Impact of volume,immunoglobulin G concentration,and feeding method of colostrum product on neonatal nursing behavior and transfer of passive immunity in beef calves

One-third of beef calves fail to achieve adequate transfer of passive immunity (TPI) through timely ingestion of colostrum, which substantially increases their risk of preweaning morbidity and mortality. Two randomized clinical trials were designed to assess the impact of volume, immunoglobulin G (IgG) concentration, and feeding method of colostrum product on neonatal nursing behavior and TPI. In Trial 1, 47 calves were randomly assigned to receive one of three colostrum interventions by oro-esophageal tube feeder (OET): 1 L with 100 g/L IgG, 1.4 L with 70 g/L IgG, or 2 L with 100 g/L IgG. In Trial 2, 29 calves were randomly assigned to be fed 1 L of colostrum product with 100 g/L IgG by either nipple bottle (NB) or OET. Colostrum intervention (i.e. feeding of colostrum product) occurred within 60 minutes of birth. Cow-calf pairs were monitored by video surveillance in individual stalls for 24 h. Dam colostrum was collected at 10 minutes and calf serum was collected at 24–36 h after birth to assess IgG concentration. Differences among colostrum intervention groups on latency to stand and nurse were analyzed using Kaplan-Meier survival curves and Cox proportional hazard models. The impact of colostrum intervention group on TPI was assessed using multivariable linear regression modeling. In Trial 1, calves fed 1.4 L with 70 g/L IgG by OET nursed from their dams statistically significantly earlier compared to calves fed 1 L with 100 g/L IgG (P = 0.003) and calves fed 2 L with 100 g/L IgG (P = 0.008). Six of the 15 calves in the NB group in Trial 2 refused to consume part of the colostrum feeding offered by bottle and required follow-up tube feeding of the remaining volume. These calves were analyzed as a separate group (NB + OET). Calves fed 1 L by NB stood and nursed statistically significantly earlier than calves fed by OET (P = 0.005) or a combination of NB + OET (P = 0.003). Calf serum IgG concentrations were not statistically significantly different among colostrum intervention groups (P > 0.1). Overall, the colostrum interventions assessed in this study led to only one calf with failed TPI. While statistically significant differences in serum IgG concentrations were not detected in this study, subsequent nursing behavior did vary and was improved by feeding a moderate volume (1.4 L with 70 g/L IgG) of colostrum when using an OET, and by using the NB when feeding a smaller volume (1 L with 100 g/L IgG).     

Heat treatment of bovine colostrum: effects on colostrum metabolome and serum metabolome of calves

Bovine colostrum is important for neonates' health due to its nutritive and non-nutritive components. Heat treatment of colostrum is a well-established management tool, but it may influence colostrum components and affect the health status of calves. In our previous studies, we had shown that colostrum proteome and serum proteome of calves were altered by heat treatment to different degrees. Our objectives in this study were to investigate the effects of heat treatment on colostrum metabolome and the effect of feeding heat-treated colostrum on the serum metabolome of newborn calves. Further, the changes in serum metabolome from before to after colostrum feeding were characterized. Newborn Holstein female calves (n = 10) were randomized within pairs and fed heat-treated (n = 5; 60 °C, 60 min) or raw (n = 5) colostrum at 8.5% of birth BW by esophageal feeder within 1 h of birth. After a single colostrum feeding, calves were not fed until after the 8 h time point. Blood samples were taken immediately prior to feeding (0 h) and 8 h after feeding. The colostrum and serum metabolome were first analyzed using reverse-phase chromatography and tandem MS, and serum metabolome was then further analyzed using hydrophilic interaction chromatography and tandem MS. In colostrum metabolome, 458 features were identified and 328 were annotated and a trend of separation between raw and heat-treated colostrum could be observed through multivariate analysis. In serum metabolome, 3 360 features were identified and 1 439 were annotated, but no trend of separation was observed between the two groups of calves fed raw colostrum vs. heat-treated colostrum. The serum metabolome presented substantial differences comparing before (0 h) and after colostrum feeding (8 h); in particular, a tripeptide, β-homovaline-β-homoalanine-β-homoleucine, and 1-(2-acetamido-2-deoxy-α-d-glucopyranosyl)-1D-myo-inositol had higher concentrations after colostrum feeding than before, along with other metabolites that were not fully annotated. Based on a relatively small sample size, our findings point to the effect of heat treatment on the change of colostrum metabolome, but not on the change of serum metabolome of calves fed raw colostrum vs. heat-treated colostrum. Further studies using larger sample size and complementary analytical techniques are warranted to further explore potential heat treatment-induced alterations in colostrum metabolome.     

