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1.
Sci Total Environ ; 773: 145573, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33940733

RESUMEN

In Colombia, the beef production chain accounts for approximately 11.6 million cattle heads and annually produces 933 million kg of the beef carcass. There are no life cycle assessment (LCA) studies that have evaluated the environmental performance of Colombian beef systems. The present study aimed to estimate the carbon footprint (CF), non-renewable energy use, and land use of 251 cow-calf and 275 fattening farms in Colombia. The study also aimed to identify the main hotspots of adverse environmental impacts and propose possible mitigation options and their cost-effectiveness. The impact categories were estimated using the 2006 IPCC and the 2019 Refinement to 2006 IPCC guidelines, databases, and locally estimated emission factors. The functional units used were 1 kg fat and protein corrected milk (FPCM) and 1 kg live weight gain (LWG), leaving the farm gate. Three methods of allocating environmental burdens to meat and milk products were applied: economic, energy, and mass allocation. The adoption of improved pastures was considered a mitigation measure, and an economic assessment was performed to estimate the relative cost-effectiveness of its establishment. A principal component multivariate analysis and a Hierarchical Clustering on Principal Components were performed. The economic allocation method assigned a greater environmental burden to meat (83%), followed by energy content (80%) and mass production (73%). The largest sources of GHG emissions were enteric fermentation and manure deposited on pasture. Both cow-calf and fattening systems had a cluster of farms with better productivity, pasture and cattle management practices, and environmental performance. The CF for meat could be reduced by 33 to 56% for cow-calf and 21 to 25% for fattening farms, by adopting improved pastures. Therefore, our results suggest that GHG emissions can be reduced by adopting improved pastures, better agricultural management practices, efficient fertilizer usage, using the optimal stocking rate, and increasing productivity.


Asunto(s)
Huella de Carbono , Industria Lechera , Animales , Bovinos , Colombia , Femenino , Estadios del Ciclo de Vida , Leche
2.
Water Sci Technol ; 83(5): 1250-1264, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33724951

RESUMEN

The present investigation was focused to compare chitosan based nano-adsorbents (CZnO and CTiO2) for efficient treatment of dairy industry wastewater using Response Surface Methodology (RSM) and Artificial Neural Network (ANN) models. The nano-adsorbents were synthesized using chemical precipitation method and characterized by using scanning electron microscope with elemental detection sensor (SEM-EDS) and atomic force microscope (AFM). Maximum %RBOD (96.71 and 87.56%) and %RCOD (90.48 and 82.10%) for CZnO and CTiO2 nano-adsorbents were obtained at adsorbent dosage of 1.25 mg/L, initial biological oxygen demand (BOD) and chemical oxygen demand (COD) concentration of 100 and 200 mg/L, pH of 7.0 and 2.00, contact time of 100 and 60 min, respectively. The results obtained for both the nano-adsorbents were subject to RSM and ANN models for determination of goodness of fit in terms of sum of square errors (SSE), root mean square error (RMSE), R2 and Adj. R2, respectively. The well trained ANN model was found superior over RSM in prediction of the treatment effect. Hence, the developed CZnO and CTiO2 nano-adsorbents could be effectively used for dairy industry wastewater treatment.


Asunto(s)
Quitosano , Purificación del Agua , Industria Lechera , Redes Neurales de la Computación , Aguas Residuales
3.
J Dairy Sci ; 104(5): 6080-6095, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33663825

RESUMEN

Providing optimal calf care remains a challenge on many dairy farms and has important implications for the future health, welfare, and productivity of male and female calves. Recent research suggests that male dairy calves receive a lower quality of care early in life than female calves, but further investigation is required to determine the factors that influence this disparity. The objectives of this study were to understand dairy producer perspectives on neonatal calf care practices and explore differences between male and female calf care. Overall, 23 dairy producers in Ontario, Canada, participated in 4 focus groups about calf care practices that were recorded and evaluated qualitatively using thematic analysis. Major barriers for good calf care included lack of knowledge about the best management practices for calf care and the prioritization of farm resources toward the milking herd. Some producers also noted that farm infrastructure (particularly during challenging weather) and employee training were important limitations. The economic cost of providing good neonatal calf care was important primarily for male calves and acted as a motivation or a barrier depending on the producer's beliefs about calf care and how they chose to market their calves. The primary source of knowledge producers used to develop calf care practices was their own experience, although many also relied on dairy-industry advisors, most often veterinarians. Producers were motivated by social norms, along with intrinsic pride and obligation to provide good calf care, and these motives were influenced by their emotional state. Producers expressed beliefs about which aspects of calf care are most important-notably colostrum management-and appreciated simple and economical solutions to calf-rearing challenges. Calf care practices were varied, and we identified a diversity of knowledge, motivations, and barriers to adopting best management practices, which sometimes differed between male and female calves. Some producers said that they did not know what happened to their male calves after they left the farm and tended to prioritize the care of female over male calves in subtle ways, such as less timely provision of colostrum. The infrastructure investment and other costs associated with caring for male calves often limited their care, but producers were still motivated to provide adequate care for male calves. These findings represent potential targets for additional research and intervention strategies to improve calf care practices on dairy farms.


