Transfer of passive immunity and serum proteinogram in the first six months of life of Criollo Lageano and black and white holstein calves

The objective of this study was to evaluate and compare the transfer of passive immunity and the proteinogram in Criollo Lageano (CL) and Black and White Holstein (BWH) calves. Two groups were utilized with 13 Criollo Lageano and 10 BWH calves. Blood samples were collected for the measurement of total serum protein, electrophoresis of serum proteins, activity of the gamma glutamyl transferase, and concentration of IgG by the method of the zinc sulfate turbidity in periods between 24 and 36 hours of life, 15, 30, 60, 90, 120, 150 and 180 days. Statistical analysis was performed by ANOVA and Tukey test at 5% significance level, and correlations between variables were calculated. Variations of serum proteins followed a pattern of physiological behavior over the first six months of life and production of immunoglobulins was active earlier in BWH calves and slower in the Criollo Lageano, without causing any impact on their health. Gamma globulin in the first days of life (24-36h) was correlated with IgG (r=0.87 for CL and r=0.89 for BWH), PTS (r=0.91 for CL and r=0.92 for BWH), Glob (r=0.99 for CL and r=0.98 for BWH) and GGT (r=0.14 for CL and r=0.83 for BWH). It was concluded that there was no failure in the transfer of passive immunity in Criollo Lageano calves but this failure occurred in the BWH calves. IgG values estimated by the zinc sulfate turbidity and serum proteins were considered good indicators of the transfer of passive immunity in calves between 24 and 36 hours of life.

Effects of environmental modification on mastitis occurrence and hormonal changes in Holstein cows

The purpose of this research was to evaluate the effects of evaporative cooling in freestall on mastitis occurrence, milk production, and composition, as well as cortisol, T3 (triiodothyronine), and T4 (thyroxin) levels in lactating dairy cows. Twenty-eight multiparous cows averaging 70 ± 10 day postpartum were used in four treatments from January to March 2003. The treatments were: Day (cooling from 7:00 a.m. to 7:00 p.m.); Night (cooling from 7:00 p.m. to 7:00 a.m.); 24-hour (cooling 24-hour); and Control (no cooling). Wired cup test was used for clinical mastitis diagnosis, and the California Mastitis Test (CMT) was used to identify subclinical mastitis. Blood and milk samples were taken weekly for microbiological and hormonal analyses. The cortisol levels were higher than normal values in all treatment groups, suggesting stress conditions, but T3 and T4 levels remained normal in all groups. The occurrence of subclinical mastitis was lower in Day and Night groups than in Control and 24-hour groups. Regarding the microbiological analyses, in all groups the isolation of Corynebacterium sp. from milk samples increased while negative coagulase staphylococci (CNS) declined as etiological agents of subclinical mastitis. However, in Day and 24-hour groups, coagulase positive staphylococci (CPS) increased mainly Staphylococcus aureus (49.8% and 47.7% respectively). The Night group showed a decrease in subclinical mastitis occurrences. Our data indicate that all animals subjected to treatments presented high levels of cortisol, indicating a stress condition. The Night treatment presented a reduction in microbial isolation, suggesting a reduced susceptibility to mastitis.

Partial budget analysis of prepartum antimicrobial therapy and Escherichia coli J5 vaccination of dairy heifers and their effect on milk production and milk quality parameters

Abstract: This study aimed to determine whether prepartum antimicrobial and/or Escherichia coli J5 vaccination in dairy heifers influence the milk production, milk quality, and estimate their economic benefit. Thus, 33 dairy heifers were enrolled in four groups using a split-splot design. Groups were: (G1) prepartum antimicrobial infusion and vaccination with an E. coli J5 bacterin, (G2) prepartum antimicrobial infusion, (G3) vaccination with an E. coli J5 bacterin, and (G4) control heifers. Composite milk samples for somatic cell count, total bacteria count and milk composition were collected 15 days after calving and every 15 days until the end of the experiment. Bacteriological analysis was carried out at the end of study. The milk production and the incidence of clinical cases of mastitis, as well as the costs associated with them were recorded. The results demonstrate a reduction on clinical mastitis rates by preventive strategies, which implicated in lower volume of discarded milk (0.99, 1.01, 1.04 and 3.98% for G1, G2, G3 and G4, respectively) and higher economic benefit. Thus, in well-managed dairy herds the prevention of heifer mastitis by vaccination or antimicrobial therapy can reduce the amount of antimicrobials needed to treat clinical mastitis cases and the days of discarded milk.

