Feeding rumen-protected lysine prepartum alters placental metabolism at a transcriptional level.

Rumen-protected Lys (RPL) fed to Holstein cows prepartum resulted in a greater intake and improved health of their calves during the first 6 wk of life. However, whether increased supply of Lys in late gestation can influence placental tissue and, if so, which pathways are affected remain to be investigated. Therefore, we hypothesize that feeding RPL during late gestation could modulate placental metabolism, allowing for improved passage of nutrients to the fetus and thus influencing the offspring development. Therefore, we aimed to determine the effects of feeding RPL (AjiPro-L Generation 3, Ajinomoto Health and Nutrition North America) prepartum (0.54% DM of TMR) on mRNA gene expression profiles of placental samples of Holstein cows. Seventy multiparous Holstein cows were randomly assigned to 1 of 2 dietary treatments, consisting of TMR top-dressed with RPL (PRE-L) or without (control, CON), fed from 27 ± 5 d prepartum until calving. After natural delivery (6.87 ± 3.32 h), placentas were rinsed with physiological saline (0.9% sodium chloride solution) to clean any dirtiness from the environment and weighed. Then, 3 placentomes were collected, one from each placental region (cranial, central, and caudal), combined and flash-frozen in liquid nitrogen to evaluate the expression of transcripts and proteins related to protein metabolism and inflammation. Placental weights did not differ from cows in PRE-L (15.5 ± 4.03 kg) and cows in CON (14.5 ± 4.03 kg). Feeding RPL prepartum downregulated the expression of NOS3 (nitric oxide synthase 3), involved in vasodilation processes, and SOD1, which encodes the enzyme superoxide dismutase, involved in oxidative stress processes. Additionally, feeding RPL prepartum upregulated the expression of transcripts involved in energy metabolism (SLC2A3, glucose transporter 3; and PCK1, phosphoenolpyruvate carboxykinase 1), placental metabolism and cell proliferation (FGF2, fibroblast growth factor 2; FGF2R, fibroblast growth factor 2 receptor; and PGF, placental growth factor), Met metabolism (MAT2A, methionine adenosyltransferase 2-α), and tended to upregulate IGF2R (insulin-like growth factor 2 receptor). Placental FGF2 and LRP1 (low-density lipoprotein receptor-related protein 1) protein abundance were greater for cows that received RPL prepartum than cows in CON. In conclusion, feeding RPL to prepartum dairy cows altered uteroplacental expression of genes and proteins involved in cell proliferation, and in metabolism and transport of glucose. Such changes are illustrated by increased expression of SLC2A3 and PCK1 and increased protein abundance of FGF2 and LRP1 in uteroplacental tissue of cows consuming RPL.

Feeding rumen-protected lysine to dairy cows prepartum improves performance and health of their calves.

Providing adequate concentrations of AA in the prepartum diet is pivotal for the cow's health and performance. However, less is known about the potential in utero effects of particular AA on early-life performance of calves. This experiment was conducted to determine the effects on dairy calves when their dams were fed rumen-protected lysine (RPL; AjiPro-L Generation 3, Ajinomoto Heartland Inc.; 0.54% dry matter of total mixed ration as top dress) from 26 ± 4.6 d (mean ± standard deviation) before calving until calving. Seventy-eight male (M) and female (F) Holstein calves were assigned to 2 treatments based on their dams' prepartum treatment, RPL supplementation (PRE-L) or without RPL (CON). At the time of birth (0.5-2 h after calving), before colostrum was fed, blood samples were collected. An initial body weight was obtained at 1 to 3 h after birth. Calves were fed 470 g of colostrum replacer (Land O'Lakes Bovine IgG Colostrum Replacer, Land O'Lakes, Inc.) diluted in 3.8 L of water. Calves were provided water ad libitum and fed milk replacer (Advance Excelerate, Milk Specialties Global Animal Nutrition; 28.5% crude protein, 15% fat) at 0600 h and 1700 h until 42 d of age. Calves were measured weekly, at weaning (d 42), and at the end of the experimental period (d 56). Plasma concentrations of AA were measured on d 0, 7, and 14 d using ultra-performance liquid chromatography-mass spectrometry (Waters) with a derivatization method (AccQ-Tag Derivatization). Final body weight was greater for M (87 ± 11 kg) than F (79 ± 7 kg). Calves in PRE-L tended to have greater dry matter (814 ± 3 g/d) and crude protein (234 ± 6 g/d) intakes than those in CON (793 ± 9 g/d and 228 ± 11 g/d, respectively). Calves in PRE-L had greater average daily gain (0.96 ± 0.04 kg/d) than calves in CON (0.85 ± 0.03 kg/d) during wk 6 to 8. Calves in PRE-L tended to be medicated fewer days than CON (4.7 ± 1.2 d vs. 6.2 ± 3.4 d, respectively). Calves in PRE-L-M and CON-F (2,916 ± 112 µM and 2,848 ± 112 µM, respectively) had greater total AA concentration in plasma than calves in PRE-L-F and CON-M (2,684 ± 112 µM and 2,582 ± 112 µM, respectively). Calves in PRE-L-F and CON-M (4.09 ± 0.11% and 4.16 ± 0.11%, respectively) had greater concentration of Lys as a percentage of total AA compared with calves in CON-F and PRE-L-M (3.91 ± 0.11% and 3.90 ± 0.11%, respectively). Calves in PRE-L tended to have greater percentage of phagocytic neutrophils (39.6 ± 1.59%) than calves in CON (35.9 ± 1.59%). In conclusion, increasing the metabolizable lysine provided to prepartum dairy cows had modest effect over offspring performance, with the major result being a greater average daily gain for calves in PRE-L during the preweaning phase (wk 6-8).