Asunto(s)
Calostro , Industria Lechera , Animales , Bovinos , Granjas , Femenino , Grupos Focales , Recién Nacido , Masculino , Ontario , Embarazo
4.
J Dairy Sci ; 104(5): 5665-5674, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33663826

RESUMEN

Zero-grazing (ZG; the mechanical harvesting and feeding of fresh grass) is increasingly used in grass-based milk production systems alongside conventional grazing. It allows farmers to supply fresh grass from land parcels that are outside of the main grazing block during seasonal shortages and periods when climatic conditions limit animal grazing opportunities. The objective of this study was to establish an understanding of current ZG practices on Irish dairy farms, to capture farmer perceptions on the implementation of this management practice, and to identify farmer knowledge requirements on ZG. An online survey was distributed and completed by 130 dairy farmers who use or have used ZG. Zero-grazing was used alongside conventional grazing by 92% of respondents. These farms were particularly fragmented, with between 1 and 14 separate land blocks. Respondents felt ZG helped them overcome fragmentation, increase grass use, and extend grass feeding in spring and autumn. However, extra cost and time input associated with ZG were recognized as key challenges. The majority of respondents rated current technical information available on ZG in the Republic of Ireland as "poor" or "very poor," and knowledge deficits were identified in the areas of cost analysis, grass management and productivity, cow productivity, cow health and nutrition, and soil fertility.


Asunto(s)
Industria Lechera , Lactancia , Alimentación Animal/análisis , Animales , Bovinos , Dieta , Agricultores , Granjas , Femenino , Humanos , Irlanda , Leche , Percepción , Encuestas y Cuestionarios
5.
J Dairy Sci ; 104(5): 6051-6060, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33663835

RESUMEN

The objectives of this exploratory study were to (1) describe the association between herd-level udder hygiene and clinical mastitis and (2) investigate how sample size and milking stage affect the accuracy and precision of herd udder hygiene assessments made at milking time. A prospective longitudinal study was conducted in a dairy herd in Northern Australia as part of a previously published clinical trial of premilking teat disinfection. Video footage from 35 afternoon milkings was used to conduct 12,544 udder hygiene scores from 504 cows during an 89-d period and measure udder hygiene of the herd (proportion of cows with udder hygiene ≥3 out of 4). Linear interpolation was used to estimate herd udder hygiene on the days that were not scored, such that a herd-level udder hygiene measure was available for all cow-days in the study. Clinical mastitis events occurring during the study period were detected and recorded by farm staff according to a standardized definition. The relationship between herd udder hygiene on each of 1, 2, and 3 d before each study day (d -1, -2, and -3, respectively) and clinical mastitis at the cow level on each study day (each in turn being set as d 0) was determined using multivariable generalized estimating equations (family = Poisson, link = log), with the unit of analysis being the cow-day, adjusting for potential confounders and the clustering within the data. In addition, sampling strategies were evaluated by simulating herd udder hygiene assessments using a subset of cows in the herd. Herd udder hygiene from d -1, -2, and -3 was positively associated with clinical mastitis on d 0 (incidence rate ratio = 1.4 per 10-point increase in the percentage of cows with poor udder hygiene). Sampling strategy simulation found that at least 80 cows needed to be scored to achieve sufficiently precise estimations of herd udder hygiene. Furthermore, cows scored later during milking were slightly more likely to have poor udder hygiene than those scored earlier (risk ratio = 1.02 for cows that were 10% later in the milking order). More research is needed to evaluate risk factors for poor udder hygiene and potential interventions in pasture-based dairy cows.


Asunto(s)
Enfermedades de los Bovinos , Mastitis Bovina , Mastitis , Animales , Australia , Bovinos , Industria Lechera , Femenino , Higiene , Estudios Longitudinales , Glándulas Mamarias Animales , Mastitis/veterinaria , Mastitis Bovina/epidemiología , Leche , Estudios Prospectivos
6.
J Dairy Sci ; 104(5): 5921-5931, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33663849

RESUMEN

Claw lesions are a serious problem on dairy farms, affecting both the health and welfare of the cow. Automated detection of lameness with a practical, on-farm application would support the early detection and treatment of lame cows, potentially reducing the number and severity of claw lesions. Therefore, in this study, a method was proposed for the detection of claw lesions based on the acoustic analysis of a cow's gait. A panel was constructed to measure the impact sound of animals walking over it. The recorded impact sound was edited, and 640 sound files from 64 cows were analyzed. The classification of animal-lameness status was performed using a machine-learning process with a random forest algorithm. The gold standard was a 2-point scale of hoof-trimming results (healthy vs. affected), and 38 properties of the recorded sound files were used as influencing factors. A prediction model for classifying the cow lameness was built using a random forest algorithm. This was validated by comparing the reference output from hoof-trimming with the model output concerning the impact sound. Altering the likelihood settings and changing the cutoff value to predict lame animals improved the prediction model. At a cutoff at 0.4, a decreased false-negative rate was generated, and the false-positive rate only increased slightly. This model obtained a sensitivity of 0.81 and a specificity of 0.97. With this procedure, Cohen's Kappa value of 0.80 showed good agreement between model classification and diagnoses from hoof-trimming. In summary, the prediction model enabled the detection of cows with claw lesions. This study shows that lameness can be detected by machine learning from the impact sound of hoofs in dairy cows.


