The relationship between serum IgG levels and age, leg injuries, infections and weight gains in dairy calves

Serum IgG profiles for calves up to 50 days varied markedly depending on the level of passively acquired immunity. A relationship between serum IgG at 5 days of age and prevalence of leg injuries (skin lesions) was found, whereas no associations were seen regarding IgG and diarrhoea or liveweight gain.     

Effects of parenteral supply of iron and copper on hematology, weight gain, and health in neonatal dairy calves

The objective of the present study was to examine the effects of parenteral administration of iron and copper on hematological parameters, weight gain, and health of neonatal dairy calves in the period when iron and copper deficiency could be existed. Twenty-four Holstein calves were used for the experiment and randomly assigned to four different treatments. Treatments consisted of (1) control (no injections of Fe and Cu), (2) test 1 (1000 mg Fe as fe-dextran was injected to each calf at day 2 of age), (3) test 2 (160 mg Cu as methionine-copper complex was injected to each calf at day 14 of age), and (4) test 3 (Fe and Cu were injected to each calf as mentioned previously). Blood samples were collected from all of the calves within 24-48 hours after birth and at 7, 14, 21 and 28 days of age for measuring hematological parameters and within 24-48 hours after birth and at 14, 21 and 28 days of age for the determination of iron, copper, TIBC concentrations, and AST activity. Anti-coagulated blood was analyzed shortly after collection for: number of red blood cell (RBC), hemoglobin (Hb), heamatocrit (HCT), total leukocyte count (WBC), Platelet (Plt), MCH, MCV, MCHC, and differential leukocyte counts. The amounts of iron, copper, TIBC, and AST were measured in serum. Group had significant effects on the amounts of HCT, RBC, hemoglobin, MCV, neutrophil, weekly weight gain, and daily gain during each week (p < 0.05). Sampling time had significant effects on the amounts of RBC, MCV, MCH, MCHC, WBC, neutrophil, lymphocyte, monocyte, platelet, fibrinogen, copper, TIBC, AST, weight, weekly gain and, daily gain during each week (p < 0.05). significant interactions between sampling time and group were seen for HCT, RBC, hemoglobin, MCV, platelet, total protein, fibrinogen, iron, and TIBC (p < 0.05). Improved RBC parameters and MCV were seen in calves of group 4 (test 3) in comparing with control group. Total and daily gains were also significantly improved in test groups in comparing with control group (p < 0.05). No significant difference was seen for the days of treatment between groups.     

牛初乳IgG对仔猪增重和血液指标的影响

选取10窝1日龄大白仔猪60头,随机分为3组。按不同剂量(0、500mg、1000mg)灌服牛初乳IgG,分别测定不同处理组仔猪日增重、血清总蛋白含量、血清牛IgG浓度,旨在探讨新生仔猪吸收异源IgG能力及异源IgG对仔猪生产性能及机体免疫功能的影响。结果显示,灌服IgG1000mg的仔猪,0～15日龄日增重、5、10日龄血清总蛋白含量显著高于对照组(0)(P<0.05),实验组5日龄血清牛IgG浓度较高,并能有效降低仔猪腹泻头次。     

Evaluation of antibody formation, daily weight gain and meat quality after vaccination of piglets against Mycoplasma hyopneumoniae

A Mycoplasma hyopneumoniae vaccine (Respisure, Pfizer AH) was tested for its effects on antibody formation, daily weight gain (DWG) in different growing periods, lung lesions and quality of meat (chemical composition, physicochemical properties and fatty acid composition). Two groups of conventional piglets were used for the investigation. One group of 11 females and 11 males was vaccinated intramuscularly at the age of 1 and 3 weeks. The other group of 22 piglets was left nonvaccinated as control. The results showed that antibodies against M. hyopneumoniae in the vaccinated group had been formed 14 days after the second vaccination and remained present till the end of the study at 147 days of age. In the nonvaccinated group, seroconversion started at 49 days of age and by the end of the study 10 out of 22 pigs had become seropositive. Vaccinated pigs achieved significantly higher daily weight gain (+30 g) and finishing body weight (+6.04 kg) than the nonvaccinated animals. In addition, the vaccinated pigs showed lesions involving 3.27% of the lung surface in average, while in the nonvaccinated pigs 9.04% of the lung surface was affected. Investigation of meat quality showed that the longissimus dorsi muscle of vaccinated pigs contained significantly lower percentage of fat (-0.63%) and its tryptophan/hydroxyproline ratio was significantly lower (-23.57) in comparison with the control animals. In addition, some other parameters also showed a favourable tendency, e.g. lean meat percentage was 0.91% higher, the protein content of the longissimus dorsi muscle was 0.35% higher, its water-binding capacity was also higher by 0.78%, its monounsaturated fatty acid concentration was 2.97% lower, while its polyunsaturated fatty acid content was 1.65% higher in the vaccinated pigs than in the nonvaccinated animals.     

