Effects of feeding pregnant beef cows selenium-enriched alfalfa hay on passive transfer of ovalbumin in their newborn calves.
ABSTRACT: Intestinal absorption of immunoglobulins is critical for health and survival of newborn calves because there is no transfer of immunoglobulins in utero. The objective of this study was to determine if feeding beef cows Se-enriched alfalfa hay during the last trimester of gestation improves passive transfer of ovalbumin (OVA), a surrogate protein marker for IgG absorption. Control cows (n?=?15) were fed non-Se-fortified alfalfa hay (5.3?mg Se/head daily) plus a mineral supplement containing inorganic Se (3?mg Se/head daily). Med-Se (n?=?15) and High-Se cows (n?=?15) were fed Se-biofortified alfalfa hay (27.6 and 57.5?mg Se/head daily, respectively); both groups received mineral supplement without added Se. Calves were randomly assigned to receive orally administered OVA at 12, 24, or 36?h of age. Calves that received their oral dose of OVA at 12?h of age had higher serum OVA concentrations across the first 48?h of life if born to High-Se cows compared to calves born to Control cows (P = 0.05), with intermediate values for calves born to Med-Se cows. Our results, using OVA as a model for passive transfer, suggest that if calves do not receive adequate colostrum to reach maximum pinocytosis, then supranutritional Se supplementation in beef cattle may improve passive transfer in their calves, if calves receive colostrum within the first 12?h of age.
Project description:Selenium (Se) is an essential trace mineral important for immune function and overall health of cattle. The nasopharyngeal microbiota in cattle plays an important role in overall respiratory health, especially when stresses associated with weaning, transport, and adaptation to a feedlot affect the normal respiratory defenses. Recent evidence suggests that cattle diagnosed with bovine respiratory disease complex have significantly less bacterial diversity. The objective of this study was to determine whether feeding weaned beef calves Se-enriched alfalfa (Medicago sativa) hay for 9 weeks in a preconditioning program prior to entering the feedlot alters nasal microbiota. Recently weaned beef calves (n = 45) were blocked by sex and body weight, randomly assigned to 3 treatment groups with 3 pens of 5 calves per treatment group, and fed an alfalfa hay based diet for 9 weeks. Alfalfa hay was harvested from fields fertilized with sodium selenate at a rate of 0, 45.0 or 89.9 g Se/ha. Blood samples were collected biweekly and analyzed for whole-blood Se concentrations. Nasal swabs were collected during week 9 from one or two calves from each pen (total n = 16). Calculated Se intake from dietary sources was 3.0, 15.6, and 32.2 mg Se/head/day for calves consuming alfalfa hay with Se concentrations of 0.34 to 2.42 and 5.17 mg Se/kg dry matter, respectively. Whole-blood Se concentrations after 8 weeks of feeding Se-fertilized alfalfa hay were dependent upon Se-application rates (0, 45.0, or 89.9 g Se/ha) and were 155, 345, and 504 ng/mL (PLinear < 0.0001). Microbial DNA was extracted from nasal swabs and amplified and sequenced. Alpha rarefaction curves comparing the species richness (observed OTUs) and overall diversity (Chao1, Observed OTU, and Shannon index) between calves fed selenium-biofortified alfalfa hay compared with control calves showed that Se-supplementation tended to be associated with an enriched nasal microbiota. ANOSIM of unweighted UniFrac distances showed that calves fed high Se-biofortified alfalfa hay clustered separately when compared with control calves in the PCoA plot (R = 0.216, P = 0.04). The bacterial orders Lactobacillales and Flavobacteriales were increased in healthy control calves compared with Clostridiales and Bacteroidales being increased in calves fed Se-biofortified alfalfa hay. Although there were strong trends, no significant differences were noted for any of the bacterial taxa. Based upon these findings, we suggest that weaned beef calves fed Se-biofortified hay tend to have an enriched nasal microbiota. Feeding Se-biofortified alfalfa hay to weaned beef calves prior to entering the feedlot is a strategy for increasing nasopharyngeal microbial diversity.
