Management Of Dairy Cows Research Articles

A multi-objective optimization model for dairy feeding management

The allocation of feedstuff to intensively managed dairy cows to achieve different objectives is challenging due to the inherent complexity of the system and the combinatorial problem that has to be solved. Pareto-based multi-objective optimization approaches using evolutionary algorithms can help to address these challenges and show the trade-offs and synergies among various objectives. Here we present a framework for multi-objective optimization with the Differential Evolution (DE) algorithm applied to dairy feeding systems with grazing and concentrate supply to generate an approximation of the Pareto front. The available feed resources are located in different feeding areas, and the number of animals and groups of animals with similar feeding requirements are distributed across these areas for feeding purposes. To evaluate the DE algorithm, we performed two in-silico experiments to: (1) compare the solutions quality of single-objective DE with exact Linear Programming (LP) solutions, and (2) assess the influence of different stocking rates (number of cows/ha) on milk production, feed allocation and economic performance indicators. The DE solutions that minimize the feeding costs for different stocking rates (1.1–2.6 cows/ha) closely approached the solutions derived with LP, confirming the quality of the heuristic algorithm. The multi-objective model scenarios demonstrated that increasing stocking density would enhance milk production and gross margin per unit of area at largely unchanged productivity per animal by shifting the feed ration from roughage to a large proportion of supplementary concentrate feed. At low stocking rates solutions with high productivity and gross margin and a large proportion of roughage in the ration and limited supplementary feeding were identified. We conclude that the multi-objective optimization with a Pareto-based DE algorithm is highly effective to explore the interrelations among conflicting objectives and to find suitable solutions.

Individual dairy cow management: achievements, obstacles and prospects.

This review deals with the prospects and achievements of individual dairy cow management (IDCM) and the obstacles and difficulties encountered in attempts to successfully apply IDCM into routine dairy management. All aspects of dairy farm management, health, reproduction, nutrition and welfare are discussed in relation to IDCM. In addition, new IDCM R&D goals in these management fields are suggested, with practical steps to achieve them. The development of management technologies is spurred by the availability of off-the-shelf sensors and expanded recording capacity, data storage, and computing capabilities, as well as by demands for sustainable dairy production and improved animal wellbeing at a time of increasing herd size and milk production per cow. Management technologies are sought that would enable the full expression of genetic and physiological potential of each cow in the herd, to achieve the dairy operation's economic goals whilst optimizing the animal's wellbeing. Results and conclusions from the literature, as well as practical experience supported by published and unpublished data are analyzed and discussed. The object of these efforts is to identify knowledge and management routine gaps in the practical dairy operation, in order to point out directions and improvements for successful implementation of IDCM in the dairy cows' health, reproduction, nutrition and wellbeing.

Is it just about grazing? UK citizens have diverse preferences for how dairy cows should be managed

Conflicting views between the dairy industry and the public about how dairy cows should be managed, together with an increase in the availability of alternatives to dairy foods, challenge future markets for milk producers. Members of the public value animal welfare as well as naturalness and grazing, but neither the relative importance of specific aspects of management nor the diversity of views underlying these preferences have been established. To better understand these issues, 2,054 UK citizens recruited through a research panel took part in an online survey. They were asked to rank 17 attributes relating to dairy cow management and milk production through the novel application of best-worst scaling, a discrete choice methodology that allows a trade-off between items. Hierarchical Bayesian analysis of the results revealed 3 attributes of equal top importance: (1) access to grazing, (2) cow health and welfare, and (3) cow comfort. Alongside this overarching ranking, underlying differences in preferences were identified in 6 approximately equally sized citizen groups within the sample, which were identified through latent class analysis. Each latent class expressed significantly different priorities from the other, and each had different indicative sociodemographic, attitudinal, experiential, and value-oriented characteristics, as established through a multinomial logistic model. If the diversity of preference between the citizen groups found in the sample is reflected within wider populations, there may be opportunities for the dairy industry to improve communication about positive practices, develop new dairy product markets, and consider changes to dairy farming systems to better meet different citizens' needs. Furthermore, the defining characteristics and priorities of each group raise the question of whether grazing in particular, but also other attributes presented within the study, is understood in different ways by different subgroups of citizens.

