Effects of dietary supplementation of pioglitazone on metabolism, milk yield, and reproductive performance in transition dairy cows

The effect of dietary pioglitazone supplementation on milk yield, insulin sensitivity and GH-IGF-I axis in Holstein dairy cows during the transition period

BACKGROUND

High-yielding dairy cows develop insulin resistance during late gestation associated with disruption of the growth hormone (GH)-insulin-like growth factor (IGF)-I axis and cause metabolic and reproductive disorders.

OBJECTIVE

This study aimed to determine the effects of dietary pioglitazone (PIO) supplementation as an insulin sensitizer agent on milk yield, plasma metabolite status and GH-IGF-I axis in transition Holstein dairy cows.

METHODS

Twenty multiparous cows were randomly assigned into two experimental groups (n = 10 animals per group) and either fed with a basal diet (control) or the basal diet supplemented with 6 mg PIO/kg body weight (BW) from day 14 before parturition to day 21 postpartum. The BW and body condition score (BCS), non-esterified fatty acids, beta-hydroxybutyrate (BHBA), insulin, glucose, GH and IGF-I concentrations, milk production and composition were measured weekly.

RESULTS

BW and BCS losses were lower in PIO than in control cows (p < 0.05). The percentage and amount of milk fat were decreased, and the amount of protein increased only in the first post-calving week in the PIO-treated cows compared to the control (p < 0.05). Dietary PIO supplementation increased glucose concentration at calving, but insulin concentration was increased at calving and in the first post-calving week (p < 0.05). Plasma concentrations of IGF-I and the ratio of IGF to GH were increased in the PIO group (p < 0.05). The mean revised quantitative insulin sensitivity check index with BHBA, as an insulin sensitivity index, was greater in PIO-supplemented cows (p < 0.05).

CONCLUSIONS

Our results showed beneficial effects of PIO supplementation on improving insulin sensitivity and the GH-IGF-I axis that may cause lower negative energy balance and better metabolic and health status in transition dairy cows.

Berberine supplementation modulates the somatotropic axis and ameliorates glucose tolerance in dairy goats during late gestation and early lactation

BACKGROUND

Pregnancy, parturition, and the onset of lactation represent an enormous physiological and hormonal challenge to the homeostasis of dairy animals, being a risk for their health and reproduction. Thus, as a part of the homothetic changes in preparturition period, goats undergo a period of IR as well as uncoupled GH/IGF-1 axis. The objective for this study was to determine the effect of berberine (BBR) during the peripartal period on hormonal alteration and somatotropic axis in dairy goats as well as glucose and insulin kinetics during an intravenous glucose tolerance test (IVGTT). At 21 days before the expected kidding date, 24 primiparous Saanen goats were assigned randomly to 4 dietary treatments. Goats were fed a basal diet from wk. 3 antepartum (AP) until wk. 3 postpartum (PP) supplemented with 0 (CTRL), 1 (BBR1), 2 (BBR2), and 4 (BBR4) g/d BBR. Blood samples were collected on days - 21, - 14, - 7, 0, 7, 14, and 21 relative to the expected kidding date. An IVGTT was also performed on day 22 PP.

RESULTS

Compared with CTRL, supplementation with either BBR2 or BBR4 increased DMI at kidding day and PP, as well as body conditional score (BCS) and milk production (p ≤ 0.05). On d 7 and 14 PP plasma glucose was higher in BBR2- and BBR4-treated than in CTRL. The glucagon concentration was not affected by BBR during the experimental period. However, supplemental BBR indicated a tendency to decrease in cortisol concentration on days 7 (p = 0.093) and 14 (p = 0.100) PP. Lower plasma GH was observed in BBR than in non-BBR goats (p ≤ 0.05). Plasma IGF-1 concentration was enhanced in both BBR2 and BBR4 at kidding and day 7 PP (p ≤ 0.05). During the IVGTT, glucose area under the curve (AUC), clearance rate (CR), T1/2, and Tbasal was lower (p ≤ 0.05) in both BBR2 and BBR4 goats as compared with CTRL. Likewise, the insulin CR was higher (p ≤ 0.05) in goats receiving either BBR2 or BBR4 which was accompanied by a lower insulin T1/2 and AUC.

CONCLUSIONS

Altogether, our results indicated an improved glucose and insulin status along with the modulation of the somatotropic axis and glucose and insulin response to IVGTT in dairy goats supplemented with 2 and 4 g/d BBR.

