Short communication: Supply of methionine during late pregnancy enhances whole-blood innate immune response of Holstein calves partly through changes in mRNA abundance in polymorphonuclear leukocytes.

The supply of methionine (Met) in late pregnancy can alter mRNA abundance of genes associated with metabolism and immune response in liver and polymorphonuclear leukocytes (PMN) of the neonatal calf. Whether prenatal supply of Met elicits postnatal effects on systemic inflammation and innate immune response of the calf is not well known. We investigated whether enhancing the maternal supply of Met via feeding ethyl-cellulose rumen-protected Met (RPM) was associated with differences in calf innate immune response mRNA abundance in PMN and systemic indicators of inflammation during the first 50 d of life. Calves (n = 14 per maternal diet) born to cows fed RPM at 0.09% of diet dry matter per day (MET) for the last 28 ± 2 d before calving or fed a control diet with no added Met (CON) were used. Blood for biomarker analysis and isolation of PMN for innate immune function assays and mRNA abundance was harvested at birth (before colostrum feeding) and at 7, 21 and 50 d of age. Whole blood was challenged with enteropathogenic bacteria (Escherichia coli 0118:H8) and phagocytosis and oxidative burst of neutrophils and monocytes were quantified via flow cytometry. Although concentration of haptoglobin and activity of myeloperoxidase among calves from both maternal groups increased markedly between 0 and 7 d of age followed by a decrease to baseline at d 21 the responses were lower in MET compared with CON calves. Nitric oxide concentration decreased markedly between 0 and 7 d regardless of maternal group but MET calves tended to have lower overall concentrations during the study. In vitro phagocytosis in stimulated neutrophils increased markedly over time in both CON and MET calves but responses were overall greater in MET calves. Oxidative burst in both neutrophils and monocytes increased over time regardless of maternal treatment. The mRNA abundance of lactate dehydrogenase (LDHA) signal transducer and activator of transcription 3 (STAT3) and S100 calcium binding protein A8 (S100A8) in PMN was overall greater in MET calves. Overall data suggest that increasing the maternal supply of Met during late pregnancy could affect the neonatal calf inflammatory status and innate immune response. Although changes in mRNA abundance could play a role in coordinating the immune response the exact mechanisms merit further study.

Hepatic 1-carbon metabolism enzyme activity, intermediate metabolites, and growth in neonatal Holstein dairy calves are altered by maternal supply of methionine during late pregnancy.

Maternal supply of methyl donors such as methionine (Met) during late pregnancy can affect offspring growth and development. The objective was to investigate the effect of postruminal Met supply during late pregnancy on 1-carbon, Met cycle, and transsulfuration pathways in the calf liver. During the last 28 d of pregnancy, cows were individually fed a control diet or the control diet plus rumen-protected dl-Met (MET; 0.09% dry matter intake). Liver samples obtained from calves (n = 14/group) at 4, 14, 28, and 50 d of age were used for metabolomics, real-time PCR, and enzyme activity analyses. Genes associated with 1-carbon metabolism, DNA methylation, and the cytidine 5'-diphosphocholine-choline pathway were analyzed via real-time PCR. Activity of betaine homocysteine methyltransferase, cystathionine ß-synthase, and 5-methyltetrahydrofolate homocysteine methyltransferase (MTR) was analyzed using 14C isotopes. Data were analyzed using a mixed model that included the fixed effects of maternal treatment, day, and their interaction, and the random effect was calf within maternal diet. Calves born to dams offered MET tended to have greater birth body weight and had overall greater body weight during the first 9 wk of life. However, no differences were detected for daily feed intake and average daily gain between groups. Concentrations of betaine and choline, reflecting Met cycle activity, at d 14 through 28 were greater in MET calves. Transsulfuration pathway intermediates also were altered in MET calves, with concentrations of cysteine sulfinic acid and hypotaurine (d 4 and 14) and taurine being greater (d 4, 14, 28, and 50). Despite the lack of differences in daily feed intake, the greater concentrations of the tricarboxylic acid cycle intermediates fumarate and glutamate along with NAD/NADH in MET calves indicated enhanced rates of energy metabolism. Although activity of betaine homocysteine methyltransferase was greater in MET calves at d 14, cystathionine ß-synthase was lower and increased at d 14 and 28, where it was greater compared with the control diet. Activity of MTR was lower at d 4 and 50 in MET calves. Among gene targets measured, MET calves had greater overall expression of MTR, phosphatidylethanolamine N-methyltransferase, and choline kinase α and ß. An interaction of maternal diet by time was detected for mRNA abundance of DNA methyltransferase 3α (involved in de novo methylation) due to greater values at d 4 and 14 in MET calves. Overall, the data indicate that enhanced postruminal supply of Met to cows during late pregnancy may program hepatic metabolism of the calf in the context of maintaining Met homeostasis, phosphatidylcholine and taurine synthesis, DNA methylation, and energy metabolism. These alterations potentially result in better efficiency of nutrient use, hence conferring the calf a physiologic advantage during a period of rapid growth and development. The precise biologic mechanisms remain to be established.