Holstein white coat color and performance: phenotypic, genetic and environmental correlations

Correlations of measures of percentages of white coat color, five measures of production and two measures of reproduction were obtained from 4293 first lactation Holsteins from eight Florida dairy farms. Percentages of white coat color were analyzed as recorded and transformed by an extension of Box-Cox procedures. Statistical analyses were by derivative-free restricted maximum likelihood (DFREML) with an animal model. Phenotypic and genetic correlations of white percentage (not transformed) were with milk yield, 0.047 and 0.097; fat yield, 0.002 and 0.004; fat percentage, -0.047 and -0.090; protein yield, 0.024 and 0.048; protein percentage, -0.070 and -0.116; days open, -0.012 and -0.065; and calving interval, -0.007 and -0.029. Changes in magnitude of correlations were very small for all variables except days open. Genetic and phenotypic correlations of transformed values with days open were -0.027 and -0.140. Modest positive correlated responses would be expected for white coat color percentage following direct selection for milk, fat, and protein yields, but selection for fat and protein percentages, days open, or calving interval would lead to small decreases.

Effects of age on histological parameters of the sweat glands of Nellore cattle

The sweat glands are important in thermoregulation of cattle in a warm environment as they help dissipate heat through evaporation. Studies on gland histology are important to define its secretion potential and the capacity of perspiration and heat removal. The objective of this study was to determine, by histomorphometry, glandular epithelium height, the depth of the gland, length of the glandular portion and number of glands per cm2 of the sweat glands of the three age groups of Nellore cattle. Thirty females were used in this study. They were equally divided into calves, heifers and cows. Histological sections were obtained and analyzed by digital images in Trinocular BX40 Olympus microscope coupled to an Oly - 200 camera, connected to a computer. The images were obtained with microscope with 2x, 4x, 10x and 40x magnification objectives. The measurements were performed using HL Image 97 program. The height of glandular epithelium, depth of the glands, length and density of the glandular portion per cm2 , were all analyzed. The calves showed greater height of the glandular epithelium than heifers (P = 0.0024), and cows (P = 0.0191). The depth of the gland was not influenced by age. Cows had higher length of secretory portion than heifers (P = 0.0379) and calves (P = 0.0077). Heifers had a greater number of sweat glands per cm2 of skin than cows (P = 0.023). In cattle, the height of glandular epithelium and the density decreases as animals get older. On the other hand, the length of the secretor portion increases but with no changes in the depth of the sweat glands

Estudo sôbre a variação da produção leiteira na raça holandesa malhada de preto

The authors studied the effects of calving time, season and time elapsed after calving on milk production of the Holstein Friesian Breed of the "Escola Superior de Agricultura "Luiz de Queiroz" (Piracicaba, Brasil), 180 lactation periods of 300 days were studied, with 15 calvings in each month. Statistical analysis of the data proved : 1. That calving in May, June, July or August, that is, in the driest months, the cows give a milk production 17,3% larger than calving in December, January, February, March or April. August is the best month for calving, and February is the worst. 2. Spring is the most favorable, and Autumn the most unfavorable season for milk production. 3. The decrease of milk production during the lactation period depends largely on calving time. But, on the whole, linear regression can be used as a good aproximation, with a correlation coefficient r = - 0,9926 and a monthly decrease, per month elapsed after calving, of 8,06 percent of the general mean. 4. Diagram 1 shows the effects of calving month on milk production. The limits of 5%, 1% and l%o of probabilities are given there.