Early pregnancy diagnoses based on physiological indexes of dairy cattle: a review.

With the development of standardization and scaling in the dairy farming industry, timely and accurate pregnancy diagnosis is required to improve the benefits of breeding by shortening the calving interval. However, the current pregnancy diagnostic methods cannot meet the requirements of the industry. Here, we review changes in the physiological indexes and in the function and morphological status of the reproductive organs of dairy cows at the early stages of pregnancy. In addition, the corresponding pregnancy diagnostic methods based on certain indexes are well development, and the pregnancy diagnostic approaches based on remote sensing and automation technology have become inevitable trends in the industry. These applications will reveal physiological regularities in pregnancy and benefit the detailed management of dairy cows during early pregnancy.

Invited Review: Design and management of group maternity areas for dairy cows

ABSTRACT Purpose The purpose of this review is to describe the research to date on the housing and management of dairy cows in group maternity areas. Sources We used a review of the peer-reviewed literature to identify articles that included an experimental study using dairy cows kept in groups at calving. Our review also includes studies from the broader literature using cows kept in individual maternity pens, dry cows, lactating cows, and beef cattle. Synthesis Housing cows in group maternity areas creates unique challenges compared with housing cows in individual pens. Advantages to calving in group pens include limited pen moves, reduced risk that cows calve in freestalls, and potentially improved labor efficiency. Disadvantages of group maternity areas include the limited ability of cows to express natural behaviors before calving such as seclusion from pen mates, the risk of the calf being nursed by the wrong dam, a lack of space for cows as they prepare to give birth, social instability caused by regrouping, and challenges with pen cleanliness. Conclusions and Applications Research to date has focused on creating opportunities for isolation-seeking behavior for dairy cows in group maternity areas. Cows in group pens are motivated to seek isolation at calving, but the ability to do so can be limited by competition. Research is still needed to determine potential negative effects of high stocking density and frequent regrouping in group maternity areas on cow behavior and health.

Management of cull dairy cows: Culling decisions, duration of transport, and effect on cow condition

Many cows culled from dairy farms arrive at livestock markets or abattoirs in compromised condition, but it is unknown whether cows are compromised at the time of culling or deteriorate during the marketing process. This study followed cull cows from farm to abattoir, monitored any deterioration, and tested the effect of providing such information on subsequent culling. For 11 mo, data were collected from 20 dairy farms, livestock markets, and abattoirs. Cows' body condition, lameness, and udder condition (as binary outcomes) were assessed at 4 points: when placed on the culling list, before leaving the farm, at auction, and at the abattoir. Based on the first 5 mo of data (baseline period), information materials were provided to 10 randomly selected farms (Informed treatment), and the other 10 served as a Control. Logistic mixed models were used to test differences in cows' condition at the 4 points of assessment, using the assessment before leaving the farm as a reference value and cow-within-farm as a random effect. The effects of providing information on outcome measures (proportion thin, severely lame, with udder edema, poor fitness for transport, euthanized, and died) were tested with a general linear model. As demand for milk increased during the baseline period, additional linear mixed models were fitted to test whether the same outcome measures were affected by time (baseline or treatment period) and treatment (Informed or Control) using farm as a random effect. While cows were on the culling list (before shipping) the odds of being thin or having poor fitness for transport increased. After leaving the farms, cows spent (mean ± standard deviation) 82 ± 46 h in the marketing system before being slaughtered. Shipping from farm to abattoir increased the odds of being thin, having udder edema, or showing poor fitness for transport [odds ratio (OR) 5.8, 95% confidence interval 4.2 to 8.1; OR 14.7, 10.7 to 20.2; and OR 7.3, 5.7 to 9.5, respectively]. Providing this information to farmers (Informed treatment) did not affect the outcome measures. Compared with the baseline, during the treatment period fewer cows were shipped when thin (4.9 versus 9.0%) and with poor fitness for transport (15.7 versus 25.8%), and fewer cows died (5.4 versus 11.9%) or were euthanized (13.3 versus 20.5%). Increased demand for milk appeared to lead to delayed culling, such that more compromised cows were sent to slaughter. The results of this study show a need for clear and specific guidelines to assess fitness for transport of cull dairy cows.

