Effect of Maternal or Formulated Transition Milk on the Health and Performance of Dairy Calves

The study aimed to evaluate the effect of maternal or formulated transition milk with colostrum powder on the performance and health of dairy calves. After receiving 12% of their birth weight in high-quality colostrum, 36 Holstein calves (17 males and 19 females) were blocked according to sex, birth date and birth weight (29.16 kg ± 1.34) and randomly distributed into three treatments: (1) Milk: supplying 4 L/d of whole milk (WM) for three days (n = 12); (2) Transition milk (TM): supplying 4 L/d of maternal transition milk for three days (n = 12); (3) Formulated transition milk (FTM): supplying 4 L/d of whole milk enriched with 280 g/d of colostrum powder, for three days (n = 12). Daily feeding was split into two feedings, and after the sixth feeding of the transition diet calves were fed 6 L/d of whole milk and had ad libitum access to water and calf starter until 56 d, when the study ended. Calves fed TM or FTM presented a higher total solids intake (p < 0.05). Concentrations of glucose (p = 0.096) and lactate (p = 0.063), evaluated from 0 h to 72 h, tended to be higher in WM-fed calves compared to TM. There were no effects on calf's health or performance and weight; at the week 8 averaged 65.06 kg ± 1.85. All treatments resulted in adequate performance and good health, however, the potential benefits of providing TM or FTM were not seen in this study. The transition milk composition and the number of meals after colostrum feeding need more investigation.

The effects of maternal supplementation of rumen-protected lysine during the close-up dry period on newborn metabolism and growth in Holstein calves

This study aimed to evaluate the effects of rumen-protected lysine (RPL) supplementation during the close-up period on blood metabolites and calf growth. Forty multiparous Holstein dams were selected based on parity, body condition score, and expected calving date, and randomly assigned to a group: with RPL (n = 22) or without (control [CON], n = 18). RPL dams were supplied daily with 80 g of RPL from Day 21 before the expected calving date to parturition. Blood samples were obtained from the dams before the start of supplementation, 1 week before calving, and immediately after calving, and from calves immediately after birth and weekly until 8 weeks of age. Body weight measurements were performed immediately after birth in all calves and at weekly intervals until 8 weeks of age in female calves. No significant difference was observed in serum metabolite levels and plasma amino acid concentrations between the RPL and CON dams before supplementation, whereas plasma lysine concentrations tended to be higher in RPL dams immediately after calving (p = 0.07). Serum total protein levels (p < 0.05) were higher, whereas plasma total amino acid, total essential amino acid, total non-essential amino acid, and other amino acid concentrations were lower in the calves of RPL dams than those of CON dams (p < 0.05). There were no significant differences in calf birth weight between the two groups, although female calves of RPL dams (n = 7) had higher serum total protein (p < 0.05) and tended to have greater body weight (p = 0.09) from 1 to 8 weeks of age than those of CON dams (n = 11). Overall, RPL supplementation during the close-up period may increase placenta-mediated amino acid transfer to the foetus and enhance protein synthesis in the calf, leading to improved weight gain during the suckling period.

Regulatory role of phosphoproteins in the development of bovine small intestine during early life

The small intestine is the primary site of nutrient digestion and absorption, which plays a key role in the survival of neonatal calves. A comprehensive assessment of the phosphoproteomic changes in the small intestine of neonatal calves is unavailable; therefore, we used phosphopeptide enrichment coupled with liquid chromatography-tandem mass spectrometry to investigate the changes in the phosphoproteome profile in the bovine small intestine during the first 36 h of life. Twelve neonatal male calves were assigned to one of the following groups: (1) calves not fed colostrum and slaughtered approximately 2 h postpartum (n = 3), (2) calves fed colostrum at 1 to 2 h and slaughtered 8 h postpartum (n = 3), (3) calves fed 2 colostrum meals (at 1-2 and 10-12 h) and slaughtered 24 h postpartum (n = 3), (4) calves fed 3 colostrum meals (at 1-2, 10-12, and 22-24 h) and slaughtered 36 h postpartum (n = 3). Mid-duodenal, jejunal, and ileal samples of the calves were collected after slaughter. We identified 1,678 phosphoproteins with approximately 3,080 phosphosites, which were mainly Ser (89.9%), Thr (9.8%), and Tyr (0.3%) residues; they belonged to the prodirected (52.9%), basic (20.4%), acidic (16.6%), and Tyr-directed (1.7%) motif categories. The regional differentially expressed phosphoproteins included zonula occludens 2, sorting nexin 12, and protein kinase C, which are mainly associated with developmental processes, intracellular transport, vesicle-mediated transport, and immune system process. They are enriched in the endocytosis, tight junction, insulin signaling, and focal adhesion pathways. The temporal differentially expressed phosphoproteins included occludin, epsin 1, and bridging integrator 1, which were mainly associated with macromolecule metabolic process, cell adhesion, and growth. They were enriched in the spliceosomes, adherens junctions, and tight junctions. The observed changes in the phosphoproteins in the tissues of small intestine suggest the protein phosphorylation plays an important role in nutrient transport and immune response of calves during early life, which needs to be confirmed in a larger study.