Maternal body condition during late-pregnancy is associated with in utero development and neonatal growth of Holstein calves.

BACKGROUND: Nutritional management in the dry period can alter body condition score (BCS) in dairy cows, a subjective measure of body fat. As such, differences in BCS during late-pregnancy not only mirror nutrient utilization by fat depots, but also can play important roles on the metabolic and hormonal environment. We investigated the association between cow BCS during late-pregnancy on developmental parameters and blood variables of neonatal calves. Forty-nine multiparous Holstein cows were retrospectively divided by prepartal BCS into normal BCS ≤3.25 (NormBCS; 3.02 ± 0.17, n = 30) or high BCS ≥3.75 (HighBCS; 3.83 ± 0.15, n = 19) groups. Plasma samples were collected from cows at - 10 d relative to parturition. Body weight, hip and wither height, hip width and body length were measured at birth and weekly through weaning (42 d of age) and until 9 weeks of age. Calf blood samples were collected from the jugular vein at birth (before receiving colostrum, 0 d), 24 h after first colostrum and at 7, 21, 42 and 50 d of age. The data were subjected to ANOVA using the mixed procedure of SAS. The statistical model included day, BCS, and their interactions. RESULTS: Dry matter intake (kg/d or % of body weight) during the last 4 weeks of pregnancy was lower (P ≤ 0.06) in HighBCS cows. Plasma concentrations of fatty acids, ceruloplasmin, and nitric oxide were greater overall (P < 0.05) at d - 10 prior to calving in HighBCS cows, and they tended (P = 0.08) to have greater concentrations of reactive oxygen metabolites. Birth body weight was lower (P = 0.03) in calves born to dams with HighBCS. In addition, plasma concentrations of fatty acids, albumin and urea (P < 0.05) were greater in those calves. Although calves born to cows with HighBCS maintained a lower postnatal body weight (P = 0.04), hip and wither height, hip width, and body length, there was no difference (P > 0.05) in daily starter intake and average daily gain due to maternal BCS. CONCLUSIONS: Overall, results highlight an association between BCS during late-gestation on in utero calf development and postnatal growth. A high maternal BCS during late-gestation was associated with lower calf body weights, which could be due to lower maternal intakes and a state of inflammation and metabolic stress.

Effect of dietary inclusion of graded levels of distillers dried grains with solubles on the performance, blood profile and rumen microbiota of Najdi lambs.

An experiment was conducted in a completely randomized design to evaluate the effect of including graded levels (0, 20, 30, 40 and 50% of diet) of dried distiller's grains with solubles (DDGS) on growth performance, slaughter parameters, blood serum metabolites and rumen microbiota in weaned Najdi male lambs. Thirty-five lambs, initial body weight of 33.45 ± 0.75 kg, and approximately three-month old were used in a 94-day feeding experiment. Performance measurements were conducted biweekly and blood samples were collected monthly. Inclusion of DDGS in the diets of growing Najdi lambs at levels up to 50% did not affect body weight gain (BWG) compared with the lambs fed the control diet (CON, 0% DDGS). Lambs fed the 50% DDGS diet consumed less feed compared with lambs in other groups (98 vs 112.5 kg DM) but had no adverse effect on BWG. Rumen pH values at 0, 6, 12 and 18 h post feeding and concentrations of blood serum total proteins, glucose, triglycerides, urea-N or albumin were similar across treatments. Slaughter parameters including slaughter weight, hot and cold carcass weights and dressing % (hot and cold carcass) were not affected by the treatments. There was no difference in the weights of full compartmental stomach and intestines, liver, omental fat, Kidney Knob and Channel Fat (KKCF) and tail fat between DDGS treatments and CON. The study concluded that the inclusion of DDGS in the diets of growing Najdi lambs had no adverse effects on growth performance and slaughter parameters. Rumen microbiota was not affected, however, our data suggest significant interactions between DDGS and selected bacterial groups and DDGS driven rearrangement of Prevotella species.