Influence of weaning regimen on intake,growth characteristics and plasma blood metabolites in male buffalo calves

Experiment was conducted to evaluate the effect of weaning age on growth performance, feed intake, feed efficiency (FE) and blood metabolites in Nili-Ravi male buffalo (Bubalus bubalis) calves. Twenty-four male buffalo calves were assigned to one of the three treatment groups: continuous milk feeding (CMF), limited milk feeding (LMF) and early weaning (EW), and weaned off milk at 12, 10 and 8 weeks of age, respectively. For the first 3 days after birth, calves in all three treatments were fed colostrum, and were then moved to individual milk feeding at 10% of BW for the next 6 weeks. Thereafter, the provision of milk to the CMF group was gradually tapered to zero through week 12, using week 6 intakes as a base. The LMF calves were fed milk at 7.5%, 5.0%, 3.5%, and 1.5% of BW during weeks 7 to 10, respectively. Lastly, calves in the EW group were fed milk at 5.0% and 2.5% of BW at weeks 7 and 8, respectively. Calf starter (CS) feed was also provided ad libitum from weeks 2 to 12 and individual intakes were recorded on a daily basis. Blood samples were taken from weeks 6 to 12, on a weekly basis; whereas, the BW, heart girth, withers height and hip width were measured at the start of experiment and later on a weekly basis. Weight gain, average daily gain, and body measurements were the same across all three groups. Milk intake was lower (P < 0.05), whereas CS intake was greater (P < 0.05) in the EW calves compared with the other treatment groups. Dry matter intake was greater (P < 0.05) in the EW and LMF calves compared with the CMF calves. The FE was greater (P < 0.05) in the CMF calves compared with the LMF and EW treatment groups. Blood glucose concentration was similar among the treatments; however, blood urea nitrogen was greater (P < 0.05) in the EW calves compared with the CMF and LMF groups. Plasma concentration of non-esterified fatty acids was higher (P < 0.05) in the EW calves compared with the CMF calves. In light of these results, it is evident that buffalo calves can be successfully weaned as early as 8 weeks of age without negatively affecting their growth performance.     

Association study between relative expression levels of eight genes and growth rate in Hungarian common carp (Cyprinus carpio)

One of the most important issues in improving the competitiveness of the fish production sector is to improve the growth rate of fish. The genetic background to this trait is at present poorly understood. In this study, we compared the relative gene expression levels of the Akt1s1, FGF, GH, IGF1, MSTN, TLR2, TLR4 and TLR5 genes in blood in groups of common carps (Cyprinus carpio), which belonged to different growth types and phenotypes. Fish were divided into groups based on growth rate (normal group: n = 6; slow group: n = 6) and phenotype (scaled group: n = 6; mirror group: n = 6). In the first 18 weeks, we measured significant differences (p < 0.05) between groups in terms of body weight and body length. Over the next 18 weeks, the fish in the slow group showed more intense development. In the same period, the slow group was characterized by lower expression levels for most genes, whereas GH and IGF1 mRNA levels were higher compared to the normal group. We found that phenotype was not a determining factor in differences of relative expression levels of the genes studied.     

