Plasma concentrations of branched-chain amino acids differ with Holstein genetic strain in pasture-based dairy systems.

In pasture-based systems, there are nutritional and climatic challenges exacerbated across lactation; thus, dairy cows require an enhanced adaptive capacity compared with cows in confined systems. We aimed to evaluate the effect of lactation stage (21 vs. 180 days in milk, DIM) and Holstein genetic strain (North American Holstein, NAH, n = 8; New Zealand Holstein, NZH, n = 8) on metabolic adaptations of grazing dairy cows through plasma metabolomic profiling and its association with classical metabolites. Although 67 metabolites were affected (FDR < 0.05) by DIM, no metabolite was observed to differ between genetic strains while only alanine was affected (FDR = 0.02) by the interaction between genetic strain and DIM. However, complementary tools for time-series analysis (ASCA analysis, MEBA ranking) indicated that alanine and the branched-chain amino acids (BCAA) differed between genetic strains in a lactation-stage dependent manner. Indeed, NZH cows had lower (P-Tukey < 0.05) plasma concentrations of leucine, isoleucine and valine than NAH cows at 21 DIM, probably signaling for greater insulin sensitivity. Metabolic pathway analysis also revealed that, independently of genetic strains, AA metabolism might be structurally involved in homeorhetic changes as 40% (19/46) of metabolic pathways differentially expressed (FDR < 0.05) between 21 and 180 DIM belonged to AA metabolism.

Low serum vitamin D concentrations in Spring-born dairy calves are associated with elevated peripheral leukocytes.

A role for vitamin D in the immune system is emerging from human research but data in the bovine is limited. In the current study, 48 Holstein-Friesian calves were randomly assigned to one of 4 groups designed to expose calves to divergent vitamin D levels for a 7 month period and to determine its effects on circulating immunity in young calves. Concentrations of circulating 25-hydroxyvitamin D (25OHD) was measured in serum using a commercial ELISA with validated bovine standards. Results showed that mean circulating concentrations of 25OHD at birth was 7.64 ± 3.21 ng/ml indicating vitamin D deficiency. Neither the injection of Vit D3 at birth nor the elevated levels in milk replacer yield discernible changes to pre-weaning circulating concentration of 25OHD. No calf reached the recommended level of vitamin D immune sufficiencyof 30 ng/ml of 25OHD until at least 3 months of age (T4). Increasing dietary Vit D3 via ration in the post-weaning period significantly elevated 25OHD concentrations in serum in VitD-In calves. Maximal levels of circulating 25OHD were achieved in VitD-Out calves, reaching 60.86 ± 7.32 ng/ml at 5 months of age (T7). Greatest divergence in haematology profile was observed between Ctl-In vs VitD-In groups with Ctl-In calves showing an elevated count of neutrophils, eosinophils, and basophils associated with reduced 25OHD concentrations. Neither IL-8 expression nor ROS production in serum were significantly different between calves with high and low 25OHD, indicating that other vitamin D-dependent mechanisms may contribute to the divergent circulating cellular profiles observed. This novel data on the vitamin D status of neonatal calves identifies a significant window of vitamin D insufficiency which is associated with significant differences in circulating immune cell profiles. Vitamin D insufficiency may therefore exacerbate pre-weaning disease susceptibility, and further work in now warranted.

Postpartum nutrition affects the insulin-like growth factor system in dominant follicles and plasma of anestrous beef cows.

Effects of nutrition on insulin-like growth factor-I (IGF-I), IGF binding proteins (IGFBP), and insulin in plasma and dominant follicles were evaluated at day 72 and 56 (Exp. 1, n = 12 and Exp. 2, n = 28, respectively) postpartum in anovulatory primiparous beef cows. Cows were stratified based on body condition score at calving and randomly assigned to nutritional treatments: maintain (M), 2.27 kg of a 40 % CP supplement per day and ad libitum hay; or gain (G), ad libitum access to a 50 % concentrate diet and ad libitum hay. Blood samples were collected twice weekly starting 30 days postpartum. Ovarian follicles were evaluated using ultrasonography commencing 42 (Exp. 1) or 30 (Exp. 2) days postpartum. Body weight and condition score were greater (P < 0.05) for cows of G than M groups and postpartum interval to luteal function was longer for cows of the M than G group. Insulin and IGF-I concentrations in follicular fluid (FF) and plasma were greater (P < 0.05) for cows of the G than M group at follicular aspiration. Plasma and FF IGFBP4 and IGFBP5 concentrations were greater (P <  0.05) in Exp. 2, and IGFBP5 was greater in Exp. 1 for cows of the G than M group. Treatment did not affect FF steroid concentrations or granulosal cell CYP19A1, PAPPA, IGFBP4, and IGFBP5 mRNA abundance. These results indicate concentrations of IGF-I, insulin, IGFBP4, and IGFBP5 in FF and plasma are affected by nutritional intake and may be related to follicular function.