A comparative study of four rumen buffering agents on productive performance, rumen fermentation and meat quality in growing lambs fed a total mixed ration.

Controlling rumen fermentation using buffering agents could contribute to enhancing ruminant productivity and performance. This study was realized to investigate the effect of dietary supplementation of AcidBuf, sodium bicarbonate, calseapowder and WMC seaweed (Utva Lactuca extra) on the animal performance, volatile fatty acids, rumen pH, rumen histology and carcass characteristics of growing male Awassi lambs. A total of 60 lambs was divided into five groups. One group served as a control and fed only on a concentrate diet without any buffering, whereas the other four groups were fed the concentrate diet supplemented with 0.4% AcidBuf (Buf1), 0.4% AcidBuf plus sodium bicarbonate, 50 : 50 (Buf2), 0.4% calseapowder (Buf3) or 0.4% WMC Seaweed (Buf4) for 98 days. The feed conversion ratio was (P<0.05) improved in Buf2 compared to the control and other treatment groups. The propionic acid decreased, whereas butyric acid was increased in the treatment groups (P<0.05) compared to the control. The pH of the rumen fluid and the length of submucosa were (P<0.05) higher in Buf4 and Buf1, respectively, compared to the control. Hot and cold carcass weights were (P<0.05) higher in Buf4 compared to Buf1. Lean meat percentage and rib eye area were (P<0.05) higher in Buf4; while the fat percentage was (P<0.05) lower in Buf2 and Buf4 groups compared to the control. The lightness and yellowness of meat were (P<0.05) higher in Buf1 and Buf4 compared to the control. The meat pH was (P<0.05) higher in Buf3 and Buf4 compared to Buf2 (at 1 h) and control (at 24 h). The visceral depot fat (%) was reduced with Buf3 and Buf4 compared to the control. The results indicated that dietary supplementation of different buffering agents improved feed efficiency, rumen pH, carcass characteristics and decreased the body fat in growing Awassi lambs.

A pandemic risk assessment of middle east respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia.

Since the initial emergence of Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, a high incidence rate has been observed in Saudi Arabia. This suggests that the country is at continuous risk. The epidemic level of MERS-CoV infection was examined in Saudi Arabia by the Susceptible-Infectious-Recovered (SIR) model using a Bayesian approach for estimation of time dependent reproduction number (R) across a two-year interval (May, 2013-May, 2015) in five defined clusters, followed by sensitivity analysis of the most significant clusters. Significant MERS-CoV peaks were detected in the period between March and May of each year. Moreover, MERS-CoV infection was highlighted in western (40.8%) and central (31.9%) regions, followed by eastern region (20%). The temporal-based Bayesian approach indicated a sub-critical epidemic in all regions in the baseline scenario (R: 0.85-0.97). However, R potential limit was exceeded in the sensitivity analysis scenario in only central and western regions (R: 1.08-1.12) that denoted epidemic level in those regions. The impact of sporadic cases was found relatively insignificant and pinpointed to the lack of zoonotic influence on MERS-CoV transmission dynamics. The results of current study would be helpful for evaluation of future progression of MERS-CoV infections, better understanding and control interventions.

Comparative effects of direct-fed microbials alone or with a trace minerals supplements on the productive performance, blood metabolites, and antioxidant status in grazing Awassi lambs.

Twenty Awassi lambs were used to find the effects of direct-fed microbials (DFM) and long-acting trace minerals rumen bolus (TMB) supplements on performance, blood biochemical variables, and antioxidant status of the lambs under grazing conditions. The lambs were randomly distributed into four groups as follows: (1) untreated, (2) oral dose of 5 mL DFM, (3) TMB, or (4) oral dose of 5 mL DFM and TMB. The treatments were carried out for 90 days. Supplementation with TMB significantly increased (P < 0.05) average daily gain (ADG) and feed efficiency compared with the control. A significant (P < 0.05) increase in blood albumin in the DFM and a significant (P < 0.05) decrease in aspartate aminotrasferase were found in the lambs supplemented with TMB alone or in combination with DFM. Supplementing lambs with TMB resulted in higher glutathione peroxidase, total antioxidant capacity (P < 0.001) and activity of superoxide dismutase (P < 0.05) compared with no supplementation and supplementation with DFM only. In conclusion, TMB supplementation had a positive impact on performance traits and the antioxidant system of the lambs under grazing condition.