In Vivo Selection of Resistant E. coli after Ingestion of Milk with Added Drug Residues

Antimicrobial resistance represents a major global threat to modern medicine. In vitro studies have shown that very low concentrations of drugs, as frequently identified in the environment, and in foods and water for human and animal consumption, can select for resistant bacteria. However, limited information is currently available on the in vivo impact of ingested drug residues. The objective of our study was to evaluate the effect of feeding preweaned calves milk containing antimicrobial drug residues (below the minimum inhibitory concentration), similar to concentrations detected in milk commonly fed to dairy calves, on selection of resistant fecal E. coli in calves from birth to weaning. At birth, thirty calves were randomly assigned to a controlled feeding trial where: 15 calves were fed raw milk with no drug residues (NR), and 15 calves were fed raw milk with drug residues (DR) by adding ceftiofur, penicillin, ampicillin, and oxytetracycline at final concentrations in the milk of 0.1, 0.005, 0.01, and 0.3 µg/ml, respectively. Fecal samples were rectally collected from each calf once a week starting at birth prior to the first feeding in the trial (pre-treatment) until 6 weeks of age. A significantly greater proportion of E. coli resistant to ampicillin, cefoxitin, ceftiofur, streptomycin and tetracycline was observed in DR calves when compared to NR calves. Additionally, isolates from DR calves had a significant decrease in susceptibility to ceftriaxone and ceftiofur when compared to isolates from NR calves. A greater proportion of E. coli isolates from calves in the DR group were resistant to 3 or more antimicrobial drugs when compared to calves in the ND group. These findings highlight the role that low concentrations of antimicrobial drugs have on the evolution and selection of resistance to multiple antimicrobial drugs in vivo.     

Feeding behaviour and activity as early indicators of disease in pre-weaned dairy calves

Across the industry, there is large variation in health status of dairy calves and as a result, disease incidence and antibiotic use is high. This has significant implications for animal welfare, productivity and profitability of dairy and dairy-beef production systems. Technology-based early detection systems could alleviate these issues; however, methods of early detection of disease in dairy calves have not been widely explored. This study aimed to determine whether changes in activity and feeding behaviour can be used as early warning indicators of respiratory disease in calves. In total, 100 pre-weaned male Holstein calves (age: ~ 8−42 days) were used. Calves were group-housed and provided with starter diet, straw bedding and ad libitum water. Calves were fed milk replacer ad libitum through an automatic calf feeder, and each calf was fitted with a leg-mounted activity monitor. Daily activity and feeding behaviour variables were calculated for each calf. Each calf was assessed daily using a modified version of the Wisconsin Scoring System to assess respiratory disease status. Calves were classed as ‘Diseased’, ‘Intermediate’ or ‘Healthy’ based on their cumulative health score. The peak day of the most extreme illness event was identified for each calf. Data from Diseased and Healthy calves were paired for analysis based on age and BW. Data were compared for the day of peak illness, and for the 3 days previous and post. Compared to healthy calves, diseased calves lay for longer and tended to have longer lying bouts (daily lying: 17.6 ± 0.3 vs 16.7 ± 0.2 h, P < 0.01; bout length: 74.8 ± 10.6 vs 56.0 ± 3.7 min, P = 0.09 for diseased and healthy calves, respectively). Diseased calves fed for a shorter time and had fewer feeder visits (with intake) each day compared to healthy calves (feeding time (min): 19.3 ± 1.4 vs 22.8 ± 1.5; P < 0.05; visits: 2.1 ± 0.2 vs 3.2 ± 0.4; P < 0.05). Importantly, differences between diseased and healthy calves were evident in both activity and feeding behaviour on the days prior to the peak day of disease. Lying bout length was greater in diseased calves for the 2 days prior to the peak day (P < 0.05), lying time was longer on day − 1 (P < 0.05) and feeder visits with milk intake were less frequent on day − 3 (P < 0.05). Thus, measurement of feeding and activity using precision technology within early detection systems could facilitate early intervention and optimized treatment.     

