High-yielding Dairy Cattle Research Articles

Antimicrobial Study of Clinical Mastitic Milk Samples of Cows in and Around Bikaner

Mastitis, an inflammatory condition of the mammary gland, is one of the most economically important diseases of dairy herds. This disease is more prevalent in high yielding dairy cattle. It is caused due to colonization of pathogenic bacteria causing series of events that lead to major alteration in the mammary tissues and composition of milk secreted from the tissue cells (Batavani et al., 2007; Goel et al., 2008). Clinical mastitis is recognized by abnormal milk, varying degree of mammary gland inflammation (redness, heat, swelling and pain) with or without illness of the cow. Mastitis in dairy animals leads to heavy economic losses due to reduction in milk production, altered composition, and cost of treatment of affected animals. The clinical mastitis in different cases can be identified by external symptoms such as udder swelling, touch, pain, redness and hardness of the udder. The objective of the present study was to assess the sensitivity of bacterial isolates from mastitic milk samples of cows to some selected antibiotics.

Mastitis pathogens and their resistance against antimicrobial agents in herds of dairy cows situated in marginal parts of Slovakia

Marginal regions are relatively large part of the area Slovakia which in terms of the economy breeding ruminants can efficiently produce animal commodities only occasionally. Geographic, social and economic stability of these regions is strongly influenced by breeding of ruminants with market milk production. Mastitis is a disease complex that assumes highest clinical and economic significance in milk animals particularly medium to high yielding dairy cattle, usually in and around periparturient period. The objective of this study was to evaluate the effectiveness of different antibiotics against mastitis causing microorganisms during first month of lactation in two herds of 230 and 310 dairy cows situated in marginal parts of Slovakia. Milk samples from quarters were cultured and identified bacteria were subjected to antimicrobial susceptibility test by disc diffusion method to a large number of antibiotics. The prevalence of mastitis in the monitored herds of dairy cows was 26.1% to 17.6%, respectively. A total of 1663 milk samples from udder quarters were investigated, 446 (21.3%) samples were positive. No pathogens were isolated from 1663 (78.4%) milk samples. From all tested bacteria Staphylococcus spp. and Streptococcus spp. which were isolated from subclinical and clinical mastitis, were found amoxicillin + clavulanat and tetradelta to be most effective drug followed by ceftiofur and rifaximin. The significant difference was confirmed between the Staph. aureus and coagulase-negative staphylococci (CoNS) isolates with respect to their susceptibility to the various antibiotics. Antibiotic susceptibility tests should be done to determine the effectiveness of drug that can be used for successful treatment of diseases. Proper isolation and identification of the causative organism play significant role in prevention and control of the diseases.

Candidate gene association analyses for ketosis resistance in Holsteins

High-yielding dairy cattle are susceptible to ketosis, a metabolic disease that negatively affects the health, fertility, and milk production of the cow. Interest in breeding for more robust dairy cattle with improved resistance to disease is global; however, genetic evaluations for ketosis would benefit from the additional information provided by genetic markers. Candidate genes that are proposed to have a biological role in the pathogenesis of ketosis were investigated in silico and a custom panel of 998 putative single nucleotide polymorphism (SNP) markers was developed. The objective of this study was to test the associations of these new markers with deregressed estimated breeding values (EBV) for ketosis. A sample of 653 Canadian Holstein cows that had been previously genotyped with a medium-density SNP chip were regenotyped with the custom panel. The EBV for ketosis in first and later lactations were obtained for each animal and deregressed for use as pseudo-phenotypes for association analyses. Results of the mixed inheritance model for single SNP association analyses suggested 15 markers in 6 unique candidate genes were associated with the studied trait. Genes encoding proteins involved in metabolic processes, including the synthesis and degradation of fatty acids and ketone bodies, gluconeogenesis, lipid mobilization, and the citric acid cycle, were identified to contain SNP associated with ketosis resistance. This work confirmed the presence of previously described quantitative trait loci for dairy cattle, suggested novel markers for ketosis-resistance, and provided insight into the underlying biology of this disease.