Estudo comparativo entre silagem de milho e cana taquara na alimentação suplementar de vacas leiteiras

The A. A. compare corn silage (Zea mays L.) with sugar cane (Saccharum sinensis Roxb.) in the supplementary feeding of dairy cow. Both the feeds were studied in relation to the following points: composition and nutritive value; influence of milk production, milk fat, milk acidity and body weight; cost of production. Both corn silage and sugar cane were analysed by ordinary methods, and their digestibility was determined by means of digestibility coefficients; their composition and nutritive value are, practically, equivalent, but silage showed slight superiority. The feeding experiment was carried out with two groups of six Holstein Friesian cows each, of the Escola Superior de Agricultura "Luiz de Queiroz" herd. Both groups were fed with the same basic concentrates mixture, calculeted according to MORRISON. During the various periods of the experiment, only the roughage supplement varied. The supplementary feeding consisted of 15 kg of chopped sugar cane or corn, silage, per day and per cow, given in two daily meals in the barn. At 4,30 p.m., the cows are set free in the field, where they pass the over night. The experiment was divided into six periods, in which there was a gradative change of the supplementary feeding between the two groups. The milk was weighed every day; the analysis of milk fat and acidity and the weighing of the animals, were made only on the first three days of every week. The analysis of data showed that: a) Milk production was increased significantly by silage feeding; b) The ri was not any influence on milk fat; c) The silage caused higher milk acidity; d) The sugar cane gave a greater increase of body weight. The cost of production of corn silage was 2,12 time higher, than sugar cane, hence, although the silage gave a higher milk production, its use is not economical, compared with sugar cane, in our conditions.

Estudo comparativo entre métodos de contrôle quantitativo da produção leiteira

This paper deals with the estimation of milk production by means of weekly, biweekly, bimonthly observations and also by method known as 6-5-8, where one observation is taken at the 6th week of lactation, another at 5th month and a third one at the 8th month. The data studied were obtained from 72 lactations of the Holstein Friesian breed of the "Escola Superior de Agricultura "Luiz de Queiroz" (Piracicaba), S. Paulo, Brazil), being 6 calvings on each month of year and also 12 first calvings, 12 second calvings, and so on, up to the sixth. The authors criticize the use of "maximum error" to be found in papers dealing with this subject, and also the use of mean deviation. The former is completely supersed and unadvisable and latter, although equivalent, to a certain extent, to the usual standard deviation, has only 87,6% of its efficiency, according to KENDALL (9, pp. 130-131, 10, pp. 6-7). The data obtained were compared with the actual production, obtained by daily control and the deviations observed were studied. Their means and standard deviations are given on the table IV. Inspite of BOX's recent results (11) showing that with equal numbers in all classes a certain inequality of varinces is not important, the autors separated the methods, before carrying out the analysis of variance, thus avoiding to put together methods with too different standard deviations. We compared the three first methods, to begin with (Table VI). Then we carried out the analysis with the four first methods. (Table VII). Finally we compared the two last methods. (Table VIII). These analysis of variance compare the arithmetic means of the deviations by the methods studied, and this is equivalent to compare their biases. So we conclude tht season of calving and order of calving do not effect the biases, and the methods themselves do not differ from this view point, with the exception of method 6-5-8. Another method of attack, maybe preferrable, would be to compare the estimates of the biases with their expected mean under the null hypothesis (zero) by the t-test. We have: 1) Weekley control: t = x - 0/c(x) = 8,59 - 0/ = 1,56 2) Biweekly control: t = 11,20 - 0/6,21= 1,80 3) Monthly control: t = 7,17 - 0/9,48 = 0,76 4) Bimonthly control: t = - 4,66 - 0/17,56 = -0,26 5) Method 6-5-8 t = 144,89 - 0/22,41 = 6,46*** We denote above by three asterisks, significance the 0,1% level of probability. In this way we should conclude that the weekly, biweekly, monthly and bimonthly methods of control may be assumed to be unbiased. The 6-5-8 method is proved to be positively biased, and here the bias equals 5,9% of the mean milk production. The precision of the methods studied may be judged by their standard deviations, or by intervals covering, with a certain probability (95% for example), the deviation x corresponding to an estimate obtained by cne of the methods studied. Since the difference x - x, where x is the mean of the 72 deviations obtained for each method, has a t distribution with mean zero and estimate of standard deviation. s(x - x) = √1+ 1/72 . s = 1.007. s , and the limit of t for the 5% probability, level with 71 degrees of freedom is 1.99, then the interval to be considered is given by x ± 1.99 x 1.007 s = x ± 2.00. s The intervals thus calculated are given on the table IX.

