Oversupplying metabolizable protein during late gestation to beef cattle does not influence ante- or postpartum glucose-insulin kinetics but does affect prepartum insulin resistance indices and colostrum insulin content

The objective of this study was to evaluate whether oversupplying metabolizable protein (MP) during late gestation influences glucose and insulin concentrations, and insulin resistance (IR) in late gestation and early lactation. Crossbred Hereford, first-lactation heifers were individually fed diets to supply 133% (HMP, n = 11) or 100% (CON, n = 10) of their predicted MP requirements for 55 ± 4 d (mean ± SD) prior to calving. All heifers received a common lactation ration formulated to meet postpartum requirements (103% MP and 126% ME). After feed was withheld for 12 h, cattle underwent an intravenous glucose tolerance test (IVGTT) on d -6.7 ± 0.9 and 14.3 ± 0.4 by infusing a 50% dextrose solution (1.36 g glucose/kg BW 0.75) through a jugular catheter with plasma collected at -10, 0 (immediately after infusion), 5, 10, 15, 20, 25, 30, 45, 60, 75, 90, and 120 min, respective to the infusion. Glucose and insulin concentrations were assessed. Insulin resistance indices (homeostasis model of insulin resistance [HOMA-IR], quantitative insulin sensitivity check index [QUICKI], revised quantitative insulin sensitivity check index [RQUICK], and RQUICKI incorporating serum beta-hydroxybutyrate concentrations [RQUICKIBHB]) were calculated from measurements of serum non-esterified fatty acids and beta-hydroxybutyrate and plasma glucose and insulin concentrations on d -34 ± 4, -15 ± 4, 7 ± 1, 28 ± 3, 70 ± 3, and 112 ± 3. Colostrum samples were collected within an hour of calving (prior to suckling) and analyzed for insulin concentration. Data were analyzed as a randomized block design using the PROC GLIMMIX of SAS, accounting for repeated measurements when necessary. Baseline (-10 min) plasma glucose and insulin concentrations were elevated (P ≤ 0.038) for HMP heifers during the antepartum IVGTT, but not (P ≥ 0.25) during the postpartum IVGTT. Plasma glucose and insulin concentrations throughout the antepartum or postpartum IVGTT did not differ (P ≥ 0.18) by prepartum treatment, nor did other glucose and insulin IVGTT parameters (i.e., max concentration and time to reach max concentration, nadir values, clearance rates and half-lives, area-under-the-curve, and insulin sensitivity index; P ≥ 0.20). Antepartum IVGTT IR indices indicated that HMP heifers were more (P ≤ 0.011) IR than their counterparts. Similarly, the prepartum HOMA-IR was greater (P = 0.033) for HMP heifers, suggesting increased IR. Postpartum IR indices did not (P ≥ 0.25) indicate that prepartum MP consumption impacted postpartum IR. Colostrum insulin concentration was increased (P = 0.004) by nearly 2-fold for HMP relative to CON heifers. These data demonstrate that prepartum MP overfeeding alters baseline glucose-insulin concentrations in late-pregnant beef heifers and increases colostrum insulin content without having carry-over effects on postpartum glucose-insulin concentrations and IR.

Cloning and over Expression Studies of Ovine Somatotropin cDNA of Kajli (sheep breed) in a Prokaryotic System

Genetic studies including the quest, cloning and expression of genes encoding proteins responsible for various vital physiological processes and beneficial characteristics of economic perspective have made the biotechnology research progressively auspicious. Due to its great zootechnical and industrial importance somatotropin gene have been cloned from various animal species. Current study was designed to clone mature ovine growth hormone complementary DNA (oGH cDNA) of a sheep breed, Kajli and carry out over expression studies of cloned GH cDNA in a suitable prokaryotic expression system. Sheep GH cDNA was cloned in T/A (thymine / adenine) vector with signal peptide and confirmed by nested polymerase chain reaction (PCR) and restriction digestion. The gene was then ligated in pLEX expression vector and restricted plasmids showed a fragment insert of ~ 600 bps. Restriction analysis confirmed positive clones, were induced for protein expression analysis. The pET vectors (plasmid for expression by T7 RNA polymerase) have an isopropylthio-β-galactoside (IPTG) inducible strong T7 promoter and Escherichia coli expression strain of BL21 (DE3) pLysS contains DNA fragment from T7 phage which harbors RNA polymerase. Therefore, for expressing recombinant proteins, cells were induced with various IPTG concentrations to optimize expression levels. Cells were induced with different IPTG concentrations (0.1 to 0.8 mM) followed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Results indicated maximum expression level of oGH at 5 hrs after induction of cells with 0.3 mM IPTG concentration with a molecular weight of 22 kDa. As for as cellular localization of protein is concerned accumulation of expressed oGH is observed in inclusion bodies. The successful expression of the cloned GH cDNA of sheep confirmed the functional viability of the clone. The above mentioned technique of genetic engineering has provided to boost the dairy industry by the production of large quantities of recombinant bovine somatotropin (rbST).

