Archivos Latinoamericanos de Producción Animal. 2024. 32 (1)
Effect of additional herbage areas on grazing dairy cows in commercial
farms: A GPS and LoRaWAN based case study on herbage intake and
milk yield
Received: 20230209. Reviewed: 20230517. Accepted: 20240305
1Chalcombe Ltd, Mountwood House, Biddenfield Lane, Shedfield, Southampton, Hants, SO32 2HP, United Kingdom.
2Rothamsted Research Ltd, West Common, Harpenden, Herts AL5 2JQ, United Kingdom.
3Correspondence author: M. Jordana Rivero jordana.riveroviera@rothamsted.ac.uk Net Zero & Resilient Farming, Rothamsted Research Ltd,
North Wyke, Okehampton, Devon, EX20 2SB, United Kingdom.
4University of Nottingham, School of Biosciences, Sutton Bonington Campus, Loughborough, Leics, LE12 5RD, United Kingdom.
37
A. Tom Chamberlain1
Abstract: Although grazing systems are widely used for lactating dairy cattle, feed intake is generally lower than in a
fully housed system even when the feed quality and animals’ nutritional requirements are similar. Running trials in
commercial settings, long range wide area network (LoRa) technology and GPS positioning were used to track animal
activity and position to investigate whether allocating additional herbage at a time linked to the cow’s behaviour
could increase productivity. In particular, we examined whether additional herbage allowance increases daily herbage
intake and milk production without compromising grazing efficiency. Fourteen trials were undertaken on eight
commercial dairy herds in 2019, 2020 and 2021 generally with cows in mid to late lactation. The ‘GrazeMoreaddi
tional grazing was compared to a standard daily herbage allocation. The ‘GrazeMore treatment period always
followed an initial control period, sometimes with a subsequent control period. The composition of the grazing groups
was largely consistent over the duration of each trial, enabling the responses to be compared directly. Cow location
could be tracked while they grazed and their grazing activity determined allowing the timing of additional grazing
allocation to be linked to grazing behaviour. Responses to additional ‘GrazeMore pasture allocations were
inconsistent. The pattern of grazing was changed, but increased intakes during day grazing periods were sometimes
balanced by reduced intakes in the following night periods, suggesting that factors other than the quantity of herbage
on offer and the timing of its allocation during day grazing were responsible for limiting total 24 h herbage intake and
milk production. Synchronising additional pasture allocation with grazing behaviour does not always increase
herbage intake and milk production. We have also highlighted some of the challenges encountered while conducting
research in commercial settings, as opposed to controlled experiments in research facilities.
Keywords: grazing management; Long range wide area network; grazing efficienc grazing behaviou Global
Positioning System.
https://doi.org/10.53588/alpa.320104
Rothamsted Research Ltd, West Common, Harpenden, Herts AL5 2JQ, United Kingdom
Andrew Mead2
Efecto de áreas de pasto adicionales en el pastoreo de vacas lecheras
en granjas comerciales: Un estudio de caso basado en GPS y
LoRaWAN sobre el consumo de forraje y la producción de leche
Resumen: Aunque los sistemas de pastoreo se utilizan ampliamente para el ganado lechero lactante, el consumo de
alimento es generalmente menor que en un sistema completamente estabulado, incluso cuando la calidad del
alimento y los requisitos nutricionales del animal son similares. Se utilizaron pruebas en entornos comerciales,
tecnología de red de área amplia (LoRa) de largo alcance y posicionamiento GPS para rastrear la actividad y la
posición de los animales e investigar si la asignación de forraje adicional en un momento relacionado con el
comportamiento de la vaca podría aumentar la productividad. En particular, examinamos si la asignación adicional
de forraje aumenta el consumo diario de forraje y la producción de leche sin comprometer la eficiencia del pastoreo.
Se realizaron catorce ensayos en ocho rebaños lecheros comerciales en 2019, 2020 y 2021, generalmente con vacas en
lactancia media o tardía. El pastoreo adicional 'GrazeMore' se comparó con una asignación diaria estándar de
forraje. El período de tratamiento con 'GrazeMore' siempre siguió a un período de control inicial, a veces con un
período de control posterior. La composición de los grupos de pastoreo fue en gran medida consistente durante la
M. Jordana Rivero3 J. Michael Wilkinson4
38
Introduction
Rivero et al.
Global competition for limited arable land that can
produce either human food or animal feed highlights a
key role for grazed livestock in producing human food
from less productive pastureland that cannot be
cultivated to produce crops (Wilkinson and Lee, 2018).