Recent advances and future directions for uterine diseases diagnosis, pathogenesis, and management in dairy cows.

Researchers, veterinarians, and farmers' pursuit of a consistent diagnosis, treatment, and prevention of uterine diseases remains challenging. The diagnosis and treatment of metritis is inconsistent, a concerning situation when considered the global threat of antimicrobial resistance dissemination. Endometritis is an insidious disease absent on routine health programs in many dairy farms and from pharmaceutical therapeutics arsenal in places like the US market. Conversely, a multitude of studies advanced the understanding of how uterine diseases compromise oocyte, follicle, and embryo development, and the uterine environment having long-lasting effects on fertility. The field of uterine disease microbiome also experienced tremendous progress and created opportunities for the development of novel preventives to improve the management of uterine diseases. Activity monitors, biomarkers, genomic selection, and machine learning predictive models are other innovative developments that have been explored in recent years to help mitigate the negative impacts of uterine diseases. Albeit novel tools such as vaccines for metritis, immune modulators, probiotics, genomic selection, and selective antimicrobial therapy are promising, further research is warranted to implement these technologies in a systematic and cost-effective manner.

Diagnostic performance of ultrasonography in clinical management of dairy cattle identified with left-sided ping sounds.

Objectives:Left displaced abomasum (LDA) is a common postparturient condition of high yielding dairy cattle. The diagnosis of LDA is challenging and has historically been based on findings that are not specific to the condition. The objective of the current study was to investigate the diagnostic performance of ultrasonography (USG) in the clinical management of dairy cows identified with left-sided ping sound postpartum.Materials and methods:Cows with reduced appetite postpartum and had audible left-sided ping sounds on abdominal auscultation were eligible to be prospectively recruited onto the study. The results of clinical findings and abdominal USG were recorded along with milk β-hydroxybutyrate levels, pH levels of abomaso/rumenocentesis samples, and findings on exploratory laparotomy. The diagnostic performance of USG and other clinical investigations was assessed by calculating the test sensitivity and specificity using exploratory laparotomy as a gold standard test.Results:A definitive diagnosis of LDA was made in 23 cows, 8 cows were diagnosed with peritonitis, and 4 cows with frothy tympany. The USG findings that were consistent with LDA were present in all cattle diagnosed with LDA at exploratory laparotomy. The USG findings over the past three intercostal space characteristics of LDA, however, were also present in five cases subsequently diagnosed with peritonitis and in all cases diagnosed with frothy tympany on exploratory laparotomy. The pH of abdomaso/rumenocentesis samples yielded the highest diagnostic accuracy (97.14%) as a single test in the current study.Conclusions:USG over the left abdominal wall despite being a highly sensitive test for the diagnosis of LDA has limitations as a diagnostic tool due to suboptimal specificity.