Growth performance,intestinal histomorphology,gut microflora and ghrelin gene expression analysis of broiler by supplementing natural growth promoters: A nutrigenomics approach

In an epoch of escalating number of antibiotic-resistance bacteria, there is a dire need to develop efficient and novel feeding strategies for animal nutrition as alternatives to antibiotics. Here, implicating nutrigenomic approach, phytobiotics and organic acids were used to evaluate ghrelin gene expression levels, gut microflora composition, performance parameters and intestinal histomorphological changes in broiler chickens. One-day-old chicks (n = 315) were reared for 42 days and distributed randomly into five experimental groups; each with three replicates (21 birds per replicate). Experimental groups were control: basal diet only, antimicrobial growth promoter: 40 g/metric ton of basal diet (virginiamycin), organic acids: 4 kg/metric ton of basal diet, phytobiotics: 3 kg/metric ton of basal diet, combination: 7 kg/metric ton of basal diet (organic acids 4 kg and phytobiotics 3 kg metric ton of feed). Growth performance, histological and ghrelin gene expression analysis were executed on 21 and 42 days while, quantitative bacterial analysis of cecum and ileum was performed on day 42. Increased feed intake and body weight (p < 0.05) were noticed in phytobiotics group. Addition of phytobiotics significantly improved (p < 0.05) villus height and ratio of villus height/crypt depth in ileum, jejunum, and duodenum and down-regulated ghrelin gene expression levels. Total coliform and Escherichia coli in cecal and ileal digesta were decreased significantly (p < 0.05) in organic acids group. Correlation analysis revealed Lactobacillus spp. were positively correlated to villus height/crypt depth ration in duodenum. The findings indicated the importance of gene-nutrient-microbiota interactions based on nutrigenomics approach. Hence, phytobiotics and organic acids might be suitable alternatives to antibiotics for improved performance and immunity, along with healthier meat production in poultry.     

Large-size fattening calves’ lots fed with automatic milk feeders may have an increased risk for Mycoplasma bovis infection spread and for antibiotic use

Bovine respiratory disease is the leading user of antibiotics (AB) in calf production. Mycoplasma (M.) bovis could lead to greater use of AB as it is a persistent and AB resistant causative agent for respiratory diseases. Two cross-sectional studies were set up to assess the effects of lot size and feeding system on M. bovis infection and the effects of M. bovis seroconversion, lot size and feeding system on AB use in calves’ feedlots. Twenty-six lots in 22 fattening farms were monitored for 41–81 days, from all-in entry of calves until three consecutive weeks without using any collective antibiotics. M. bovis spread was estimated by measuring seroconversion at entry and at the end of study period in 10–15 calves randomly sampled in each lot. All AB treatments used in the meanwhile were recorded. The lots were selected according to feeding system, i.e. individual bucket (n = 7) vs. automated milk feeder (AMF, n = 19), and lot size (30–519 calves), less than 50 calves (n = 9) vs. more than 50 calves (n = 17). Statistical analysis was performed using multivariable generalised linear models with fattening farms as random effect. M. bovis spread increased with lot size (odds ratio (OR) 2.9[1.4; 5.8] per two-fold increase in lot size). This proportion of seroconverted calves was lower in bucket-fed lots compared to lots fed with the AMF using a shared nipple (OR = 0.03[0.003; 0.41]). The main risk factor for AB use was the lot size, with an increase of 1.5[0.94; 1.98] treatments per two-fold increase in lot size. For same size lots, the use of bucket can decrease AB consumption by up to 1.03[−2.18; 0.14] treatments per calf compared to AMF. Analysis of the association between seroconversion to M. bovis and AB use was inconclusive. We found that bucket feeding in small-size lots, i.e. up to a maximum of 50 calves in the same space, limits seroconversion to M. bovis and enables lower use of AB in veal calf production.     

