Influence of energy level and nicotinic acid supplementation on apoptosis of blood leukocytes of periparturient dairy cows

Influences of glyphosate residues and different concentrate feed proportions in dairy cow rations during early gestation on performance, blood parameters, functional properties and DNA damage of blood cells in cows and their offspring

Maternal exposure to various stimuli can influence pre- and postnatal development of the offspring. This potential has been discussed for glyphosate (GLY), active substance in some non-selective herbicides. Accordingly, present study investigated putative effects of GLY residues in rations on cows and their offspring. Dams received either GLY-contaminated (GLY groups) or control (CON groups) rations combined with low (LC groups) or high (HC groups) concentrate feed proportions (CFP) for 16 weeks during mid- and late lactation and early gestation (59±4 days at beginning of GLY exposure; mean±SE). During this feeding trial, average daily GLY exposures of dams were 1.2 (CONLC), 1.1 (CONHC), 112.5 (GLYLC) and 130.3 (GLYHC) μg/kg body weight/d. After a depletion period (107±4 days; mean±SE) and calving, blood samples of dams and their calves were collected (5-345 min after birth) before calves were fed colostrum and analyzed for hematological and clinical-chemical traits, redox parameters, functional properties of leukocytes and DNA damage in leukocytes. No evidence for malformations of newborn calves could be collected. At parturition, most analyzed blood parameters were not affected by dietary treatment of dams during gestation. Significant GLY effects were observed for some traits, e.g. blood non-esterified fatty acids (NEFA) in calves. These deviations of GLY groups from CON groups likely resulted from strong time-dependent responses of NEFA levels within the first 105 minutes after birth and before colostrum intake (Spearman´s rank correlation R = 0.76, p<0.001). Additionally, significant GLY effects did not result in differences in measures that were beyond normally observed ranges questioning a pathological relevance. In summary, no evidence for teratogenic or other clear effects of GLY or CFP on analyzed parameters of dams and their newborn calves could be collected under applied conditions. However, detailed studies including GLY exposure during late and complete gestation period would be needed to rule out teratogenic effects.

Influences of Glyphosate Contaminations and Concentrate Feed on Performance, Blood Parameters, Blood Cell Functionality and DNA Damage Properties in Fattening Bulls

Glyphosate (GLY), the active substance in non-selective herbicides, is often found in ruminant feed. The present feeding study aimed to investigate the effects of GLY-contaminated rations and different concentrate feed proportions (CFP) on the health of fattening German Holstein bulls. Bulls were grouped by low (LC) or high (HC) CFP with (GLY_LC, GLY_HC) or without GLY-contaminations (CON_LC, CON_HC) in their rations. Intakes (dry matter, water) and body weight were documented continuously lasting over an average range from 392.2 ± 60.4 kg to 541.2 ± 67.4 kg (mean ± SD). Blood samples collected at the trial's beginning, and after 7 and 15 weeks, were analyzed for hematological and clinical-chemical traits, functional properties of leukocytes, redox parameters and DNA damage. The average GLY exposures of 128.6 (GLY_HC), 213.7 (GLY_LC), 1.3 (CON_HC) and 2.0 µg/kg body weight/d (CON_LC) did not lead to GLY effects for most of the assessed parameters relating to animal health and performance. CFP and time displayed marked influences on most of the experimental parameters such as higher dry matter intake and average daily gain in HC compared with the LC groups. GLY effects were rather weak. However, the observed interactive effects between GLY and CFP and/or time occurring in an inconsistent manner are likely not reproducible. Finally, all animals remained clinically inconspicuous, which brings into question the physiological relevance of putative GLY effects.

Effects of glyphosate residues and different concentrate feed proportions in dairy cow rations on hepatic gene expression, liver histology and biochemical blood parameters