158 Comparison of different presynch-based synchronization protocols in postpartum dairy cattle

Abstract Objectives were to evaluate three timed AI presynch-based synchronization protocols in lactating Holstein-Frisian cattle. Lactating cows (n = 207) were randomly divided into one of the three treatments: 1)PG-PG-Ovsynch (n = 71), cows were subjected to PG(PGF2α;i.m) at 11-d apart. On 11d post 2nd PG shot, standard Ovsynch (GnRH PG–GnRH) was introduced, 2) G7G-Ovsynch(n = 59), PGF2α-2d-GnRH-7d-Ovsynch, 3) Ovsynch-Ovsynch(n = 67), Ovsynch-7d-Ovsynch. Progesterone profile was measured on d30 and d60 post TAI. For monitoring of ovarian status ultrasonography was done at 1st GnRH, PG and 2nd GnRH of the breeding protocol. Pregnancy was diagnosed on d30, 60 and 90 post TAI and pregnancy loss was also on d60 and 90 post TAI. Pregnancy data was analyzed using Chi-square test and plasma P4 profile by ANOVA in SAS. Ovulatory follicle diameter (mean± SD) was 15.02±1.05 in PG-PG-Ovsynch, 15.41±1.28 in G7G-Ovsynch and 15.23±1.23 in Ovsynch-Ovsynch, respectively (P = 0.167). Plasma P4 profile (ng/mL;Mean±SD) on d30 post TAI was 6.46±1.54,7.07±1.19 and in 6.65±1.40 PG-PG-Ovsynch, G7G-Ovsynch and Ovsynch-Ovsynch groups, respectively (P = 0.08). On d60 post TAI, P4 profile was recorded to be 7.35±1.16,8.06±1.27 and 7.81±0.91 in PG-PG-Ovsynch, G7G Ovsynch and Ovsynch Ovsynch, respectively (P = 0.005). Pregnancy rate on day 30 was 50.70(36/71), 58.20(39/67) and 52.50(31/59) in PG-PG-Ovsynch, G7G-Ovsynch and Ovsynch-Ovsynch, respectively (P = 0.88). Similarly,PR on d60 and d90 post TAI was 46.50(33/71):43.70(31/71), 55.20(37/67): 53.70(36/67) and 50.80(30/59):47.50(28/59) in PG-PG-Ovsynch, G7G-Ovsynch and Ovsynch-Ovsynch groups (P = 0.84:0.78), respectively. Pregnancy loss on d60 post TAI was 8.30,5.0 and 3.20% in PG-PG-Ovsynch, G7G-Ovsynch and Ovsynch-Ovsynch, respectively (P = 0.69). Although statistically non-significant (P = 0.73), overall pregnancy loss on d90 post TAI was also numerically higher in PG-PG-Ovsynch(14.0%) protocol as compared to G7G-Ovsynch (8.30%) and Ovsynch-Ovsynch (9.70%). We concluded that G7G-Ovsynch protocol has resulted in increased PR, P4 profile in comparison with PG-PG-Ovsynch and Ovsynch Ovsynch. Similarly, reduced pregnancy loss,ease and economics makes G7G-Ovsynch as a protocol of choice for improved reproductive management in postpartum dairy cows.

Field study on bovine paratuberculosis using real-time PCR and liquid culture for testing environmental and individual fecal samples implemented in dairy cow management

Bovine paratuberculosis (Johne's disease) is a bacterial, chronic, and wasting intestinal disease caused by Mycobacterium avium ssp. paratuberculosis (MAP). Johne's disease causes severe losses in dairy farm productivity and is also suspected to be a potential trigger for Crohn's disease in humans. The fecal-oral infection of MAP to neonates is recognized as an important within-herd transmission route. Our objective was to recommend diagnostic methods for herds with suspected paratuberculosis requiring fast results, as well as for herds with breeding programs or others that aim at being nonsuspected of paratuberculosis infection. We determined a period of 8 wk from sampling to diagnostic findings suitable for testing of cows during the dry period. We therefore tested environmental and individual fecal samples with one rapid and one highly sensitive diagnostic method. Environmental samples (boot swabs) were taken as a first step in 3 herds and tested using a DNA extraction protocol for feces and subsequent real-time PCR (referred to as fecal PCR). Additionally, cultivation in liquid medium for 6 wk was performed and verified with real-time PCR (referred to as liquid culture). Automation of DNA extraction based on magnetic beads and the PCR setup was performed with pipetting robots. As a result, we successfully detected MAP in boot swabs of all herds by both methods. In a second step, 245 individual fecal samples from the 3 herds were examined using also fecal PCR and liquid culture. The results obtained by fecal PCR were compared with detection of MAP using cultivation in liquid medium for 6 wk. Testing individual cows, we identified MAP-specific DNA in 53 fecal samples using the liquid culture. Using fecal PCR, we revealed 43 positive samples of which 39 also tested positive in the liquid culture, revealing MAP-positive cows in all 3 herds. The fecal PCR procedure allows rapid detection of MAP-specific DNA with 74% of the sensitivity of liquid culture. For the purpose of testing with maximal sensitivity, cultivation in liquid medium is recommended. Cultivation of MAP in liquid medium M7H9C means a significant time gain in comparison to cultivation on solid media, which requires twice as much time. Thus, this testing fits within the 6- to 8-wk dry period of gravid cows and provides test results before calving, a prerequisite to prevent fecal-oral transmission to newborn calves.

Health and welfare priorities in goats

The UK goat population is small, numbering around 108,000 animals in total.1 However, even with such a small population, it is important to recognise the wide variation in goat-keeping practices....