Relationship Between Dietary Fatty Acids and Reproductive Functions in Dairy Cattle

Selection of dairy cattle for higher milk yield, without considering important non-production traits, has decreased reproductive efficiency. Thus, low reproductive performance is a major problem in high yielding dairy cattle. Previous studies showed that dietary manipulation to improve fertility holds much promise and dietary fats have positive effects on reproductive functions in high yielding dairy cattle. Positive effects of fats on reproductive performance due to the fatty acids, which are the precursors of progesterone and prostaglandins. Progesterone and prostaglandins hormones are most important factors that play a role on the control of reproductive functions. The amount of linoleic, linolenic and arachidonic fattty acids in ration can be increase or decrease progesterone and prostaglandins synthesis especially PGF2α from ovary and uterus, respectively. Also fatty acids can be influence follicular development, ovulation, embryonic implantation and maternal recognition of pregnancy. This review focuses on the relationships between dietary fatty acids and reproductive functions such as hormone profiles, ovarian function and follicular development, oocyte quality, embryo development, embryonic implantation and maternal recognition of pregnancy in dairy cattle.

High yielding dairy cattle husbandry and their production performance at Baghabari Milk Vita areas of Bangladesh

The aim of this study was to identify the recent husbandry practices of high yielding dairy cows including their production performances surrounding the Baghabari Milk Vita areas of Bangladesh. The survey was conducted on 15 households of Pabna (Santhia) and Sirajgonj (Shahjadpur) districts. Data were also collected from six bathans at Sahajadpur of Sirajgonj district. Medium scale farming (67%) observed more compared to small (27%) and large (7%) in the studied areas with maximum 20 milch cows. Highest average milk production recorded 213 liters per day in few households and the milk price varied between 31 to 35 BDT per liter. Most of the farmers (80%) used the semen of Milk Vita because of its excellence (73%) for better productivity in their progenies. About 73% farmers directly depended on Milk Vita for selling their cows’ milk while 27% on contract persons (Ghos). Two feeding systems were available in the surveyed areas based on the availability of greed grass/fodder: stall feeding (July to November) and bathan feeding (December to June). Total number of AI services (1.62) differed according to crossbreeds (P< 0.05) and rearing system (P< 0.01) with peak milk production 17.57 liters per day. Breeding of the high yielding cows was conducted through artificial insemination (80%) and mainly by the free semen of Milk Vita (80%). Hybrid fodder production, ensuring quality feed/ingredients and milk price, and recorded breeding based on predominant breed could strengthen the overall dairying at Baghabari Milk Vita regions of Bangladesh.
 Asian Australas. J. Biosci. Biotechnol. 2017, 2 (1), 60-67

Comparison of milk fatty acid profiles measured on Kouri cows near Lake Chad and on dairy cattle as reported by meta-analytical data.

Kouri (Bos taurus) is a breed aboriginal from Lake Chad and threatened with extinction. This study aimed to compare milk fatty acid profiles measured on Kouri cows and on high-yielding dairy cattle in Europe and elsewhere as reported by meta-analytical data (22 experimentations). Milk samples were collected from 14 Kouri dairy cows in dry season (March to June) and fatty acids (FA) were determined by gas chromatography. Overall, 32 FA have been identified. Kouri showed lower values (P<0.001) in the sum of saturated FA (SFA, -10.9 pts), cis-9, cis-12 18:2 (-1.00pt) (P<0.01, higher values (P<0.001) in the sum of monounsaturated FA (MUFA, +15.3 pts), C18:0) (+3.5 pts), cis-9, trans-11 C18:2-CLA (+1.00 pts), trans-11 18:1 (+1.4 pts) and (P<0.01) in cis-9, C18:1 (+3.00 pts) acids. The differences between the milk FA profile of the Kouri cows and that obtained from meta-analytical data could be the possible consequence of the use of particular lake pastures by Kouri cows.