Histidine deficiency has a negative effect on lactational performance of dairy cows.

A 10-wk randomized complete block design experiment with 24 Holstein cows was conducted to investigate the long-term effects of feeding a His-deficient diet on lactational performance of dairy cows. Cows were blocked by days in milk, milk yield, and parity, and randomly assigned to 1 of the following 2 treatments: (1) His-adequate diet [HAD; providing +166 g/d over metabolizable protein (MP) requirements, according to the National Research Council (2001) and digestible His (dHis) supply of 68 g/d, or 2.5% of MP requirements] and (2) His-deficient diet (HDD; +37 g/d over MP requirements and dHis supply of 49 g/d, or 1.9% of MP requirements). Both HAD and HDD were supplemented with rumen-protected (RP) Met and Lys supplying digestible Met and digestible Lys at 2.4 and 2.4% and 7.2 and 7.1% of MP requirements, respectively. At the end of the 10-wk experiment, HDD was supplemented with RPHis (HDD+RPHis; total dHis supply of 61 g/d, or 2.4% of MP requirements) for an additional 9 d. Dry matter intake (DMI; 25.4 and 27.1 kg/d, standard error of the mean = 0.41), yields of milk (37.6 and 40.5 kg/d, standard error of the mean = 0.62), protein and lactose, energy-corrected milk, and milk and plasma urea-N were decreased by HDD compared with HAD. Feed and energy-corrected milk feed efficiencies, milk fat, protein and lactose concentrations, body weight, and body condition score of the cows were not affected by treatment. Apparent total-tract digestibility of dry and organic matter, crude protein, and neutral detergent fiber, and excretion of urinary N and urea-N were decreased by HDD compared with HAD. Concentration of plasma leptin tended to be decreased for HDD compared with HAD. Plasma concentrations of EAA (His, Leu, Lys, Val) and carnosine decreased and total EAA tended to be decreased in cows fed HDD compared with HAD. Muscle concentrations of free His, Leu, and Val decreased and Gly and ß-alanine tended to be increased by HDD compared with HAD. Cows fed HDD had a lower blood hemoglobin concentration than cows fed HAD. At the end of the 10-wk study, the 9-d supplementation of HDD with RPHis (i.e., HDD+RPHis) increased DMI and plasma His, and tended to increase energy-corrected milk yield and plasma carnosine, compared with HDD. In conclusion, feeding a diet deficient in dHis supplying adequate MP, digestible Met, and digestible Lys affected negatively lactational performance of dairy cows. These results confirm our previous findings that low dietary His supply can impair DMI, yields of milk and milk protein, and blood hemoglobin in dairy cows.

Effects of rumen-protected methionine, lysine, and histidine on lactation performance of dairy cows.

The objective of this study was to evaluate the effects of supplementing a metabolizable protein (MP)-deficient diet with rumen-protected (RP) Met, Lys, and His, individually or combined, on the performance of lactating dairy cows. The experiment was a 9-wk randomized complete block design with 72 Holstein cows. Following a 2-wk covariate period, cows were blocked by days in milk, milk yield, and parity, and randomly assigned to 1 of the following 6 treatments: (1) MP-adequate diet [MPA; +243g/d MP balance, according to the National Research Council (2001) requirements]; (2) MP-deficient diet (MPD; -54g/d MP balance); (3) MPD supplemented with RPMet (MPDM); (4) MPD supplemented with RPLys (MPDL); (5) MPD supplemented with RPHis (MPDH); and (6) MPD supplemented with RPMet, RPLys, and RPHis (MPDMLH). Dry matter intake (DMI), yields of milk and milk components (fat, protein, lactose) and energy-corrected milk (ECM), feed and ECM feed efficiencies, and milk and plasma urea N were decreased by MPD, compared with MPA. Supplementation of the MPD diet with RPLys increased milk protein content and plasma glucose concentration and tended to increase milk urea N. Addition of RPHis tended to increase DMI, increased milk protein concentration, and numerically increased yields of milk fat, protein, and ECM. In addition to the trends for increased DMI and milk fat content, and higher milk protein concentration, supplementation of the 3 RP AA also increased yields of milk fat, protein, and ECM and ECM feed efficiency. Relative to MPA, milk N efficiency tended to be increased by MPD. Concentrations of plasma essential AA (except Met and Thr) were decreased by MPD compared with MPA. Supplementation of RPMet, RPLys, and RPHis increased plasma Met (except for MPDM), Lys, and His concentrations, respectively. Cows fed MPD had lower blood hemoglobin concentration and numerically higher plasma ghrelin than cows fed MPA. Concentration of total saturated fatty acids in milk fat were or tended to be higher for MPD compared with MPA and MPDMLH, respectively. Concentration of total polyunsaturated and yield of milk odd- and branched-chain fatty acids were or tended to be decreased by MPD compared with MPA. Overall, the results of this study confirm our previous data and suggest that His stimulates DMI and the combination of the 3 RP AA (Met, Lys, and His) has the potential to improve milk and milk component yields in dairy cows fed MP-deficient diets.