Contribution of family labour to the profitability and competitiveness of small-scale dairy production systems in central Mexico

The objective of this work was to determine the effect of family labour on the profitability and competitiveness of small-scale dairy farms in the highlands of Central Mexico. Economic data from 37 farms were analysed from a stratified statistical sampling with a Neyman assignment. Three strata were defined taking herd size as criterion. Stratum 1: herds from 3 to 9 cows plus replacements, Stratum 2: herds from 10 to 19 cows and Stratum 3: herds from 20 to 30 cows. The policy analysis matrix was used as the method to determine profitability and competitiveness. The coefficient of private profitability (CPP) when the economic cost of family labour is included in the cost structure was 8.0 %, 31.0 % and 46.0 %. When the economic cost of family labour is not included, CPP increase to 47.0 %, 57.0 % and 66.0 % for each strata, respectively. The private cost ratio (PCR) when family labour is included was 0.79, 0.51 and 0.42 for strata 1, 2 and 3, respectively. When family labour is not included, the PCR was 0.07, 0.25 and 0.26. Net profit per litre of milk including family labour was US$0.03 l^-1 for Stratum 1, US$0.09 for Stratum 2 and US$0.12 l^-1 for Stratum 3; but increased to $0.12, 0.14 and 0.15, respectively, when the economic cost of family labour is not included. It is concluded that family labour is a crucial factor in the profitability and competitiveness of small-scale dairy production.     

High level of multidrug-resistant Escherichia coli in young dairy calves in southern Vietnam

This study investigated the occurrence of antimicrobial-resistant Escherichia coli in dairy calves in southern Vietnam. Fecal samples were taken directly from the rectum of 84 calves from 41 smallholder dairy farms, when newborn and at 14 days of age for isolation of E. coli. Escherichia coli strains were isolated from 144 of the 168 fecal samples tested. Of the 144 E. coli isolates, 40% were found to be susceptible to all 12 antimicrobial drugs tested and 53% of the E. coli isolates were resistant to at least three antimicrobials. Calves were colonized with antimicrobial-resistant E. coli already on the day of birth. Resistance to tetracycline was most common, followed by resistance to sulfamethoxazole, ampicillin, trimethoprim, and ciprofloxacin. Four isolates carried a gene encoding for extended-spectrum cephalosporinases (ESC), and these genes belonged to bla_CTX-M group 1 (2 isolates), bla_CTX-M group 9 (1 isolate), and bla_CMY-2 (1 isolate). Thirty-three isolates had a plasmid-mediated quinolone resistance (PMQR) phenotype, and 30 of these carried the qnrS gene. These results are of importance for management routines of dairy cattle to prevent the spread of antimicrobial resistance.

     

Effect of adjuvant administration on weight gain,infectious diseases,and mortality of veal calves

Summary

Young weaned calves are susceptible to viral and bacterial infections. In two studies 279 and 500 weaned calves were injected at random with an adjuvant, with saline or were left untreated in order to evaluate their weight gain or illness and mortality during the first 10 weeks of fattening on a fat‐stock farm. However, in contrast to studies reported in the literature, no significantly higher increase in weight gain and no significant improvement of illness and mortality were found with adjuvant treatment.     