Impact of Babesia bovis and Babesia bigemina on the production of beef cattle in Uruguay

Uruguay is situated in a marginal area for the development of Boophilus microplus (30- 35- South Lat.) with important areas of enzootic instability for Babesia bovis and B. bigemina. The livestock products represent 70% of our exports, for wich reason it is fundamental to evaluate the losses in the production that these haemoparasites cause as basic information to take future decisions. In the period 1988-1990, several works were carried out by our laboratory to know the incidence of babesiosis in the reduction of liveweight gains. The results are shown and discussed in the work. Experiment I: the weight increase of the control group (x = 0,248kg/day), was 23% higher than that of the infected group with Babesia spp (from Uruguay), but significant statistical differences were not found (P < 0,05). These animals were kept in boxes and the food was controlled for 76 days. Experiment II: the incidence of Babesis spp (same strain ) was studied for 140 on Hereford heifers (n = 14) on natural pastures. The control group obtained x = 25,29kg of liveweight gain and it was 45% higher than that of the infected group, significant statistical difference were found (P < 0,05). Experiments with attenuated strains III: four studies were carried out inoculating B. bovis and B. bigemina in bovines about one year old, in different growth systems, searching for the limit of application. Significant statistical differences between those groups were found during the experiment (about 180 days) (P < 0,05). Experiment combining and pathogenic strains IV: the liveweight gain, in immune and challanged group (n = 14) was the same than that of the unchallenged group and did not show significant statistical differences (P < 0,05). However the control challenged group had less weight gain and statistical differences were found (P < 0,05). Although this is a preliminary information, it shows that: (a) the incidence of babesiosis on the reduction of weight gains is important; (b) the decrease in weight gain was not observed when attenuated strains were used; when the challenge was done in immunized animals, losses in liveweight gain were not observed. These results are discussed in order to plan future studis in different real systems of production.

Daily intake of lactating crossbred cows grazing elephant grass rotationally

The goal of this trial was to estimate the total dry matter (TDMI) and daily pasture dry matter intakes (PDMI) by lactating crossbred Holstein - Zebu cows grazing elephant grass (Pennisetum purpureum Schum.) paddocks submitted to different rest periods. Three groups of 24 cows were used during two years. The paddocks were grazed during three days at the stocking rate of 4.5 cows/ha. Treatments consisted of resting periods of 30 days without concentrate and resting periods of 30, 37.5 and 45 days with 2 kg/cow/day of 20.6% crude protein concentrate. From July to October, pasture was supplemented with chopped sugarcane plus 1% urea. Total daily dry matter intake was estimated using the extrusa in vitro dry matter digestibility and the fecal output with chromium oxide. Regardless of the treatment the estimated average TDMI was 2.7, 2.9 and 2.9±0.03% and the mean PDMI was 1.9, 2.1 and 2.1±0.03% of body weight in the first, second and third grazing day, respectively (P<0.05). Only during the summer pasture quality was the same whichever the grazing day. Sugarcane effectively replaced grazing pasture, mainly in the first day when pasture dry matter intake was lowest.

Genetic diversity and population structure of Brazilian native bovine breeds

Conservation and improvement strategies should be based on the association between genetic and phenotypic characteristics. The objective of this work was to characterize five native Brazilian cattle breeds (Caracu, Crioulo Lageano, Curraleiro, National Polled and Pantaneiro) and two commercial breeds (Holstein and Nellore) using RAPD technique to estimate genetic distances and variability between and within breeds. Genetic relationships were investigated using 22 primers which generated 122 polymorphic bands. Analysis of molecular variance indicated that most of the genetic variation lay among individuals within populations. The genetic variabilities between pairs of breeds were statistically significant. The smallest genetic divergence was between Crioulo Lageano and Curraleiro.The National Polled, although historically considered to be of Bos taurus aquitanicus origin,similar to theCaracu, was grouped together with the other breeds of Bos taurus ibericus origin. Generally, the individual breeds formed distinct clusters except the National Polled. The RAPD technique was capable to distinguish genetically between the breeds studied; the Caracu, Crioulo Lageano, Curraleiro and Pantaneiro may be considered distinct genetic entities thereby proving the uniqueness of the populations; the National Polled has not been able to re-establish itself after its decline in the 1950s, thereby losing its genetic identity.