Dietary protein level and performance of growing Baladi kids.

A study was conducted to evaluate the effect of feeding different levels of protein to black Baladi breed kids. Weanling Baladi kids (n=18; 75 to 90 days old) were selected and individually housed at our experimental farm. Kids were divided randomly to one of the three treatments for 12 weeks. The three dietary treatments were: T1: control ration, formulated according to NRC to cover the protein (level 1) and other nutrients requirements. T2: ration formulated to cover only 75% of protein (level 2) recommended by NRC. T3: control diet + 2.4 g undegradable methionine (Smartamine®)/day/kid (level 3). Feed intake, initial and monthly body weights were recorded. Blood samples were collected monthly and analyzed for metabolites and Co, Zn and Cu levels. Decreasing the dietary level of protein (T2) negatively affected (P<0.05) the total live weight gain, average daily gain and feed conversion ratio when compared with the control and T3 groups. Moreover, treatment, time and time × treatment caused a significant change on Co concentration in blood serum with higher value at the end of the experiment. Treatments had a significant effect (P<0.05) on blood serum cholesterol and protein levels. Undegradable methionine supplementation (T3) significantly increased longissimus dorsi weight, fat thickness and omental fat%. In conclusion, feeding Baladi kids below the NRC requirements of protein negatively affect the growth performance and feed efficiency. The recommended protein level by NRC for growing kids cover the requirements of growing black Baladi kids for maximum growth and productivity.

Impact of feeding saltbush twigs on feed intake, weight gain, and some mineral levels of fattening awassi lambs.

This experiment was conducted to investigate the effect of the inclusion of saltbush (Atriplex sp.) on the productive performance and blood mineral profile of fattening lambs. Eighteen Awassi lambs, 70 +/- 3 days of age and 23 +/- 1.8 kg body weights, were randomly selected and divided into three equal groups. Lambs in group one (control) were offered 0.2 kg/day shredded straw of barley (tibin) as the sole source of roughage, while lambs in treatment groups 2 and 3 were provided either 0.2 kg/day Atriplex nummularia or Atriplex halimus as their sole roughage content for 10 weeks. All lambs were also provided 1.1 kg/day of concentrate ration. Although lambs fed A. halimus had significantly (P < 0.05) lower dry matter intake than the control group, the daily weight gain of the two groups of lambs were not significantly different (P > 0.05). Lambs fed either A. nummularia or A. halimus had significantly lower (P < 0.05) calcium and copper levels but significantly higher (P < 0.05) cobalt levels in their blood serum than the control group. Zinc blood serum level was not affected (P > 0.05) by the treatment diets. These results suggested that A. nummularia and A. halimus can substitute for barley straw in the ration of fattening Awassi lambs without compromising lambs weight gain; however, special attention should be given to the mineral status in lambs if saltbush is a major feed component for prolonged periods of time.

Effect of selenium supplementation of cows on maternal transfer of selenium to fetal and newborn calves.

A trial was conducted to determine the effect of maternal supplementation of Se on transfer of Se to the fetus during late gestation. Holstein cows were randomly assigned at dry-off to receive no Se or 3 mg/d of supplemental Se as selenite delivered via an intraruminal bolus. Supplementation significantly increased concentrations of Se in blood of dams at parturition. Similarly, calves of cows that were supplemented with Se had higher Se in blood and liver. Colostral concentrations of Se were increased by maternal Se supplementation; Se increased in the casein fraction. The Se concentrations in blood, plasma, and liver of calves were positively correlated with the Se concentrations in plasma of the dam at parturition. Concentrations of Se in colostrum and in calf liver also were closely correlated. Concentrations of Se in calf liver at d 42 were closely correlated with concentrations of Se in liver at birth. Maternal supplementation of Se increased Se reserves in the liver of the newborn and in colostrum. Carryover effects of Se supplementation of dams were evident in calves at 42 d of age.

Deposition of copper, manganese, zinc, and selenium in bovine fetal tissue at different stages of gestation.