Glyphosate (GLY) is worldwide one of the most used active substances in non-selective herbicides. Although livestock might be orally exposed via GLY-contaminated feedstuffs, not much is known about possible hepatotoxic effects of GLY. As hepatic xenobiotic and nutrient metabolism are interlinked, toxic effects of GLY residues might be influenced by hepatic nutrient supply. Therefore, a feeding trial with lactating dairy cows was conducted to investigate effects of GLY-contaminated feedstuffs and different concentrate feed proportions (CFP) in the diets as tool for varying nutrient supply to the liver. For this, 61 German Holstein cows (207 ± 49 days in milk; mean ± standard deviation) were either fed a GLY-contaminated total mixed ration (TMR, GLY groups, mean GLY intake 122.7 μg/kg body weight/day) or control TMR (CON groups, mean GLY intake 1.2 μg/kg body weight/day) for 16 weeks. Additionally, both groups were further split into subgroups fed a lower (LC, 30% on dry matter basis) or higher (HC, 60% on dry matter basis) CFP resulting in groups CONHC (n = 16), CONLC (n = 16), GLYHC (n = 15), GLYLC (n = 14). Blood parameters aspartate aminotransferase, γ-glutamyltransferase, glutamate dehydrogenase, cholesterol, triglyceride, total protein, calcium, phosphorus, acetic acid and urea and histopathological evaluation were not influenced by GLY, whereas all mentioned parameters were at least affected by time, CFP or an interactive manner between time and CFP. Total bilirubin blood concentration was significantly influenced by an interaction between GLY and CFP with temporarily elevated concentrations in GLYHC, whereas the biological relevance remained unclear. Gene expression analysis indicated 167 CFP-responsive genes, while seven genes showed altered expression in GLY groups compared to CON groups. Since expression changes of GLY-responsive genes were low and liver-related blood parameters changed either not at all or only slightly, the tested GLY formulation was considered to have no toxic effects on the liver of dairy cows.

Niacin nutrition and rumen-protected niacin supplementation in dairy cows: an updated review

As the precursor to NAD+ and NADP+, niacin is important for catabolic and anabolic redox reactions. In addition, niacin is known for its anti-lipolytic action via a hydroxycarboxylic acid-2-receptor-dependent mechanism. The anti-lipolytic effects of traditional free niacin supplementation during transition periods had been studied extensively, but the reported effects are ambiguous. In the past decade, a series of studies were conducted to evaluate the effects of rumen-protected niacin (RPN) on production performance and metabolic status in early lactation and on heat stress in dairy cows. Feeding RPN seems more effective than free niacin regarding increasing circulating niacin concentration. The rebound of plasma NEFA was found after termination of niacin abomasal infusion. Feeding RPN or infusion of niacin via the abomasum could suppress lipolysis and reduce insulin resistance in early lactation. Additionally, RPN supplementation could possibly relieve heat stress through vasodilation during moderate to severe heat stress condition. However, these beneficial effects of niacin supplementation have not always been observed. The inconsistent results across studies may be related to dosages of niacin supplementation, rebound of plasma NEFA concentration, stage of lactation or severity of heat stress. Overall, the current review is to present updated information on niacin nutrition in dairy cows and the recommendations are given for future research.

The relationship between neutrophil-lymphocyte ratio and onset of lactation among postpartum women: A prospective observational cohort study

BACKGROUND

Delayed onset of lactation is a key factor in the low rate of exclusive breast-feeding in 6 months after caesarean section. The mechanism of delayed onset of lactation is not clear. Milk production depends largely on mitochondrial adenosine triphosphate synthesis, and the neutrophil-lymphocyte ratio is closely related to mitochondrial deoxyribonucleic acid copy number and adenosine triphosphate production. Presently, it is unclear whether a difference in the neutrophil-lymphocyte ratio exists between those undergoing vaginal delivery and those undergoing caesarean delivery and, if so, whether the difference correlates to the time of onset of lactation.

OBJECTIVES

To identify whether the neutrophil-lymphocyte ratio at 24 hours after delivery is different between mothers delivering by caesarean section and those giving birth vaginally and whether the neutrophil-lymphocyte ratio is related to the delayed onset of lactation.

DESIGN

The study adopted a prospective cohort study design.

SETTINGS

Maternity units of an Obstetrics & Gynecology Hospital.

PARTICIPANTS

327 mother-infant pairs who met inclusion/exclusion criteria and were followed up to the time of onset of lactation.

METHODS

Mother-infant pairs were allocated to the vaginal birth group or the caesarean section group according to birth method. The neutrophil-lymphocyte ratio was calculated as the absolute value of neutrophils divided by the absolute value of lymphocytes based on full blood counts. Before delivery, full blood counts were obtained from medical records. After delivery, blood samples were drawn 24 hours postpartum, and blood cells were classified and counted. The onset of lactation was confirmed by the maternal perception of breast fullness. The neutrophil-lymphocyte ratio and its relationship with lactation onset were analyzed by multivariable regression.

RESULTS

The neutrophil-lymphocyte ratios of both groups were elevated after delivery. Based on the covariance analysis, after adjusting for baseline full blood counts before delivery, the neutrophil-lymphocyte ratio in the caesarean group was higher than the ratio in the vaginal group after delivery (p = .000). In addition, after adjustment for confounding factors, multivariable regression analyses showed that an increased neutrophil-lymphocyte ratio was correlated with delayed onset of lactation (95% confidence interval 0.285-1.646).