Synergic effects of exercise training and octopamine on peroxisome proliferator-activated receptor-gamma coactivator -1a and uncoupling protein 1 mRNA in heart tissue of rat treated with deep frying oil

Octopamine (OCT) have an adverse effect on heart function. One of the positive effects of exercise training is improving cardiac function and cardiomyocytes signaling, which along with herbal supplements can have better effects on the heart tissue. Therefore, the aim of this study was to evaluate the effects of exercise training and OCT on changes of PGC1α and UCP1 expression in heart tissue of rat treated with deep frying oil (DFO). In this study, 45 male wistar rats were divided into 5 groups (n = 9 in each): I) control (Co), II) DFO, III) DFO + exercise, IV) DFO + OCT, and V) DFO + OCT + exercise. The quantification of apoptotic effects of DFO in heart tissue was assessed by TUNEL assay. Masson's trichrome stain applied to study cardiomyocytic fibers. Moreover, PGC1α and UCP1 genes and proteins expression in all groups were investigated using quantitative real-time PCR and immunohistochemical method. A significant increase in apoptotic cells was observed in the DFO-treated group (p < 0.05). In Masson's Trichrome stain study, more cardiomyocytic fibers were observed and some lymphocytic cells were present in some fibers. Also, the expression of PGC1α and UCP1 was significantly increase in DFO + exercise group, DFO + OCT group, and DFO + OCT + exercise group compare to DFO group (p < 0.05). Based on these findings, exercise and octopamine can be considered as factors affecting the expression of PGC1α genes and UCP1 as well as drug poisoning.     

Long-Term Effects of Subacute Ruminal Acidosis (SARA) on Milk Quality and Hepatic Gene Expression in Lactating Goats Fed a High-Concentrate Diet

Purpose

The mechanism underlying the decline in milk quality during periods of feeding high-concentrate diets to dairy ruminants is not well documented. The aim of this study was to investigate the metabolic changes in the liver that contribute to the input of substrate precursors to the mammary gland after feeding a high-concentrate diet to lactating goats for a long period.

Experimental Design

Eight mid-lactating goats with rumen cannulas were randomly assigned to two groups. For 9 weeks, the treatment group was fed a high-concentrate diet (60% concentrate of dry matter, HC) and the control group was fed a low-concentrate diet (40% concentrate of dry matter, LC). Ruminal fluid, plasma, and liver tissues were sampled, microarray techniques and real-time polymerase chain reaction were used to evaluate metabolic parameters and gene expression in liver.

Results

Feeding a 60%-concentrate diet for 9 weeks resulted in a significant decrease in rumen pH. Changes in fat and protein content also occurred, which negatively affected milk quality. Plasma levels of leptin (p = 0.058), non-esterified fatty acid (p = 0.071), and glucose (p = 0.014) increased markedly in HC group. Plasma cortisol concentration was significantly elevated in the treatment group (p<0.05). Expression of the glucocorticoid receptor protein gene was significantly down-regulated (p<0.05) in the liver. The expression of genes for interleukin 1β, serum amyloid A, C-reactive protein, and haptoglobin mRNA was significantly increased (p<0.05) in the HC group. GeneRelNet analysis showed that gene expression involved in inflammatory responses and the metabolism of lipids, protein, and carbohydrate were significantly altered by feeding a high-concentrate diet for 9 weeks.

Conclusions

Activation of the acute phase response and the inflammatory response may contribute to nutrient partitioning and re-distribution of energy in the liver, and ultimately lead to a decline in milk quality.     

Extended transition milk feeding for 3 weeks improves growth performance and reduces the susceptibility to diarrhea in newborn female Holstein calves