Ratio of selenium concentrations between soil, forage plants and blood serum of beef cattle studied in organic and conventional farms.

The aim of the study was to compare the selenium (Se) status of beef cattle from conventional farms with the status of cattle from organic farms located in western Pomerania and to determine the ratios of Se concentration between soil, forage plants and animals at these locations. The mean total Se (SeT) content in soil was 0.208 mg/kg dry matter (DM) on organic farms and 0.254 mg/kg DM on conventional farms. Animals from conventional farms had significantly (p < 0.05) higher serum Se concentration than those on organic farms. As Se deficiency were classified in 75% of animals from organic farms and in 42% animals from conventional farms. A lack of Se supplementation is associated with a serious risk of deficiency in ruminants, particularly in areas with low Se levels in the soil-plant system. Therefore, more attention should be devoted to increasing the bioavailability of Se for plants by enhancing the physicochemical properties of soil. In addition, the composition of swards for grazing should be adjusted to increase the share of forage plants capable of collecting larger amounts of Se from soil.

Effect of antepartum vitamin D3 (cholecalciferol) and postpartum oral calcium administration on serum total calcium concentration in Holstein cows fed an acidogenic diet in late gestation.

Several strategies are available to control periparturient hypocalcaemia in dairy cows. Three complementary strategies were applied in this study: feeding a low DCAD (acidogenic) ration during late gestation, oral vitamin D3 (cholecalciferol) administration in late gestation, and oral Ca administration immediately after parturition. Multiparous Holstein cows (n = 240) were fed an acidogenic ration in late gestation and randomly assigned to one of three treatment groups. Group A (n = 80) were fed the acidogenic diet without supplementary Ca or cholecalciferol. Group Ca + A (n = 80) received 50 g of Ca as an oral bolus at calving and 12 h later. Group D3 + Ca + A (n = 80) were administered 3 mg of cholecalciferol orally each day starting 3 to 5 days before the anticipated calving date and 50 g of Ca as an oral bolus at calving and 12 h later. Blood and urine samples were obtained periodically from a random subset of 20 cows in each group from day 5 antepartum to day 21 postpartum and selected analytes measured. Data was analyzed using mixed models analysis. Serum Ca concentrations in group D3 + Ca + A were higher 12 h before and at parturition, compared to the two other groups. Oral Ca administration transiently increased mean serum Ca concentrations at 6 h after treatment initiation in groups D3 + Ca + A and Ca + A. We conclude that daily oral administration of 3 mg of cholecalciferol for up to 5 days before calving, combined with feeding an acidogenic ration in late gestation and oral Ca immediately after parturition, provided the highest periparturient serum Ca concentrations.

Effect of feeding Bacillus subtilis on rumen fermentation, blood metabolites, nutrient digestibility, and energy and nitrogen balances in non-lactating crossbred cows.

The purpose of this study was to investigate the effects of feeding Bacillus subtilis on rumen fermentation, blood metabolites, nutrient digestibility, and energy and nitrogen balances in non-lactating crossbred (Holstein-Friesian × Bos indicus) cows. Four cows were assigned to the control and B. subtilis diets in a crossover design, and respiratory and metabolic experiments were conducted. For the B. subtilis diet, B. subtilis DSM15544 spores were added at the rate of 1.0 × 1010  CFU/head/day to the control diet. At 4 hr after feeding, cows fed the B. subtilis diet had increased levels of i-butyric acid in the rumen fluid and tended to have lower concentrations of plasma non-esterified fatty acids when compared with cows fed the control diet. This suggests that feeding B. subtilis could improve energy efficiency. However, there was no effect on energy retention in this study. Although there were no effects on nutrient digestibility, nitrogen balance, or methane production, heat production was significantly higher in cows fed the B. subtilis diet than in those fed the control diet.

Supplementation of overripe pulp extract and green peel extract or powder of banana fruit peel (musa. cavendish) to diets of neonatal dairy calves: Effects on haematological, immunological and performance characteristics.