Quantitative comparative phosphoproteomic analysis of the effects of colostrum and milk feeding on liver tissue of neonatal calves

Posttranslational modifications, mostly phosphorylation, are critical for protein structure and function. However, the association between liver phosphoproteins in neonatal calves and colostrum intake is not well understood. In this study, we examined the liver phosphoproteome profile in neonatal calves after receiving colostrum or milk. Liver tissue samples were collected from control calves (CON, n = 3) 2 h after birth and from calves that received colostrum (CG, n = 3) or milk (MG, n = 3) 24 h after birth. Hepatic phosphoprotein expression profiles were analyzed using quantitative proteomics based on the liquid chromatography-tandem mass spectrometry method. In total, 1,587 phosphorylated sites were identified in 1,011 liver proteins. The most abundant phosphorylation site AA was serine (87.5%), followed by threonine (11.9%) and tyrosine (0.5%). Among the 1,011 phosphoproteins, 219, 453, and 26 displayed differential expression in the CG versus MG, CG versus CON, and MG versus CON comparisons, respectively. Differentially expressed phosphoproteins in the CG-MG comparison included 3-phosphoinositide-dependent protein kinase 1, glucose transporter member 4, protein kinase N2, and vinculin, which were mainly involved in the glycogen metabolic process, transport, growth and development, and cell adhesion process, according to Gene Ontology analysis. Pathway analysis indicated their enrichment in the insulin signaling pathway, spliceosome, and adherens junction. The CG-CON comparison identified differentially expressed phosphoproteins and their target genes that were largely involved in the cellular process, macromolecule metabolic process, developmental process, and transport. Pathway analysis indicated their association with endocytosis, mechanistic target of rapamycin, AMP-activated protein kinase, and insulin signaling pathways. These data demonstrate that changes in the phosphoproteins of liver tissues may play an important role in energy metabolism and immune response in the calves that received colostrum. These results provide novel insights into the crucial roles of protein phosphorylation during the early life of newborn calves.

Short communication: Effect of delaying the first colostrum feeding on small intestinal histomorphology and serum insulin-like growth factor-1 concentrations in neonatal male Holstein calves