50 Role of fatty acid nutrition in milk fat synthesis

Abstract Our understanding of fatty acid (FA) digestion and metabolism in dairy cows has advanced significantly in the last few decades. We now recognize that FA, both of dietary and rumen origin, can have different and specific effects on feed intake, rumen metabolism, small intestine digestibility, milk fat synthesis in the mammary gland, and energy partitioning between the mammary gland and other tissues. We will present research focusing on specific FA and how dairy cows respond differently to combinations of FA. Recent research has highlighted differences in intestinal digestibility among palmitic acid (C16:0), stearic acid (C18:0), and oleic (cis-9 C18:1) acids, which impacts the amount and profile of absorbed FA available for metabolic purposes including milk fat synthesis. C16:0, C18:0, and cis-9 C18:1 usually comprise the majority of FA present in milk fat and adipose tissue of dairy cows. In addition, these FA comprise the major FA in a wide range of commercially available fat supplements. While these FA have different functions in metabolism, they may also interact with each other by competitive or complementary mechanisms under different physiological conditions. In the mammary gland, milk FA are derived from 2 sources; 16 carbon FA originating from extraction from plasma. 16-carbon FA originate from either de novo or preformed sources. Milk lipid synthesis in the mammary gland is dependent upon the simultaneous supply of short/medium-chain FA and long-chain FA. C16:0 has a higher preference as a substrate to start triglyceride synthesis than C18:0 or cis-9 C18:1. Also, if the amount of preformed FA surpasses the capacity of the mammary gland, these might be redirected to other tissues (e.g. adipose tissue) altering energy partitioning. In the future, the opportunity and challenge will be to continue to improve our understanding of how and which FA affect nutrient digestion, energy partitioning, and milk synthesis in lactating dairy cows and effectively apply this knowledge in the feeding and management of high producing dairy cows.

23 Dietary management of the transition animal: Perspectives from dairy cows to sows

Abstract Since the 1990s, the impact of late gestational nutrition and management on lactation and reproduction has become the focus of dairy management. Transition cow management has been credited with having greater influence on herd performance as compared to previous focus on lactation nutrition. Several seminal papers published in 1990s and early 2000s directed management practices of dry cows, rightly or wrongly, toward critical factors impacting calving and lactation. Dairy cow gestational protein requirements cited a 1956 study on Red Danish cows until Bell (1995) characterized the modern Holstein fetus’ chemical composition over the last 70 days of gestation. Recognized health effects of “fat cow syndrome”, similarly described for pigs, focuses late pregnant dairy cow management on body condition management starting in late lactation. Optimum condition was emphasized, recognizing negative impacts of excessive limited BC on lactation and reproduction. Maximizing dry matter intake was a nutritional goal for preventing energy-based metabolic challenges, until research indicated excessive energy during early, non-lactating period was more critical to managing postpartum metabolic derangements than the weeks prior to calving; which is like controlling energy intake of sows. Delivery of amino acids, estimated by metabolizable protein intake, has recently earned focus of research, relative to immune function, metabolic stability and reproductive success during early lactation. Identifying amino acids as critical fetal metabolic fuel, and consequences of excessive maternal protein mobilization, has become a focal point of swine and dairy transition nutrition. Although management of the transition cow has been greatly refined through nutritional research, improved cow performance has not yet been realized in the field. Recognition of the interplay between nutrition, environment and management relative to enhancing cow behavior has provided insight to the challenges of managing the transition cow. Metabolic, environmental and management challenges facing the physiologic transition from pregnancy into lactation occur in all production species. Although cows and sows procure essential nutrients by different digestive modes, cross-species applications can provide new or reinforcing perspectives on collective management approaches.