The present study investigated the effects of overripe pulp and green peel extract and powder of banana fruit (Musa. cavendish) on haematological, biochemical, immunological, health, and performance of Holstein dairy calves. In all, 40 newborn calves were randomly divided into four groups of 10 animals. In the control group, animals received no banana meal. In group 1, calves were supplemented with 2 g (dry matter)/kg body weight/day of overripe banana pulp extract. The calves in group 2 were supplemented with 1 g (dry matter) of overripe banana pulp extract/kg body weight/day and 1 g (dry matter) of green banana peel extract/kg body weight/day. The animals in group 3 were supplemented with 2 g/kg body weight/day of green banana peel powder. The feeding period of calves on the tested supplements was 5 days. Blood samples and other evaluations were taken on day 0 (at birth, before supplementation) and on days 7, 15 and 30. Just a trend towards better average daily weight gain was seen in groups 2 and 3 than others (p = 0.073). Significant group and sampling time interactions were seen for the quantities of RBC (group 1 was lower than other groups at day 30), MCV (group 3 was lower than other groups at day 30) and MCH (group 1 was higher than other groups at day 30) (p < 0.05). A trend towards significance in values of IgG (group 1 was lower than other groups at days 15 and 30) and bilirubin (higher values at day 7 in groups 1 and 2 than control, higher amounts at days 15 and 30 in groups 3 and 2 than control, respectively) was also observed. In conclusion, banana supplementation in neonatal calves had beneficial effects on the values of RBC, MCV, MCH, bilirubin, IgG and average daily weight gain in dairy calves.

Short communication: Effects of dietary deoiled soy lecithin supplementation on circulating choline and choline metabolites, and the plasma phospholipid profile in Holstein cows fed palm fat.

Dietary lecithin is a source of choline. Our objective was to evaluate the effects of dietary deoiled soy lecithin feeding on circulating choline, choline metabolites, and the plasma phospholipid profile in lactating dairy cows fed fractionated palm fatty acids. In a split-plot Latin square design, 16 Holstein cows (160 ± 7 d in milk; 3.6 ± 1.2 parity) were randomly allocated to a main plot receiving a corn silage and alfalfa haylage-based diet with palm fat containing either moderate or high palmitic acid content at 1.75% of ration dry matter (moderate and high palmitic acid containing 72 or 99% palmitic acid in fat supplement, respectively; n = 8/palm fat diet). Within each palm fat group, deoiled soy lecithin was top-dressed at 0, 0.12, 0.24, or 0.36% of ration dry matter in a replicated 4 × 4 Latin square design with 14-d experimental periods. A 14-d covariate period was used to acclimate cows to palm fat feeding without lecithin supplementation. Blood sampling occurred during the final 3 d of each experimental period. Plasma choline and choline metabolites were quantified using liquid chromatography and mass spectrometry. Plasma phospholipids were profiled using time-of-flight mass spectrometry. Whereas no effects of treatments were detected for plasma choline or methionine, lecithin feeding increased the plasma concentrations of choline metabolites trimethylamine N-oxide and dimethylglycine (24 and 11%, respectively). Plasma phosphatidylcholine (PC) and sphingomyelin (SM) concentrations increased with deoiled lecithin feeding (e.g., PC 16:0/22:6 and SM d18:1/18:3). Lecithin supplementation also increased plasma lysophosphatidylcholine (LPC) concentrations (e.g., LPC 18:0) while reducing plasma phosphatidylethanolamine (PE) concentrations (e.g., PE 16:0/20:5). Although increases in microbial-derived trimethylamine N-oxide suggest gastrointestinal lecithin degradation, elevations in plasma dimethylglycine, PC, LPC, and SM suggest that choline availability was improved by lecithin feeding in cows, thus supporting enhanced endogenous phospholipid synthesis.

Determinants of vitamin D status in Kenyan calves.

Vitamin D plays a critical role in calcium homeostasis and in the maintenance and development of skeletal health. Vitamin D status has increasingly been linked to non-skeletal health outcomes such as all-cause mortality, infectious diseases and reproductive outcomes in both humans and veterinary species. We have previously demonstrated a relationship between vitamin D status, assessed by the measurement of serum concentrations of the major vitamin D metabolite 25 hydroxyvitamin D (25(OH)D), and a wide range of non-skeletal health outcomes in companion and wild animals. The aims of this study were to define the host and environmental factors associated with vitamin D status in a cohort of 527 calves from Western Kenya which were part of the Infectious Disease of East African Livestock (IDEAL) cohort. A secondary aim was to explore the relationship between serum 25(OH)D concentrations measured in 7-day old calves and subsequent health outcomes over the following 12 months. A genome wide association study demonstrated that both dietary and endogenously produced vitamin D metabolites were under polygenic control in African calves. In addition, we found that neonatal vitamin D status was not predictive of the subsequent development of an infectious disease event or mortality over the 12 month follow up period.

Feeding colostrum or a 1:1 colostrum:whole milk mixture for 3 days after birth increases serum immunoglobulin G and apparent immunoglobulin G persistency in Holstein bulls.