Climate Change and Livestock Production in India: Effects and Mitigation Strategies

Climate change poses formidable challenge to the development of livestock sector in India. The anticipated rise in temperature between 2.3°c and 4.8°c over the entire country together with increased precipitation resulting from climate change is likely to aggravate the heat stress in dairy animals, adversely affecting their productive and reproductive performance, and hence reducing the total area where high yielding dairy cattle can be economically reared. Given the vulnerability of India to rise in sea level, the impact of increased intensity of extreme events on the livestock sector would be large and devastating for the low-income rural areas. The predicted negative impact of climate change on Indian agriculture would also adversely affect livestock production by aggravating the feed and fodder shortages. The livestock sector which will be a sufferer of climate change is itself a large source of methane emissions, an important greenhouse gas. In India, although the emission rate per animal is much lower than the developed countries, due to vast livestock population the total annual methane emissions are about 9–10 Tg from enteric fermentation and animal wastes. Other direct or indirect effect such as feed resources, water resources and health contributed significantly to the change in production pattern in India`s livestock industry that support more than 70% of rural populace. It is suggested that strong and sound policies to be implemented to preserve local indigenous breeds of livestock, improvement of pasture, water resource management, research and development would mitigate the monumental consequences of climate change on livestock in India.

Nutritional status of high yielding crossbred cow around parturition

Objective: The objective of this study was to evaluate nutritional status of high yielding dairy cattle around parturition. Materials and methods: Nutritional status of cows around the peri-parturient period was investigated for six months in dairy farm. Seven to eight months’ pregnant cows were selected for this study. Blood samples from 24 randomly selected cows were collected at stage-1, -2 and -3. The serum was stored at -20C until analyzing glucose, total protein (TP), albumin (Alb), triglycerides (Tg), cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), calcium (Ca), magnesium (Mg) and phosphorus (P). Results: An increasing trend of glucose level was evidenced (P=0.07) during stage-1. Instead, higher levels of TP were found during stage-3 as compared to the stage-1 and -2. The Alb levels differed significantly (P

Administration of early post-partum oral drench in dairy cows: effect on metabolic profile

&lt;p&gt;Some prophylactic treatments have been proposed in high-yielding dairy cattle in order to minimize the effects of negative energy balance and some disturbances such as hypocalcaemia and ketosis. The objective of this study was to evaluate the effects of two doses of Drench within 24 h after calving on the metabolic profile and prevention of ketosis. A total of 48 cows from a herd in Rio Grande do Sul state (southern Brazil) was used in the study. The animals were randomly selected and treated orally with Drench (N= 32, propylene glycol, electrolytes and choline in 40 L of water) and water (N= 16) used as control. Blood samples were collected by blood coccygeal venipuncture through a vacutainer plain system tubes. Biochemical determinations were performed in serum (albumin, urea, cholesterol, triglycerides, non-esterified fatty acids -NEFA-, calcium, phosphorus, magnesium, aspartate transaminase -AST- and gammaglutamyl-transferase -GGT-) and a cow-side determination of beta-hydroxybutyrate (BHB) was performed using the Abbot blood Precision Xtra system. All cows in the experiment had their milk production controlled. The Drench treatment produces a tendency to a better milk yield (32.5 vs 29.6 L/cow/day) and helps to prevent subclinical ketosis, as indicated by a lesser prevalence of subclinical ketosis (29.7 vs 37.2%) and mean values of BHB (1.19 vs 1.27 mmol/L) as well as a lesser lipolysis as indicated by NEFA values (509 vs 1.560 µmol/L). The other components of the metabolic profile did not have substantial effects between treatments. In short, on the conditions of the present work, the Drench treatment is an effective management tool for prevention of subclinical ketosis and severe lipolysis.&lt;/p&gt;

A Treatise on Bovine Mastitis: Disease and Disease Economics, Etiological Basis, Risk Factors, Impact on Human Health, Therapeutic Management, Prevention and Control Strategy