The primary objective of this study was to determine the effect of delaying the first colostrum feeding on small intestinal histomorphology and serum insulin-like growth factor-1 (IGF-1) concentrations, and the secondary objective was to characterize the ultrastructure of the small intestine of neonatal calves at 51 h of life. Twenty-seven male Holstein calves were fed pooled, pasteurized colostrum (7.5% of birth body weight; 62 g of IgG/L) at 45 min (0H, n = 9), 6 h (6H, n = 9), or 12 h (12H, n = 9) after birth. At 12 h after their respective colostrum feeding, calves were fed milk replacer at 2.5% of birth body weight per meal and every 6 h thereafter. Blood samples were collected every 6 h using a jugular catheter and analyzed for serum IGF-1 concentrations using an automated solid-phase chemiluminescent immunoassay. At 51 h of life, calves were euthanized to facilitate collection of the duodenum, proximal and distal jejunum, and ileum. All segments of the small intestine were assessed for histomorphology, whereas scanning electron and transmission electron microscopy analyses were conducted only for the proximal jejunum and ileum. The results revealed that there was no overall effect of colostrum feeding time on serum IGF-1 concentrations; however, serum IGF-1 concentrations were influenced by time. Specifically, concentrations of serum IGF-1 at 48 h were 29% greater than concentrations at 0 h of life (312.8 ± 14.85 vs. 241.9 ± 14.06 ng/mL). Although there was no overall effect of colostrum feeding time on all histomorphological measures assessed, treatment × segment interactions were observed. Villi height was 1.4 times greater in the distal jejunum of 0H calves than in 6H and 12H calves, and 0H calves tended to have 1.2 times greater ileal villus height than 12H calves. In addition, 0H calves had 1.2 and 1.3 times greater ileal crypt depth than 6H and 12H calves, respectively, and 1.3 times greater surface area index than 12H calves in the distal jejunum. Qualitative ultrastructural evaluation of small intestinal enterocytes conducted irrespective of colostrum treatment revealed the presence of large vacuoles of electron-dense material, apical mitochondria, and apical canalicular systems in the jejunum and ileum. These results indicate that the calf intestine at 51 h of life contains unique enterocyte characteristics similar to fetal enterocytes and that delaying colostrum feeding may negatively influence intestinal growth and development.

Alterations of the circular RNA profile in the jejunum of neonatal calves in response to colostrum and milk feeding

Circular RNA (circRNA) have been suggested to contribute to regulating gene expression in various tissues and cells of eukaryotes. However, little is known regarding the expression pattern of circRNA and their potential function in the small intestine of neonatal calves that receive colostrum. In the current study, jejunum tissue samples were collected from control calves (2 h after birth; CT; n = 3) and neonatal calves that ingested colostrum (24 h after birth; CO; n = 3) or milk (24 h after birth; MK; n = 3) to compare the circRNA expression patterns using a high-throughput RNA sequencing approach. A total of 21,213, 17,861, and 21,737 circRNA were identified in the CT, CO, and MK groups, respectively. Only 13,254 of these circRNA were common to the 3 groups, suggesting high specificity of circRNA expression depending on nutrient type. In total, 243, 249, and 283 circRNA were differentially expressed in the CO versus CT, CO versus MK, and MK versus CT comparisons, respectively. Gene ontology analysis showed that the differentially expressed circRNA and their predicted or known target genes from the CO and MK groups were mainly involved in macromolecule metabolic process, response to stress, and vesicle-mediated transport. Moreover, pathway analysis showed that the Rap1 signaling pathway, focal adhesion, ubiquitin-mediated proteolysis, and extracellular matrix-receptor interaction were the most significantly enriched pathways. These data collectively indicate that circRNA are abundant and dynamically expressed when calves receive colostrum and act as microRNA sponges to regulate their target genes for jejunum function during the early development of newborn calves.

Short communication: Manipulation of neonatal leptin profile via exogenous glucocorticoids in beef calves

The link between circulating glucocorticoids and leptin in beef calves has not been explored but has been noted in several studies. The aim of this study is to determine the effects of exogenous glucocorticoids given at birth and 1 day of age on serum leptin concentrations in beef calves. Ruminant animals secrete leptin, which is thought to be important for the programming of the hypothalamic appetite centers. Angus crossbred cows (n = 31) bred via natural service were utilized for this experiment. At parturition (day 0), calf BW was recorded and each calf was infused intravenously with either a hydrocortisol sodium succinate solution (HC, 8 males and 8 females) at a dosage of 3.5 μg/kg of BW or a similar volume of saline solution (CONT, 7 males and 8 females). Each calf was given a second infusion of its respective treatment 24 h postpartum at 1.5 μg/kg of BW for HC treatment. Calf treatment was blocked by sex, dam body condition score (BCS), and dam age. Blood samples were taken via jugular venipuncture before infusion, daily from days 0 to 5, then every other day up to day 17. Serum leptin and cortisol concentrations were analyzed via radioimmunoassay. Dam age, dam BCS, calf BW, and serum leptin and cortisol concentrations were analyzed using MIXED procedure of SAS. Dam age was not different (P = 0.81) among HC and CONT calves (4.9±0.5 and 4.7±0.5, respectively). Dam BCS was not different between treatments (5.7±0.2 and 5.6±0.2 HC and CONT, respectively; P = 0.66). There was no difference in calf birth BW between treatments (P = 0.87) and averaged 38.3±1.4 kg. Cortisol concentrations were not different between both treatments (P = 0.23) from birth to day 4 of age. Calves that received the HC treatment showed significantly reduced (P = 0.03) leptin concentrations on days 1 to 13. Calf BW from 60 to 150 days of age was not different between CONT and HC treated calves (P = 0.65). These data indicate that exogenous glucocorticoids can be used to suppress neonatal leptin levels in calves. This could lead to changes in voluntary feed intake of treated calves.