Asunto(s)
Enfermedades de los Bovinos , Pezuñas y Garras , Acústica , Animales , Bovinos , Enfermedades de los Bovinos/diagnóstico , Industria Lechera , Granjas , Femenino , Cojera Animal/diagnóstico , Aprendizaje Automático
7.
J Dairy Sci ; 104(5): 5652-5664, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33685701

RESUMEN

The objectives of this study were to (1) use partial budget analysis to estimate the cash impact for herds that switch from blanket dry cow therapy (BDCT) to culture- or algorithm-guided selective dry cow therapy (SDCT) and (2) conduct a sensitivity analysis to investigate effects in situations where SDCT increased clinical and subclinical mastitis risk during the subsequent lactation. A partial budget model was created using Monte Carlo simulation with @Risk software. Expenditures associated with dry-off procedures and health outcomes (clinical and subclinical mastitis) during the first 30 d in milk were used to model herd-level effects, expressed in units of US dollars per cow dry-off. Values for each economic component were derived from findings from a recent multisite clinical trial, peer-reviewed journal articles, USDA databases, and our experiences in facilitating the implementation of SDCT on farms. Fixed values were used for variables expected to have minimal variation within the US dairy herd population (e.g., cost of rapid culture plates) and sampling distributions were used for variables that were hypothesized to vary enough to effect the herd net cash impact of one or more DCT approach(es). For Objective 1, herd-level udder health was assumed to be unaffected by the implementation of SDCT. For culture-guided SDCT, producers could expect to save an average of +$2.14 (-$2.31 to $7.23 for 5th and 95th percentiles) per cow dry-off as compared with BDCT, with 75.5% of iterations being ≥$0.00. For algorithm-guided SDCT, the mean net cash impact was +$7.85 ($3.39-12.90) per cow dry-off, with 100% of iterations being ≥$0.00. The major contributors to variance in cash impact for both SDCT approaches were percent of quarters treated at dry-off and the cost of dry cow antibiotics. For Objective 2, we repeated the partial budget model with the 30-d clinical and subclinical mastitis incidence increasing by 1, 2, and 5% (i.e., risk difference = 0.01, 0.02, and 0.05) in both SDCT groups compared with BDCT. For algorithm-guided SDCT, average net cash impacts were ≥$0.00 per cow dry-off (i.e., cost effective) when mastitis incidence increased slightly. However, as clinical mastitis incidence increased, economic returns for SDCT diminished. These findings indicate that when SDCT is implemented appropriately (i.e., no to little negative effect on health), it might be a cost-effective practice for US herds under a range of economic conditions.


Asunto(s)
Enfermedades de los Bovinos , Mastitis Bovina , Algoritmos , Animales , Antibacterianos/farmacología , Bovinos , Enfermedades de los Bovinos/tratamiento farmacológico , Recuento de Células/veterinaria , Industria Lechera , Femenino , Lactancia , Glándulas Mamarias Animales , Mastitis Bovina/tratamiento farmacológico , Leche
8.
J Dairy Sci ; 104(5): 5111-5124, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33714581

RESUMEN

Genetic selection has been a very successful tool for the long-term improvement of livestock populations, and the rapid adoption of genomic selection over the last decade has doubled the rate of gain in some populations. Breeding programs seek to identify genetically superior parents of the next generation, typically as a function of an index that combines information about many economically important traits into a single number. In the United States, the data that drive this system are collected through the national dairy herd improvement program that began more than a century ago. The resulting information about animal performance, pedigree, and genotype is used to compute genomic evaluations for comparing and ranking animals for selection. However, the full expression of genetic potential requires that animals are placed in environments that can support such performance. The Agricultural Research Service of the US Department of Agriculture and the Council on Dairy Cattle Breeding collaborate to deliver state-of-the-art genomic evaluations to the dairy industry. Today, most breeding stock are selected and marketed using the net merit dollars (NM$) selection index, which evolved from 2 traits in 1926 (milk and fat yield) to a combination of 36 individual traits following the last NM$ update in 2018. Updates to NM$ require the estimation of many different values, and it can be difficult to achieve consensus from stakeholders on what should be added to, or removed from, the index at each review, and how those traits should be weighted. Over time, the majority of the emphasis in the index has shifted from yield traits to fertility, health, and fitness traits. Phenotypes for some of these new traits are difficult or expensive to measure, or require changes to on-farm habits that have not been widely adopted. This is driving interest in sensor-based systems that provide continuous measurements of the farm environment, individual animal performance, and detailed milk composition. There is also a need to capture more detailed data about the environment in which animals perform, including information about feeding, housing, milking systems, and infectious and parasitic load. However, many challenges accompany these new technologies, including a lack of standardization or validation, need for high-speed internet connections, increased computational requirements, and interpretations that are often not backed by direct observations of biological phenomena. This work will describe how US selection objectives are developed, as well as discuss opportunities and challenges associated with new technologies for measuring and recording animal performance.