Mastitis is a disease complex that assumes highest clinical and economic significance in milch animals particularly medium to high yielding dairy cattle, usually in and around periparturient period. The disease is the infection of milk synthesizing alveolar tissue and is clinically manifested by gross abnormality of milk associated with pathological changes of udder in the form of pain, udder edema, fibrosis, and indurations, the extent depending on the severity of infection. Sub-clinical mastitis remains to be an obscure and latent form of this disease that poses more serious economic concern to the dairy livestock sector, as the incidence is much higher in a dairy herd than the clinical one. Sub-clinical mastitis accounts 40 times more than the clinical mastitis in dairy herds. Even though great technological advances have been made, mastitis continues to be a major economic issue for dairy producers, necessitating researchers and dairy advisors continue to refine the recommended mastitis control programme.

2 ELEVATED NONESTERIFIED FATTY ACID CONCENTRATIONS HAMPER IN VITRO BOVINE OVIDUCTAL EPITHELIAL CELL PHYSIOLOGY

Elevated nonesterified fatty acids (NEFA) have been recognised as an important link between lipolysis-based metabolic conditions and impaired fertility in high-yielding dairy cattle. However, NEFA effects on the oviductal micro-environment currently remain unknown. We hypothesise that elevated NEFAs may contribute to the complex pathology of subfertility and infertility by exerting a negative effect on bovine oviductal epithelial cell (BOEC) physiology. Therefore, the objectives of this study were to elucidate NEFA toxicity effects on BOEC, both qualitatively and morphologically, by assessing BOEC-sperm binding affinity, monolayer integrity, proliferation capacity and morphology. The BOEC of 4 bovine oviducts (4 replicates) at Day 3–5 of the oestrous cycle from a local slaughterhouse were mechanically isolated, pooled, and cultured in a polarized cell culture system (ThinCert, Greiner Bio-One, Frickenhausen, Germany) with DMEM/F12-based culture medium for 9 days until transepithelial electric resistance (TER) reached at least 700 Ω cm2 to prevent leakage between the 2 compartments. At Day 10, monolayers were exposed to a 720 µM NEFA mixture of OA, SA, and PA, for 24 h in 4 treatment groups according to exposure side: control, basal (B), apical (A), and A+B. The BOEC were washed and monolayer quality was assessed by means of a sperm binding assay (30 min co-culture of BOEC monolayer and 106 spermatozoa mL–1), TER measurements (pre- and post-exposure) and a wound healing assay (8-h observation of BOEC proliferation capacity after over an artificial gap). Morphology of BOEC was assessed by scanning electron microscopy on cell polarity, presence of microvilli and cilia, and monolayer integrity. Data (mean ± s.d.) were analysed by mixed model ANOVA. In A+B, monolayers (31.28 ± 6.16 sp/0.05 mm2) showed a significantly reduced sperm binding affinity compared to the control (97.90 ± 10.76 sp/0.05 mm2; P &lt; 0.05), and treatment A tended to be more affected (39.95 ± 19.30 sp/0.05 mm2) than treatment B (68.55 ± 15.38 sp/0.05 mm2; P = 0.051). The absolute TER increase post-NEFA exposure in the control (110 ± 11 Ω cm2) was significantly higher than in all the other treatments. Also, the TER increase differed significantly depending on the exposure side: in treatment A (3 ± 6 Ω cm2), the TER increase was lower than in treatment B (29 ± 8 Ω cm2), and monolayers in treatment A+B were even associated with a significant TER reduction (–15 ± 10 Ω cm2; P &lt; 0.05). Cell proliferation capacity showed a significant closure of the gap in all treatments, but only the control group (41.64% closure) differed significantly (P &lt; 0.05) from the other groups (B = 28.3%, A = 31.62%, A+B = 30.9% closure) irrespective of the exposure side; BOEC morphology was not affected. Depending on the exposure side, elevated NEFA exert a negative effect on BOEC physiology but not morphology. Ultimately, these physiological alterations in its micro-environment may result in suboptimal development of the pre-implantation embryo and a reduced reproductive outcome.