Essential oils improved weight gain,growth and feed efficiency of young dairy calves fed 18 or 20% crude protein starter diets

The objective was to evaluate interactions between starter protein (180 vs. 200 g/kg, DM basis) and a mixture of essential oils (EOs; containing thymol, eugenol, vanillin, limonene and guaiacol) on growth, metabolic and ruminal functions of Holstein dairy calves. In a completely randomized 2 × 2 factorial design, 48 calves, 3 days old (averaging BW 42.7 ± 1.9 kg), were allocated into groups fed the following diets: (i) 180 g/kg CP with no EO (180P‐NEO); (ii) 180 g/kg CP with EO (180P‐EO); (iii) 200 g/kg CP with no EO (200P‐NEO); and (iv) 200 g/kg CP with EO (200P‐EO). The EO was supplemented as 1 g/kg of starter DM. Calves were fed ad libitum starter diet and were weaned at day 59 of age, but diets continued until day 80. There were no interactive effects of CP and EO on intake and growth. Pre‐weaning feed efficiency tended to be increased for 200P‐EO (p = .09). Average daily gain and feed efficiency during pre‐weaning period as well as weaning weight were increased (p < .05) by EO, whereas wither height was increased by EO (p = .03) and tended to be increased for 200P vs. 180P (p = .06). Post‐weaning blood urea nitrogen concentration tended to be lower in 180P vs. 200P (p = .08). Ruminal short‐chain fatty acids concentration was greatest in 200P‐EO. The EO increased both butyrate (p = .02) and propionate proportions (p = .01) and reduced acetate proportional ratio (p < .01). Ruminal ammonia‐N was tended to be lower in calves‐fed EO (p = .05) and was lower in those fed 180P vs. 200P (p < .01). In conclusion, supplementation of the starter diet with essential oil improved weight gain, growth and feed efficiency of dairy calves, irrespective of dietary protein content.     

An epidemiological study of factors affecting serum IgG levels in dairy calves

Serum IgG was used to evaluate the immune status of calves up to 180 days of age in 300 Norwegian dairy herds. Several factors were found to significantly affect the levels. Among these were geographical district, season, and factors related to housing and feeding.     

Characterisation of smallholder dairy production systems using animal welfare and milk quality

The aim of the current study was to characterise and evaluate production system of smallholder dairy farmers using an index based on combined score of animal welfare and milk quality. Farms were grouped into three categories, tier 1, tier 2 and tier 3. To test the robustness of the characterisation, milk yield (MY), calving interval (CI) and body condition scores (BCS) were used. In the study area, the majority (66.3%) of smallholder dairy farmers practiced cut-and-carry as compared to 15.3% who grazed their cows. The rest combined cut-and-carry and grazing. Cows of farmers in tier 1 had the lowest mean MY (5.4?kg/day, SE?=?0.4), lowest mean BCS (2.1?kg/day, SE?=?0.09) and longest mean CI (603?days, SE?=?27) than farmers in tier 3, mean MY (10.8?kg/day, SE?=?0.6), mean BCS (2.6, SE?=?0.06) and mean CI (404?days, SE?=?17). The study demonstrated that a simple and yet novel method based on farm level indicators can be developed and could assist to timely identify specific problems on the farm.     

Relations between body weight, feed intake, daily weight gain, and exocrine pancreatic secretion in chronically catheterized growing pigs

The aim of this investigation was to develop models that would make it possible to correct exocrine pancreatic secretion data for the effect of BW and feed intake in growing pigs. In addition, the significance of exocrine pancreatic secretion for daily weight gain (DWG) was studied. Data were used from 10 pigs (16 to 32 kg BW) surgically fitted with chronic pancreatic catheters. The samples were collected under controlled conditions for two to five experimental days per animal (a total of 39 observations), during 2 h preprandially and during 2 h when feeding (postprandially). The exocrine pancreatic secretion traits included the hourly output of volume, the amount of protein, and trypsin and amylase activities. Multiple linear regressions were used to develop models to describe exocrine pancreatic secretion. The individual pig was the most important source of variation in the model. With increasing BW, 7 out of 10 pigs showed an increase in exocrine pancreatic secretion. However, the slopes of the regression lines differed between animals, which made it impossible to develop general models for the correction of secretion data for the effect of BW. Postprandial exocrine pancreatic secretion was always higher than preprandial secretion, but the amount of feed intake per se did not seem to affect secretion. Exocrine pancreatic secretion and DWG were positively correlated. We concluded that, under the present circumstances, expressing secretion per kilogram BW or kilogram feed intake was not feasible. Expressing secretion per hour was the best way to present the data.     