Asunto(s)
Condicionamiento Físico Animal , Animales , Bovinos/genética , Industria Lechera , Genotipo , Leche , Fenotipo , Selección Genética
9.
J Environ Manage ; 287: 112313, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33714041

RESUMEN

The purpose of this paper is to adjust the measure of eco-efficiency to account for specific sustainability targets at farm level. We assess eco-efficiency and adjust the scores according to a target of absolute levels of greenhouse gas (GHG) emissions, using Data Envelopment Analysis (DEA) and data from Swedish dairy farms as an illustrative example. In particular, the Swedish target of net-zero emissions in 2045 and vision of a fossil free economy are used to specify the GHG emission target used for assessing the adjusted eco-efficiency scores. We test for possible factors associated with the adjusted and unadjusted eco-efficiency using OLS-regression analysis. The study is based on data from the farm accounting data network (FADN) in year 2016 and considers the environmental pressures nutrients and contribution to global warming. Adjusted as well as unadjusted eco-efficiency scores suggest that Swedish dairy farms are highly inefficient, and that economic value added could increase by 64% (adj) or 67% (unadj) for conventional farms and by 42% (adj) or 41% (unadj) for organic farms at the same level of environmental pressure. Findings further suggest that adjusting the scores towards absolute levels of GHG emissions increases industry average efficiency. Comparing the unadjusted and adjusted efficiency scores using Spearman rank correlation indicates similar efficiency rankings between the unadjusted and adjusted scores. However, findings also indicate that adjusted and unadjusted eco-efficiency scores are associated with different influencing factors, which lends empirical support to the idea that the two types of efficiency scores are conceptually different. Policy recommendations can be made based on insights from the second stage analysis of possible influencing factors. In particular, adjusted eco-efficiency is associated with higher intensity of farming defined as output per livestock unit. Further, adjusted eco-efficiency is associated with a higher number of livestock units in conventional farms and with lower levels of labour per livestock unit in organic farms.


Asunto(s)
Industria Lechera , Gases de Efecto Invernadero , Animales , Granjas , Leche , Suecia
10.
Prev Vet Med ; 190: 105323, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33756433

RESUMEN

Calf gastrointestinal disease remains one of the main causes of productivity and economic losses on dairy operations. The majority of pre-weaned calf mortality is attributed to diarrhea or other digestive problems. Five enteric pathogens are commonly associated with diarrhea in dairy calves, including bovine rotavirus, bovine coronavirus, Escherichia coli, Salmonella spp., and Cryptosporidium parvum. Pathogen-associated differences in health outcomes and case fatality rates have not been well-characterized. Additionally, updated prevalence estimates may reflect important changes in the epidemiology of the pathogens on dairy farms. For this cohort study, fecal samples were collected from 276 clinically ill calves across 5 central Ohio dairy farms on the first day of diarrheal diagnosis. Genomic techniques, including reverse transcription polymerase chain reaction (RT-PCR) and droplet digital polymerase chain reaction (ddPCR) were used to test for the presence of the five enteric pathogens. A Poisson regression model was used to estimate the relative risk of mortality, and a survival analysis with a Cox regression model was used to analyze time to return to a healthy clinical status by pathogen. Rotavirus was the most frequently identified at 68.1 % (188/276), followed by F5 (K99)+E. coli at 42.5 % (114/268), C. parvum at 28.4 % (66/232), coronavirus at 5.8 % (16/276), and Salmonella had the lowest prevalence at 3.7 % (10/268). Risk of mortality tended to be higher for calves infected with Salmonella (RR = 3.83; 95 %CI: 0.93, 16.02, p = 0.062); however, the time to return to a healthy clinical status was not different for different pathogens. Only farm was a significant predictor of time to return to health (p = 0.017); the within-farm median duration of signs substantially varied between 2 and 7 days. The results suggest that the prevalence and distribution of rotaviral infections is higher than reported in prior studies. With the exception of infections caused by Salmonella spp., pathogen diagnosis on the first day of diarrhea was a poor predictor of the outcome and duration of disease. These results are critical to guide the implementation of prevention measures to detect, treat, and prevent calf diarrhea.