Invited review: The influence of immune activation on transition cow health and performance-A critical evaluation of traditional dogmas

The progression from gestation into lactation represents the transition period, and it is accompanied by marked physiological, metabolic, and inflammatory adjustments. The entire lactation and a cow's opportunity to have an additional lactation are heavily dependent on how successfully she adapts during the periparturient period. Additionally, a disproportionate amount of health care and culling occurs early following parturition. Thus, lactation maladaptation has been a heavily researched area of dairy science for more than 50 yr. It was traditionally thought that excessive adipose tissue mobilization in large part dictated transition period success. Further, the magnitude of hypocalcemia has also been assumed to partly control whether a cow effectively navigates the first few months of lactation. The canon became that adipose tissue released nonesterified fatty acids (NEFA) and the resulting hepatic-derived ketones coupled with hypocalcemia lead to immune suppression, which is responsible for transition disorders (e.g., mastitis, metritis, retained placenta, poor fertility). In other words, the dogma evolved that these metabolites and hypocalcemia were causal to transition cow problems and that large efforts should be enlisted to prevent increased NEFA, hyperketonemia, and subclinical hypocalcemia. However, despite intensive academic and industry focus, the periparturient period remains a large hurdle to animal welfare, farm profitability, and dairy sustainability. Thus, it stands to reason that there are alternative explanations to periparturient failures. Recently, it has become firmly established that immune activation and the ipso facto inflammatory response are a normal component of transition cow biology. The origin of immune activation likely stems from the mammary gland, tissue trauma during parturition, and the gastrointestinal tract. If inflammation becomes pathological, it reduces feed intake and causes hypocalcemia. Our tenet is that immune system utilization of glucose and its induction of hypophagia are responsible for the extensive increase in NEFA and ketones, and this explains why they (and the severity of hypocalcemia) are correlated with poor health, production, and reproduction outcomes. In this review, we argue that changes in circulating NEFA, ketones, and calcium are simply reflective of either (1) normal homeorhetic adjustments that healthy, high-producing cows use to prioritize milk synthesis or (2) the consequence of immune activation and its sequelae.

Conjugated linoleic acid improves meiotic spindle morphology and developmental competence of heat-stressed bovine oocyte

This study was conducted to elucidate the effects of introducing conjugated linoleic acid (CLA) on meiotic spindle organization of heat stressed (HS) matured oocytes and the resulting blastocysts DNA methylation as well as the expression of the genes involved in DNA methylation (DNMT3a, DNMT3b and DNMT1). Immature bovine oocytes were cultured at 41 °C for the first 12 h and 38.5 °C for the second 12 h of maturation time in the presence of 0 and 50 μM of CLA (HS and HS + CLA groups, respectively). A group of oocytes cultured in medium with no CLA supplementation at normal temperature (38.5 °C for 24 h) was considered as negative control (C). Percentage of normal spindle, and cleavage and blastocyst rates were significantly decreased in the HS group compared to the C group (P < 0.05). The global DNA methylation and expression level of DNMT3a gene were increased in HS group compared to the C groups (P < 0.05), while the expression level of DNMT3b was decreased. The CLA supplementation improved the percentage of normal microtubules shape in MII oocytes as well as the developmental competence in the HS + CLA group compared to the HS group (P < 0.05). However, global DNA methylation and expression level of DNMT3a/b were not ameliorated by CLA supplementation (P > 0.05). Based on the obtained results, CLA proved to be capable of improving the oocyte developmental competence as well as decreased the aberrant spindle organization of heat-stressed oocytes and it would not cause epigenetic alteration in the obtained blastocysts.

Effect of pomegranate by-product silage on feed intake, blood metabolites, inflammatory responses, and prostaglandin F2α metabolites in Holstein dairy cows

Dairy cows often suffer metabolic disorders due to the challenges of the transition period. The aim of study was to determine the effects of feeding pomegranate by-product silage (PBS) on feed intake and some blood parameters, such as non-esterified fatty acids (NEFA) and beta hydroxy butyric acid (BHBA), interleukin-1 (IL-1), serum amyloid-A (SAA), prostaglandin F_2α metabolites (PGFM), and progesterone (P4) in fresh Holstein cows. The experimental groups were as follows: CON (0 g PBS of DM) and PBS (120 g PBS of DM). Results showed that replacing corn silage with PBS had no effect on dry matter intake (DMI) throughout the study. The CON group had highest (p < .05) NEFA at 14 d postpartum and serum BHBA was decreased by feeding PBS, especially on days 21 (p < .05) and 28 (p < .05) and the entire study (p < .01). Cows fed PBS had lower (p < .05) serum Malondialdehyde (MDA) than CON cows at different times. Feeding PBS decreased (p < .01) serum IL-1 compared to CON group (216.7 versus. 515.5 Pg/ml) at 28 d postpartum, and also cows fed 120 g PBS had higher (p < .01) serum P4. It was concluded that feeding PBS had no adverse effect on feed intake, milk production, and some reproductive parameters. Moreover, PBS positively affected serum metabolites in fresh dairy cows.