Foraging behavior and ruminal fermentation of dairy cows grazing ryegrass pasture alone or with white clover

The objective of this work was to evaluate the influence of pasture composition and regrowth age on the relationship between feeding behavior and ruminal fermentation in dairy cows grazing perennial ryegrass with or without white clover. The experiment was carried out in a 2x2 factorial arrangement, with two sward types and two ages of regrowth. Swards of perennial ryegrass sown alone (PRG) and of perennial ryegrass mixed with white clover (GC) were evaluated. Twelve late-lactation Holstein cows, fistulated at the rumen, were distributed in a 4x4 latin square experimental design with four 12-day periods. Daily distribution of grazing was similar in the PRG and the GC swards, but the concentration of rumen volatile fatty acids (VFA) was higher and the proportion of propionate was lower on mixed swards during the day. Daily distribution of grazing was similar in pastures of different ages. However, in the oldest swards, rumen fluid pH increased and VFA concentration decreased after evening milking. Time spent grazing does not influence ruminal fermentation, which depends on the changes that occur as different sward layers are grazed.

Thermal efficiency of individual shelters for girolando calves in brazilian semi-arid regions

ABSTRACT The objective of this research was to evaluate the thermal efficiency of roofs used on individual shelters during milk-feeding stage of Girolando calves. The research was conducted at a farm located in a dry region of Pernambuco state, Brazil. The experimental design was completely randomized, with 27 Holstein × Gir dairy crossbred calves housed in shelters with three roofing materials (fibre cement tile, recycled tile, and thatched roofs). The recycled tiles and thatched roofs provided reductions of 18.7 and 14.6% in radiant thermal load, respectively. Regardless the roofing material, all animals increased their respiratory rate to maintain thermal equilibrium.

Adherence and experimental infection of bacteria associated with periodontal infections of young cattle in Brazil ("Cara inchada")

In vitro- and in vivo-assays were conducted, to study the possible role of streptomycin- and actinomycin-producing soil actinomycetes for the pathogenesis of "Cara inchada" in cattle (CI). Adherence of Bacteroides spp. to epithelial cells of the bovine gingiva, known to be associated with the progressive lesions of CI, was significantly increased by the addition of streptomycin, actinomycin or antibiotic culture supernatants of the soil actinomycetes. Applications of these mixtures together with Actinomyces pyogenes to the marginal gingiva of the upper premolar teeth of about 1 month old Holstein Friesian calves did not lead to progressive lesions of CI. Only one calf exhibited a slight diarrhea and a temporary retraction of the gingiva at the site of application.

Field evaluation of safety during gestation and horizontal spread of a recombinant differential bovine herpesvirus 1 (BoHV-1) vaccine

Bovine herpesvirus type 1 (BoHV-1) is recognized as a major cause of respiratory, reproductive disease and abortion in cattle. Vaccination is widely applied to minimize losses induced by BoHV-1 infections; however, vaccination of dams during pregnancy with modified live virus (MLV) vaccines has been occasionally associated to abortions. We have previously reported the development of a BoHV-1 recombinant virus, constructed with basis on a Brazilian BoHV-1 (Franco et al. 2002a) from which the gene coding for glycoprotein E (gE) was deleted (gE-) by genetic manipulation. Such recombinant has been previously evaluated in its potential as a differential vaccine (gE- vaccine) that allows differentiation between vaccinated and infected animals. Here, in the first part of the present study, the safety of the gE- vaccine during pregnancy was evaluated by the intramuscular inoculation of 10(7.4) tissue culture 50 % infective doses (TCID50) of the virus into 22 pregnant dams (14 BoHV-1 seronegative; 8 seropositive), at different stages of gestation. Other 15 pregnant dams were kept as non-vaccinated controls. No abortions, stillbirths or fetal abnormalities were seen after vaccination. Seroconversion was observed in both groups of previously seronegative vaccinated animals. In the second part of the study, the potential of the gE- vaccine virus to spread among beef cattle under field conditions was examined. Four heifers were inoculated intranasally with a larger amount (10(7,6) TCID50) of the gE- vaccine (to increase chances of transmission) and mixed with other sixteen animals at the same age and body condition, in the same grazing area, at a population density equal to the average cattle farming density within the region (one cattle head per 10,000 m²), for 180 days. All animals were monitored daily for clinical signs. Serum samples were collected on days 0, 30, 60 and 180 post-vaccination. Seroconversion was observed only in vaccinated heifers. These results indicate that, under the conditions of the present study, the gE- vaccine virus did not cause any noticeable harmful effect on pregnant dams and on its offspring and did not spread horizontally among cattle.