Project description:The objective of this study was to evaluate the benefits of supplementation of mannan oligosaccharide (MOS) to cows during the last 3 wk of the dry period on immune function of the cows and subsequent transfer of passive immunity to their calves. Indicators of nonspecific and specific immunity were evaluated. Cows were vaccinated against rotavirus at 4 and 2 wk before expected parturition. Blood samples were obtained from cows before vaccination and at weekly intervals until calving and from calves at birth and 24 h for analysis of serum protein concentrations, packed cell volume, white blood cell counts, white blood cell differentials, and serum rotavirus neutralization titers. Colostrum quantity and quality were measured at calving, and immunoglobulin isotype concentrations in colostrum were determined. Specific immunity was enhanced by MOS supplementation as evidenced by greater serum rotavirus neutralization titers at calving in cows supplemented with MOS compared with control cows. Colostral rotavirus neutralization titers were not affected by treatment. Although numerical differences appeared large, there was a high degree of variability in the colostral rotavirus neutralization titers. Calves from cows fed MOS tended to have greater serum rotavirus neutralization titers compared with calves from cows fed the control diet. There was a tendency for greater increases in serum protein concentrations from birth to 24 h in calves from cows fed MOS compared with calves from cows fed the control diet. Results indicate that supplementation of MOS to cows during the dry period enhanced their immune response to rotavirus and tended to enhance the subsequent transfer of rotavirus antibodies to calves.
Project description:BACKGROUND:Salmonellosis is a major cause of morbidity and mortality in neonatal calves, often occurring before preventative vaccines can be administered. HYPOTHESIS/OBJECTIVE:To evaluate the protective effect on calves of colostrum from cows vaccinated with a commercially available Salmonella Newport bacterin against a Salmonella Typhimurium challenge. ANIMALS:Twenty Holstein bull calves from a university dairy farm. METHODS:Nonrandomized placebo-controlled trial in which colostrum was harvested from 30 cows that received 2 doses of either Salmonella bacterin or saline before calving. Colostrum collected from each group was pooled and fed to 2 groups of 10 calves at birth. At approximately 2 weeks of age, calves were challenged with Salmonella Typhimurium. Clinical, hematologic, microbiological, and postmortem findings were compared between the 2 groups. RESULTS:No differences in mortality, clinical findings, hematology results, blood and fecal cultures, or necropsy findings between the 2 groups were observed. Vaccinated cows had higher colostral titers, and calves fed this colostrum had higher serum titers (mean difference, 0.429; mean [SE], 0.852 [0.02] for vaccinated versus 0.423 [0.02] for control calves). CONCLUSIONS AND CLINICAL IMPORTANCE:Transfer of colostral immunoglobulins from Salmonella enterica serotype Newport bacterin to neonatal calves was not sufficient to decrease mortality, clinical signs, sepsis, intestinal damage, or fecal shedding when exposed to a highly pathogenic Salmonella isolate. A large-scale randomized controlled clinical trial is needed to evaluate the efficacy of this bacterin when administered in the dry period for prevention of salmonellosis in neonatal calves.
