Prediction of excretion of manure and nitrogen by Holstein dairy cattle

A compilation of N balance data (n = 1801) was partitioned into four groups to define the mean excretion of manure and N and to develop empirical equations to estimate these excretions from Holstein herds. Mean excretion of manure for cows that averaged 29 kg/d of milk production was 3 kg/d per 1000 kg of body weight (BW) more than the value for dairy cows reported by the American Society of Agricultural Engineers; N excretion was 0.09 kg/d per 1000 kg of BW higher than the value reported by the American Society of Agricultural Engineers. Mean excretion of manure and N for cows that averaged 14 kg/d of milk production and that for nonlactating cows were substantially lower than the values reported by the American Society of Agricultural Engineers. Growing and replacement cattle excreted 10 kg/d per 1000 kg of BW more manure and 0.11 kg/d per 1000 kg of BW more N than was reported by the American Society for Agricultural Engineers for beef cattle. Estimation of manure and N excretion was more accurate than mean values when using regression equations that included variables for milk production, concentration of crude protein and neutral detergent fiber in the diet, BW, days in milk, and days of pregnancy. Equations that contained intake variables did not significantly affect predictions of manure and N excretion, and the use of such equations is discouraged unless dry matter intake is measured and not estimated. Accurate estimates of excreta output could improve the planning of storage and handling systems for manure and the calculation of nutrient balances on dairy farms.     

Use of physiologic variables to predict milk yield after clinical mastitis in dairy cattle

OBJECTIVE: To determine the association between intramammary infections caused by various bacteria and hepatic damage, as measured by serum sorbitol dehydrogenase (SDH) activity, WBC counts, and PCV and the association of clinical variables with milk production after a case of clinical mastitis. DESIGN: Prospective, cohort study. ANIMALS: 82 cows with clinical mastitis. PROCEDURE: Information on milk production, mastitis status, and selected physiologic variables was collected during a 1-year period. Milk samples for bacteriologic evaluation were collected on day 1 of an episode of clinical mastitis. Physical examination was performed and blood samples for laboratory evaluation were collected on days 1, 5, and 9. Primary outcome was mature equivalent 305-day (ME305) milk production. Correlations were assessed using a multiple regression model. RESULTS: Higher WBC counts were associated with higher ME305 values. For cows with coliform mastitis, increases in SDH values were associated with higher ME305 values. For cows with coliform and streptococci/staphylococci mastitis, PCV was associated with ME305 values. Higher PCV values were associated with lower ME305 values for streptococci/ staphylococci and coliform infections. CLINICAL IMPLICATIONS: The association between milk production and WBC count indicated that cows mobilizing WBC were better able to neutralize mammary gland infections, which may result in better milk production. The association between milk production and PCV suggested that maintaining hydration in cows with clinical mastitis may be a critical aspect of treating all cows with mastitis.     

Body composition of mice of different body condition score and sex

After a critical review of recent research on the whole body chemical composition of laboratory animals, especially that of the mouse, the authors present data on the body composition of a mouse line of different body condition score, varying from normal to double-muscled ("culard", "compact") type. One hundred male and 100 female mice of different compact categories were measured in vivo, using total body electrical conductivity (TOBEC method), then by direct chemical analysis performed on day 77 of life. In male mice, body weight and protein content were found to increase while fat content decreased parallel to the increase in phenotypic condition score. Female mice showed a rather constant fat, protein and ash content in the dry matter of the body. The precision and validity of TOBEC data under 40 grams of body weight proved to be insufficient.     

Assessment of the dairy production needs of cattle owners in southeastern Sicily

This study was undertaken to investigate research and outreach priorities for Progetto Ibleo (Project Ibleo), a center created in 1990 with tripartite government funding to serve dairy producers in the Hyblean region of Sicily. Data comprised values for production and composition of milk from 1984 to 1989 from 35 herds of Modicana cows on a system based on pasture and that from 69 input-intensive herds of Holstein cows, associated lactation and reproduction measures, and yield and composition of forages from 4 of these farms in 1988. Season had a large effect on the neutral detergent fiber and crude protein composition of forages, production and composition of milk, and predicted yield of fresh Ragusano cheese manufactured from the milk of these cows. The poorest forage quality and the poorest cow performance were observed in summer and fall months (May to October). Lactation curves that were flat, without a discernible peak, or convex were observed for both systems, especially for cows calving in spring and in the dry summer seasons (March to July). These abnormalities, signifying substantial sacrifices in production potential, probably had a complex etiology that stemmed from low nutrient intake and high neutral detergent fiber and low crude protein composition of the grazed and preserved forages. Research and outreach priorities to support the Hyblean dairy industry should include chemical evaluation of forages and other feedstuffs, low moisture ensiling of high quality winter forages, better formulation of diets that are dense with nutrients, and the shifting of calving patterns to better exploit high quality winter forages.     