Dairy calves may benefit from extending the duration of feeding transition milk (TM; the subsequent two to six milkings after parturition) to enhance performance and health during early life. The objective of this study was to assess the effect of replacing pasteurized waste milk (non-saleable milk containing antibiotic and/or drug residues) with pasteurized TM for 3 weeks on the growth performance and health of dairy calves. A total of 84 healthy newborn female Holstein calves were blocked by birth order and assigned randomly to 4 treatment groups with partial replacement of pasteurized waste milk by TM (second milkings after parturition) at 0 (0 l/day TM + 6 l/day milk), 0.5 (0.5 l/day TM + 5.5 l/day milk), 1 (1 l/day TM + 5 l/day milk), or 2 l (2 l/day TM + 4 l/day milk) for a 21-day period. From day 22 onward, all calves were fed individually with 6 l/day pasteurized waste milk. Calves were weaned on day 60 and monitored until day 90 of the study. Liquid feed DM intake (DMI) was increased with increasing levels of TM (P = 0.001). Starter feed DMI and total DMI (liquid feed DMI + starter feed DMI) were not affected by the treatment effect. Calves were fed 2 l/day TM gained more BW compared with those in the control group during the postweaning and overall periods. The average daily gain tended (P = 0.06) to be higher in calves fed 2 l/day TM compared with calves fed 0 (+ 65 g/day), 0.5 (+ 53 g/day), or 1 (+ 76 g/day) l/day TM during the preweaning period. Daily weight gain was also higher in calves fed 2 l/day TM compared with calves in the control group during the postweaning (+ 137 g/day; P = 0.04) and overall (+ 89 g/day; P < 0.01) periods, respectively. Calves fed 2 l/day TM had a higher feed efficiency compared with calves in the control group during all studied periods. The calves fed TM2 had a lower chance of having diarrhea compared with other treatment groups. Duration but not the frequency of diarrhea was lower in calves fed TM2 vs TM0 (2.5 vs 4.2 days; P = 0.03). In general, partial replacement of waste milk with TM (2 l/day) may be recommended to feed dairy calves at an early stage of life to support a higher growth rate and health benefits.     

The effects of feeding high or low milk levels in early life on growth performance,fecal microbial count and metabolic and inflammatory status of Holstein female calves

Gut microbial colonization and immune response may be affected by milk feeding method. The objective of this study was to determine the effects of feeding high or low volumes of milk on fecal bacterial count, inflammatory response, blood metabolites and growth performance of Holstein female calves. Colostrum-fed calves (n = 48) were randomly assigned to either high milk (HM; n = 24) or low milk (LM; n = 24) feeding groups. Low milk-fed calves were fed pasteurized whole milk at 10% of BW until weaning. In HM group, milk was offered to calves at 20% of BW for the first 3 weeks of life. Then, milk allowance was decreased gradually to reach 10% of BW on day 26 and remained constant until weaning on day 51. Calves were allowed free access to water and starter throughout the experiment. Body weight was measured weekly, and blood samples were taken on days 14, 28 and 57. Fecal samples were collected on days 7, 14 and 21 of age for the measurement of selected microbial species. By design, HM calves consumed more nutrients from milk during the first 3 weeks and they were heavier than LM calves on days 21, 56 and 98. High milk-fed calves had greater serum glucose and triglyceride levels on day 14 with no significant difference between groups on days 28 and 57. Blood urea nitrogen was higher in LM calves on day 14, but it was lower in HM calves on day 28. Calves in LM group had significantly greater blood tumor necrosis factor-α (TNF-α) than HM calves throughout the experiment. Serum amyloid A (SAA) concentration was higher in LM calves on day 14. However, HM calves showed higher levels of SAA at the time of weaning. Feeding high volumes of milk resulted in lower serum cortisol levels on days 14 and 28 but not at the time of weaning in HM calves compared to LM counterparts. Lactobacillus count was higher in feces sample of HM calves. Conversely, the numbers of Escherichia coli was greater in the feces of LM calves. Calves in HM group showed fewer days with fever and tended to have fewer days treated compared to LM group. In conclusion, feeding higher amounts of milk during the first 3 weeks of life improved gut microbiota, inflammation and health status and growth performance of Holstein dairy calves.     

Effect of substitution of groundnut with high glucosinolate mustard (Brassica juncea) meal on nutrient utilization,growth, vital organ weight and blood composition of lambs