Asunto(s)
Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/virología , Diarrea/veterinaria , Animales , Animales Recién Nacidos , Bovinos , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/prevención & control , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/veterinaria , Coronavirus Bovino/aislamiento & purificación , Criptosporidiosis/epidemiología , Cryptosporidium parvum/aislamiento & purificación , Industria Lechera , Diarrea/epidemiología , Diarrea/microbiología , Diarrea/virología , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/veterinaria , Granjas , Estudios Longitudinales , Ohio/epidemiología , Prevalencia , Rotavirus/aislamiento & purificación , Infecciones por Rotavirus/epidemiología , Infecciones por Rotavirus/veterinaria , Salmonella/aislamiento & purificación , Salmonelosis Animal/epidemiología , Resultado del Tratamiento , Destete
11.
Int J Mol Sci ; 22(4)2021 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-33670752

RESUMEN

The reproductive status of dairy cows remains a challenge for dairy farmers worldwide, with impaired fertility linked to a significant reduction in herd profitability, due in part to impaired immunity, increased metabolic pressure, and longer postpartum anestrous interval (PPAI). Exosomes are nanovesicles released from a variety of cell types and end up in circulation, and carry proteins, bioactive peptides, lipids, and nucleic acids specific to the place of origin. As such, their role in health and disease has been investigated in humans and animals. This review discusses research into exosomes in the context of reproduction in dairy herds and introduces recent advances in mass-spectrometry (MS) based proteomics that have a potential to advance quantitative profiling of exosomal protein cargo in a search for early biomarkers of cattle fertility.


Asunto(s)
Bovinos/fisiología , Industria Lechera , Exosomas/metabolismo , Reproducción/fisiología , Animales , Epigénesis Genética , Modelos Biológicos , Proteómica , Reproducción/genética
12.
J Dairy Sci ; 104(4): 3789-3819, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33663845

RESUMEN

Because a growing proportion of the beef output in many countries originates from dairy herds, the most critical decisions about the genetic merit of most carcasses harvested are being made by dairy producers. Interest in the generation of more valuable calves from dairy females is intensifying, and the most likely vehicle is the use of appropriately selected beef bulls for mating to the dairy females. This is especially true given the growing potential to undertake more beef × dairy matings as herd metrics improve (e.g., reproductive performance) and technological advances are more widely adopted (e.g., sexed semen). Clear breed differences (among beef breeds but also compared with dairy breeds) exist for a whole plethora of performance traits, but considerable within-breed variability has also been demonstrated. Although such variability has implications for the choice of bull to mate to dairy females, the fact that dairy females themselves exhibit such genetic variability implies that "one size fits all" may not be appropriate for bull selection. Although differences in a whole series of key performance indicators have been documented between beef and beef-on-dairy animals, of particular note is the reported lower environmental hoofprint associated with beef-on-dairy production systems if the environmental overhead of the mature cow is attributed to the milk she eventually produces. Despite the known contribution of beef (i.e., both surplus calves and cull cows) to the overall gross output of most dairy herds globally, and the fact that each dairy female contributes half her genetic merit to her progeny, proxies for meat yield (i.e., veal or beef) are not directly considered in the vast majority of dairy cow breeding objectives. Breeding objectives to identify beef bulls suitable for dairy production systems are now being developed and validated, demonstrating the financial benefit of using such breeding objectives over and above a focus on dairy bulls or easy-calving, short-gestation beef bulls. When this approach is complemented by management-based decision-support tools, considerable potential exists to improve the profitability and sustainability of modern dairy production systems by exploiting beef-on-dairy breeding strategies using the most appropriate beef bulls.


Asunto(s)
Industria Lechera , Carne Roja , Animales , Bovinos/genética , Femenino , Masculino , Leche , Reproducción , Semen
13.
J Dairy Sci ; 104(4): 4549-4560, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33663863

RESUMEN

We developed a custom bovine leukemia virus (BLV) control program for the Alberta dairy industry, consisting of a risk assessment and a comprehensive list of best management practices (BMP) aimed at prevention of BLV transmission between cattle. This control program was implemented on 11 farms for approximately 1 yr. Blood samples were collected from all cattle ≥12 mo old, and serum was tested with a commercial ELISA. Risk assessments were performed on each farm, risk-connected on-farm management was identified, and management changes expected to prevent transmission of BLV between cattle were suggested by the first author and agreed upon with each farmer. Throughout the following year, all participating farmers were visited multiple times to identify and overcome barriers to implementation and to monitor progress. After approximately 1 yr of implementing BLV control, all cattle ≥12 mo old on farm with a negative or no previous test result were sampled, and the within-herd prevalence was determined. The median number of cattle on farm that were ≥12 mo was 195 (range 110-524). The initial prevalence averaged 39% (13-66%). On average, 5 BMP (3-7) were suggested to each farmer. On average, 4 BMP (1-7) were implemented. At the second sampling, the average within-herd prevalence of all animals that tested positive (including the previous sampling) was 36% (12-62%). Eight farms reduced their within-herd BLV prevalence, within-herd prevalence stayed constant on 1 farm, and it increased on 1 farm. The remaining farm terminated their participation before the second sampling. The number of seroconversions per farm ranged from 3 to 109, highlighting the success of some producers to minimize new infections. The risk assessment was proven to be a valuable tool to identify flaws in on-farm management, although risk assessment score was unrelated to the within-herd BLV prevalence. Finally, it appeared that implementation of BMP aimed at prevention of BLV transmission between cattle could reduce within-herd BLV prevalence when farmers committed to their implementation.