Short- and long-term production losses and repeatability of clinical mastitis in dairy cattle

Between 1985 and 1990, a study of 5313 lactations of 2477 Black and White cows was carried out. A stepwise least squares method was used to obtain unbiased estimates of milk, fat, and protein losses that were due to clinical mastitis and the carry-over effect from the previous lactation. Logistic regression was used to estimate the probability that a cow would have clinical mastitis in the next month. The effect of clinical mastitis on production within one lactation was estimated at 527 kg of milk (8.1%), 22.7 kg of fat (8.0%), and 13.7 kg of protein (6.2%) for > or = 3 cases of clinical quarters in the second lactation. One or 2 cases of clinical quarters in a lactation did not significantly affect the production in the next lactation. The negative carry-over effect of > or = 3 cases of clinical quarters was estimated at 381 kg of milk (5.9%), 23.7 kg of fat (8.4%), and 10.1 kg of protein (4.6%) up to and including mo 8 of the second lactation. The fat content in milk produced after the onset of mastitis decreased, and the protein content increased. The risk of clinical mastitis infection in the following month was influenced by month of lactation (a higher risk early in lactation), lactation number (risk increased with lactation number), production level (higher risk for high producing cows), number of clinical quarters in the previous lactation, number of clinical quarters in the previous months of the current lactation, and occurrence of clinical mastitis in the current month.     

Relationships between the presence of Johne's disease and farm and management factors in dairy cattle in England

The data collected by a postal questionnaire sent to 3772 randomly selected dairy farmers in England and the border regions in Wales were used to estimate the relationships between the presence of clinical Johne's disease and farm and management factors associated with that disease. Two binary outcomes (case reported in 1993, case reported in 1994) and 27 predictor variables were considered. Only two variables were consistently and significantly associated with clinical disease in multivariable analysis. Farms on which Channel Island breeds were predominant were associated with an increased risk of reporting disease (odds ratios (ORs) ranged from 10.9 to 12.9). The presence of farmed deer on the farm also increased the risk of reporting disease (ORs ranged from 15.2 to 209.3). There were other significant but inconsistent associations involving the source of replacements, age of first-offering hay, type of concentrate feed to calves, and calving in individual pens when the cows were at grass. Since Johne's disease is predominantly subclinical, these contributing factors may play important roles in switching subclinical infection to overt disease.     

An immunological approach to the evaluation of welfare in Holstein Frisian cattle

Clinical immunological and haematological parameters, along with clinical conditions and growth rate, were studied in 413 male Holstein Frisian calves introduced into a large centre for genetic selection in different seasons of the year. Abnormalities were revealed by the laboratory tests in the great majority of calves after transportation stress, a general tendency to the restoration of physiological values being evident thereafter. Laboratory parameters were highly correlated with disease conditions: with three exceptions only, animals showed altered laboratory parameters some days before the occurrence of clinical symptoms. Eighteen per cent of animals showed altered laboratory parameters with no obvious clinical signs of disease; yet they experienced a reduced weight gain. Results suggest that clinical immunological and haematological parameters could be the foundation of a new, large-scale, robust approach to the control of welfare in cattle, which should be integrated preferably by a further range of records and measures.     

Adrenal cortex response to adrenocorticotropic hormone in dairy cattle

Adult dairy cows were treated with a range of doses (0.0125mg to 0.4mg) of synthetic ACTH1-24 and the plasma cortisol response was measured. Peak response was independent of dose. Higher doses of ACTH had a more prolonged effect such that the integrated response was dose dependent. Dose response curves were examined by regression analyses. Individual cows had a significant effect on y-axis intercept but not on the slope of the regression lines examined. A dose rate of 0.05mg ACTH iv was identified as a suitable dose rate for use in clinical assessment of adrenal cortex function, with 0, 50 and 120 min following ACTH being critical sampling times to identify the response.     

Effect of vaccination with an Escherichia coli bacterin-toxoid on milk production in dairy cattle

OBJECTIVE: To determine whether vaccination of lactating cattle with an Escherichia coli J5 bacterin-toxoid would produce a significant short-term change in milk production. DESIGN: Randomized, controlled clinical trial. ANIMALS: 84 healthy, lactating cows (42 Holsteins and 42 Jerseys). PROCEDURE: Control and vaccinated cows were paired on the basis of breed, days in milk, daily milk production 1 week prior to vaccination, and parity. One cow in each pair was inoculated IM with a commercially available bacterin-toxoid according to label directions; the other cow was given saline solution. Cows were milked twice daily for 5 days before and 5 days after inoculation. Milk production was compared by ANCOVA. RESULTS: Vaccinated cows produced significantly less milk than did control cows at the second and third milkings after inoculation. At these milkings, milk production in vaccinated cows was approximately 7% less than that of controls. CLINICAL IMPLICATIONS: Vaccination of lactating cattle with an E coli J5 bacterin-toxoid may cause a significant short-term decrease in milk production.     

