Effect of a mechanical grooming brush on the behavior and health of recently weaned heifer calves.

BACKGROUND: Calf stress at weaning and during transition to group pens represents a concern in dairy operations. Favoring natural behaviors, such as grooming, may help on reducing this challenge. Our objective was to evaluate the effect of a mechanical grooming brush on behavior and health of recently weaned calves, after transferring from individual to group housing. Two treatment groups (control [CON, n = 81]; automated brush [AB, n = 81]) were compared enrolling Holstein heifers (94 ± 7 d old) that were monitored for 20 days. Four cohorts, considering one CON and one AB group (19-20 calves/pen/cohort) were enrolled sequentially. Each calf was weighed, clinically evaluated, and affixed with a 3-D accelerometer sensor attached to the ear at enrolment. Continuous measurements (min/h) were generated for the following behaviors: Not-active, active, highly active, eating, and ruminating. Cameras for continuous video recording were installed in each pen, and calves were weighted at the last day of the study (d 20). Behavioral data were summarized as daily averages (min/h). Data was examined using repeated measures analysis for nested factors, with day as the time unit. RESULTS: Overall, calves had their first interaction with the brush within 2.5 days with a mean (SE) of 7 (±9.6) h after being transferred to group pens. A significant effect was determined for the interaction day by treatment on the time spent not-active and eating. Average not-active time was greater in CON compared to AB (22.8 ± 0.82 min/h vs. 21.7 ± 0.82 min/h), while eating time was greater in AB compared with CON (7.01 ± 0.40 min/h vs. 6.43 ± 0.40 min/h). Treatment groups had a similar weight gain and time to the first disease. CONCLUSIONS: We concluded that the use of a mechanical brush influenced behavior, reducing not-active time, while increasing eating time. The consequences of this change in activity require further investigation.

Effect of prebiotic supplementation with stabilized rice bran in milk of pre-weaned organic Holstein calves.

BACKGROUND: The first month of life possess significant challenges for dairy calves due to high susceptibility to digestive diseases. The objective of this study was to evaluate the effect of prebiotic supplementation with stabilized rice bran (SRB) in milk on health, immunity, and performance of pre-weaned organic dairy calves. Holstein heifer calves (n = 90) were enrolled at 6 ± 1 days old and monitored for 28 days, from July to August 2017. Calves were randomly assigned to a control (CTR; n = 45) or a treatment group (SRB; n = 45). The CTR group received milk alone and the SRB group received 120 g of SRB per day in milk to achieve a 10% w/w dose of the total calories. Daily health evaluations were conducted to score health status and disease severity (healthy, slightly affected, moderately or severely sick) of calves, through integrated assessment of diarrhea, dehydration, attitude, and milk intake. Body weights and fecal IgA quantification were completed on the first and last day of the study. RESULTS: Overall, weight gain and fecal IgA concentrations were not affected by the dietary addition of SRB. The total number of calf-days classified as healthy or sick were not different between treatment groups. Similarly, the number of calf-days categorized as slightly affected, moderately sick, or severely sick did not differ between treatment groups. Time to event analyses indicated a tendency for a treatment effect in the time to the first moderate case of diarrhea (P = 0.08), as well as in the time to recovery from diarrhea (P = 0.052), favoring control calves. CONCLUSIONS: These results indicated that the dietary addition of SRB in milk did not have an effect in health, immunity or performance of pre-weaned dairy calves.

The relationship of pulmonary artery copper concentrations and genes involved in copper homeostasis in cattle, Swine, and goats.