Factors associated with negative energy balance in periparturient dairy cows raised under tropical climate of Thailand-A mini-review

This review attempted to explain factors associated with negative energy balance (NEB) occurring during the periparturient period in dairy cows raised under tropical climatic conditions. The NEB has long been proven as an inevitable event in periparturient dairy cows. This condition had negative effects on the overall performances of dairy cows, including milk production, reproduction, and health condition. Therefore, periparturient management to overcome the NEB problem is vital for optimizing profit in dairy farming. In most tropical countries such as Thailand, dairy cows have been predominantly kept by small-holder farmers. Consequently, baseline milk yields, feed availability, feeding management, and general farming practices are different from typical commercial dairy farming. Heat stress also plays a crucial role in NEB conditions, and elevated temperature-humidity indexes above-normal conditions are recorded throughout the year. These factors influence the NEB in tropical dairy cows, which could result in different outcomes and consequences. Understanding the affecting components of NEB in dairy cows would help alleviate the severity of the NEB and its consequences, optimizing the dairy cow’s performance.

Moderate over-feeding of different sources of metabolizable energy and protein improved gestational insulin resistance markers and maternal metabolic status of sheep around lambing

The objective of this study was to determine the effect of moderate over-nutrition of energy (using flaxseed as a source of n-3 fatty acids) and protein (using rumen-protected lysine and methionine) around parturition on prepartal insulin resistance (IR) and periparturient metabolic status and performance of ewes. For this purpose, 32 apparently healthy ewes (2.5 ± 1 years old, 42.19 ± 1.65 kg body weight (BW)) were randomly selected out of 200 pregnant Zell ewes on d 50 before the expected lambing. After receiving a ten-day adaptation diet, eight ewes were randomly allocated to one of the following four dietary treatments: 1) the adaptation diet that meets the metabolizable energy (ME) and protein (MP) requirements of ewes during late pregnancy as recommended by National Research Council = NRC (2007) (Control = CON). 2) A diet with 10% higher levels of ME than NRC (2007) recommendations using corn grain as a source of extra ME (HEC). 3) A diet with 10% higher levels of ME compared to NRC (2007) recommendations using flaxseed for additional ME (HEF). 4) A diet with a 10% higher level of MP than NRC (2007) recommendations using rumen-protected lysine and methionine as a source of extra MP (PRO). While the dietary treatments did not affect animals' dry matter intake (DMI), the CON ewes lost more BW starting from d 10 to d 30 relative to parturition compared to others (P < 0.05). Milk protein and fat yield (g/d) were significantly higher for PRO and HEF compared to HEC and CON ewes (P < 0.05). Moderately over-fed ewes with MP and ME had an improved insulin sensitivity (IS) compared to CON ones. The source of additional ME also impacted IR indices because HEC showed an enhancement in IS than HEF animals (P < 0.05). A lower IS in CON ewes was parallel with higher concentrations of plasma urea at prepartum (P < 0.01), lower levels of plasma cholesterol, triglyceride (P < 0.01) and glucose post-partum (P < 0.05), and a tendency for higher levels of beta-hydroxybutyrate (BHB) and non-esterified fatty acids (NEFA) in CON ewes during both pre- and post-partum periods. There were negative correlations between plasma urea, BHB, and NEFA with IR markers on d 7 prepartum in line with these results. Comparing data, we could not find a significant change in metabolic status among ewes fed with either PRO or HEF/HEC. In conclusion, the inclusion of 10% extra MP and ME could improve late gestation maternal IS and the metabolic status of dams around lambing.