Bayesian analysis via Gibbs sampling of susceptibility to intramammary infection in Holstein cattle

A Bayesian analysis was undertaken to assess the susceptibility of Holsteins to mastitis from 120 to 305 d in milk. Data included 595 lactations from 267 cows. The response variable was presence or absence of intramammary infection; explanatory variables were period and season of calving, somatic cell score, and cow. The logistic model adopted had period and season of calving and the regression on somatic cell score with vague prior distributions, and cow effects had a normal prior with unknown variance sigma u2, which, in turn, had a gamma prior. Implementation was by Gibbs sampling. Posterior densities of location parameters were unimodal and symmetric. The probability of intramammary infection of a sample cow was skewed. The posterior distribution of sigma u2 was skewed also. Gibbs samples of sigma u2 had high lag correlations, which gave an effective sample ranging between 47 and 117 from a chain of size 3000. There were differences between estimates of sigma u2 found using Gibbs sampling and those obtained using approximations. The low information content arising from the small size of the data and the binary nature of the response are reasons for such differences. A sensitivity analysis revealed influences of hyperparameters of the prior distribution of sigma u2 on inferences about this parameter.     

The detection of oestrus in dairy cattle

A survey attempted to determine the extent to which cows are being inseminated when not in oestrus. The method used to check the farmers' diagnoses of oestrus was based on peripheral plasma progesterone concentrations analysed by radioimmunoassay. Of 141 cows examined in this way, a total of 30 (21-28 per cent) showed abnormalities of the progesterone levels. The fertility within this group was very poor with only two of the cows being known to have conceived to the service in question.     

Genetic analysis of clinical lameness in dairy cattle

Scores for clinical lameness from two separate studies were combined, and genetic parameters were estimated based on linear and threshold models. Cows were from 24 herds in Minnesota, Wisconsin, and Virginia. To evaluate clinical lameness, cows were observed walking and were assigned a score between 0 and 4 (where 0 = no observable problems to 4 = inability to walk). Data included 1624 records on 1342 cows. The models included fixed effects of herd visit, parity, and stage of lactation. Random effects were additive genetics, permanent environment to account for repeated records, and residual. Estimates of heritability were 0.10 and 0.22 from the linear and threshold models, respectively. The correlation between ETA from linear and threshold models based on all animals was 0.974. Deregressed ETA of sires and REML were used to estimate genetic correlations between clinical lameness and conformation traits. Among the type traits, foot angle, rear legs (rear view), and rump width had strongest associations with clinical lameness; absolute values for genetic correlations between these traits and clinical lameness were approximately 0.65. Low foot angle, hocking in, and wide rumps were associated with increased clinical lameness. Correlations with strength and body depth ranged from 0.20 to 0.43, indicating that heavier cows were more prone to clinical lameness.     

Incidence and prevalence of lameness in dairy cattle

A survey was made of 37 dairy farms in Wirral, mid-Cheshire, mid-Somerset and Dyfed, Wales, to assess the incidence and prevalence of lameness in the cows between May 1989 and September 1991. The incidence was obtained from records made whenever a cow was examined for lameness or received preventive foot-trimming. The mean annual incidence was 54.6 new cases per 100 cows with a range from 10.7 to 170.1 and the mean values during summer and winter were 22.9 and 31.7, respectively. The prevalence of lameness was measured by regular visits at which locomotion was scored on a scale of 1 to 5, and the prevalence of lameness was calculated for each visit as the proportion of cows with scores of 3 or more. The mean annual prevalence over the whole period was 20.6 per cent with a range from 2.0 to 53.9 per cent for the 37 farms. The mean prevalences during summer and winter were 18.6 and 25.0 per cent, respectively. The prevalence measured at a single visit in midsummer or midwinter was significantly correlated with the mean prevalence over the whole corresponding period and may be useful as an assessment of the extent of lameness in a herd and the efficacy of control measures. There was evidence that training farmers to recognise early cases of lameness and request veterinary treatment resulted in a marked reduction in the duration of cases of lameness.     