Conflicting reports exist on whether prolonged IgG consumption can further increase serum IgG in neonatal calves. Given that higher serum IgG in neonates has lifelong benefits, our objective was to determine whether serum IgG can be increased by providing multiple meals containing IgG to neonatal calves. Twenty-seven Holstein bulls were all fed 1 colostrum meal (7.5% body weight; 62 g of IgG/L) at 2 h after birth and randomly assigned to be fed (5% body weight) colostrum (COL; n = 9), whole milk (WM; n = 9), or a 1:1 colostrum:whole milk mixture (MX; n = 9) every 12 h from 12 to 72 h. Serum IgG was measured at 1, 2, 3, 6, 9, 11, and 12 h after birth. After the 12-h meal, IgG was determined at 0.5-h intervals until 16 h and then at 1-h intervals from 16 to 24 h. Serum IgG was then measured at 27 h, then every 6 h from 30 to 60 h. From 60 to 64 h, IgG was measured every 0.5 h, then at 65 and 66 h, and then every 2 h until 72 h. Serum IgG increased rapidly between 2 and 12 h for all calves. A treatment × time interaction occurred as serum IgG began to diverge between treatments after they were fed at 12 h; the interaction was greatest over the entire period for COL compared with both MX and WM and was greater for MX than for WM. Maximum IgG concentrations (Cmax) were 30.4 ± 0.8, 27.2 ± 0.8, and 23.9 ± 0.8 g/L for COL, MX, and WM, respectively. Although MX Cmax was equivalent to both COL and WM Cmax, COL Cmax was greater than WM Cmax. Feeding COL and MX also prolonged the time to reach Cmax. Respectively, these calves achieved Cmax at 29.5 and 27.0 ± 3.4 h, whereas WM IgG peaked at 13.4 ± 3.4 h. No differences were observed for apparent efficiency of absorption between treatments from 0 to 12 h and 0 to 24 h. Immunoglobulin G area under the curve (AUC) was the same for COL and MX calves over the entire experimental period and from when treatments were fed. The IgG AUC for 0 to 72 h for WM calves was 27.4% lesser than that for COL calves but not different from MX calves. However, the IgG AUC for 12 to 72 h for WM calves differed relative to that for both COL (30.8% less) and MX (19.6% less) calves. Serum IgG concentrations were more persistent when COL (88.2 ± 2.4%) and MX (91.2 ± 2.4%) were fed rather than WM (75.3 ± 2.4%). Prolonged IgG consumption increased serum IgG concentrations, corresponding to the mass of IgG fed, and improved apparent IgG persistency in Holstein bulls. Neonatal calves should be fed at least 62 g of IgG at 12 h after birth to further increase serum IgG concentrations.

Effect of continued metabolic acidification into the first 3 days of lactation on blood calcium status in postpartum dairy cattle: A randomized controlled trial.

Although incidence of clinical hypocalcemia in postpartum dairy cows is low in US dairies, subclinical hypocalcemia after calving is common and has been associated with metabolic and infectious disease. It is widespread farm practice to feed a diet rich in anions to prepartum dairy cattle to support calcium homeostasis. However, this diet is typically discontinued at parturition, when calcium needs are still high. The objective of this trial was to determine the effects of extending metabolic acidification into the first 3 d of lactation in multiparous Holstein cows with the use of magnesium chloride (MgCl2) hexahydrate drenches on blood ionized calcium concentrations. Adult Holstein cows at a commercial dairy in their second or higher lactation, with a urine pH of 6.8 or less on the day of calving, were randomly assigned to either treatment or control groups, resulting in 13 cows in the treatment group and 14 cows in the control group. Treatment cows received 480 g of oral MgCl2 hexahydrate once daily for 3 d for continued acidification starting on the day of calving, whereas cows in the control group received no treatment. Urine pH was measured daily for 5 d, starting on the day of calving (0 DIM), to assess acidification status; blood was collected on day of calving (0 DIM), 2 DIM, and 4 DIM and analyzed for ionized calcium concentrations. Differences in blood ionized calcium and urine pH over time were compared using longitudinal data analysis. Urine pH was lower in treatment cows compared with control cows at 1, 2, and 3 DIM. Blood ionized calcium concentrations were different from baseline, taken at enrollment (0 DIM) and at 2 and 4 DIM in both treatment and control cows. However, no difference was detectable between treatment and control cows at 2 or 4 DIM with respect to blood ionized calcium concentrations. Oral supplementation with MgCl2 hexahydrate resulted in the desired acidification of urine pH in the treatment group, similar to feeding of an anionic close-up diet. Continued acidification of dairy cows until 2 DIM did not result in clinically meaningful higher blood calcium concentrations compared with controls, and further research is needed, to identify physiological reasons for this finding.