Project description:Background:Pregnancy and early life are critical periods of plasticity during which the fetus and neonate may be influenced by environmental factors such as nutrition. Maternal methionine (Met) supply in non-ruminants during pregnancy can affect offspring development and growth. Thus, the objective of this study was to investigate if increasing Met supply during late-pregnancy affects developmental parameters of the calf at birth and if either maternal Met or colostrum from Met-fed cows alters calf growth. Calves born to Holstein cows individually-fed a basal control [CON; 1.47 Mcal/kg dry matter (DM) and 15.3% crude protein] diet with no added Met or CON plus ethylcellulose rumen-protected Met (MET; Mepron® at 0.09% of diet DM; Evonik Nutrition & Care GmbH, Germany) during the last 28?±?2 d of pregnancy were used. A total of 39 calves were in CON (n?=?22 bulls, 17 heifers) and 42 in MET (n?=?20 bulls, 22 heifers). At birth, calves were randomly allocated considering dam treatment and colostrum as follows: 1) calves from CON cows and colostrum from CON cows (n?=?21); 2) calves from CON cows and colostrum from MET cows (n?=?18); 3) calves from MET cows and colostrum from MET cows (n?=?22); and 4) calves from MET cows and colostrum from CON cows (n?=?20). All calves were housed, managed, and fed individually during the first 9 wk of life. Results:Despite greater daily DM intake pre-partum in cows fed MET (15.7 vs. 14.4?±?0.12 kg/d, P?<?0.05), colostrum quality and quantity were not affected by maternal diet. At birth, MET calves had greater (P???0.05) body weight (BW, 44.1 vs. 42.1?±?0.70 kg), hip height (HH, 81.3 vs. 79.6?±?0.53 cm) and wither height (WH, 77.8 vs. 75.9?±?0.47 cm). In contrast, concentrations of His, Lys, and Asn in plasma were lower (P???0.05) in MET calves. Regardless of colostrum source, the greater BW, HH, and WH in MET calves at birth persisted through 9 wk of age resulting in average responses of +?3.1 kg BW, +?1.9 cm HH, and?+?1.8 cm WH compared with CON. Average daily gain during the 9 wk was (P?<?0.05) 0.72?±?0.02 kg/d in MET compared with 0.67?±?0.02 kg/d in CON calves. Respiratory scores were normal and did not differ (P?>?0.05) due to maternal Met supply or colostrum source. However, fecal scores tended to be lower (P???0.10) in MET calves regardless of colostrum source. Conclusions:Increasing the maternal supply of MET during late-pregnancy enhanced growth in utero as well as during the pre-weaning and early post-weaning periods. Although the ~?1 kg/d greater DM intake during the last 2-3 wk prior to parturition could explain a portion of the 2 kg extra body mass of MET calves at birth, other mechanisms potentially encompassing nutrient assimilation efficiency likely played a role. Assessing the exact mechanisms sensitive to supply of Met or total amino acid supply during the latter stages of growth in utero merit further research.
Project description:Neonatal calves possess a very immature and naïve immune system and are reliant on the intake of maternal colostrum for passive transfer of immunoglobulins. Variation in colostrum management of beef and dairy calves is thought to affect early immune development. Therefore, the objective of this study was to examine changes in gene expression and investigate molecular pathways involved in the immune-competence development of neonatal Holstein dairy calves and naturally suckled beef calves using next generation RNA-sequencing during the first week of life. Jugular whole blood samples were collected from Holstein (H) dairy calves (n?=?8) artificially fed 5% B.W. colostrum, and from beef calves which were the progenies of Charolais-Limousin (CL; n?=?7) and Limousin-Friesian beef suckler cows (LF; n?=?7), for subsequent RNA isolation. In dairy calves, there was a surge in pro-inflammatory cytokine gene expression possibly due to the stress of separation from the dam. LF calves exhibited early signs of humoral immune development with observed increases in the expression genes coding for Ig receptors, which was not evident in the other breeds by 7 days of age. Immune and health related DEGs identified as upregulated in beef calves are prospective contender genes for the classification of biomarkers for immune-competence development, and will contribute towards a greater understanding of the development of an immune response in neonatal calves.