Liver and pulmonary artery tissue from 5 Angus cross bred steers, 6 goats, and 6 pigs were collected at a commercial abattoir to examine the relationship of pulmonary artery copper (Cu) concentrations and genes involved in copper homeostasis. Liver and pulmonary artery samples were collected at the time of harvest and snap frozen. Liver and pulmonary artery Cu concentrations were determined via flame atomic absorption spectrophotometry and gene expression was determined via real time PCR. Liver Cu concentrations (mg Cu/kg DM±SE) were higher (p<0.01) in cows (396.4±109.1) and goats (181.4±37.0) than in pigs (19.2±3.5). All liver Cu concentrations were within normal ranges and considered adequate for each species. Liver Cu concentration was more variable in cows and goats compared to pig liver Cu concentrations. Pulmonary artery ß-hydroxylproline was higher (p<0.01) in cow and pig than goat. Real Time PCR revealed that goat liver atp7a was positively correlated (r(2) = 0.92; p<0.01) to liver Cu concentrations while cow and pig atp7a was not correlated to liver Cu concentration. In the pig, liver atp7a concentration was positively correlated to atp7b (r(2) = 0.66; p<0.05). Pulmonary artery Cu concentration was highest in cows (14.9±4.7), intermediate in pigs (8.9±3.3), and lowest in goats (3.9±1.1). Goat pulmonary artery Cu concentration was not correlated to ctr1 concentration, however, atp7a concentration was positively correlated with ctr1 (r(2) = 0.90; p<0.01). In cow pulmonary artery, loxl1 concentration was positively correlated to eln mRNA concentration (r(2) = 0.91; p<0.02). Pulmonary artery CTR1 protein concentration was positively correlated to pulmonary artery Cu (r(2) = 0.85; p = 0.03) concentration while negatively correlated to liver Cu (r(2) = -0.79; p<0.04). Pulmonary artery Cu concentration was not correlated to concentration of Cu homeostatic genes in the pig. These data indicate that genes involved in Cu homeostasis (ctr1, atp7A, atp7B, loxl1 and eln) are differently regulated in different species.

Persistent fetal infection with bovine viral diarrhea virus differentially affects maternal blood cell signal transduction pathways.

The consequences of viral infection during pregnancy include impact on fetal and maternal immune responses and on fetal development. Transplacental infection in cattle with noncytopathic bovine viral diarrhea virus (ncpBVDV) during early gestation results in persistently infected (PI) fetuses with life-long viremia and susceptibility to infections. Infection of the fetus during the third trimester or after birth leads to a transient infection cleared by a competent immune system. We hypothesized that ncpBVDV infection and presence of an infected fetus would alter immune response and lead to downregulation of proinflammatory processes in pregnant dams. Naïve pregnant heifers were challenged with ncpBVDV2 on day 75 (PI fetus) and day 175 [transiently infected (TI) fetus] or kept uninfected (healthy control fetus). Maternal blood samples were collected up to day 190 of gestation. Genome-wide microarray analysis of gene expression in maternal peripheral white blood cells, performed on days 160 and 190 of gestation, revealed multiple signal transduction pathways affected by ncpBVDV infection. Acute infection and presence of a TI fetus caused upregulation of the type I interferon (IFN) pathway genes, including dsRNA sensors and IFN-stimulated genes. The presence of a PI fetus caused prolonged downregulation of chemokine receptor 4 (CXCR4) and T cell receptor (TCR) signaling in maternal blood cells. We conclude that: 1) infection with ncpBVDV induces a vigorous type I IFN response, and 2) presence of a PI fetus causes downregulation of important signaling pathways in the blood of the dam, which could have deleterious consequences on fetal development and the immune response.

Trace mineral source influences ruminal distribution of copper and zinc and their binding strength to ruminal digesta1,2,3.

Eight crossbred steers (BW 719.0 ± 65.0 kg) with ruminal and duodenal cannulae were used to examine the effect of trace mineral (TM) source on digestibility; ruminal and duodenal solubility of Cu, Zn, and Mn; and in vitro release of Cu, Zn, and Mn from the solid fraction of ruminal digesta. Experiment 1 determined the effect of TM source on DM and NDF digestibility in steers fed a corn silage and steam-flaked corn-based diet. Treatments consisted of 10 mg Cu, 20 mg Mn, and 30 mg Zn/kg DM from either sulfate TM (STM) or hydroxy TM (HTM) sources. Following a 14-d adaptation period, total fecal output was collected for 5 d. Dry matter digestibility was not affected by treatment, but NDF digestibility tended (P < 0.09) to be greater in HTM vs. STM supplemented steers. In Exp. 2, steers were fed a diet without supplemental Cu, Zn, or Mn for 19 d. Steers were then administrated a pulse dose of STM or HTM (2× the National Research Council requirements for Cu, Mn, and Zn) via the rumen fistula. Ruminal and duodenal samples were obtained at 2-h intervals starting at -4 and ending at 24 h relative to dosing. Ruminal soluble Cu and Zn concentrations were affected by treatment, time, and treatment × time. Soluble concentrations and percent soluble Cu and Zn in ruminal digesta increased (P < 0.05) above 0-h values for 10 h following dosing with STM, but not HTM. Concentrations of Cu and Zn in ruminal solid digesta were also affected by treatment, time, and treatment × time. Steers dosed with STM had greater (P < 0.05) solid digesta Cu concentrations at 2 and 4 h but lesser (P < 0.05) concentrations from 6 to 20 h post-dosing than those receiving HTM. Ruminal solid digesta Zn concentrations were greater (P < 0.05) in HTM vs. STM-dosed steers from 6 through 24 h post-dosing. Distribution of Mn in ruminal digesta was affected by TM source, but to a lesser extent than Zn and Cu. Duodenal soluble TM concentrations were variable and not affected by treatment. Binding strength of TM to ruminal solid digesta was estimated at 0, 6, and 12 h post-dosing using dialysis against chelating agents. The percentage of Cu and Zn released from ruminal solid digesta by dialysis against Tris-EDTA was greater (P < 0.05) at 12 h post-dosing from steers receiving HTM vs. STM. Results indicate that Cu and Zn from HTM have low solubility in the rumen and appear to be less tightly bound to ruminal solid digesta than Cu and Zn from STM.