CONCLUSIONS

The neutrophil-lymphocyte ratio in the caesarean section group was higher than that in the vaginal delivery group and was related to a delayed onset of lactation. Given the decreased mitochondrial copy number in the elevated neutrophil-lymphocyte ratio and therefore the associated reduction in adenosine triphosphate synthesis, these findings may elucidate the mechanism for delayed onset of lactation in caesarean section births.

Kinetic studies on clinical and immunological modulations by intramuscular injection of Escherichia coli LPS in laying hens

The present study investigated clinical and immunological modulations due to intramuscular injection of Escherichia coli LPS in 49-wk-old laying hens over 48 h post injection (p.i.). LPS induced characteristic sickness behavior but no significant body temperature alterations (P > 0.05). During experimental period decreases in blood albumin, calcium, phosphorus and tryptophan concentrations, hyperglycemia, increased plasma nitrite concentrations, leucopenia, decreased thrombocyte counts, lymphopenia, heterophilia and an increased heterophilic granulocyte/lymphocyte (H/L) ratio were observed after LPS administration. Time-dependent effects were shown on T and B cell subsets in caecal tonsils (CT) and on splenic CD3⁺/CD4⁺/CD8⁺ proportions, on IL-1β and -10 and inducible NO synthase mRNA expression in peripheral blood lymphocytes (PBL), liver, spleen and CT, and on the mRNA expression of the TLR4 in PBL, liver and spleen p.i. (P < 0.05). The main responding period of mentioned alterations due to LPS appears to include the period from 2 until 8 h p.i. According to the H/L ratio, the most stressful phase was 5 h p.i. T and B cell subsets in CT, the IL-1β and TLR4 mRNA expression in liver and plasma nitrite concentrations seemed to be affected for a longer period.

Radioprotective Activity and Preliminary Mechanisms of N-oxalyl-d-phenylalanine (NOFD) In Vitro

The radiation-induced damage to the human body is primarily caused by excessive reactive oxygen species (ROS) production after irradiation. Therefore, the removal of the increase of ROS caused by ionizing radiation (IR) has been the focus of research on radiation damage protective agents. Hypoxia inducible factor (HIF) is a transcription factor in human and plays an important role in regulating the body metabolism. Factor inhibiting HIF (FIH) is an endogenous inhibitor factor of HIF protein under normoxia conditions. It has been shown that the high expression of HIF protein has a certain repair effect on radiation-induced intestinal injury and hematopoietic system damage in mice; however, it is not clear about the effect of HIF on the level of ROS after radiation. In this study, the role of N-oxalyl-d-phenylalanine (NOFD), an FIH inhibitor, for its effect on alleviating ROS level is investigated in the cells. Our results indicate that pretreatment with NOFD can mitigate ROS level and alleviate IR-induced DNA damage and apoptosis in vitro. Therefore, HIF can be used as a target on scavengers. Furthermore, in order to explore the relevant mechanism, we also test the expression of relevant HIF downstream genes in the cells, finding that Notch-2 gene is more sensitive to NOFD treatment. This experiment result is used to support the subsequent mechanism experiments.

Hepatic transcript profiling in early-lactation dairy cows fed rumen-protected niacin during the transition from late pregnancy to lactation

In dairy cows, administration of high dosages of niacin (nicotinic acid, NA) was found to cause antilipolytic effects, which are mediated by the NA receptor hydroxyl-carboxylic acid receptor 2 (HCAR2) in white adipose tissue (WAT), and thereby an altered hepatic lipid metabolism. However, almost no attention has been paid to possible direct effects of NA in cattle liver, despite evidence that HCAR2 is also expressed in the liver and is even more abundant than in WAT. Because of this, we hypothesized that feeding a high dosage of rumen-protected NA to dairy cows influences critical metabolic or signaling pathways in the liver by inducing changes in the hepatic transcriptome. To identify these pathways, we applied genome-wide transcript profiling in liver biopsies obtained at d 7 postpartum (p.p.) from dairy cows used in our recent study; cows received either no NA (control group, n = 9) or 79 mg of rumen-protected NA/kg of body weight daily (NA group, n = 9) from 21 d before calving until 3 wk p.p. Hepatic transcript profiling revealed that 487 transcripts were differentially expressed (filter criteria: fold change >1.2 or <-1.2 and P < 0.05) in the liver at d 7 p.p. between cows fed NA and control cows. Substantially more transcripts were downregulated (n = 338), whereas only 149 transcripts were upregulated by NA in the liver of cows. Gene set enrichment analysis for the upregulated transcripts revealed that the most-enriched gene ontology biological process terms were exclusively related to immune processes, such as leukocyte differentiation, immune system process, activation of immune response, and acute inflammatory response. Gene set enrichment analysis of the downregulated transcripts showed that the most-enriched biological process terms were related to metabolic processes, such as cellular metabolic process, small molecule metabolic process, lipid catabolic process, organic cyclic compound metabolic process, small molecule biosynthetic process, and cellular lipid catabolic process. In conclusion, hepatic transcriptome analysis showed that rumen-protected NA induces genes that are involved mainly in immune processes, including acute phase response and stress response, in dairy cows at d 7 p.p. Thus, supplementation of a high dosage of rumen-protected NA to dairy cows in the periparturient period may induce or amplify the systemic inflammation-like condition that is typically observed in the liver of high-yielding dairy cows in the p.p. period.