高杂质下生产高纯阴极铜方法的探讨

通过对阳极铜杂质在电解过程中行为以及电解液成分的分析,了解了阴极铜质量恶化的主要原因,通过相应的对策,降低阳极铜的杂质,改善电解生产的条件,加强电解液的净化,实现高杂质条件下生产出高纯阴极铜。     

Aetiology and Pathogenesis of abomasal displacement in dairy cattle

A clinical chemical survey is given of the complex of factors which are involved during development of clinically manifest hypotony or atony of the abomasum prior to abomasal displacemnts. The importance of a change in the acid-base balance of the animals is especially stressed as a predisposing factor. The further pathogenesis of abomasal displacement is supposed to follow different ways, according to the feeding and to prevailing periods of indigestion.     

The seasonal variation of thermophilic campylobacters in beef cattle, dairy cattle and calves

The epidemiology of clinical cases of campylobacter in temperate climates shows a striking seasonality. In the search for a seasonal environmental reservoir changes in the carriage rate and population size of campylobacters in bovine hosts with time have been measured. Most probable number (MPN) methodology was used to enumerate thermophilic campylobacters in samples taken from the small intestines of beef cattle at slaughter and the fresh faeces of four dairy herds and new-born calves. Statistical analyses revealed significant evidence for seasonal periodicity in the data from dairy herds (P = 0.044). Not only was there a departure from constancy within a 12-month interval but these data revealed a true seasonality, that is, the same periodicity in numbers from one year to the next. Each herd had two peaks per year, in approximately spring and autumn. Peaks coincided in herds on neighbouring farms but those on farms in the north preceded those on farms in the south by 2 and 1 months, respectively (P = 0.0057). Intestinal carriage by beef cattle at slaughter was 89.4% (n = 360) with an average MPN campylobacters per gram fresh weight (MPN gfw-1) of 6.1 x 10(2). Average MPN gfw-1 in faeces from the dairy herds and calves were 69.9 (S.D. 3) and 3.3 x 10(4) (S.D. 1.7 x 10(2)). There was no evidence of seasonal periodicity in the size of the campylobacter population in beef cattle at slaughter. Calves were campylobacter free at birth but became colonized with a few days.     

Relationships between the number of small follicles prior to superovulatory treatment and superovulatory response in Holstein cows

In order to determine relationships between the number of small follicles prior to superovulatory treatment and superovulatory response, a total of 55 superovulations were induced in Holstein cows. The ovaries were examined ultrasonographically once 0-1.5 days before the initiation of superovulatory treatment. The number of small follicles 3-6 mm in diameter on both ovaries before superovulatory treatment was found to be significantly correlated with the numbers of corpora lutea after superovulation (r = 0.440, P < 0.001), total ova recovered (r = 0.503, P < 0.001) and transferable embryos recovered (r = 0.482, P < 0.001). These results indicate that a single ultrasonographic examination of follicles 3-6 mm in diameter prior to superovulatory treatment can be utilized to predict superovulatory response.     

Humoral response of dairy cattle to spirochetes isolated from papillomatous digital dermatitis lesions

OBJECTIVE: To determine whether a humoral response against spirochetes isolated from papillomatous digital dermatitis (PDD) lesions is elicited in dairy cattle affected with PDD. SAMPLE POPULATION: 41 cattle with PDD from 8 dairies (study population) and 30 cattle from 2 dairies free of PDD (control population). Additionally evaluated were 32 cattle from a dairy with a past history of PDD but no current disease, and 52 cattle from a dairy with high prevalence of PDD, 25 with and 27 without detectable lesions. PROCEDURE: ELISA were used to evaluate the humoral response of all cattle to representative isolates from 2 groups of spirochetes of unknown species isolated from PDD lesions. Specificity of the response was evaluated, using immune sera prepared against each of the spirochetes, and by adsorption studies of immune and field sera. The potential for confounding by an antibody response to other spirochetes associated with diseases of cattle was assessed. RESULTS: The antibody response (specific) to both PDD spirochete groups of cows with PDD was significantly increased, compared with that of cows from PDD-free dairies. There was no association between antibody response to PDD-associated spirochetes and antibody response to other spirochetal diseases of cattle. None of the cattle from the dairy with previous history of PDD but without current disease were classified as test positive by either PDD ELISA. There was a significant (P < 0.01) difference in classification results for both PDD ELISA for cattle with PDD from the dairy with a high herd prevalence of PDD, compared with cattle without detectable disease from the same dairy. CONCLUSIONS AND CLINICAL RELEVANCE: The humoral response in cattle with PDD lesions was significantly different from that in cattle without detectable lesions, thus providing additional information regarding the potential role of spirochetes isolated from PDD lesions in the etiopathogenesis of PDD.