Asunto(s)
Enfermedades de los Bovinos , Leucosis Bovina Enzoótica , Virus de la Leucemia Bovina , Alberta/epidemiología , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/prevención & control , Industria Lechera , Leucosis Bovina Enzoótica/epidemiología , Leucosis Bovina Enzoótica/prevención & control , Granjas
14.
Sensors (Basel) ; 21(4)2021 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-33671216

RESUMEN

The prediction of health disorders is the goal of many sensor systems in dairy farming. Although mastitis and lameness are the most common health disorders in dairy cows, these diseases or treatments are a rare event related to a single day and cow. A number of studies already developed and evaluated models for classifying cows in need of treatment for mastitis and lameness with machine learning methods, but few have illustrated the effects of the positive predictive value (PPV) on practical application. The objective of this study was to investigate the importance of low-frequency treatments of mastitis or lameness for the applicability of these classification models in practice. Data from three German dairy farms contained animal individual sensor data (milkings, activity, feed intake) and were classified using machine learning models developed in a previous study. Subsequently, different risk criteria (previous treatments, information from milk recording, early lactation) were designed to isolate high-risk groups. Restricting selection to cows with previous mastitis or hoof treatment achieved the highest increase in PPV from 0.07 to 0.20 and 0.15, respectively. However, the known low daily risk of a treatment per cow remains the critical factor that prevents the reduction of daily false-positive alarms to a satisfactory level. Sensor systems should be seen as additional decision-support aid to the farmers' expert knowledge.


Asunto(s)
Crianza de Animales Domésticos/instrumentación , Enfermedades de los Bovinos/diagnóstico , Industria Lechera , Cojera Animal/diagnóstico , Mastitis/diagnóstico , Animales , Bovinos , Granjas , Femenino , Lactancia , Leche
15.
Animal ; 15(1): 100005, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33573960

RESUMEN

A recently developed methodological approach for determining the greenhouse gas emissions impact of national breeding programs was applied to measure the effects of current and future breeding goals on the emission intensity (EI) of the Canadian dairy industry. Emission intensity is the ratio of greenhouse gas outputted in comparison to the product generated. Traits under investigation affected EI by either decreasing the direct emissions yield (i.e. increasing feed performance), changing herd structure (i.e. prolonging herd life) or through the dilution effect of increased production (i.e. increasing fat yield). The intensity value (IV) of each trait, defined as the change in emissions' intensity per unit change in each trait, was calculated for each of the investigated traits. The IV trend of these traits was compared for the current and prospective selection index, as well as for a system with and without quota (the supply management policy designed to prevent overproduction). The overall EI of the average genetic merit Canadian dairy herd per breeding female was 5.07 kg CO2eq/kg protein equivalent output. The annual reduction in EI due to the improvement of production traits was -0.027, -0.018 and -0.006 for fat, protein and milk other solids, respectively. The functional traits, herd life and mastitis resistance, had more modest effects (-0.008 and -0.001, respectively). These results are consistent with international studies that identified traits related to production, survival, health and fertility as having the largest impact on the environmental footprint of dairy cattle. Overall, the dairy industry is becoming more efficient by reducing its EI through selection of environmentally favorable traits, with a 1% annual reduction of EI in Canada.


Asunto(s)
Industria Lechera , Leche , Animales , Canadá , Bovinos/genética , Ambiente , Femenino , Estudios Prospectivos
16.
Animal ; 15(1): 100008, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33573991

RESUMEN

Validation of precision dairy-monitoring technologies establishes technology behavioral-monitoring efficacy for research and commercial application. Technology metrics should be associated with behaviors of known physiological importance. The objective of this research project was to evaluate the Nedap SmartTag Neck (Nedap Livestock Management, Groenlo, the Netherlands) for dairy cow behavior measuring accuracy. The behaviors measured were eating, ruminating, and inactivity. Thirty-six lactating Holstein dairy cows were randomly selected from the University of Kentucky's Coldstream Dairy Research Herd and fitted with a Nedap SmartTag Neck. Cows were observed by a single observer for a total of 4 h per cow, including 2 h after the morning milking (0800 h) and 2 h after the evening milking (2000 h), from May to December 2017. The observer recorded the time behaviors occurred using a synchronized watch (CASIO, CASIO America, Inc., Dover, NJ, USA). The hour, minute, and second of the day each behavior occurred were compared with corresponding technology measurements. Pearson correlation coefficients (r; CORR procedure; SAS Institute Inc., Cary, NC, USA), concordance correlation coefficients (CCC; epiR package; R Foundation for Statistical Computing, Vienna, Austria), and Bland-Altman plots (epiR package; R Foundation for Statistical Computing) were used to determine association between visual observations and technology-recorded behaviors. Visually recorded eating, ruminating, and inactive time were moderately to strongly correlated with technology data (CCC ≥ 0.88) and Bland-Altman plots showed no bias, indicating a high level of agreement. In conclusion, the Nedap SmartTag Neck accurately monitored eating, ruminating, and inactivity behaviors and is expected to be effective in monitoring these behaviors in lactating dairy cattle in research or commercial farm settings.