Changes in fatty acids in plasma and association with the inflammatory response in dairy cows abomasally infused with essential fatty acids and conjugated linoleic acid during late and early lactation.

Dairy cows are exposed to increased inflammatory processes in the transition period from late pregnancy to early lactation. Essential fatty acids (EFA) and conjugated linoleic acid (CLA) are thought to modulate the inflammatory response in dairy cows. The present study investigated the effects of a combined EFA and CLA infusion on the fatty acid (FA) status in plasma lipids, and whether changes in the FA pattern were associated with the acute phase and inflammatory response during late pregnancy and early lactation. Rumen-cannulated Holstein cows (n = 40) were assigned from wk 9 antepartum to wk 9 postpartum to 1 of 4 treatment groups. Cows were abomasally supplemented with coconut oil (CTRL, 76 g/d), linseed and safflower oil (EFA, 78 g/d of linseed oil and 4 g/d of safflower oil; ratio of oils = 19.5:1; n-6:n-3 FA ratio = 1:3), Lutalin (CLA, 38 g/d; isomers cis-9,trans-11 and trans-10,cis-12; each 10 g/d), or both (EFA+CLA). Blood samples were taken to measure changes in FA in blood plasma on d -63, -42, 1, 28, and 56, and in plasma lipid fractions (cholesterol esters, free fatty acids, phospholipids, and triglycerides) on d -42, 1, and 56 relative to calving, and in erythrocyte membrane (EM) on d 56 after calving. Traits related to the acute phase response and inflammation were measured in blood throughout the study. Liver samples were obtained for biopsy on d -63, -21, 1, 28, and 63 relative to calving to measure the mRNA abundance of genes related to the inflammatory response. The concentrations of α-linolenic acid and n-3 FA metabolites increased in lipid fractions (especially phospholipids) and EM due to EFA supplementation with higher α-linolenic acid but lower n-3 metabolite concentrations in EFA+CLA than in EFA treatment only. Concentration of linoleic acid decreased in plasma fat toward calving and increased during early lactation in all groups. Concentration of plasma arachidonic acid was lower in EFA- than in non-EFA-treated groups in lipid fractions and EM. The cis-9,trans-11 CLA increased in all lipid fractions and EM after both CLA treatments. Plasma haptoglobin was lowered by EFA treatment before calving. Plasma bilirubin was lower in EFA and CLA than in CTRL at calving. Plasma concentration of IL-1ß was higher in EFA than in CTRL and EFA+CLA at certain time points before and after calving. Plasma fibrinogen dropped faster in CLA than in EFA and EFA+CLA on d 14 postpartum. Plasma paraoxonase tended to be elevated by EFA treatment, and was higher in EFA+CLA than in CTRL on d 49. Hepatic mRNA abundance revealed time changes but no treatment effects with respect to the inflammatory response. Our data confirmed the enrichment of n-3 FA in EM by EFA treatment and the inhibition of n-3 FA desaturation by CLA treatment. The elevated n-3 FA status and reduced n-6:n-3 ratio by EFA treatment indicated a more distinct effect on the inflammatory response during the transition period than the single CLA treatment, and the combined EFA+CLA treatment caused minor additional changes on the anti-inflammatory response.

Effects of rumen-protected methionine or methionine analogs in starter on plasma metabolites, growth, and efficiency of Holstein calves from 14 to 91 d of age.

