Grazing plays an important role in milk production in most regions of the world. In this review, some challenges to the grazing cow are discussed together with opportunities for future improvement. We focus on daily feed intake, efficiency of pasture utilization, output of milk per head, environmental impact of grazing and the nutritional quality to humans of milk produced from dairy cows in contrasting production systems. Challenges are discussed in the context of a trend towards increased size of individual herds and include limited and variable levels of daily herbage consumption, lower levels of milk output per cow, excessive excretion of nitrogenous compounds and requirements for minimal periods of grazing regardless of production system.A major challenge is to engage more farmers in making appropriate adjustments to their grazing management. In relation to product quality, the main challenge is to demonstrate enhanced nutritional/processing benefits of milk from grazed cows.Opportunities include more accurate diet formulations, supplementation of grazed pasture to match macro-and micronutrient supply with animal requirement and plant breeding. The application of robotics and artificial intelligence to pasture management will assist in matching daily supply to animal requirement. Wider consumer recognition of the perceived enhanced nutritional value of milk from grazed cows, together with greater appreciation of the animal health, welfare and behavioural benefits of grazing should contribute to the future sustainability of demand for milk from dairy cows on pasture. K E Y W O R D Sgrazed pasture, grazing management, herbage intake, milk production, milk quality, nitrogen use efficiency Highlights• Grazing plays a central role in the nutrition of dairy cows in many regions of the world.• Challenges to efficient management of grazed pastures include variable herbage supply and low herbage intake, which limit milk output per head.• Opportunities for improved efficiency include more accurate diet formulation, breeding superior plant cultivars to improve ruminal efficiency and enhance product nutritional quality, application of robotics, sensors and artificial intelligence to improve grazing management and pasture utilization, and wider consumer recognition of the perceived enhanced value of milk from grazed cows.TA B L E 1 Average size of dairy herd, average annual milk yield per cow and average annual output of milk per herd in New Zealand,

The objective of this work was to assess the potential of near infrared spectroscopy to predict the immunoglobulin G (IgG) content in bovine colostrum. Liquid colostrum samples (n=157) were collected from Holstein cows from 2 dairy farms in southern Chile. Samples were obtained within 1h of parturition and scanned in folded transmission (transflectance) in the visible-near infrared range. Multivariate regression models (modified partial least squares) were developed with spectral data against IgG content measured by radial immunodiffusion. The best calibration included a mathematical treatment of the spectra by a second derivative plus standard normal variate and detrending. The best equation explained a high proportion of the variation in IgG content (R(2) of 0.95 in calibration and 0.94 in cross-validation). Average (91.5 g/L), standard deviation (37.6g/L), and range, as highest minus lowest values (171.9 g/L) of reference values were 10.1, 4.2, and 19 times the value of the root mean square error of cross-validation (9.03 g/L) respectively. Near-infrared spectroscopy, scanned in folded transmission, is an effective tool to predict the IgG content in liquid colostrum.

The objective was to evaluate water‐soluble carbohydrate (WSC) and crude protein (CP) concentration of perennial ryegrass (PRG) cultivars with different genetic potential for producing WSC under two contrasting agronomic managements in temperate climate (southern Chile). A 4 × 2 factorial design was randomly allocated to 24 plots (31 m2 each, three blocks): four PRG cultivars (diploid standard cultivar, “2nSt”; tetraploid standard cultivar, “4nSt”; diploid high sugar cultivar developed in New Zealand, “2nHSNZ”; and tetraploid high sugar cultivar developed in Europe, “4nHSEU”) and two agronomic managements (“favourable,” defoliations at three leaves per tiller and nitrogen (N) fertilization rate of 83.3 kg N ha−1 year−1; “unfavourable,” defoliations at two leaves per tiller and N fertilization rate of 250 kg N ha−1 year−1). Herbage samples were collected in early spring, spring, summer and autumn. Concentration of WSC did not differ among cultivars in spring and summer, averaging 194 and 251 g/kg DM, respectively. The cultivar 4nHSEU had the greatest WSC concentration in early spring and autumn (187 and 266 g/kg DM, respectively) and the greatest CP concentration across samplings (average 230 g/kg DM). Favourable management improved WSC concentrations in early spring and summer and decreased CP in spring, summer and autumn. Annual DM yield did not vary with cultivar or management, averaging 8.43 t/ha. Within a 12‐month study at one site in a temperate environment in southern Chile, PRG cultivars have not shown a consistent expression of the “high sugar” trait, where a genetic × environment interaction might be operating.