Mineral supplementation stimulates the immune system and antioxidant responses of dairy cows and reduces somatic cell counts in milk

The aim of this study was to evaluate whether the use of subcutaneous mineral supplementation would affect metabolic parameters, immunological response, milk quality and composition of dairy cows in the postpartum period. Twelve pregnant primiparous Holstein cows, were divided into two groups: six animals supplemented with the mineral complex (magnesium, phosphorus, potassium, selenium and copper), and six animals used as controls. Milk samples were collected every two other weeks postpartum up to sixty days of lactation to analyze composition and quality. Blood samples were collected, and the levels of ketone bodies, total proteins, glucose, albumin, and globulin were measured. The catalase and superoxide enzymes, reactive oxygen species, tumor necrosis factor, and interleukins were determined. Animals supplemented with minerals showed lower levels of ketone bodies and somatic cell counts on days 30, 45 and 60 of the experiment, without changes in milk composition compared to the control group. Supplemented cows had lower levels reactive oxygen species and increased superoxide enzymes activity. Total protein, globulin and cytokine levels were higher in cows supplemented with mineral complexes. Therefore, we can conclude that subcutaneous mineral supplementation improved the immune response and minimized the oxidative stress in dairy cows during lactation.

Animal models to study the impact of nutrition on the immune system of the transition cow

The immune system is particularly challenged in transition cows as marked physiological changes occur in this period which are driven by late gestation, partus and onset of lactation. As a consequence, the metabolic and nutritional state of the cow also changes significantly with possible implications for the plasticity and flexibility of the immune system. In order to understand how the balance between metabolism, nutritional status and the immune system is maintained under challenging conditions, such as an infection, various animal models can be used which specifically manipulate the nutritional status through various feeding and management strategies. Such models aim at exploring the immunological response to a challenge under largely varying nutritional and metabolic states. As energy balance (EB) is strongly associated both with the metabolic state and with the immunoreactivity of the cows the manipulation of the EB by either influencing energy intake or energy excretion with milk, or by both, offers model opportunities for studying EB effects on the immune system. For example, assigning cows with a higher body condition score (BCS) at least 6 weeks prior to calving to an energy-dense diet exceeding the energy requirement in combination with a decelerated increase in the concentrate feed proportion post partum was shown to be effective in inducing a ketotic metabolic state under ad libitum feeding conditions. Compared to an adequately managed control group this model allows studying immune responses in the transit period and in dependence on dietary interventions.

Symposium review: Modulating adipose tissue lipolysis and remodeling to improve immune function during the transition period and early lactation of dairy cows

Despite major advances in our understanding of transition and early lactation cow physiology and the use of advanced dietary, medical, and management tools, at least half of early lactation cows are reported to develop disease and over half of cow deaths occur during the first week of lactation. Excessive lipolysis, usually measured as plasma concentrations of free fatty acids (FFA), is a major risk factor for the development of displaced abomasum, ketosis, fatty liver, and metritis, and may also lead to poor lactation performance. Lipolysis triggers adipose tissue (AT) remodeling that is characterized by enhanced humoral and cell-mediated inflammatory responses and changes in its distribution of cellular populations and extracellular matrix composition. Uncontrolled AT inflammation could perpetuate lipolysis, as we have observed in cows with displaced abomasum, especially in those animals with genetic predisposition for excessive lipolysis responses. Efficient transition cow management ensures a moderate rate of lipolysis that is rapidly reduced as lactation progresses. Limiting FFA release from AT benefits immune function as several FFA are known to promote dysregulation of inflammation. Adequate formulation of pre- and postpartum diet reduces the intensity of AT lipolysis. Additionally, supplementation with niacin, monensin, and rumen-protected methyl donors (choline and methionine) during the transition period is reported to minimize FFA release into systemic circulation. Targeted supplementation of energy sources during early lactation improves energy balance and increases insulin concentration, which limits AT lipolytic responses. This review elaborates on the mechanisms by which uncontrolled lipolysis triggers inflammatory disorders. Details on current nutritional and pharmacological interventions that aid the modulation of FFA release from AT and their effect on immune function are provided. Understanding the inherent characteristics of AT biology in transition and early lactation cows will reduce disease incidence and improve lactation performance.