During weaning, methionine (Met) supply decreases as liquid feed intake is reduced and ruminal function is developing. During this transition, the calf starter should both promote ruminal development and provide adequate nutrients post-ruminally. In mature ruminants, rumen-protected Met (RPM) and the Met analogs, 2-hydroxy-4-(methylthio)-butanoic acid (HMTBa) and HMTBa isopropyl ester (HMBi), are used to increase Met supply, stimulate ruminal fermentation, or exert both effects, respectively. To evaluate the effects of these forms of Met on calf performance during development of ruminal function, 74 Holstein calves were raised until 91 d of age, in 2 enrollment periods. Calves were individually housed from birth and, at 14 d of age, balanced for sex and randomly assigned to receive a starter with no added Met (CTRL, n = 20) or one supplemented with RPM (Smartamine M, Adisseo USA Inc., Alpharetta, GA; n = 16), HMTBa (RumenSmart, Adisseo; n = 19), or HMBi (MetaSmart, Adisseo; n = 19). Milk replacer [28% crude protein (CP), 15% fat] was offered up to 1.6 kg of dry matter (DM)/d and fed 3 times daily. Weaning was facilitated from d 49 to 63. The 4 starters (25% CP, 2.5 Mcal of metabolizable energy/kg of DM) were offered ad libitum, and supplement inclusion was set to provide an additional 0.16% DM of Met equivalents, and equal amounts of HMTBa within the analogs. Body weight and stature were measured, and blood was collected and analyzed for plasma urea nitrogen, ß-hydroxybutyrate, and free AA on a weekly basis. Supplementation of RPM and HMBi increased free plasma Met, but no differences in growth or feed efficiency compared with calves fed the CTRL starter could be attributed to the additional Met supply alone. The addition of HMBi in the starter increased feed intake and body weight during the last weeks of the experiment. On the contrary, HMTBa failed to increase plasma Met and depressed intake and growth after weaning, likely because the level included in the diet was too high and intake was greater than previous studies, exacerbating the level of HMTBa ingested. No differences were observed in stature, feed efficiency, or non-AA plasma measurements among groups. These results demonstrate that RPM and HMBi are effective sources of metabolizable Met; however, Met was apparently not limiting calves fed the basal diet in this study. The increased feed intake observed with the inclusion of HMBi in the starter during the weaning and early postweaning period might be mediated by its metabolism in the rumen, and further research is needed to determine the mechanisms involved.

Effect of Beta-Carotene Supplementation on the Peripheral Blood Leukocyte Population in Japanese Black Calves.

The purpose of this study was to determine the effect of beta-carotene supplementation to Japanese Black calves on the peripheral blood leukocyte population. Twenty-two Japanese Black calves were alternately assigned to two groups. Eleven calves received 20 mg/d of beta-carotene orally from 2 to 8 wk of age (BC group), and the other 11 calves did not receive (control group). The serum beta-carotene concentration in the BC group at 4, 8 and 12 wk of age were significantly higher than those in the control group (p<0.05). The numbers of CD4+ cells in the BC group were significantly higher than those in the control group at 4 wk of age (p<0.05). These results confirmed that beta-carotene supplementation to Japanese Black calves affected the peripheral blood leukocyte population.

Heat treatment of bovine colostrum: II. Effects on calf serum immunoglobulin, insulin, and IGF-I concentrations, and the serum proteome.

In-depth analysis of colostrum components has identified hundreds of proteins, but data are sparse regarding their systemic uptake in the newborn calf. Moreover, heat treatment may influence these colostral components and their absorption. Our objectives were to describe the serum proteome of newborn calves before and after colostrum feeding and the possible effects of colostral heat treatment. Newborn Holstein heifer calves (n = 22) were randomized within pair and fed heat-treated (n = 11; 60°C, 60 min) or raw (n = 11) colostrum at 8.5% of birth body weight by esophageal feeder within 1 h of birth. After the single colostrum feeding, calves were not fed until after the 8-h time point, when milk was offered free-choice. Blood samples were taken immediately before feeding (0 h), as well as 4, 8, and 24 h after feeding. Whole blood packed cell volume (%), serum Brix percentage, and plasma glucose concentrations were determined for all time points. Plasma insulin and insulin-like growth factor-I concentrations were determined by radioimmunoassay for selected time points. Serum IgA and IgG were measured by radial immunodiffusion at 24 h. The serum proteome was analyzed using nano-scale reverse-phase chromatography and tandem mass spectrometry (nano LC-MS/MS) in 0- and 8-h samples. For proteomics analysis, ratios of results for 8-h to 0-h samples were analyzed with false discovery rate adjustment. For all other outcomes, repeated-measures ANOVA was performed with the fixed effects of group, time, and their interaction, and random effect of pair. Serum Brix percentage and glucose concentrations increased over time and were independent of colostrum treatment. Serum IgG and IgA concentrations at 24 h did not differ between groups. Nano LC-MS/MS identified a total of 663 unique proteins in serum, of which 261 increased in abundance, whereas 67 decreased in abundance after feeding in both groups. Among serum proteins that increased in abundance and that were previously identified in colostrum, many belonged to those involved in immune response, coagulation, the classical complement pathway, or the antimicrobial peptide class of cathelicidins. Serum proteins that decreased in abundance and that were identified in colostrum belonged to the alternative complement pathway and the membrane attack complex. Thirty-eight proteins differed in calves that were fed heat-treated colostrum compared with those fed raw colostrum. Decreased abundances in calves fed heat-treated colostrum included several enzymes involved in glycolysis or glycogenolysis, whereas the incretin gastric inhibitory polypeptide and serum insulin were increased in this group. Our findings point to important innate immune defense pathways associated with colostrum ingestion in newborn calves. Furthermore, calves fed heat-treated colostrum showed differences in serum proteins and enzymes associated with carbohydrate metabolism.