Asunto(s)
Conducta Alimentaria , Lactancia , Animales , Austria , Conducta Animal , Bovinos , Industria Lechera , Ingestión de Alimentos , Femenino , Países Bajos
17.
Epidemiol Infect ; 149: e69, 2021 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-33622436

RESUMEN

The Ethiopian government has several initiatives to expand and intensify the dairy industry; however, the risk of bovine tuberculosis (bTB) spread is a challenge. To assess the rate of expansion and risk factors for transmission of bTB within-herds, we carried out a repeated cross-sectional survey at two time points, 2016/17 and 2018, in three regional cities, namely, Gondar, Hawassa and Mekelle, representing the emerging dairy belts of Ethiopia. The total number of herds involved was 128, comprising an average of 2303 cattle in each round. The Single Intradermal Comparative Cervical Tuberculin (SICCT) test was used to identify reactor status and data on herd-level risk factors were collected using a structured questionnaire. In the first survey, the apparent prevalence of bTB, as measured by the SICCT test, was 4.5% (95% CI 3.7-5.4%) at the individual animal-level and 24% (95% CI 17.5-32%) at the herd-level. There was no statistically significant change in the overall apparent prevalence or regional distribution at the second survey, consistent with the infection being endemic. The incidence rate was estimated at 3.6 (95% CI 2.8-4.5) and 6.6 (95% CI 3.0-12.6) cases/100 cattle (or herd)-years at the animal- and herd-levels, respectively. Risk factors significantly associated with the within-herd transmission of bTB were age group and within-herd apparent prevalence at the start of the observation period. We noted that farmers voluntarily took steps to remove reactor cattle from their herds as a consequence of the information shared after the first survey. Removal of reactors between surveys was associated with a reduced risk of transmission within these herds. However, with no regulatory barriers to the sale of reactor animals, such actions could potentially lead to further spread between herds. We therefore advocate the importance of setting up regulations and then establishing a systematic bTB surveillance programme to monitor the impact prior to implementing any control measures in Ethiopia.


Asunto(s)
Industria Lechera , Tuberculosis Bovina/epidemiología , Animales , Bovinos , Estudios Transversales , Etiopía/epidemiología , Agricultores , Humanos , Incidencia , Factores de Riesgo , Pruebas Cutáneas/veterinaria
18.
Animal ; 15(2): 100117, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33573948

RESUMEN

The use of embryo transfer helps to improve reproductive performance during periods of heat stress. In vitro produced embryo transfer (IVP-ET) is more expensive than artificial insemination. We hypothesized that the value IVP-ET in seasonal herds depends on herd constraints, such as the maximum number of milking cows and the maximum number of calvings that can be accommodated throughout the year. Therefore, the objective of this study was to estimate how profitability in dairy herds exposed to summer heat stress is affected by the number of months in which IVP-ET is used, the use of IVP-ET in repeat-breeder cows, IVP-ET cost, and herd constraints. We built and used a nonlinear programming model of a dairy herd with young stock and cows with monthly Markov Chain transitions. The model varied the number of heifers calving in each calendar month to maximize herd profitability. We varied IVP-ET cost ($100 or $200), duration of the IVP-ET program (2 or 4 months), and the breeding number in which IVP-ET started (1st or 3rd). In total, 20 scenarios were simulated. Maximum profitability was obtained when IVP-ET was not used, regardless of herd constraints. The 16 scenarios in which IVP-ET was used showed increased seasonality in milk yield, numbers of milking cows, total cows, total calvings, and heifer calvings because the program tried to limit the number of IVP-ET breedings in the summer. The addition of the calving constraint increased the value of IVP-ET. The breakeven cost per IVP-ET ranged from -$6.79 to $24.38 compared with conventional semen cost of $20. In conclusion, the current market costs of IVP-ET did not warrant application with the objective to increase reproductive performance during heat stress. Herd constraints on the maximum allowable seasonality in the monthly number of milking cows and calvings affected the value of IVP-ET during heat stress.