Selection for ‘environmental fit’ from existing domesticated species

The selection of farm animals through breeding for human benefit has a very long history. In more recent times the practice of animal breeding has become highly sophisticated and the speed of change in 'production traits' such as rate of growth and milk yield has correspondingly increased dramatically. This narrow focus on production traits led to a number of well-documented examples of 'unfavourable' correlated responses such as negative fertility and health issues in high-yielding dairy cattle, with concerns that animal breeding is inherently antagonistic to animal welfare. In this paper the authors explore some of the questions surrounding breeding and welfare and, specifically, how to conceptualise and improve the 'fit' between the selected animal and the environment, or system, in which the animal is reared and managed. The authors conclude that there is a need for a better understanding of genotype x environment effects on health and welfare traits in order to inform the development of breeding programmes that lead to improved environmental fit in animals. They also see the need for the development of valid traits for assessing health and welfare, greater consideration of early life effects that can also potentially affect environmental fit and a need to consider the impacts of climate change on breeding programmes.

Impact of Climate Change on Livestock Production: A Review

Climate change is seen as a major threat to the survival of many species, ecosystems and the sustainability of livestock production systems in many parts of the world. Green house gases (GHG) are released in the atmosphere both by natural sources and anthropogenic (human related) activities. An attempt has been made in this article to understand the contribution of ruminant livestock to climate change and to identify the mitigation strategies to reduce enteric methane emission in livestock. In Indian subcontinent, heat stress is the most important climatic stress. Heat stress adversely affecting productive and reproductive performance of livestock, and hence reducing the total area where high yielding dairy cattle may be economically reared. The livestock sector which will be a sufferer of climate change is itself a large source of methane emissions contributing about 18% of total enteric methane budget. Ruminant livestock such as cattle, buffalo, sheep and goats contributes the major proportion of total agricultural emission of methane .In India, although the emission rate per animal is much lower than the developed countries, due to vast livestock population the total annual methane emissions from Indian livestock ranged from 7.26 to 10.4 MT/year. In India more than 90% of the total methane emission from enteric fermentation is being contributed by the large ruminants (cattle and buffalo) and rest from small ruminants and others. Generally CH 4 reduction strategies can be grouped under two broad categories such as management and nutritional strategies. Although the reduction in GHG emissions from livestock industries are seen as high priorities, strategies for reducing emissions should not reduce the economic viability of enterprises if they are to find industry acceptability.

Enteric methane emissions and efficiency of use of energy in Holstein heifers and steers at age of six months1

Twenty 5-mo-old Holstein cattle (10 steers and 10 heifers) were selected from a dairy herd for a 28 d study of enteric methane emissions and energy utilization. The cattle were offered a completely mixed diet with grass silage and concentrates (0.45 and 0.55, DM basis, respectively). They were housed as a single group in cubicle accommodation for the first 20 d, transferred to metabolism units for 3 d, and subsequently housed in indirect open-circuit respiration calorimeter chambers for next 5 d with measurements of feed intake, feces and urine outputs, and gaseous exchange. There were no significant differences (P>0.05) between the 2 groups in terms of animal performance (feed intake, BW, or BW gain), energy metabolism (energy intake, energy outputs, or energy use efficiency), or methane emission rates (total methane emissions expressed on feed intake or energy intake basis). Therefore, the data from the 2 groups were pooled to develop a range of relationships between inputs and outputs. The regression of energy balance or heat production against ME intake (r2=0.85; P<0.001) indicated a NEm of 0.57 MJ/kg BW0.75, which is greater than reported for adult dairy cattle. The methane energy output was found to be 0.068 of GE intake when the intercept was omitted from the linear equation (r2=0.73; P<0.001), which is greater than the commonly accepted value (0.065) for adult cattle used for development of methane emission inventories for dairy and beef production systems. These data can add useful information, as there is little information available on measurements of maintenance energy requirement or methane emissions in young stock (6 mo old) of the current high-yielding dairy cattle. The use of these data can potentially improve the accuracy of prediction of energy requirement and methane emissions for dairy and beef production systems in these dietary conditions.