Prediction and management of herbage growth,
allocation of herbage to grazed livestock and
optimising production per animal and per hectare are
critical challenges facing pasturebased farmers
(Wilkinson et al., 2020). A major objective in pasture
management is to provide an adequate daily supply of
dense herbage comprising young vegetative growth
throughout the grazing season to meet the nutritional
requirement of the grazing animal (McGilloway et al.,
1996). This must be achieved despite potentially large
variations in the rate of plant growth due to season,
Efeito de áreas adicionais de forragem em vacas leiteiras pastando em fazendas
comerciais: Um estudo de caso baseado em GPS e LoRaWAN sobre consumo de
forragem e produção de leite
Resumo: Embora os sistemas de pastoreio sejam amplamente utilizados para bovinos leiteiros em lactação, o
consumo de ração é geralmente menor do que em um sistema totalmente alojado, mesmo quando a qualidade da
ração e as exigências nutricionais do animal são semelhantes. A realização de testes em ambientes comerciais, a
tecnologia de rede de longa distância (LoRa) e o posicionamento GPS foram usados para rastrear a atividade e a
posição dos animais para investigar se a alocação de forragem adicional em um momento ligado ao comportamento
da vaca poderia aumentar a produtividade. Em particular, examinamos se a oferta adicional de forragem aumenta a
ingestão diária de forragem e a produção de leite sem comprometer a eficiência do pastoreio. Quatorze ensaios
foram realizados em oito rebanhos leiteiros comerciais em 2019, 2020 e 2021, geralmente com vacas no meio ou no
final da lactação. O pastoreio adicional ‘GrazeMore’ foi comparado com uma alocação diária padrão de forragem. O
período de tratamento do ‘GrazeMore’ sempre seguiu um período de controle inicial, às vezes com um período de
controle subsequente. A composição dos grupos de pastoreio foi bastante consistente ao longo de cada ensaio,
permitindo que as respostas fossem comparadas diretamente. A localização das vacas poderia ser rastreada
enquanto pastavam e a sua atividade de pastoreio determinada, permitindo que o momento da atribuição adicional
de pasto fosse ligado ao comportamento de pastoreio. As respostas às alocações adicionais de pastagens
‘GrazeMore’ foram inconsistentes. O padrão de pastoreio foi alterado, mas o aumento do consumo durante os
períodos de pasto diurno foi por vezes compensado por consumos reduzidos nos períodos noturnos seguintes,
sugerindo que outros fatores para além da quantidade de forragem oferecida e o momento da sua distribuição
durante o pastoreio diurno foram responsáveis por limitar o consumo total de forragem. Consumo de forragem em
24 h e produção de leite. Sincronizar a alocação adicional de pastagens com o comportamento de pastoreio nem
sempre aumenta o consumo de forragem e a produção de leite. Também destacamos alguns dos desafios
encontrados durante a realização de investigação em ambientes comerciais, em oposição a experiências controladas
em instalações de investigação.
Palavraschave: manejo de pastagem; Rede de longa distância; eficiência de pastoreio; comportamento de pastoreio;
Sistema de Posicionamento Global.
duración de cada prueba, lo que permitió comparar las respuestas directamente. Se podría rastrear la ubicación de
las vacas mientras pastaban y determinar su actividad de pastoreo, lo que permitiría vincular el momento de la
asignación de pasto adicional al comportamiento de pastoreo. Las respuestas a las asignaciones adicionales de
pastos de 'GrazeMore' fueron inconsistentes. Se cambió el patrón de pastoreo, pero el aumento del consumo
durante los períodos de pastoreo diurno a veces se vio compensado por un consumo reducido en los períodos
nocturnos siguientes, lo que sugiere que factores distintos de la cantidad de forraje ofrecido y el momento de su
distribución durante el pastoreo diurno fueron los responsables de limitar el total de pastos. Consumo de forraje 24
h y producción de leche. Sincronizar la asignación de pastos adicionales con el comportamiento de pastoreo no
siempre aumenta el consumo de forraje y la producción de leche. También hemos destacado algunos de los desafíos
encontrados al realizar investigaciones en entornos comerciales, a diferencia de los experimentos controlados en
instalaciones de investigación.
Palabras clave: manejo del pastoreo; Red de área amplia de largo alcance; eficiencia del pastoreo; comportamiento
de pastoreo; Sistema de Posicionamiento Global.
ISSNL 10221301. Archivos Latinoamericanos de Producción Animal. 2024. 32 (1): 37  54
39
Additional herbage areas on grazing dairy cows
temperature, water and nutrient supply. In addition,
the feed intake of the dairy cow varies with live
weight, milk yield and stage of lactation (Chamberlain
and Wilkinson, 1996). The diurnal grazing pattern
emerges from a series of grazing decisions such as
‘when’ to begin, the intensity (i.e., herbage intake rate),
‘what’ frequency and ‘how’ to distribute the grazing
events in time (Gregorini, 2012) and, for a milking cow,
what other activities she has to perform such as visiting
the milking parlour. Therefore, the causes for a grazing
cow to initiate and terminate the grazing event are
complex and multifactorial (Chilibroste et al., 2015).
