileal digestibility (SID) Lys and balanced in Met, Thr, Trp, and Val. No dietary effects were found on sow body weight (BW) and backfat thickness (BF) change and feed intake during lactation. However, the Lys intake (p = 0.04) of lactation increased linearly with increasing dietary Lys levels. In addition, 1.14% Lys for primiparous sow and 0.94% Lys for second parity sow during lactation increased the survival rate (p = 0.04), weight (p = 0.04), and ADG of piglets at d 21 (p = 0.03). The dietary Lys level did not affect colostrum compositions. However, the dry matter (p = 0.04) and protein (p = 0.03) in milk increased linearly with the increase in dietary Lys levels, whereas moisture decreased linearly (p = 0.05). The level of plasma urea nitrogen (PUN) also increased at d 21 of weaning (p = 0.04). These results indicate that high-yielding lactating sows required 1.14% SID Lys during parity 1, and 0.94% SID Lys during parity 2 to maximize the survival rate of piglets and litter gain, respectively. Moreover, the effects of dietary amino acid (AA) on the production performance of weaning pigs could be mediated through milk composition change.

Effects of dietary valine supplementation during late gestation on the reproductive performance and mammary gland development of gilts

Background

Mammary gland development during late gestation in gilts is a major factor that alters the composition of colostrum and growth performance of piglets. Plasma valine is taken up and metabolized extensively by the mammary gland; however, the effects of valine on mammary gland development during late gestation are still unclear. Thirty primiparous gilts were divided into three treatment groups (n = 10) and received one of the three diets starting on day 75 of gestation until the day of farrowing. The total dietary valine to lysine ratio of the three diets was 0.63 (LV), 0.73 (MV), and 0.93 (HV), respectively.

Results

Dietary valine supplementation during late gestation did not affect (P > 0.05) the litter size and weight at farrowing; however, the piglet weight and average daily gain at weaning were linearly increased (P < 0.05) as the dietary valine increased. The highest piglet weight at weaning was observed when the gilts were provided the HV diet. Dietary valine supplementation linearly elevated (P < 0.05) protein, fat and solids-not-fat and some free amino acids content in colostrum. The concentration of prolactin in plasma of gilts was linearly increased in response to valine supplementation at days 1 and 10 of lactation (P < 0.05). Furthermore, with increasing dietary valine allowance, a linear increase (P < 0.05) was observed in the area of the lumen of alveolus and the content of DNA, RNA, and total protein in the mammary tissues at day 1 of lactation. Moreover, the protein expression of cyclin D1, p-mTOR, p-S6, and p-4EBP1 was also linearly increased (P < 0.05) in the mammary tissue at day 1 of lactation. However, no difference (P > 0.05) was observed in the indices related to mammary development and the mTOR signaling pathway at day 21 of lactation.

Conclusion

The results revealed that increasing the total dietary valine to lysine ratio to 0.93 during late gestation significantly enhances the piglet weight and average daily gain at weaning probably due to improved development of mammary gland.