Prevalence of subclinical mastitis and isolated udder pathogens in dairy cows in Southern Vietnam

Dairy production is not traditional in Vietnam. The farmers have little practical knowledge and udder health control is generally lacking. In order to give the farmers appropriate advice, knowledge about the distribution of udder pathogens is crucial. The aim of the study was to investigate the prevalence of sub-clinical mastitis and to identify udder pathogens isolated from smallholder dairy herds in Southern Vietnam. Twenty farms with a herd somatic cell count (SCC) ranging from low (≤400?×?10³?cells/mL) to high (>400?×?10³?cells/mL) were randomly selected. Milk samples were collected from 458 quarters of 115 clinically healthy cows. SCC was analyzed on farm by a portable cell counter. Bacteriological samples were taken using Mastistrip^© cassettes and sent to Sweden for examination. For all herds the mean herd SCC was 632?×?10³/mL milk. The prevalence of subclinical mastitis at quarter SCC basis was 63.2 % and at cow basis 88.6 %. Only 40 % of all cows were bacteriologically negative in all quarters. Streptococcus agalactiae was the most commonly found bacteria species, isolated from 96 of the 458 quarter samples, in 13 of the 20 farms. The results indicate pronounced subclinical mastitis problems among the dairy cows in this region mainly due to infections with S. agalactiae. The high prevalence of this highly contagious pathogen is probably attributable to the generally poor milking hygiene and low awareness of proper measures to prevent occurrence and spread of udder infections. A strict, targeted action program for the herds in this area is required in order to lower the prevalence of subclinical mastitis.     

Serum IgG and total protein concentrations in dairy calves fed two colostrum replacement products

OBJECTIVE: To evaluate effects of 2 commercially available colostrum replacement products on serum IgG and total protein concentrations in dairy calves. DESIGN: Prospective clinical trial. ANIMALS: 84 Holstein bull calves from a single dairy. PROCEDURES: Calves were randomly assigned to be given 4 quarts of colostrum (group 1; n = 21), 2 packages of a colostrum replacement product (product A; group 2; 21), 1 package of a different colostrum replacement product (product B; group 3; 21), or 2 packages of product B (group 4; 21). Treatments were given within 3 hours after birth, and blood samples were collected 24 hours later and submitted for determination of serum total protein and IgG concentrations. RESULTS: Group 1 calves had significantly higher serum total protein and IgG concentrations than did calves in the other 3 groups. However, the percentage of calves with adequate passive transfer (ie, serum IgG concentration > 1,000 mg/dL) was not significantly different among groups 1 (90%), 3 (81%), and 4 (95%). In contrast, only 10% of calves in group 2 had adequate passive transfer. It was predicted that calves fed product B that had serum total protein concentrations > 5.2 g/dL would have serum IgG concentrations > 1,000 mg/dL at least 90% of the time. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that product B could be considered as an alternative to colostrum in dairy calves, but product A failed to routinely provide adequate serum IgG concentrations when fed according to label directions.     

Longitudinal identification of Enterocytozoon bieneusi in dairy calves on a farm in Southern Xinjiang,China