Detecção de corpos estranhos metálicos por meio de ferroscopia em rebanho bovino de leite de alta produção

Avaliou-se a presença de corpos estranhos metálicos (CEM) por meio de ferroscopia transabdominal em vacas de rebanho leiteiro de alta produção (&gt; 9.000 kg/lactação) mantidas em estabulação livre com fornecimento de ração total através de vagão alimentador. A ocorrência de CEM nos anos de 2005 e 2006 foi, respectivamente, igual a 83,67% e 51,52%, sendo que a amperagem máxima obtida durante a realização do exame foi igual a 9,36 ± 7,54 µA em 49 vacas examinada no ano de 2005 e igual a 6,44 ± 7,54 µA em 66 vacas examinada no ano de 2006. Verificou-se que em 44% (33/75) dos animais o CEM estava localizado no retículo (entre o quinto e sétimo espaço intercostal) e que em 56% (42/75) dos animais o corpo estranho estava localizado no rúmen. Após a exclusão de possíveis outras causas desta ocorrência, concluiu-se que no rebanho examinado a presença de CEM em mais da metade dos animais deveu-se, principalmente, a falhas na manutenção do vagão alimentador.

Milk protein/fat ratio on day 7 postpartum as a predictor of left displacement of abomasum

Left displaced abomasum (LDA) affects high-yielding dairy cattle, but the aetiopathogenesis for this condition is not clearly understood. Studies conducted on the aetiology of LDA have recognised breed, age, diet,...

Quantification of pericaudal adipocyte diameter in dairy cattle during peripartum: a complementary method to study energetic status using conventional histology

The energetic status of high-yielding Holstein-Friesian dairy cattle was studied during peripartum under field conditions using body condition score (BCS), glycemia, seric ß-hydroxybutyrate and adipose tissue cellularity. This last method was tested as a complementary tool for energetic status assessment. Biopsies of pericaudal subcutaneous adipose tissue were obtained from 25 multiparous animals at 28 days before and 21 days after parturition. Samples were routinely processed for histological examination and stained with haematoxylin and eosin (H&E). The mean diameter of adipocytes (MDA) was measured with the aid of a digital image processor. During the same period, blood samples were collected weekly for metabolite determinations. The MDA at 28 days pre-partum and 21 days post-partum were 72.1 vs. 66.2 μm respectively (p = 0.055), and the corresponding BCS at these moments was 3.32 vs. 3.19 (p = 0.068). At -28 days pre-partum, the BCS was positively correlated with MDA (Pearson's r = 0.521, p = 0.016) and with glycemia (Pearson's r = 0.404, p = 0.056). Correlations between BCS and MDA, and between BCS and glycemia, with ß-hydroxybutyrate although not significant, suggest that routine histological preparations of biopsies from subcutaneous adipose tissue could be included as an easy and valuable tool for research purposes to evaluate metabolic adaptation of dairy cows to peripartum, as well as the incidence of metabolic disorders and productive performance.

Practical Aspects of the Fertility of Dairy Cattle

To establish sustainability in the dairy industry, it is important that cows become pregnant at a biologically optimal time and at an economically profitable interval after calving. In this review, the results obtained from Holstein cattle in an experimental herd for dairy research are summarized. First, the effect of age at first calving of heifers on productive and reproductive performance was examined. A reduction in calving age from 25.1 to 21.5 months with the same growth rate during the first 12 months after birth had no negative effects on the heifers' performance. Second, the postpartum follicular dynamics of lactating cows were traced in relation to their fertility, and the emergence and fate of cystic ovarian follicles were examined. The premature initiation of ovarian activity does not always improve the fertility of cows as indicated by the number of days open. Third, the occurrences of anestrous ovulation during the early postpartum period were analyzed with reference to the frequency of reversion to anestrus. The premature onset of estrous activity also did not improve fertility, and relapse back into anestrus after the onset of the estrous cycle often occurred during the breeding period. Fourth, some indices for the occurrence of postpartum reproductive events were evaluated as an indicator of the reproductive performance of lactating cows. The milk yield and percentage of body weight loss could be indicators for reproductive events. Finally, the potency of a pedometry system for the detection of typical and atypical estrous behaviors of heifers and lactating cows was evaluated in terms of efficiency and accuracy. The location of the pedometers and housing conditions for the animals affected the estrus detection of the system. These results represent the reproductive potential of modern high-yielding dairy cattle and provide a baseline to evaluate their reproduction.