Body condition and insulin resistance interactions with periparturient gene expression in adipose tissue and lipid metabolism in dairy cows

Adipose tissue plays an important role in a cow's ability to adapt to the metabolic demands of lactation, because of its central involvement in energy metabolism and immunity. High adiposity and adipose tissue resistance to insulin are associated with excessive lipid mobilization. We hypothesized that the response to a glucose challenge differs between cows of different body condition 21 d before and after calving and that the responses are explainable by gene expression in subcutaneous adipose tissue (SAT). In addition, we aimed to investigate insulin resistance with gene expression in SAT and lipid mobilization around parturition. Multiparous Holstein cows were grouped according to body conditions score (BCS) 4 wk before calving, as follows: BCS ≤ 3.0 = thin (T, n = 14); BCS 3.25 to 3.5 = optimal (O, n = 14); BCS ≥ 3.75 = over-conditioned (OC, n = 14). We collected SAT on d -21 and d 21 relative to calving. A reverse-transcriptase quantitative (RT-q)PCR was used to measure gene expression related to lipid metabolism. One hour after the collection of adipose tissue, an intravenous glucose tolerance test was carried out, with administration of 0.15 g of glucose per kg of body weight (with a 40% glucose solution). Once weekly from the first week before calving to the third week after calving, a blood sample was taken. The transition to lactation was associated with intensified release of energy stored in adipose tissue, a decrease in the lipogenic genes lipoprotein lipase (LPL) and diacylglycerol O-acyltransferase 2 (DGAT2), and an increase in the lipolytic gene hormone-sensitive lipase (LIPE). On d -21, compared with T cows, OC cows had lower mRNA abundance of LPL and DGAT2, and the latency of fatty acid response after glucose infusion was also longer (8.5 vs. 23.3 min) in OC cows. Cows with higher insulin area under the curve on d -21 had concurrently lower LPL and DGAT2 gene expression and greater concentration of fatty acids on d -7, d 7, and d 14. In conclusion, high adiposity prepartum lowers the whole-body lipid metabolism response to insulin and causes reduced expression of lipogenic genes in SAT 3 weeks before calving. In addition, more pronounced insulin release after glucose infusion on d -21 is related to higher lipid mobilization around calving, indicating an insulin-resistant state, and is associated with lower expression of lipogenic genes in SAT.

Characterization of metabolic and inflammatory profiles of transition dairy cows fed an energy-restricted diet

Periparturient diseases of dairy cows are caused by disproportionate energy metabolism, mineral imbalance, and perturbed immune function. The aim of the present study was to characterize metabolism, innate immune endometrial gene expression, and uterine microbial populations of transition animals receiving normal or restricted energy diets. Pregnant multiparous Holstein cows (n = 14) were randomly assigned to one of the two dietary treatments from 20 d prepartum until 35 d postpartum (DPP). One group was fed a diet providing 100% energy requirements (NE), whereas the other received an energy-restricted diet providing 80% energy requirements (RE). Feed intake, milk yield, body weight, body condition score, temperature, respiratory, and pulse rate were recorded. After calving, blood was collected weekly to analyze nonesterified fatty acids (NEFAs), β-hydroxybutyrate (BHB), and total cholesterol (TC). Endometrial cytobrushes were collected for gene expression analysis of inflammatory markers, microbial populations determination, and cytological evaluation. The restricted energy diet did not alter feed intake or milk yield but changed energy balance and metabolites levels (P < 0.05). In fact, RE animals had high NEFA and BHB levels, and low TC concentrations (P < 0.05). Moreover, RE animals had upregulated gene expression of serum amyloid A3 (SAA3) at 35 DPP (P < 0.05) and CXC chemokine receptor 2 (CXCR2) at 14 DPP (P < 0.01). Interleukin (IL) 1 and IL8 genes were downregulated 14 DPP but upregulated 35 DPP in RE animals, whereas IL6 and lipopolysaccharide-binding protein (LBP) genes were upregulated at 14 DPP (P ≤ 0.05). The most abundant phyla in RE animals (n = 3) were Bacteroidetes and Fusobacteria, whereas Proteobacteria was the least abundant at both 14 and 35 DPP. In conclusion, it can be speculated that energy balance is one of the main drivers for uterine inflammation by affecting metabolism, immune function, and uterine microbiota. However, these findings should be validated in a larger sample size.