Acute non-cytopathic bovine viral diarrhea virus infection induces pronounced type I interferon response in pregnant cows and fetuses.

Bovine viral diarrhea virus (BVDV) infection occurs in the cattle population worldwide. Non-cytopathic (ncp) BVDV strains cause transient infection (TI) or persistent infection (PI) depending on the host's immune status. Immunocompetent adult animals and fetuses in late gestation resolve the infection. Fetal infection in early gestation results in PI with chronic viremia and life-long viral shedding, ensuring virus perpetuation in the population. Eighteen pregnant heifers, divided into three groups, were intranasally inoculated with ncp BVDV2 virus early (day 75) and late (day 175) in gestation, or kept BVDV-naïve. Fetuses were retrieved on day 190. Antiviral activity in blood of dams and fetuses, maternal expression of interferon (IFN) stimulated gene 15kDa (ISG15), virological and serological status of heifers and fetuses, and fetal growth were studied. A pronounced antiviral activity in blood of heifers and TI fetuses during acute BVDV infection was accompanied by drastic up-regulation of ISG15 mRNA in maternal blood. Only one PI fetus expressed low IFN response 115 days post inoculation despite high BVDV antigen and RNA levels. PI fetuses presented with growth retardation. Infection of pregnant heifers with ncp BVDV2 early in gestation adversely affects fetal development and antiviral responses, despite protective immune responses in the dam.

Low blood ISG15 mRNA and progesterone levels are predictive of non-pregnant dairy cows.

ISG15 is induced by conceptus-derived interferon-tau in the endometrium on days 15-45 of pregnancy. It was hypothesized that pregnancy induces blood cell ISG15 gene expression and that low blood ISG15 mRNA levels provide an indication of non-pregnant cows on day 18. Blood was collected either on day 18 (n = 78) or on days 15-21, 25, and 32 (n = 21; serial collection) from dairy cows following artificial insemination (AI). Plasma progesterone concentration was determined using RIA. ISG15 mRNA levels were determined using real-time PCR. Pregnancy was diagnosed on day 32 using transrectal ultrasound. ISG15 mRNA levels increased after day 16, peaked at day 20 and then declined to day 16 levels by 32 days following AI. The average pregnancy rate was 43% based on blood cell ISG15 mRNA. The average pregnancy rate was 33% based on the transrectal ultrasound. Lower levels of ISG15 mRNA or progesterone during serial collections were 100% accurate in predicting non-pregnant cows based on day 32 transrectal ultrasound. However, detection of ISG15 mRNA yielded 78% accuracy in predicting pregnant cows, while progesterone yielded 58% accuracy. Average plasma progesterone based on pregnancy status according to ultrasound was consistently higher in pregnant (> 4 ng/ml) when compared with non-pregnant cows from days 15 to 32, except on day 16. It is concluded that detection of low blood ISG15 mRNA levels during serial collection from days 17 to 25 serves as an accurate indicator of cows that are not pregnant, thus allowing re-synchronization and insemination.

Extracts of Opuntia humifusa Fruits Inhibit the Growth of AGS Human Gastric Adenocarcinoma Cells.

Opuntia humifusa (OHF) has been used as a nutraceutical source for the prevention of chronic diseases. In the present study, the inhibitory effects of ethyl acetate extracts of OHF on the proliferation of AGS human gastric cancer cells and the mode of action were investigated. To elucidate the antiproliferative mechanisms of OHF in cancer cells, the expression of genes related to apoptosis and cell cycle arrest were determined with real-time PCR and western blot. The cytotoxic effect of OHF on AGS cells was observed in a dose-dependent manner. Exposure to OHF (100 µg/mL) significantly induced (P<0.05) the G1 phase cell cycle arrest. Additionally, the apoptotic cell population was greater (P<0.05) in OHF (200 µg/mL) treated AGS cells when compared to the control. The expression of genes associated with cell cycle progression (Cdk4, Cdk2, and cyclin E) was significantly downregulated (P<0.05) by the OHF treatment. Moreover, the expression of Bax and caspase-3 in OHF treated cells was higher (P<0.05) than in the control. These findings suggest that OHF induces the G1 phase cell cycle arrest and activation of mitochondria-mediated apoptosis pathway in AGS human gastric cancer cells.