In vitro supplementation of trans-10, cis-12 conjugated linoleic acid ameliorated deleterious effect of heat stress on bovine oocyte developmental competence

Environmental stresses, such as heat stress (HS), have been shown to have diverse effects on the developmental competence of oocytes. The aim of this study was to determine the effect of exogenous conjugated linoleic acid (CLA) supplementation in maturation medium on bovine oocyte maturation and developmental competence under HS condition. Accordingly, cumulus-oocyte complexes (COCs) were cultured at 41 °C and 38.5 °C for the first and second 12 h of maturation in the presence of 0 (PC), 50 (CLA50-HS) and 100 (CLA100-HS) μM CLA. Also, a group of COCs were cultured at 38.5 °C for 24 h of maturation without CLA supplementation as negative control (NC). Nuclear maturation, level of intracellular glutathione (GSH), reactive oxygen species (ROS) content, cleavage and blastocyst rates as well as relative expression of BAX, and BCL2 genes in blastocysts were investigated. Our finding for the PC and NC groups revealed that HS decreased the percentage of MII oocytes, cleavage and blastocyst rates (P < 0.05). Moreover, HS lead to an increase in ROS levels and relative expression of BAX gene, decreased the intracellular content of GSH and relative expression of BCL2 gene (P < 0.05). However, the cleavage and blastocyst rates tended to increase in the CLA-supplemented groups compared to PC group (p < 0.10). Also, ROS and GSH levels in the matured oocytes decreased and increased in the CLA50-HS group compared to the PC group (P < 0.05), respectively. The ratio of expression levels of BAX to BCL2 genes was not different between the PC and CLA50-HS groups (P > 0.05). These findings suggest that HS has undesirable effects on the maturation competence of bovine oocyte and subsequent embryo development while administration of CLA can ameliorate some of adverse effects of HS.

2,4-Thiazolidinedione in Well-Fed Lactating Dairy Goats: I. Effect on Adiposity and Milk Fat Synthesis

Background: In a prior experiment, treatment of goats with the putative PPARγ agonist 2,4-thiazolidinedione (2,4-TZD) did not affect milk fat or expression of milk-fat related genes. The lack of response was possibly due to deficiency of vitamin A and/or a poor body condition of the animals. In the present experiment, we tested the hypothesis that PPARγ activation affects milk fat synthesis in goats with a good body condition and receiving adequate levels of vitamin A. Methods: Lactating goats receiving a diet that met NRC requirements, including vitamin A, were injected with 8 mg/kg BW of 2,4-TZD (n = 6) or saline (n = 6; CTR) daily for 26 days. Blood metabolic profiling and milk yield and components were measured including fatty acid profile. Expression of genes related to glucose and lipid metabolism was measured in adipose tissue and in mammary epithelial cells (MEC). Size of adipocytes was assessed by histological analysis. Results: NEFA, BHBA, and fatty acids available in plasma decreased while glucose increased in 2,4-TZD vs. CTR. Size of cells and expression of insulin signaling and glucose metabolism-related genes were larger in 2,4-TZD vs. CTR in adipose tissue. In MEC, expression of SCD1 and desaturation of stearate was lower in 2,4-TZD vs. CTR. Conclusions: Overall data revealed a lack of PPARγ activation by 2,4-TZD and no effect on milk fat synthesis despite a strong anti-lipolysis effect on adipose tissue.