Enterocytozoon bieneusi is the most common species responsible for human and animals microsporidiasis. A total of 250 samples were collected weekly from 25 newborn dairy calves of a farm in Southern Xinjiang, China at one to ten weeks of age. Enterocytozoon bieneusi was identified and genotyped by nested PCR amplification and sequencing of internal transcribed spacer (ITS) region.The cumulative prevalence of E. bieneusi infection was 100% (25/25), and the average infection was 52.0% (130/250). The highest infection rate was recorded at six weeks of age (92.0%, 23/25), and no infection was observed at one and two weeks of age. Sequencing analysis showed nine E. bieneusi genotypes (J, EbpC, PigEBITS5, CHV4, CHC3, CS-9, KIN-1, CH5, and CAM5) were identified. The highest genetic polymorphism was observed at ten weeks of age. Genotype J was the predominant E. bieneusi genotype. Phylogenetic analysis clustered genotype J into Group 2 and other eight genotypes (EbpC, PigEBITS5, CHV4, CHC3, CS-9, KIN-1, CH5, and CAM5), detected in 22 (16.9%, 22/130) samples, into Group 1. Among the genotypes, EbpC, KIN-1, and J have been identified in humans. The highest E. bieneusi infection rate (57.9%, 124/214) was observed in fecal samples with formed feces with no diarrhea (p < 0.01), and high genetic polymorphism was observed in class I fecal samples. The presence of zoonotic E. bieneusi genotypes in dairy calves suggests the possibility of transmitting zoonotic infections to humans. It provides the basic data on dynamic change of E. bieneusi in calves.     

Local feeding strategies and milk composition in small-scale dairy production systems during the rainy season in the highlands of Mexico

The objective of the work was to identify local feeding strategies in small-scale dairy production systems during the rainy season in the highlands of Mexico, and to determine their effects on milk yields (MY), milk composition and economic viability. Twenty-two dairy farms were monitored by monthly visits, recording and sampling milk from between two and six cows in each farm, live-weight was also recorded. Samples from feeds used in that month were taken and feeds given to the dairy herd were weighed. Economic data was also recorded. Milk composition and milk urea nitrogen were determined, as well as chemical composition of feeds. Eighteen feedstuffs were identified, grouped in: HNH feeds—high in neutral detergent fibre (NDF) and in DM matter; HNL feeds—high in NDF but low in DM; HCh feeds—high in non-fibrous carbohydrates; and HCP feeds—high in crude protein. Four feeding strategies were identified: strategy 1 uses HND, HNL and HCP; strategy 2—HND, HNL, HCh and HCP; strategy 3 HNH and HCP; and strategy 4 HNL and HCP. Of participating farms, 73.4% followed strategy 1, 11.3% strategy 2, 11.3% strategy 4 and 3.8% strategy 3. There were no statistical differences (P > 0.05) between strategies for MY and milk composition, but there were differences (P < 0.05) for ration costs. Multiple regression analysis showed no significative (P > 0.05) model relating intake of feed groups and milk fat content, but milk protein and SNF contents were significantly explained by intake of HCP. When expressed as MY and milk components yield, milk fat yield was significantly explained by intake of all four feed groups, but milk protein and SNF yields were explained only by intake of HCP and LW. MUN excretion was explained also by HCP intake. All feeding strategies produced positive economic returns, on average generating the equivalent of 3.45 minimum wages of the area.     

Oat silage for grazing dairy cows in small-scale dairy systems in the highlands of central Mexico

The objective was to evaluate the provision of oat silage (Avena sativa) to supplement grazing dairy cows on pastures of perennial ryegrass (Lolium perenne), festulolium (Lolium multiflorum × Festuca pratense) and white clover (Trifolium repens) during the dry season when pasture growth is limited. The experimental design was a 3 × 3 Latin square replicated three times, with nine milking Holstein cows (mean live weight 496.2 ± 33.6 kg and daily milk yield 14.8 ± 2.8 kg cow^?1) under on-farm participatory rural research. Experimental periods were 14 d. Simulated grazing samples of pasture herbage were analysed for chemical composition, sward height recorded and net herbage accumulation determined from exclusion cages. Treatments were the inclusion of oat silage at T0 = 0 kg DM cow^?1 d^?1 of oat silage, T3 = 3 kg DM cow^?1 d^?1 of oat silage, and T6 = 6 kg DM cow^?1 d^?1 of oat silage, plus 5.0 kg fresh weight commercial concentrate and 9 h of continuous grazing. Animal variables were milk yield and composition, live weight and body condition score. Feeding costs were calculated. Mean milk yield was 18.9 ± 0.27 kg cow^?1 d^?1 with no differences in animal variables (p > 0.05), but feeding costs per kilogram milk increased 25% for T3 and 50% for T6. Oat silage supplementation is only viable under difficult grazing conditions.