Project description:AbstractThe effect of oversupplying metabolizable protein (MP) pre-partum on pre-partum colostrum protein composition and calf serum protein composition was determined to characterize the nutritionally modulated transfer of biomarkers from mother to calf. Thirteen primiparous crossbred Hereford cows were assigned to a high protein (HP; 133% of MP requirement, n = 6) or control (CON; 100% of predicted MP requirement, n = 7) treatment. Cows were individually fed their treatment diet from d -55 relative to parturition. Colostrum was sampled equally from all quarters and calf serum was collected prior to and 6-hours post colostrum consumption. Colostrum contained 213 distinct detectible proteins. Of these, 11 proteins showed a greater than 2 fold increase in abundance from HP cows. Three of these proteins (AMER3, G3N1Y3, G3MZ21) show 1.4–6.9 fold depletion in the serum of calves fed colostrums from HP dams. The other eight proteins did not appear in detectible levels in the calves’ serum before or after colostrum. An additional 16 proteins were reduced more than 2 fold in the colostrum from HP cows, relative to CON. A total of 179 distinct proteins were detectible in the serum sampled before and after colostrum consumption. Of these, 28 were more than 2 fold greater prevalence in the serum of HP calves. Eighteen of these proteins were detectible in colostrum, with 10 enriched up to 1.25 fold in HP colostrum, and 8 depleted down to 0.82 fold in treatment colostrum. Additionally, 19 proteins were greater than 2 fold less prevalent in the serum of calves feed colostrum from HP dams, including haptoglobin antioxidant protein and IαI-heavy-chain inflammatory regulators. Thus excess of MP promotes a shift in select proteins, including immune-regulators, in colostrum which promotes an associated shift in different factors and biomarkers in calf serum post-colostrum consumption.
Project description:A study of herd-level risk factors for calf mortality in large Swedish dairy herds showed low serum concentrations of ?-tocopherol and ?-carotene in 1-7 day old calves to be more common in high mortality herds. Therefore, we aimed to investigate if calf mortality risk at herd level is associated with concentrations of ?-tocopherol and/or ?-carotene at individual level in feed, colostrum, cow and calf serum, while controlling for herd level covariates. Inclusion criteria were affiliation to the Swedish official milk recording scheme, herd size of ? 120 milking cows/year, calf mortality risk (day 1-90) of at least 6% (high mortality; HM) or less than 1% (low mortality; LM) and located within one of two regions in southern Sweden. This cross-sectional study was performed in 2010 in 19 (nHM = 9; nLM = 10) dairy herds. Questionnaires were used to collect information about feed and routines for colostrum feeding. Feed (n = 57), colostrum (n = 162), cow serum (n = 189) and calf serum samples (n = 187) were collected and analysed for ?-tocopherol and ?-carotene. Other analyses e.g. total serum protein, fat content, and total solids in colostrum were also performed. Linear regression models with vitamin concentrations in feed, colostrum, cow and calf serum as outcome were performed.Calves in HM herds had lower concentrations of ?-tocopherol in serum than calves in LM herds, but the effect depended on total protein status in serum of the calf (P = 0.036). Calves from herds that fed transition milk for 3 days or more had higher ?-tocopherol concentrations in serum than calves from herds feeding transition milk up to 2 days (P = 0.013). Fat percentage in colostrum was positively associated with ?-tocopherol (P < 0.001) and ?-carotene concentrations in colostrum (P < 0.001). A diet containing ? 20% (in kg dry matter) maize silage of the total ration was negatively associated with ?-carotene concentration in cow serum (P = 0.001).High calf mortality risks were associated with lower concentrations of ?-tocopherol in calf serum for calves with failure of passive transfer. Feeding transition milk longer was associated with higher concentrations of ?-tocopherol in calf serum. In HM herds, evaluation of the calves' ?-tocopherol status is recommended.
Project description:This study aimed to investigate the effect of early weaning by supplying calves with alfalfa hay, starter feed, and milk replacer on caecal bacterial communities and on the growth of pre-weaned yak calves. Ten 30-day-old male yak calves were randomly assigned to 2 groups. The maternal grazing (MG) group was maternally nursed and grazed, and the early weaning (EW) group was supplied milk replacer, starter feed, and alfalfa hay twice per day. Compared with the yak calves in the MG group, the yak calves in the EW group showed significantly increased body weight, body height, body length, and chest girth. When suffering to the potential mechanism of improved growth of yak calves, except for the enhanced ruminal fermentation, the significantly increased total volatile fatty acids, propionate, butyrate, isobutyrate, and valerate in the caecum in the EW group could also serve to promote the growth of calves. By using 16S rDNA sequencing, some significantly increased caecal phylum and genera, which were all related to the enhanced caecal fermentation by utilizing both the fibrous and non-fibrous carbohydrates, were identified in the EW group. In conclusion, early weaning of yak calves by supplying them with alfalfa hay, starter feed, and milk replacer is more beneficial to the growth of yak calves when compared with maternal grazing and nursing, in part due to alterations in caecal microbiota and fermentation.