Lying behavior and activity during the transition period of clinically healthy grazing dairy cows

Lying behavior and activity may provide useful information for the prediction of an imminent calving and the health of transition dairy cows; however, it is important first to understand what constitutes typical lying behavior and activity because this has not been defined for grazing dairy cows during the transition period. Our objective was to describe changes in lying behavior and activity in grazing dairy cows during the transition period using varying phenotypes typical of commercial dairy herds under grazing systems. Behavior data from IceTag or IceQube (IceRobotics, Edinburgh, Scotland) triaxial accelerometers were collected for 310 cow parities from multiparous, mixed-age (mean ± standard deviation; 4.5 ± 1.65 yr), and mixed-breed [Holstein-Friesian (HF), n = 216; and HF × Jersey, n = 94] grazing dairy cows from 4 parent experiments. The IceTags or IceQubes captured lying and activity data during the transition period (-21 to 34 d relative to calving) to allow the calculation of daily lying time (h/d), daily lying bouts (LB; no./d), mean LB duration (min/bout), and the number of steps taken (steps/d). Lying behavior and activity were analyzed using a repeated measures ANOVA during 3 periods: PRE (-21 to -3 d), POST (3 to 21 d), and the day of calving (d 0). Lying time was lower on d 0 (7.25 h/d) compared with PRE and POST lying times (10.3 and 8.58 h/d, respectively), with more frequent LB on d 0 (12.9 no./d) compared with the PRE and POST daily LB (8.15 vs. 7.74 no./d). Cows took more steps POST (4,424 steps/d) compared with d 0 and PRE (4,105 and 2,289 steps/d, respectively). Regression analysis determined that daily lying time decreased substantially from -3 to 0 d (slope = -1.03 ± 0.07 h/d) and from -2 and -1 d for daily LB (slope = 5.09 ± 0.54 no./d), which may be due to the calving event itself but also reflect restlessness. Daily lying time, daily LB, LB duration, and number of steps taken were substantially altered at the time of the calving event in grazing dairy cows. Cows were more active, spent less time lying, and took more steps postcalving compared with precalving, and it appears that this behavior may largely be due to activity associated with twice daily milking. Mean lying behavior and activity measures were more highly variable across individuals than across groups. Information available via activity monitors may contribute to the improvement of individual management of transition dairy cows, and this research provides a benchmark for typical changes in behavior during the transition period in grazing systems.

Redes neurales artificiales para estimar las pérdidas en la producción lechera

Este estudio tuvo como objetivo desarrollar redes neurales artificiales para estimar las pérdidas en la producción lechera, en función del índice de temperatura y humedad (ITU), considerándose el día del año. Accediendo al sitio del Instituto Nacional de Meteorología, se obtuvieron los valores de temperatura y humedad para una serie histórica de 27 años en el municipio de Nova Xavantina-MT. Así, se determinó el índice de temperatura y humedad máximo en cada día del año durante el referido período. Se optó por las redes de múltiples camadas del tipo “perceptron”. Se varió el número de camadas y neuronas para formar diferentes arquitecturas. La proximidad entre los valores reales y los estimados se evaluó por medio de diversos criterios estadísticos y por los coeficientes ofrecidos por el propio programa computacional utilizado. De esta forma se seleccionó la rede con mejor desempeño. Luego se concluyó que las redes presentaron adecuada confiablidad y precisión para predecir el ITU, de acuerdo con el día del año y que ellas pueden ser una herramienta útil en el manejo de vacas lecheras y en el planeamiento de medidas para amenizar el ambiente térmico.

Genetic and nongenetic factors affecting on-farm performance of peri-urban dairy cattle in west Africa

Population growth and urbanization lead to an increasing demand for milk in sub-Saharan Africa, but the production potential of the 65.9 million dairy cows in the region is far from being fully exploited to meet this demand. With the aim to support decision-making for breeding and management of dairy cattle in commercial farms, we performed a comparative study of daily milk offtake, chemical composition of milk, prevalence of metabolic disorders, and body weight development of local and crossbred cattle genotypes in peri-urban commercial farms in Ouagadougou, Burkina Faso. We used data that were collected during regular visits of 7 farms in peri-urban areas of the city over a 16-mo period. Animals belonged to 3 breed groups (123 local zebu, 49 Sahelian crossbred, and 42 European crossbred cows). We applied a mixed model approach to evaluate the genetic and seasonal effects on daily milk offtake, milk composition, and body weight. Nonlinear growth models were fitted to model the body weight development according to genotype, season, and reproductive status of cows. The milk fat-to-milk protein ratio was used to determine the prevalence of ketosis and acidosis. Daily milk offtake from crossbred cows was 3.1- to 4.3-fold higher than from local zebu cows; furthermore, crossbred cows had a higher body weight and maturity rate than local zebu cows. In contrast, no genotype differences were found in milk fat and milk protein percentage and prevalence of ketosis and acidosis. Additionally, seasonal effects suggested that higher production performances could be realized through improved management of dairy cows, particularly in the late dry and rainy season. Improved feeding management could also reduce the risk of metabolic disorders. In summary, production performances of crossbred dairy cows in peri-urban production systems in Burkina Faso are higher as compared with local zebu cows. However, environmental effects suggest that further studies are needed to systematically assess genotype by environment interactions to guide the development of sustainable breeding and management programs for dairy cattle in Burkina Faso.