Genetic polymorphisms of osteopontin (OPN), prolactin (PRL) and pituitary-specific transcript factor-1 (PIT-1) in South Anatolian and East Anatolian Red cattle

The objective of the present study was to determine the genotype and allele frequencies for osteopontin (OPN), prolactin (PRL) and pituitary-specific transcription factor-1 (PIT-1) that are claimed to be associated with milk production traits in cattle in South Anatolian Red (SAR) and East Anatolian Red (EAR) cattle. In this study, 40 cattle for each of SAR and EAR were used. OPN in intron 4, PRL in exon 3 and PIT-1 in exon 6 were amplified by polymerase chain reaction (PCR) and the resulting PCR products were subjected to digestion using BseNI, RsaI and HinfI enzymes, respectively, to determine the single nucleotide polymorphisms (SNPs). Results showed that frequencies of the OPN allele C, PRL allele B, and PIT-1 allele A which are associated with milk production tarits were found low in SAR and EAR. As a result, SAR and EAR cattle breeds have the lower allel frequencies that influence the milk production traits for three genes than high-yielding European dairy cattle breeds.

Computer-aided B-mode ultrasound diagnosis of hepatic steatosis: a feasibility study

Fatty liver (steatosis) occurs in obese patients, among others, and is related to the development of diabetes type-2. Timely diagnosis of steatosis is therefore of great importance. Steatosis is also the most common liver disease of high-yielding dairy cattle during early lactation. This makes it a suitable animal model for studying liver steatosis. Furthermore, reference of derived ultrasound parameters against a "gold standard" is possible in cattle by taking a liver biopsy for the assessment of fat concentration. The authors undertook this pilot study to investigate the hypothesis that quantitative, computer-aided B-mode ultrasound enables the noninvasive detection of hepatic steatosis. Echographic images were obtained postpartum from dairy cows (n = 12) in transcutaneous and direct (intraoperative) applications using a convex array transducer at 4.2 MHz. During surgery, a biopsy was taken from the caudate lobe to assess the liver fat content (fat score). A custom-designed software package for computer-aided ultrasound diagnosis (CAUS) was developed. After linearizing the post-processing look-up-table (LUT), the image gray levels were transferred into echo levels in decibels relative to the mean echo level in a tissue-mimicking phantom. The quantitative comparison of transcutaneous and intraoperative images enabled the correction for the attenuation effect of skin and subcutaneous fat layer on the mean echo level in the liver, as well as for the effects of the beam formation and attenuation of liver tissue on the echo level vs. depth. The residual attenuation coefficient (dB/cm) in fatty liver vs. normal liver was estimated and compensated for. Finally, echo level was estimated relative to the phantom used for calibration, and echo texture was characterized by the mean axial and lateral speckle size within the regions of interest. In the no fat/low fat group (n = 5) skin plus fat layer attenuation was 3.4 dB/cm. A correlation of skin layer thickness vs. fat score of r = 0.48 was found. The mean transcutaneous liver tissue echo level correlated well with fat score: r = 0.80. A residual liver attenuation coefficient of 0.76 dB/cm and 1.19 dB/cm was found in medium and high fat liver, respectively. In transcutaneous images, correlation of residual attenuation coefficient with fat score was r = 0.69. Axial and lateral speckle sizes were on the order of 0.2 and 1.0 cm, respectively, and no correlation was found with liver fat content. Results for transcutaneous and intraoperative images were similar. The authors conclude that this pilot study shows the feasibility of calibrated, computer-aided ultrasound for noninvasively diagnosing, possibly even screening, steatosis of the liver.