Project description:There is extensive literature addressing acceptable practices of colostrum distribution to new-born calves; however, no economic analyses are available concerning the profitability of this practice. Moreover, the health standards associated with colostrum management have been defined through the observation of reference farms without explicit reference to economic assessments. The objective of the current study was to evaluate the profitability of farm colostrum management and to define the optimal economic situations for given livestock systems and farm situations. The herd-level net value was calculated using the value of calf products, the cost of passive transfer failure and the cost of prevention. This value was determined for various beef and dairy scenarios and the various time periods spent managing colostrum. The maximal net values defined the optimal economic situations and enabled the determination of the optimal times for colostrum management and respective health standards (i.e., the prevalence of disorders at optimum). The results showed that the optimal time farmers should spend on colostrum management is approximately 15 min per calf. Furthermore, farmers should err on the side of spending too much time (> 15 min) on colostrum management rather than not enough, unless the cost of labour is high. This is all the more true that potential long term consequences of passive transfer failure on milk yields were not accounted for here due to scarcity of data, leading to consider this time threshold (15 min) as a minimal recommendation. This potential underestimation may arise from the greater nutrient content and bioactive compounds identified in colostrum although the passive immune transfer is here defined through immunoglobulins only. The present results show that for small farms that cannot hire colostrum managers, this work can be performed by the farmer after subcontracting other tasks. Moreover, the method proposed here-the definition of health standards through economic optimisation-is a promising approach to analysing health conventions in the cattle industry.
Project description:The present study aims to evaluate the effects of different early weaning paradigms, which supplied with extra alfalfa hay, or starter feeding, or both alfalfa hay and starter feeding, along with the milk replacer, on the gastrointestinal microbial community, growth, and immune performance of yak calves. Twenty 30-day-old male yak calves were randomly assigned to four groups, including the control (CON), alfalfa hay (A), starter feeding (S), and starter plus alfalfa hay (SA) groups. The gastrointestinal microbial colonization, the gastrointestinal development and function, and the growth and immune performance of all the yak calves were separately measured. Supplementation with alfalfa and starter feeding during the pre-weaning period significantly increased body weight, body height, body length, and chest girth. The significantly improved rumen fermentation and promoted intestinal digestion-absorption function in alfalfa and starter feeding groups, including the identified significantly increased concentrations of ruminal total volatile fatty acid (VFA); the significantly increased concentrations and proportions of acetate, butyrate, and isovalerate; the increased ?-amylase activities in the duodenum, jejunum, and ileum; the increased papillae length and width of rumen epithelium and rumen wall thickness; and the increased villus height and crypt depth of the duodenum, jejunum, and ileum, could all contribute to promote the growth of calves. These significant improvements on rumen fermentation and intestinal digestion-absorption function could be further attributed to the increased proliferation of starch-decomposing, and cellulose- or hemicellulose-decomposing bacteria identified in the rumen, jejunum, and ileum. Furthermore, based on the expression of intestinal inflammatory cytokines and the rumen epithelial RNA sequencing results, alfalfa supplementation reduced the occurrence of ruminal and intestinal inflammation, whereas starter feeding supplementation was mainly beneficial to the differentiation of immune cells and the improved immune function. Meanwhile, the significantly altered relative abundances of genera in the SA group, including increased relative abundance of Limnobacter, Escherichia/Shigella, and Aquabacterium in the rumen and increased relative abundance of Coprococcus, Pseudobutyrivibrio, Flavonifractor, Synergistes, and Sutterella in jejunum, were able to reduce gastrointestinal inflammation and enhance the immune function, which enhanced the immune function of the yak calves fed with alfalfa and starter feeding. Overall, milk replacer supplemented with alfalfa and starter feeding during the pre-weaning period could alter gastrointestinal microbiota and then benefit the gastrointestinal development, digestion-absorption function, growth, and immune performance of the yak calves.