Potential of milk mid-IR spectra to predict metabolic status of cows through blood components and an innovative clustering approach

Unbalanced metabolic status in the weeks after calving predisposes dairy cows to metabolic and infectious diseases. Blood glucose, IGF-I, non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) are used as indicators of the metabolic status of cows. This work aims to (1) evaluate the potential of milk mid-IR spectra to predict these blood components individually and (2) to evaluate the possibility of predicting the metabolic status of cows based on the clustering of these blood components. Blood samples were collected from 241 Holstein cows on six experimental farms, at days 14 and 35 after calving. Blood samples were analyzed by reference analysis and metabolic status was defined by k-means clustering (k=3) based on the four blood components. Milk mid-IR analyses were undertaken on different instruments and the spectra were harmonized into a common standardized format. Quantitative models predicting blood components were developed using partial least squares regression and discriminant models aiming to differentiate the metabolic status were developed with partial least squares discriminant analysis. Cross-validations were performed for both quantitative and discriminant models using four subsets randomly constituted. Blood glucose, IGF-I, NEFA and BHB were predicted with respective R2 of calibration of 0.55, 0.69, 0.49 and 0.77, and R2 of cross-validation of 0.44, 0.61, 0.39 and 0.70. Although these models were not able to provide precise quantitative values, they allow for screening of individual milk samples for high or low values. The clustering methodology led to the sharing out of the data set into three groups of cows representing healthy, moderately impacted and imbalanced metabolic status. The discriminant models allow to fairly classify the three groups, with a global percentage of correct classification up to 74%. When discriminating the cows with imbalanced metabolic status from cows with healthy and moderately impacted metabolic status, the models were able to distinguish imbalanced group with a global percentage of correct classification up to 92%. The performances were satisfactory considering the variables are not present in milk, and consequently predicted indirectly. This work showed the potential of milk mid-IR analysis to provide new metabolic status indicators based on individual blood components or a combination of these variables into a global status. Models have been developed within a standardized spectral format, and although robustness should preferably be improved with additional data integrating different geographic regions, diets and breeds, they constitute rapid, cost-effective and large-scale tools for management and breeding of dairy cows.

Evaluation and application potential of an accelerometer-based collar device for measuring grazing behavior of dairy cows

The commercially available collar device MooMonitor+ was evaluated with regards to accuracy and application potential for measuring grazing behavior. These automated measurements are crucial as cows feed intake behavior at pasture is an important parameter of animal performance, health and welfare as well as being an indicator of feed availability. Compared to laborious and time-consuming visual observation, the continuous and automated measurement of grazing behavior may support and improve the grazing management of dairy cows on pasture. Therefore, there were two experiments as well as a literature analysis conducted to evaluate the MooMonitor+ under grazing conditions. The first experiment compared the automated measurement of the sensor against visual observation. In a second experiment, the MooMonitor+ was compared to a noseband sensor (RumiWatch), which also allows continuous measurement of grazing behavior. The first experiment on n = 12 cows revealed that the automated sensor MooMonitor+ and visual observation were highly correlated as indicated by the Spearman’s rank correlation coefficient (rs) = 0.94 and concordance correlation coefficient (CCC) = 0.97 for grazing time. An rs-value of 0.97 and CCC = 0.98 was observed for rumination time. In a second experiment with n = 12 cows over 24-h periods, a high correlation between the MooMonitor+ and the RumiWatch was observed for grazing time as indicated by an rs-value of 0.91 and a CCC-value of 0.97. Similarly, a high correlation was observed for rumination time with an rs-value of 0.96 and a CCC-value of 0.99. While a higher level of agreement between the MooMonitor+ and both visual observation and RumiWatch was observed for rumination time compared to grazing time, the overall results showed a high level of accuracy of the collar device in measuring grazing and rumination times. Therefore, the collar device can be applied to monitor cow behavior at pasture on farms. With regards to the application potential of the collar device, it may not only be used on commercial farms but can also be applied to research questions when a data resolution of 15 min is sufficient. Thus, at farm level, the farmer can get an accurate and continuous measurement of grazing behavior of each individual cow and may then use those data for decision-making to optimize the animal management.