Developmental changes of Cu, Mn, Zn, and Se in fetal liver and kidney and the intracellular distributions were determined. Fetuses were obtained from crossbred beef heifers (n = 25) that were slaughtered at different stages of pregnancy. Fetal age was estimated from crown to rump measurements. Selenium concentration of fetal liver increased from d 145 to 195 but decreased from d 195 to 245. Fetal age did not affect Cu, Mn, or Zn in fetal liver and kidney or Se in kidney. Bone Ca significantly decreased with fetal age, but neither bone P nor Ca:P ratio changed. Liver Zn concentrations were correlated negatively with kidney Mn but positively with liver Se. Within fetal liver, the crude nuclear fraction had the largest amount of Cu, and the largest amounts of Zn and Mn were in the cytosolic fractions. The ribosomal fractions contained the least Cu, Zn, and Mn. Results indicate the normal changes that occur in tissue concentrations of minerals in the developing bovine fetus. Storage of minerals in fetal tissue reflects fetal demands for growth and the ability of the dam to transfer minerals.

Mineral deficiencies in grazing dairy cattle in Kordofan and Darfur regions in western Sudan.

The seasonal changes in mineral profiles in serum of grazing dairy cattle and the concentrations of nutrients available from forages were determined in western Sudan. Blood samples were collected seasonally from dairy cows, Kenana and Botana breeds, in 6 locations in Kordofan and Darfur. Data were analysed as a split-plot design with repeated measures. The results indicated there were significant seasonal changes in concentrations of P, Cu and K, Ca, Mg, Na, Co, and Zn in blood serum of grazing cows. Concentrations of P, Ca and Na in serum were lowest during the late dry season (4.5 mg/dl, 8.21 mg/dl and 129 mEq/L respectively), while concentrations of Cu, deficient throughout the year, were lowest during the rainy season (0.35 microgram/ml). The interaction of location x season was significant for serum P, Ca, Cu, Mg, Na, Co and K. Kenana cattle had lower Zn in serum (0.96 microgram/ml) than Botana cattle (1.13 microgram/ml). During the dry season, forages had very low CP (3.5 +/- 0.5%), high neutral detergent fibre (NDF) (67.5 +/- 1.8%) and high acid detergent (ADF) (38.5 +/- 1.2%) content. Calcium, P and Na levels in forages were deficient during the dry season (0.38 +/- 0.03%, 0.08 +/- 0.03% and 0.047 +/- 0.01% respectively). Copper also was deficient in forages during the dry season, but adequate during the mid-rainy season (3.0 +/- 2.4 and 26.1 +/- 1.5 mg/kg respectively). In conclusion, the low Cu concentration in sera of cattle indicated a possible nutritional deficiency throughout the year, while P, Ca, and Na were low in sera during the late dry season. Thus, seasonal deficiencies of minerals may affect productivity of cattle in the Kordofan and Darfur regions of Sudan.

Effect of selenium supplements on the distribution of selenium among serum proteins in cattle.

The objective of this study was to determine the effects of the amount and chemical form of dietary Se on the distribution of Se among serum proteins. Six growing calves were assigned in a completely randomized design to receive diets containing either adequate (0.41 microgram/g) or excess (0.73 microgram/g) dietary Se. Proteins in serum collected from the calves were separated into albumin, glutathione peroxidase, and selenoprotein P fractions, and the concentration of Se in each was determined. The concentration of Se within serum was elevated by dietary Se supplementation. The selenoprotein P fraction within serum contained the largest percentage of Se among the serum proteins. In a second study, 12 mature cows were assigned to receive one of four experimental salt mixes containing 20, 60, or 120 micrograms of Se as sodium selenite/g of salt mix; the fourth treatment was 60 micrograms of Se as selenized yeast/g of salt mix. Cows given salt with 120 micrograms of Se as selenite or 60 micrograms of Se as selenized yeast had the highest concentrations of Se in whole blood; however, concentrations of Se in serum did not differ among treatments. Concentrations of Se in the protein fractions within serum were not affected by treatment. Within serum, the highest concentration of Se was in the selenoprotein P fraction (31.6 ng/ml), the smallest concentration was in the glutathione peroxidase fraction (4.7 ng/ml), and an intermediate amount of Se was obtained from the albumin fraction (8.5 ng/ml). In conclusion, selenized yeast and selenite as sources of Se for supplementation of cattle resulted in similar patterns of Se distribution among proteins in serum. The greatest concentration of Se was found in the selenoprotein P fraction, which may contribute to Se transportation or function as an antioxidant.