A comparison of supplemental calcium soap of palm fatty acids versus tallow in a corn-based finishing diet for feedlot steers.

Rumen bypass fat is commonly added to increase energy intake in dairy cattle. The objective of this study is to examine the addition of rumen bypass fat during finishing period on performance and carcass characteristics in grain fed steers. This study was conducted as a completely randomized block design with 126 cross-bred steer calves (initial BW 471.5 ± 7.5 kg) randomly assigned to pens with 9 steers/pen (n = 7 pens/treatment). Each pen was randomly assigned to one of two treatment groups; rumen bypass fat treatment (CCS, calcium soap of palm fatty acids) and control diet (CT, tallow). The diets were formulated to be isonitrogenous and isocaloric. Animals were fed twice daily at 110 % of the previous daily ad libitum intake. Blood from each sample was taken from the jugular vein. Muscle and adipose samples were collected from the longissimus dorsi regions. Feedlot performance and carcass characteristics were assessed. To examine adipogenic gene expression, quantitative real-time PCR was completed. Steers fed the CT had a greater level of performance for most of the parameters measured. The CT group had greater DMI (P < 0.05) and tended to have greater ADG (P < 0.10). Marbling score (P < 0.05) and quality grade (P < 0.05) were greater for steers fed the CT diet than those fed CCS. The longissimus muscle area tended to be greater (P < 0.10) in steers fed CT (87.60 cm(2)) than those fed CCS (84.88 cm(2)). The leptin mRNA expression was down-regulated (P < 0.05) in adipose tissue of steers fed a CCS when compared to those fed CT. These data suggest that calcium soap of palm fatty acids can be added to finishing diets without significant reduction in final body weight, although there may be modest reductions in marbling and quality scores.

Evaluation of a point-of-care glucose and ß-hydroxybutyrate meter operated in various environmental conditions in prepartum and postpartum sheep.

OBJECTIVE: To compare ß-hydroxybutyrate (BHB) and glucose concentrations measured with a dual-purpose point-of-care (POC) meter designed for use in humans and a laboratory biochemical analyzer (LBA) to determine whether the POC meter would be reliable for on-farm measurement of blood glucose and BHB concentrations in sheep in various environmental conditions and nutritional states. ANIMALS: 36 pregnant mixed-breed ewes involved in a maternal feed restriction study. PROCEDURES: Blood samples were collected from each sheep at multiple points throughout gestation and lactation to allow for tracking of gradually increasing metabolic hardship. Whole blood glucose and BHB concentrations were measured with the POC meter and compared with serum results obtained with an LBA. RESULTS: 464 samples were collected. Whole blood BHB concentrations measured with the POC meter compared well with LBA results, and error grid analysis showed the POC values were acceptable. Whole blood glucose concentrations measured with the POC meter had more variation, compared with LBA values, over the glucose ranges evaluated. Results of error grid analysis of POC-measured glucose concentrations were not acceptable, indicating errors likely to result in needless treatment with glucose or other supplemental energy sources in normoglycemic sheep. CONCLUSIONS AND CLINICAL RELEVANCE: The POC meter was user-friendly and performed well across a wide range of conditions. The meter was adequate for detection of pregnancy toxemia in sheep via whole blood BHB concentration. Results should be interpreted with caution when the POC meter is used to measure blood glucose concentrations.

Characterization and identification of hepatic mRNA related to copper metabolism and homeostasis in cattle.