Impact of the severity of negative energy balance on gene expression in the subcutaneous adipose tissue of periparturient primiparous Holstein dairy cows: Identification of potential novel metabolic signals for the reproductive system

The severity of negative energy balance (NEB) in high-producing dairy cows has a high incidence among health diseases. The cow’s energy status during early lactation critically affects metabolic and reproductive parameters. The first objective of this study was to investigate by RNA-seq analysis and RT-qPCR the gene expression profile in white adipose tissue and by gene ontology and upstream regulation tools the relationships with energy metabolism and reproduction in two groups of primiparous dairy cows with extreme NEB statuses (NEB < -9 Mcal/day vs. NEB > -9 Mcal/day) around parturition. The second objective was to determine the potential involvement of a new adipokine identified as a candidate for the regulation of ovarian function in our RNA-seq analysis by using bovine primary granulosa culture, thymidine incorporation to determine cell proliferation and ELISA assays to measure progesterone secretion. The RNA-seq analysis revealed that 514 genes were over-expressed and 695 were under-expressed in the adipose tissue of cows with severe NEB (SNEB) and cows with moderate NEB (MNEB) during the -4 and 16 wkpp period. In addition, 491 genes were over-expressed and 705 genes were under-expressed in the adipose tissue of SNEB cows compared to MNEB cows. Among these differently expressed genes (DEGs), 298 were related to metabolic functions and 264 to reproductive traits. A set of 19 DEGs were validated by RT-qPCR, including CCL21 (C-C motif chemokine ligand 21). Moreover, CCL21, a gene known to be secreted by adipose tissue, was chosen for further analysis in plasma and ovaries. The use of next-generation sequencing technologies allowed us to characterise the transcriptome of white adipose tissue from primiparous cows with different levels of NEB during lactation. This study highlighted the alteration of the expression of genes related to lipid metabolism, including CCL21, which is released in the bloodstream and associated with the in vitro regulation of ovarian functions.

Relationships between body condition, body condition loss, and serum metabolites during the transition period in primiparous and multiparous cows

In the transition period from late gestation to early lactation, dairy cows undergo tremendous metabolic changes. Insulin is a relevant antilipolytic factor. Decreasing serum concentrations of insulin and glucose, increasing serum concentrations of nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHB), and changes in body condition score (BCS) reflect the negative energy balance around calving. This study investigated peripartum metabolic adaptation in 359 primiparous and 235 multiparous German Holstein cows from a commercial dairy herd under field conditions. Body condition score was recorded and blood samples were taken 10 to 1 d prepartum, 2 to 4 d postpartum, and 12 to 20 d postpartum. Generalized mixed models and generalized estimation equations were applied to assess associations between prepartum BCS; BCS changes during the transition period; insulin, glucose, NEFA, and BHB serum concentrations; and milk yield, which was taken from an electronic milk meter from d 6 of lactation. Serum insulin concentrations of multiparous postpartum cows were lower compared with prepartum, and compared with primiparous cows. In general, primiparous cows had lower postpartum NEFA and BHB concentrations than multiparous cows. In primiparous cows, we identified a positive association between prepartum BCS and prepartum serum insulin concentration. Prepartum obese multiparous cows, but not primiparous cows, were characterized by higher postpartum serum NEFA and BHB concentrations and lower milk yield than other cows in the same parity class. Primiparous cows with a smaller degree of BCS loss during the transition period had higher postpartum insulin and lower NEFA concentrations and lower milk yield than other primiparous cows. In conclusion, primiparous cows had less lipolysis and lower milk yield than multiparous cows, associated with higher insulin concentrations. Avoiding high body condition loss during the transition period is a main factor in preventing peripartal metabolic imbalances of glucose and fat metabolism.