For livestock production systems to play a positive role in global food security, the balance between their benefits and disbenefits to society must be appropriately managed. Based on the evidence provided by field-scale randomised controlled trials around the world, this debate has traditionally centred on the concept of economic-environmental trade-offs, of which existence is theoretically assured when resource allocation is perfect on the farm. Recent research conducted on commercial farms indicates, however, that the economic-environmental nexus is not nearly as straightforward in the real world, with environmental performances of enterprises often positively correlated with their economic profitability. Using high-resolution primary data from the North Wyke Farm Platform, an intensively instrumented farm-scale ruminant research facility located in southwest United Kingdom, this paper proposes a novel, information-driven approach to carry out comprehensive assessments of economic-environmental trade-offs inherent within pasture-based cattle and sheep production systems. The results of a data-mining exercise suggest that a potentially systematic interaction exists between 'soil health', ecological surroundings and livestock grazing, whereby a higher level of soil organic carbon (SOC) stock is associated with a better animal performance and less nutrient losses into watercourses, and a higher stocking density with greater botanical diversity and elevated SOC. We contend that a combination of farming system-wide trials and environmental instrumentation provides an ideal setting for enrolling scientifically sound and biologically informative metrics for agricultural sustainability, through which agricultural producers could obtain guidance to manage soils, water, pasture and livestock in an economically and environmentally acceptable manner. Priority areas for future farm-scale research to ensure long-term sustainability are also discussed.

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Understanding the behaviour of grazing animals at pasture is crucial in order to develop management strategies that will increase the potential productivity of grazing systems and simultaneously decrease the negative impact on the environment. The objective of this review was to summarize and analyse the scientific literature that has addressed the site use preference of grazing cattle using global positioning systems (GPS) collars in the past 21 years (2000–2020) to aid the development of more sustainable grazing livestock systems. The 84 studies identified were undertaken in several regions of the world, in diverse production systems, under different climate conditions and with varied methodologies and animal types. This work presents the information in categories according to the main findings reviewed, covering management, external and animal factors driving animal movement patterns. The results showed that some variables, such as stocking rate, water and shade location, weather conditions and pasture (terrain and vegetation) characteristics, have a significant impact on the behaviour of grazing cattle. Other types of bio-loggers can be deployed in grazing ruminants to gain insights into their metabolism and its relationship with the landscape they utilise. Changing management practices based on these findings could improve the use of grasslands towards more sustainable and productive livestock systems.

The objective of this study was to evaluate the effect of herbage allowance on pasture DM consumption by growing European wild boar. An additional objective was to evaluate the influence of pasture consumption on supplemental diet intake and BW gain. A previously sown grass-clover pasture was managed by cutting to obtain an herbage mass equivalent to 1,500 kg/ha DM. Areas of pasture were limited by fencing to obtain 3 different herbage allowances whereas the pasture was removed in other areas. Forty-eight purebred European wild boars (initial age of 120 d and initial BW of 14.4 kg) were grouped in pairs and each pair was randomly allotted to 1 of 4 treatments (6 pairs per treatment): no pasture (4 m(2); pasture removed), low (5.33 m(2); 400 g/d pasture DM available/wild boar), medium (8 m(2); 600 g/d pasture DM available/wild boar), and high (16 m(2); 1,200 g/d pasture DM available/wild boar). The treatment areas were moved daily with a 7-d rotation. For a 28-d period, wild boars entered their treatment areas from 0830 to 1630 h, after which they had free access to a supplemental diet for 1 h. Pasture consumption was estimated daily by cutting pasture samples pre- and postgrazing. Supplemental diet consumption was determined daily (feed offered minus remaining feed). Animals were weighed weekly. Pasture consumption differed (P < 0.001) among wild boars receiving different treatments, with cumulative consumptions of 3.0 and 3.9 kg DM/wild boar over 28 d for low and medium herbage allowances, respectively (P < 0.09), and 6.4 kg DM/wild boar over 28 d for high herbage allowance, with the latter consumption being greater (P < 0.001) than the consumption recorded with the decreased herbage allowance treatments. The supplemental diet consumption tended (P = 0.16) to be less in wild boars with greater herbage allowance. European wild boars with access to pasture had greater (8.48 vs. 6.27 kg; P = 0.002) BW gain than those without access to pasture. In conclusion, pasture consumption by European wild boars can be enhanced by increasing herbage allowance and greater BW gains can be achieved in wild boars with access to pasture compared with those with no pasture access.