Twenty-four 14-day-old weaner Avivastra (Russian Merino×Nali) male lambs were maintained for 180 days on ad libidum Cenchrus (Cenchrus ciliaris) hay and concentrate mixture (CM) contained groundnut meal (control) and mustard meal (MM group) as major protein source. The two CMs were isonitrogenous (21% CP) and isocaloric (2.78 Mcal ME kg⁻¹ DM), while, CM fed to MM group contained 24.6 mg glucosinolates g⁻¹ DM. Digestibility of nutrients was similar (P>0.05) in the two groups except for CP and hemicellulose, which was higher (P<0.05) in control. Urinary N loss was higher (P<0.01) in control than in MM group, whereas N retention (% of N intake and absorbed) was higher (P<0.01) in MM group compared to control. Dry matter (g kg⁻¹ BW) and glucosinolate intakes were higher in MM fed group, whereas DCP and ME intakes were similar (P>0.05) in the two groups. Average daily gain (ADG) was, however, 22% higher (P<0.01) in control than in MM group. Hemoglobin and albumin contents were lower (P<0.01) in MM group than in control. Serum thiocyanate content was 26.7 μg g⁻¹ in MM fed group, while it was not detected in control group. Thyroid weight was higher (P<0.01) while liver and kidney weights were lower (P<0.01) in MM group. Meat from dissected carcass of control group contained more protein and less fat, whereas the reverse was noticed in MM group. It is concluded that feeding mustard meal as protein supplement reduced growth rate and induced iodine deficiency. Carcass of lambs fed mustard meal had more fat and less protein.     

Effect of dietary replacement of fish meal protein with crawfish shell meal (Procambarus clarkii) on the growth performance,digestive enzyme activity and anti-oxidative capacity of Oujiang color common carp (Cyprinus carpio var. color)

This study was designed to evaluate the effects of dietary crawfish shell meal (CSM) on the growth performance, digestive enzyme activity and anti-oxidative capacity of Oujiang color common carp. 180 juvenile fish (initial weight 3.0 ± 0.5 g) were assigned to the control group and the CSM25 group (fed with 25% substitution of fish meal by CSM) for 8 weeks. Results showed that significant improvement in the weight gain rate (WGR) in CSM25 group than the control (p < .05), whereas no significant change in feed conversion ratio, specific growth rate and feeding intake between the groups (p > .05). Also, no significant difference was obsevered between the groups in terms of serum biochemical index and muscle composition (p > .05). And liver superoxide dismutase, catalase, glutathione peroxidase (GPx), lysozyme (LYZ) and protease activities in CSM25 group were significantly higher (p < .05). Moreover, histological analysis indicated that width of mucosa and thickness of muscular coat in mid-intestine were significantly changed (p < .05). In conclusion, dietary supplement with CSM25 induced high oxidative stress, promote protease activities and had no negative effects on the growth performance of Oujiang color common carp. Hence, CSM may be a viable alternative protein source to reduce the demand for fish meal.     

Effect of Feeding Selenium-Fertilized Alfalfa Hay on Performance of Weaned Beef Calves

Selenium (Se) is an essential micronutrient in cattle, and Se-deficiency can affect morbidity and mortality. Calves may have greater Se requirements during periods of stress, such as during the transitional period between weaning and movement to a feedlot. Previously, we showed that feeding Se-fertilized forage increases whole-blood (WB) Se concentrations in mature beef cows. Our current objective was to test whether feeding Se-fertilized forage increases WB-Se concentrations and performance in weaned beef calves. Recently weaned beef calves (n = 60) were blocked by body weight, randomly assigned to 4 groups, and fed an alfalfa hay based diet for 7 wk, which was harvested from fields fertilized with sodium-selenate at a rate of 0, 22.5, 45.0, or 89.9 g Se/ha. Blood samples were collected weekly and analyzed for WB-Se concentrations. Body weight and health status of calves were monitored during the 7-wk feeding trial. Increasing application rates of Se fertilizer resulted in increased alfalfa hay Se content for that cutting of alfalfa (0.07, 0.95, 1.55, 3.26 mg Se/kg dry matter for Se application rates of 0, 22.5, 45.0, or 89.9 g Se/ha, respectively). Feeding Se-fertilized alfalfa hay during the 7-wk preconditioning period increased WB-Se concentrations (P _Linear<0.001) and body weights (P _Linear = 0.002) depending upon the Se-application rate. Based upon our results we suggest that soil-Se fertilization is a potential management tool to improve Se-status and performance in weaned calves in areas with low soil-Se concentrations.     