The effect of colostrum intake on osteoprotegerin and bone metabolic markers in the blood of newborn calves during the first week of life

The aim of this study was to elucidate the bone metabolic status after taking colostrum in newborn calves. Fourteen neonatal calves were randomly allocated to two groups fed either unheated or heated (60°C, 30 min) colostrum three times on the first day (2 l every 10 hr; 6 l in total). Heat treatment on colostrum was to reduce the bone metabolic markers assumed as heat-sensitive. The concentrations of four bone metabolic markers (the enzymes from bone cells or the bone collagen fragments) and a bone protective protein, osteoprotegerin (OPG), were measured in the blood of calves during a week after the birth and in the colostrum. The colostral concentrations of four bone metabolic markers were reduced by heating. Then those circulatory markers peaked after colostrum intake in the calves fed unheated colostrum; whereas those fed heated colostrum did not show such changes. However, the plasma tartrate resistant acid phosphatase 5b (TRAP5b) activity was transiently increased after taking colostrum in both groups. Meanwhile, heating did not decrease colostral OPG and there was no significant rise in the serum OPG concentrations after the first colostrum intake in both groups. The study revealed that the blood concentrations of studied bone metabolic markers depended on those colostral values except for TRAP5b. Based on the plasma TRAP5b changes, accelerated formation of premature osteoclast cells may be induced by colostrum intake. Meanwhile, colostral OPG absorption is less likely to impact on its circulating levels.

The rapid increase of circulating adiponectin in neonatal calves depends on colostrum intake

Adiponectin, an adipokine, regulates metabolism and insulin sensitivity. Considering that the transplacental transfer of maternal proteins of high molecular weight is hindered in ruminants, this study tested the hypothesis that the blood concentration of adiponectin in neonatal calves largely reflects their endogenous synthesis whereby the intake of colostrum might modify the circulating concentrations. We thus characterized the adiponectin concentrations in neonatal and young calves that were fed either colostrum or formula. Three trials were performed: in trial 1, 20 calves were all fed colostrum for 3 d, and then formula until weaning. Blood samples were collected on d 0 (before colostrum feeding), and on d 1, 3, 11, 22, 34, 43, 52, 70, 90, and 108 postnatum. In trial 2, 14 calves were studied for the first 4 d of life. They were fed colostrum (n=7) or formula (n=7), and blood samples were taken right after birth and before each morning feeding on d 2, 3, and 4. In trial 3, calves born preterm (n=7) or at term received colostrum only at 24 h postnatum. Blood was sampled at birth, and before and 2 h after feeding. Additionally, allantoic fluid and blood from 4 Holstein cows undergoing cesarean section were sampled. Adiponectin was quantified by ELISA. In trial 1, the serum adiponectin concentrations recorded on d 3 were 4.7-fold higher than before colostrum intake. The distribution of the molecular weight forms of adiponectin differed before and after colostrum consumption. In trial 2, the colostrum group had consistently greater plasma adiponectin concentrations than the formula group after the first meal. In trial 3, the preterm calves tended to have lower concentrations of plasma adiponectin than the term calves at birth and before and 2 h after feeding. Furthermore, the adiponectin concentrations were substantially lower in allantoic fluid than in the sera from neonatal calves and from cows at parturition. Our results show that calves are born with very low blood concentrations of adiponectin and placental transfer of adiponectin to the bovine fetus is unlikely. In conclusion, colostrum intake is essential for the postnatal increase of circulating adiponectin in newborn calves.