Copper is an essential trace mineral required for growth and development. Copper homeostasis within the cell is mediated by the expression of the Cu transporter protein (CTR1), ATPase7A (ATP7A), ATPase7B (ATP7B), Cox17, and Cu chaperone for Cu-Zn superoxide dismutase (CCS) which helps to regulate Cu uptake, export, and intracellular compartmentalization in non-ruminants. Copper also serves as a cofactor of antioxidant, superoxide dismutase1 (SOD1). Liver tissue from eighteen Holstein bull calves (average BW 201 +/- 58.5 kg, 7.3 +/- 1.9 months) from a previous experiment were utilized to characterize and identify hepatic mRNA related to Cu metabolism and homeostasis in cattle. Hepatic Cu concentration was determined via flame atomic absorption, and total RNA was extracted using TRI reagent and purified using RNeasy. Hepatic Cu concentrations ranged from 86 to 801 mg of Cu/kg DM. Real-time polymerase chain reaction analysis revealed that CTR1, ATP7A, and ATP7B mRNA expressions were negatively correlated with hepatic Cu concentration, while CCS (P = 0.0887) and SOD1 had a tendency (P = 0.0733) to be negatively correlated to hepatic Cu concentration. These data indicate that higher than normal hepatic Cu concentration downregulates gene expression of CTR1, ATP7A, ATP7B, and Cox17, which are involved in bovine liver copper homeostasis.

Maternal undernutrition induces differential cardiac gene expression in pulmonary hypertensive steers at high elevation.

Pulmonary hypertension, characterized by elevated pulmonary arterial pressure (PAP) and right ventricular hypertrophy, is caused by decreased atmospheric oxygen at high altitude. We hypothesized that maternal undernutrition programs right ventricle gene expression and sensitivity to increasing PAP at high altitude (2,183 m). On day 30 of gestation, forty Angus x Gelbvieh cows received diets to induce either gain (Control) or loss of body weight (Restricted) until day 125 of gestation. On day 126 of gestation, Restricted cows were realimented to achieve the same body weight as Controls by day 250. Parturition occurred naturally. PAP, which ranged from 40 to 114 mmHg, was determined in 15-mo-old steers from Control or Restricted cows before necropsy. At necropsy, hearts were collected from steers, separated into right and left ventricles, atria, and septa and weighed. Ventricular thickness was recorded. Eight Affymetrix bovine microarrays were screened [four high PAP (two Control and two Restricted) and four low PAP (two Control and two Restricted)] with right ventricle mRNA. This analysis revealed that pentraxin-related protein, interferon-related developmental regulator, and peroxisome proliferator-activated receptor-gamma coactivator-1alpha were differentially expressed (P < 0.05) in steer right ventricle from high-PAP cows compared with low-PAP cows. Also, activation peptide and pancreas cationic trypsinogen, alpha-actin, similar to ubiquitin carboxylesterase, were differently expressed (P < 0.05) in steers from Restricted cows compared with those from Control cows. Upregulated genes in high-PAP right ventricle have been associated with pathological cardiac hypertrophy. It is concluded that right ventricle gene expression may be differentially programmed by maternal undernutrition in the fetus during early gestation and may be detrimental to health and longevity of offspring, particularly at high altitude.

Maternal nutrient restriction alters gene expression in the ovine fetal heart.

Adequate maternal nutrient supply is critical for normal fetal organogenesis. We previously demonstrated that a global 50% nutrient restriction during the first half of gestation causes compensatory growth of both the left and right ventricles of the fetal heart by day 78 of gestation. Thus, it was hypothesized that maternal nutrient restriction significantly altered gene expression in the fetal cardiac left ventricle (LV). Pregnant ewes were randomly grouped into control (100% national research council (NRC) requirements) or nutrient-restricted groups (50% NRC requirements) from day 28 to day 78 of gestation, at which time fetal LV were collected. Fetal LV mRNA was used to construct a suppression subtraction cDNA library from which 11 cDNA clones were found by differential dot blot hybridization and virtual Northern analysis to be up-regulated by maternal nutrient restriction: caveolin, stathmin, G-1 cyclin, alpha-actin, titin, cardiac ankyrin repeat protein (CARP), cardiac-specific RNA-helicase activated by MEF2C (CHAMP), endothelial and smooth muscle derived neuropilin (ESDN), prostatic binding protein, NADH dehydrogenase subunit 2, and an unknown protein. Six of these clones (cardiac alpha-actin, cyclin G1, stathmin, NADH dehydrogenase subunit 2, titin and prostatic binding protein) have been linked to cardiac hypertrophy in other species including humans. Of the remaining clones, caveolin, CARP and CHAMP have been shown to inhibit remodelling of hypertrophic tissue. Compensatory growth of fetal LV in response to maternal undernutrition is concluded to be associated with increased transcription of genes related to cardiac hypertrophy, compensatory growth or remodelling. Counter-regulatory gene transcription may be increased, in part, as a response to moderating the degree of cardiac remodelling. The short- and long-term consequences of these changes in fetal heart gene expression and induction of specific homeostatic mechanisms in response to maternal undernutrition remain to be determined.