Growth performance,nutrient digestibility,blood parameters,and carcass characteristics by lambs fed an oregano and cobalt blend

Shifting ruminal fermentation via feeding a blend of oregano (Organum vulgare L.) essential oils and Co-lactate (EOC; Rum-A-Fresh, Ralco, Inc. Marshall, MN) could improve lamb growth and carcass performance. Eighteen Suffolk × Little Han Tail F1 male lambs (20.3 ± 0.23 kg BW and approximately 3 months old) were randomly assigned using a completely random design to one of three treatments. Treatments were (1) EOC0: basal ration without EOC, (2) EOC4: basal ration plus 4 g/d EOC, and (3) EOC7: basal ration plus 7 g/d EOC. Initial and 24 d BW was similar (P > 0.10), but at 48 and 72 d, lambs fed EOC7 demonstrated greater (P = 0.01) BW compared with EOC0 fed lambs, while lambs fed EOC4 were intermediate and similar (P > 0.05). Average daily gains (ADGs) for 0–24 and 0–72 d were greater (P < 0.05) for lambs fed EOC4 and EOC7 compared with lambs fed EOC0, while DM intake was similar (P > 0.10). Feed conversions for 0–24 d were improved (P < 0.02) for lambs fed EOC4 and EOC7 compared with lambs fed EOC0. However, 0–72-d feed conversions were greater (P < 0.01) for lambs fed EOC7 compared to lambs fed EOC0, with lambs fed EOC4 being intermediate and similar (P > 0.05). DM, NDF, and ADF digestibilities were similar (P > 0.10) among treatments, while CP digestibility was greater (P < 0.01) for lambs fed EOC4 and EOC7 compared with lambs fed EOC0. Carcass weight and dressing percentages were improved (P < 0.01) for lambs fed EOC7 compared with lambs fed EOC0 and EOC4. Head width was greater (P > 0.01) for lambs fed EOC7 compared with lambs fed EOC0 and EOC4, while rump width was greater (P > 0.01) for lambs fed EOC4 and EOC7 compared with lambs fed EOC0. Plasma triglyceride and cholesterol concentrations were lower (P < 0.05) for lambs fed EOC4 and EOC7 compared with lambs fed EOC0, while albumin, total serum protein, and glucose concentrations were greater (P < 0.05) for lambs fed EOC4 and EOC7 compared with lambs fed EOC0. Feeding an EOC blend as an alternative antibiotic growth promoter at 4 and 7 g/d linearly improved lamb growth performance, feed conversions, frame growth, carcass weights, dressing percentages, and immunity.     

Comparison of glutathione peroxidase 1 and iodothyronine deiodinase 1 mRNA expression in murine liver after feeding selenite or selenized yeast

The experiment was conducted to compare the effect of different selenium sources on the expression of glutathione peroxidase 1 (GPx1) and iodothyronine deiodinase 1 (Dio1) mRNA in mice by quantitative real-time PCR. A total of 60 male Kunming mice at average body weight of 20 g were allotted to three groups in a randomized complete block design, namely two treatments and one control. Mice in Group 1 were fed a basal diet as control, while mice in Groups 2 and 3 were fed the basal diet supplemented with 0.1 mg/kg selenium as sodium selenite or selenized yeast, respectively. Whole feeding experiment lasted for 30 d. At the end of the feeding trial, liver mRNA levels of GPx1 and Dio1 were determined by quantitative real-time PCR, as well as growth performance, body composition, blood and GPx activity were determined. The results showed that no significant differences in overall growth performance and body composition, including body weight, body length, heart weight, kidney weight and liver weight, were found between the experimental groups (P>0.05). Blood GPx activity increased in all of the selenium supplemented groups compared with control group (P<0.01). However, blood GPx activity in selenized yeast group was higher than that in sodium selenite group (P<0.05). Liver mRNA levels of GPx1 and Dio1 also increased in the two selenium supplemented groups compared with the control group (P<0.05), while there was no significant difference between the sodium selenite and selenized yeast groups (P>0.05). In conclusion, selenium increased the mRNA expression of GPx1 and Dio1 genes in murine liver, and there was no significant difference between the organic or inorganic form of selenium used.