Effects of a combination of plant bioactive lipid compounds and biotin compared with monensin on body condition, energy metabolism and milk performance in transition dairy cows

The aim of this study was to test whether a combination of plant bioactive lipid compounds (also termed ‘essential oils’) and biotin (PBLC+B) could decrease the mobilization of body reserves and ketosis incidence in postpartum dairy cows. We compared non-supplemented control (CON) cows with cows receiving monensin (MON) as a controlled-release capsule at d -21, and with cows receiving PBLC+B from day (d) -21 before calving until calving (Phase 1) and further until d 37 after calving (Phase 2), followed by PBLC+B discontinuation from d 38 to d 58 (Phase 3). The PBLC+B cows had higher body weight and higher back fat thickness than CON cows and lesser body weight change than MON and CON cows in Phase 3. Body condition score was not different among groups. Milk protein concentration tended to be higher on the first herd test day in PBLC+B vs. CON cows. Milk fat concentration tended to be highest in PBLC+B cows throughout Phases 2 and 3, with significantly higher values in PBLC+B vs. MON cows on the second herd test day. Yields of energy-corrected milk were higher in PBLC+B vs. CON and MON cows in Phase 2 and higher in PBLC+B and MON cows vs. CON cows in Phase 3. The incidence of subclinical ketosis was 83%, 61% and 50% in CON, PBLC+B and MON cows, respectively, with lower mean β-hydroxybutyrate values in MON than in PBLC+B cows in Phase 1 prepartum. The serum triglyceride concentration was higher in PBLC+B vs. CON cows on d 37. No differences were observed in serum glucose, urea, non-esterified fatty acids, cholesterol and bilirubin concentrations. Aspartate transaminase and γ-glutamyltranspeptidase but not glutamate dehydrogenase activities tended to be highest in MON and lowest in PBLC+B in Phase 2. We conclude that PBLC+B prevent body weight loss after parturition and are associated with similar ketosis incidence and partly higher yields of energy-corrected milk compared to MON supplementation of dairy cows.

Effects of dietary supplementation of pioglitazone or walnut meal on metabolic profiles and oxidative status in dairy cows with high pre-calving BCS

This research paper addresses the hypothesis that dietary pioglitazone (PGT), as synthetic and specific ligand for PPAR-γ or walnut meal (WM) as a natural ligand for PPAR-γ, affect plasma metabolites and reduce the oxidative status in high body condition score (BCS) dairy cows (≥4 BCS). Total of 36 multiparous Holstein cows were randomly assigned to one of the dietary treatments: 1- Control (basal diet; CTR), 2- Walnut meal (9·45% walnut meal of DMI; WM), and 3- Pioglitazone (6 mg/kg BW; PGT). The experimental diets were fed from parturition time to 21 d postpartum. Results showed that the PGT supplementation increased dry matter intake (DMI) (22·95 kg/d) compared to the CTR (21·45 kg/d) and WM (21·78 kg/d) groups. Results showed that milk yield and milk composition were not affected by the experimental diets. Body condition score losses tended to be higher in the CTR group compared to the PGT and WM cows. The PGT group had higher plasma insulin compared to the CTR group (11·84 vs. 10·68 mIU/l), and WM cows had intermediate plasma insulin. The PGT cows had lower plasma non esterified fatty acid (NEFA) and tended to have lower β-hydroxy butyric acid (BHBA) than the CTR group. Feeding pioglitazone decreased plasma malondialdehyde (MDA) and increased plasma total antioxidant capacity (TAC) and superoxide dismutase (SOD) compared to the CTR and WM groups. It was concluded that dietary pioglitazone had positive effects on DMI, BCS change, blood metabolites and oxidative status in fresh dairy cows with high pre-calving BCS. The anti-oxidant effects of walnut meal were not supported by the present data.

2,4-Thiazolidinedione Treatment Improves the Innate Immune Response in Dairy Goats with Induced Subclinical Mastitis

Mastitis is a major disease in dairy cows resulting in significant economic losses. In vitro works suggest that ruminants peroxisome proliferator-activated receptor gamma (PPARγ) can aid in improving the response to mastitis and can control milk fat synthesis. The objectives of the present experiment were to test if treatment with the putative PPARγ agonist 2,4-thiazolidinedione (TZD) improves (1) the response to subclinical mastitis and (2) milk fat production. Lactating goats received daily injections of 8 mg/kg BW of TZD or saline for 3 weeks. After one week of TZD injection, half of the goats in each group received intramammary infusion of Strep. uberis or saline in both halves for a total of 4 groups (n = 6/group). TZD treatment did not affect milk fat but had positive effect on milk somatic cells count, blood nonesterified fatty acids, inflammatory markers, and liver function. TZD significantly increased myeloperoxidase but did not affect leukocytes phagocytosis or insulin. TZD increased adipocytes size and had minor effect on expression of PPARγ target genes in mammary epithelial cells but not in adipose tissue. Overall, TZD ameliorated the response to intramammary infection but the effect on milk fat synthesis and expression of related transcripts was less than expected.