Effects of beta-1,3-glucan supplementation on concentrations of serum metabolites in transition Holstein cows.

Objectives of this study were to evaluate the alleviating effects of a commercial beta-1,3-glucan product (Aleta, containing 50% beta-1,3-glucan, Kemin Industries) on metabolic stress in transition Holstein cows as reflected by circulating metabolites and enzymes. Fifty-four multiparous Holstein cows were randomly allocated to three groups with 18 cows each. Cows in each group received a commercial basal diet or the basal diet supplemented with Aleta calculated to supply 5 or 10 g of Aleta per cow per day. Blood samples were collected at day -21, 1, and 21 relative to calving for determination of serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDLC), very low density lipoprotein (VLDL), glucose, insulin, ß-hydroxybutyric acid (BHBA), aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamyl transpeptidase (GGT), and non-esterified fatty acid (NEFA). Supplementation with Aleta markedly elevated serum concentrations of TG, TC, HDLC, LDL-C and VLDL, implying its positive effect on lipid metabolism in transition dairy cows. Aleta treatment significantly decreased the serum concentrations of NEFA and BHBA, but markedly elevated the serum concentrations of glucose and insulin. Also, Aleta treatment significantly elevated the dry matter intake and milk production in postpartum cows, indicating the alleviating effect of Aleta on negative energy balance in transition cows. Moreover, Aleta treatment significantly reduced the serum activities of AST, ALT and GGT, indicating its hepatoprotective effect on transition cows. These results suggest that Aleta supplementation may help to improve fat metabolism disorder initiated by negative energy balance in transition dairy cows.

Short communication: Variation in serum immunoglobulin G concentrations from birth to 112 days of age in Holstein calves fed a commercial colostrum replacer or maternal colostrum.

Serum IgG concentrations in dairy calves change throughout their first weeks of life, peaking at 24 h and then steadily decreasing until calves begin to produce endogenous IgG. The objective of this study was to observe serum IgG dynamics from birth until 16 wk of life in calves fed either maternal colostrum (MC) or colostrum replacer (CR). A total of 44 Holstein calves were randomly assigned to 1 of the 4 colostrum treatments and followed throughout the study. Treatments consisted of feeding high-quality MC, low-quality MC supplemented with CR, or 1 of 2 distinct levels of IgG concentration from CR. Overall, the interaction between type of colostrum fed and sampling time was significant. Individual differences for this effect were found at d 1, 7, 14, 21, 28, and 98, while the other time points were not different.

Effects of abomasal infusion of essential fatty acids together with conjugated linoleic acid in late and early lactation on performance, milk and body composition, and plasma metabolites in dairy cows.

Rations including high amounts of corn silage are currently very common in dairy production. Diets with corn silage as forage source result in a low supply of essential fatty acids, such as α-linolenic acid, and may lead to low conjugated linoleic acid (CLA) production. The present study investigated the effects of abomasal infusion of essential fatty acids, especially α-linolenic acid, and CLA in dairy cows fed a corn silage-based diet on performance, milk composition, including fatty acid (FA) pattern, and lipid metabolism from late to early lactation. Rumen-cannulated Holstein cows (n = 40) were studied from wk 9 antepartum to wk 9 postpartum and dried off 6 wk before calving. The cows were assigned to 1 of 4 treatment groups. Cows were abomasally supplemented with coconut oil (CTRL, 76 g/d), linseed and safflower oil (EFA, 78 and 4 g/d; linseed/safflower oil ratio = 19.5:1; n-6/n-3 FA ratio = 1:3), Lutalin (CLA, 38 g/d; BASF SE, Ludwigshafen, Germany; isomers cis-9,trans-11 and trans-10,cis-12 each 10 g/d) or EFA+CLA. Milk composition was analyzed weekly, and blood samples were taken several times before and after parturition to determine plasma concentrations of metabolites related to lipid metabolism. Liver samples were obtained by biopsy on d 63 and 21 antepartum and on d 1, 28, and 63 postpartum to measure triglyceride concentration. Body composition was determined after slaughter. Supplementation of CLA reduced milk fat concentration, increased body fat mass, and improved energy balance (EB) in late and early lactation, but EB was lowest during late lactation in the EFA group. Cows with CLA treatment alone showed an elevated milk citrate concentration in early lactation, whereas EFA+CLA did not reveal higher milk citrate but did have increased acetone. Milk protein was increased in late lactation but was decreased in wk 1 postpartum in CLA and EFA+CLA. Milk urea was reduced by CLA treatment during the whole period. After calving, the increase of nonesterified fatty acids in plasma was less in CLA groups; liver triglycerides were raised lowest at d 28 in CLA groups. Our data confirm an improved metabolic status with CLA but not with exclusive EFA supplementation during early lactation. Increased milk citrate concentration in CLA cows points to reduced de novo FA synthesis in the mammary gland, but milk citrate was less affected in EFA+CLA cows, indicating that EFA supplementation may influence changes in mammary gland FA metabolism achieved by CLA.