Asunto(s)
Inseminación Artificial , Lactancia , Animales , Bovinos , Industria Lechera , Transferencia de Embrión/veterinaria , Femenino , Respuesta al Choque Térmico , Inseminación Artificial/veterinaria , Leche
19.
J Dairy Sci ; 104(5): 6175-6184, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33612208

RESUMEN

We aimed to verify whether a low number of relevant animal-based indicators was able to discriminate 33 semi-intensive (grazing during the day and confinement during the night with access to an outdoor paddock; S-INT) and 8 intensive farms (permanent confinement with access to an outdoor paddock; INT) located in the Mexican semi-desert. In addition, we implemented the resource-based assessment scheme Animal Needs Index (ANI) with the identified animal-based indicators to compare the overall level of welfare in INT and S-INT. In particular, we used a protocol made up of 2 parts. The first comprised 4 evaluation sheets (locomotion, flooring, environment, management) and resource-based indicators derived from ANI, and the second one comprised a set of validated animal-based measures focusing on physical conditions and clinical signs of disease derived from the Animal Welfare Indicators scheme and reported in 2 additional sheets. The scoring system was also derived from ANI, with partial scores for each sheet to be summed to obtain the total score. A total of 1,116 dairy goats were assessed. All the observations and recordings were performed by an expert veterinarian evaluator assisted by an auxiliary, and longevity was retrieved from the farm records. The prevalence of animals displaying dirtiness, ocular discharge, abscesses, and claw overgrowth were higher in INT than in S-INT. Disbudding was routinely performed in INT only. Therefore, scurs, indicating improper disbudding, were recorded only in INT. In addition, the longevity of goats raised in S-INT was higher than in INT. Conversely, the prevalence of goats affected by anemia (i.e., FAMACHA scores >2) or lean (i.e., body condition score <2) tended to be higher in S-INT than in INT. No significant differences between the 2 groups of farms were detected for wounds, nasal discharge, integument alterations, fecal soiling, uterine prolapse, and subclinical mastitis. The results obtained using only animal-based measures were confirmed when resource-based variables were also included in the assessment, as 3 out of 6 sheets of the evaluation scheme (i.e., flooring, environment, and health-physical conditions) were scored higher in the S-INT than in the INT. As a consequence, the total score was also higher for S-INT than for INT. We conclude that the selected set of validated animal-based measures was able to discriminate between farms from different production systems. In particular, higher welfare levels were observed in S-INT farms, where the animals were allowed to spend most of the day on natural pasture, compared with INT farms, where the animals were constantly confined. Nevertheless, a certain degree of improvement should also be promoted in terms of anemia and body condition in S-INT farms.


Asunto(s)
Industria Lechera , Vivienda para Animales , Agricultura , Bienestar del Animal , Animales , Granjas , Femenino , Cabras , México
20.
J Dairy Sci ; 104(5): 5988-5997, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33612214

RESUMEN

The aim of this observational retrospective cohort study was to identify management procedures that are associated with herd-level eradication of Streptococcus agalactiae in dairy herds. The objective was to compare herds that recovered from Strep. agalactiae with herds that remained infected with Strep. agalactiae on the basis of specific management procedures. Data from the Danish surveillance program for Strep. agalactiae, where all milk delivering dairy herds are tested yearly, were used to identify study herds. One hundred ninety-six herds that were classified in the program as infected with Strep. agalactiae, in both January 2013 and January 2014, were identified as study herds. These were followed until January 2017. One hundred forty-four herds remained infected every year until January 2017. Forty-six herds recovered from Strep. agalactiae after January 2014 (were tested negative continuously after January 2015, January 2016, or January 2017 and remained noninfected in the program from recovery until January 2017). Herd characteristics and management procedures were obtained through the Danish Cattle Database. Herd characteristics included herd size, yield, milking system, and bulk milk somatic cell count (SCC). Management procedures included the proportion of cows culled within 100 d after calving due to mastitis, the extent of diagnoses relative to the extent of mastitis treatments, the proportion of cows treated for mastitis during lactation, the proportion of cows treated for mastitis early in lactation, the proportion of cows treated at dry-off, and the median length of the dry period for cows receiving dry cow treatment. All variables were calculated on herd level. Multivariable logistic regression was used to analyze the association between herd infection status and management procedures. A higher proportion of culling due to mastitis within 100 d from calving was associated with a higher probability of herd-level recovery from Strep. agalactiae in herds with conventional milking system. For example, herds with conventional milking, a bulk milk SCC of 260,000 cells/mL, and 10% early culling due to mastitis had a recovery probability of 0.13, whereas similar herds with 20% early culling due to mastitis had a recovery probability of 0.15. A higher proportion of mastitis treatments within 250 d postcalving was associated with a higher probability of herd-level recovery for herds with a relatively high bulk milk SCC. For example, herds with conventional milking, a bulk milk SCC of 260,000 cells/mL, and 10% lactational mastitis treatments had a recovery probability of 0.12, whereas similar herds with 20% lactational mastitis treatments had a recovery probability of 0.15. Herds with a low bulk milk SCC (<220,000 cells/mL) combined with a low proportion of lactational treatments (<0.2) had a relatively high probability of herd-level recovery (>0.2). Additional variables, including the proportion of dry cow treatments, were not associated with herd-level recovery from Strep. agalactiae.


Asunto(s)
Enfermedades de los Bovinos , Mastitis Bovina , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , Recuento de Células/veterinaria , Industria Lechera , Dinamarca/epidemiología , Femenino , Lactancia , Mastitis Bovina/epidemiología , Leche , Estudios Retrospectivos , Streptococcus agalactiae
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