Association of postpartum diseases occurring within 60 days after calving with productivity and reproductive performance in dairy cows in Fukuoka: A cow-level, retrospective cohort study.

Peripartum disorders in dairy cows negatively influence their productivity and reproductive performance. However, only a few reports have clearly indicated the influence of such disorders on the productivity and reproductive performance at a local-area or cow-level in Japan. This study aimed to elucidate the influence of diseases occurring within 60 days after calving on subsequent productivity and reproductive performance. Accordingly, a wide-area database on dairy production was used for epidemiological analysis; subsequently, multivariable analysis was performed to investigate the association of such diseases with productivity or reproductive performance in 6,545 cows from 178 farms in Fukuoka. We used 305-day energy-corrected milk (305 ECM) as an index of productivity and conception and culling as indices of reproductive performance. With regard to causality, mixed-effects model was used for analyzing the association between disease and productivity, and Cox proportional hazard model was used for analyzing the association between disease and reproductive performance. Compared to the disease absence group, the disease presence group demonstrated significantly lower 305 ECM [−154 kg; 95% confidence interval (CI), −229 to −79] and risk of pregnancy [hazard ratio (HR), 0.85; 95% CI, 0.80–0.91] and higher risk of culling (HR, 1.36; 95% CI, 1.17–1.59). These results indicate that, in Fukuoka, dairy cows affected by diseases within 60 days after calving exhibit lower productivity and reproductive performance. Therefore, proper dairy cow management during the peripartum period to prevent diseases during early lactation may maintain or improve productivity.

Extended lactations in dairy production: Economic, productivity and climatic impact at herd, farm and sector level

The management concept “extended lactation” whereby farmers deliberately delay time of first insemination allow them to utilise the high milk yield potential of modern dairy cows for longer. The main objective of this study was to quantify the effect of different extended lactation strategies on herd productivity, farm economics and sustainability at product level with focus on greenhouse gas emission. The herd model SimHerd simulated cow state, production, replacement and herd dynamics that supported a quantification of the effect of managing either first lactation, older or all cows for calving intervals of either 15 or 17 months compared with 13 months. The initial herd was self-sufficient with replacement heifers, and the extended lactations were achieved by only changing time of first possible insemination while keeping insemination and conception rates as well as all other production and management parameters unchanged. The different extended lactation strategies reduced annual milk production and herd feed use up to 4.1 and 7.1%, respectively, which combined caused herd milk production per kg DM herd feed use to increase with up to 3.5%. Replacement rate per annual cow (per cow per year) was reduced with up to 13.6% points and the number of youngstock per annual cow with 27%. Managing only first lactation cows for extended lactations resulted in close to negligible production effects compared with baseline scenario and positively affected farm contribution margin whereas the other strategies had a negative effect on farm contribution margin per cow of up to 3.2%. The reduction in herd feed use reduced farm area for feed production, and the economic effect of using this area to either feed more cows or grow a cash crop was greater than the negative economic effect of the extended lactation strategy itself. Hence, the overall economic effect depends on the ability of the farmer to realise savings and utilise a potential freed area. Finally, the extended lactation strategies reduced greenhouse gas emissions with up to 8.1% per annual cow where less feed production and less enteric fermentation were determining factors.However, the weight ratio between milk and meat increased up to 34.7% across scenarios, which affected the allocation of emissions. Hence, emissions were reduced per cow but unchanged per kg milk. If the market requires an unchanged supply of milk and beef meat, then these extended lactation strategies caused an indirect emission from production of substitute beef meat, which can lead to an increased total emission. In conclusion, managing dairy cows for extended lactations can be an economically viable production strategy if the farmer is able to realise potential savings and gains. Emissions are reduced per cow but the sector level effect for milk and beef meat can be unchanged or even increased.