Changes in the metabolic profiles of dairy cows before and after calving that were mainly fed fodder beet (Beta vulgaris vulgaris L.) during the dry period.

Case history: Two commercial pasture-based farms within the North Canterbury district of New Zealand were feeding fodder beet (Beta vulgaris vulgaris L.) as a large proportion of the diet to cows during the dry period. On each farm 25 multiparous cows were blood sampled up to six times from 28 days before, to 21 days after calving (Day 0). Plasma samples were analysed for concentrations of ß-hydroxybutyrate (BHBA), non-esterified fatty acid (NEFA), Ca, Mg and P, and aspartate aminotransferase (AST) activity. The first sampling visit was performed when cows were being fed their maximum intake of fodder beet. Clinical findings: The mean body condition score (BCS) of cows on Farm 1 was 5.4 (95% CI = 5.3-5.6) and on Farm 2, 5.4 (95% CI = 5.3-5.6) at first sampling. Mean concentrations of BHBA increased between Days -15 and Day -8 then decreased postpartum on Day 2 before increasing again on Day 21. On Farm 2, concentrations remained low (<1.2 mmol/L) on all days of sampling. Mean concentrations of NEFA in plasma remained low during the periparturient period on Farm 1, then increased on Day 2. On Farm 2, concentrations were elevated above 0.3 mmol/L between Days -28 and -17 then decreased on Day -10, before increasing on Day 2. Mean concentrations of Ca, Mg and P were higher than threshold values on both farms prepartum. However on Day 2, there were 8/23 (35%) cows on Farm 1 and 6/23 (26%) cows on Farm 2 with concentrations of Ca in plasma <2.0 mmol/L, and 10/23 (44%) cows on Farm 1 and 8/23 (35%) cows on Farm 2 with concentrations of P in plasma <1.3 mmol/L. Mean AST activities remained relatively constant and below 130 IU/L on both farms at all sampling times. Clinical relevance: On both farms, post-partum hypocalcaemia and hypophosphataemia were common after calving despite differing fodder beet feeding and mineral supplementation regimes. There was more variation in energy status, especially prior to calving. More research is required on factors affecting mineral and energy status in dry cows fed fodder beet.

Effects of hydrolyzed cottonseed protein supplementation on performance, blood metabolites, gastrointestinal development, and intestinal microbial colonization in neonatal calves.

The objective of this study was to investigate the effects of an enzymatically hydrolyzed cottonseed protein (HCSP) as a peptide source on performance, blood metabolites, gastrointestinal development, and intestinal microbes. Forty-eight newborn Holstein calves were randomly assigned to 1 of the 4 dietary treatments including 0, 2, 4, and 6% of HCSP (dry matter basis). All calves received the same amount of pasteurized whole milk, weaned on d 56 of the experiment, and the study was concluded on d 70. Data were analyzed using PROC MIXED in SAS (SAS Institute Inc., Cary, NC) as a randomized complete block design with linear and quadratic contrasts. Results showed that increased amount of HCSP linearly decreased the starter intake during the postweaning (d 57 to 70) and overall period (d 1 to 70). In addition, when dietary HCSP increased during the overall period, average daily gain tended to linearly decrease. All skeletal growth variables also linearly decreased as dietary HCSP increased at the end of the study, except for body length, which did not differ among the treatments. Serum cortisol concentration was higher in calves supplemented with 6% of HCSP at weaning and at the end of the study. This indicates that these calves may have experienced a stressful condition compared with calves in other treatments. Total antioxidant capacity was quadratically affected by HCSP supplementation; calves fed 2 and 4% of HCSP diets had the highest total antioxidant capacity, whereas calves fed 0 and 6% HCSP diets had lower total antioxidant capacity at weaning and at end of the study. Calves supplemented with 6% HCSP had lower empty reticulo-rumen and omasum weights and rumen wall thickness compared with calves in other treatments at the end of the study. In conclusion, supplementation of HCSP at the rate of 2% of starter diet enhanced antioxidant status without any detrimental effects on the performance and metabolic status of calves, whereas greater inclusion rates impaired starter intake and growth of calves, and exposed them to a stressful status.