Relationship between insulin, glucose, non-esterified fatty acid and indices of insulin resistance in obese cows during the dry period and early lactation

The aim of this study was to determine to relationship between glucose, insulin, non-esterified fatty acid (NEFA) and indices of insulin resistance in the dry period (DP) and early lactation (EL). The importance of this study was in determining the relation between insulin sensitivity in DP and insulin resistance in EL. A total of 30 normally fed Holstein-Friesian cows with a high body condition score (> 3.75) were included in the study. Blood samples were collected in DP (weeks 5-7 ante partum) and EL (weeks 1-2 post partum). Cows in EL showed higher insulin resistance in comparison to DP due to a lower concentration of glucose and insulin, higher concentration of NEFA, lower value of revised quantitative insulin sensitivity check index and higher values of glucose:insulin and NEFA:insulin ratios (lower pancreas responsivnes to glucose and antilipolytic effect of insulin). Higher concentrations of insulin and glucose in the DP lead to a decrease in their concentrations and an increase in glucose:insulin and NEFA:insulin ratios in the EL. The revised quantitative insulin sensitivity check index in DP negatively correlates with the same index in EL, while positively correlating with the NEFA and NEFA:insulin ratio in EL. The EL revised quantitative insulin sensitivity check index value was influenced by dynamic changes (DP minus EL) in the insulin, NEFA, and glucose concentrations. The relationship between the indicators shows that higher insulin sensitivity in the DP increases resistance in EL in normally fed obese dairy cows.

Plasma metabolite changes in dairy cows during parturition identified using untargeted metabolomics

The metabolic responses of cows undergo substantial changes during the transition from late pregnancy to early lactation. However, the molecular mechanisms associated with these changes in physiological metabolism have not been clearly elucidated. The objective of this study was to investigate metabolic changes in transition cows from the perspective of plasma metabolites. Plasma samples collected from 24 multiparous dairy cows on approximately d 21 prepartum and immediately postpartum were analyzed using ultra-high-performance liquid chromatography/time-of-flight mass spectrometry in positive and negative ion modes. In conjunction with multidimensional statistical methods (principal component analysis and orthogonal partial least squares discriminant analysis), differences in plasma metabolites were identified using the t-test and fold change analysis. Sixty-seven differential metabolites were identified consisting of AA, lipids, saccharides, and nucleotides. The levels of 32 plasma metabolites were significantly higher and those of 35 metabolites significantly lower after parturition than on d 21 prepartum. Pathway analysis indicated that the metabolites that increased from late pregnancy to early lactation were primarily involved in lipid metabolism and energy metabolism, whereas decreased metabolites were related to AA metabolism.

Effect of reduced energy density of close-up diets on metabolites, lipolysis and gluconeogenesis in Holstein cows

Objective

An experiment was conducted to determine the effect of reduced energy density of close-up diets on metabolites, lipolysis and gluconeogenesis in cows during the transition period.

Methods

Thirty-nine Holstein dry cows were blocked and assigned randomly to three groups, fed a high energy density diet (HD, 1.62 Mcal of net energy for lactation [NE_L]/kg dry matter [DM]), a medium energy density diet (MD, 1.47 Mcal NE_L/kg DM), or a low energy density diet (LD, 1.30 Mcal NE_L/kg DM) prepartum; they were fed the same lactation diet to 28 days in milk (DIM). All the cows were housed in a free-stall barn and fed ad libitum.

Results

The reduced energy density diets decreased the blood insulin concentration and increased nonesterified fatty acids (NEFA) concentration in the prepartum period (p<0.05). They also increased the concentrations of glucose, insulin and glucagon, and decreased the concentrations of NEFA and β-hydroxybutyrate during the first 2 weeks of lactation (p<0.05). The plasma urea nitrogen concentration of both prepartum and postpartum was not affected by dietary energy density (p>0.05). The dietary energy density had no effect on mRNA abundance of insulin receptors, leptin and peroxisome proliferator-activated receptor-γ in adipose tissue, and phosphoenolpyruvate carboxykinase, carnitine palmitoyltransferase-1 and peroxisome proliferator-activated receptor-α in liver during the transition period (p>0.05). The HD cows had higher mRNA abundance of hormone-sensitive lipase at 3 DIM compared with the MD cows and LD cows (p = 0.001). The mRNA abundance of hepatic pyruvate carboxykinase at 3 DIM tended to be increased by the reduced energy density of the close-up diets (p = 0.08).

Conclusion

The reduced energy density diet prepartum was effective in controlling adipose tissue mobilization and improving the capacity of hepatic gluconeogenesis postpartum.