Although grazing plays a central role in dairy cow
nutrition in many regions of the world, low herbage
intake by the grazing animal is a major limitation to
herd productivity (Bargo et al., 2003). Target levels of
daily herbage allowance in temperate intensive
perennialryegrassbased dairy grazing systems (e.g.,
New Zealand, France) are 20 to 30 kg DM/head to
support a daily intake of 15 to 17 kg DM/head
(Wilkinson et al., 2020). In contrast, typical daily DM
intake by dairy cows given total mixed rations is some
33 % higher than that of cows given grazed pasture
(Wilkinson and Lee, 2018). Further, the intake response
by grazed cows to increased daily herbage allowance is
at the expense of efficiency of pasture utilisation
(Baudracco et al., 2010). Previous research by
MacDonald et al. (2001) in New Zealand examined
farmlets with varying stocking rates and demonstrated
that milk yields increase as stocking rate and grass
supply rise. However, it was observed that grazing
efficiency decreases as cows become more selective.
Thus, a balance has to be struck between maximising
herbage intake and maintaining an acceptable
proportion of available herbage that is actually
consumed by the animal. The area of pasture to be
allocated to a herd of cattle for grazing varies
according to size of herd, quantity of herbage available
and planned grazing intensity (proportion of the sward
to be removed). Having calculated the appropriate area
of land to be allocated, traditionally animals are
introduced to new pasture at a time convenient to the
herd manager. In the case of rotationally grazed
swards, this occurs after fences have been moved to
allow access by livestock to a new area of ungrazed
herbage. Timing of new pasture allocation to dairy
cows normally occurs when the herd is withdrawn
from the field to be milked. Consequently, allocation of
new herbage may not be in synchrony with the
natural pattern of grazing behaviour (Abrahamse et al.,
2009; O’Driscoll et al., 2010).
Development of global positioning systems (GPS)
(Turner et al., 2000; Rivero et al., 2021), sensors
(accelerometers) capable of monitoring/measuring
animal behaviour, and longrange wide area networks
(LoRaWAN) (Miles et al., 2020) introduces the
possibility of controlling grazing on commercial dairy
farms. GPS data can be used to determine when the
cows are in the grazing field and accelerometers fitted
to the cow can model when the cow is grazing. Such
data can be collected in realtime over the LoRa
network and processed in the ‘cloud’ to determine
when onfarm actions (such as gate opening) should be
triggered with information relayed back through the
LoRa network to infield actuators.
Preliminary visual observations (ATC) of cows in
commercial herds showed an intensive period of
grazing at the start of the grazing bout followed by a
period of rumination, confirmed by the findings
reported by Sheahan et al., (2013). The cows then
commenced a second grazing bout ranging over
ground they had already grazed but with less intense
grazing and more sward selection to avoid
contaminants, e.g., dung pats. This behaviour of
modifying the grazing (e.g., biting rate) due to the
presence of contaminants has been previously re
ported by Bao et al., (1998) who concluded that
selective grazing exists due to the presence of dung
and is conditioned by dung distribution. Ad hoc trials
in 2017 allocating fresh grazing at the start of the
secondary bout led to the herd of cows rapidly moving
to the new area followed by a bout of intensive grazing
(Chamberlain and Kodam, 2019) . The objective of
these trials was to determine if the starting time of the
secondary grazing bout could be determined
automatically, and a new grazing allocation opened up
without any human intervention. Such automation
would be needed for any commercial application.
The work reported here comprised a feasibility study
to test two hypotheses under commercial farm settings:
1) Allocation of a new area of herbage to be grazed can
be synchronised with natural grazing behaviour,
determined by GPS and accelerometer data collated
through LoRaWAN, and 2) Provision of additional
herbage when a new grazing bout is imminent
increases daily herbage intake and milk production in
commercial dairy herds without compromising
grazing efficiency. In addition, the suitability of
LoRaWAN technology as a tool to collate data
effectively was assessed. We have also highlighted
some of the challenges encountered while conducting
research in commercial settings, as opposed to
controlled experiments in research facilities.
ISSNL 10221301. Archivos Latinoamericanos de Producción Animal. 2024. 32 (1): 37  54
40
Materials and Methods
The ethical implications of the project were con
sidered by ATC, who was a Named Veterinary
Surgeon with the UK Home Office. Procedures that
directly involved animals were the fitting and removal
of neck collars. Commercially available weighted cow
neck collars were used (Kerbl, UK) with a gross weight
of 850 g, and these were considered indistinguishable
from other commercial collars such as activity
monitors. The procedures were therefore classed as
‘nonregulated’ under the Animals (Scientific
Procedures) Act 1986 (ASPA), and further ethical
consideration was not applicable.
Implementation of Grazing Trials
Fourteen trials were undertaken on eight com
mercial dairy units between April and September 2019,
JulyAugust 2020 and AprilMay 2021 in the counties
of Dorset, Shropshire, Somerset, Wiltshire, located in
the south of England (UK). The country is
characterised by a temperate climate. The accumulated
annual precipitation for the region where the trials
were conducted is approximately 720 mm pa (evenly
spread through the year), with an average minimum
and maximum summer air temperature of 8 and 21 °C,
respectively (Met_Office, 2023). Pastures are usually
mixed swards comprising perennial ryegrass (Lolium
perenne L.) and white clover (Trifolium repens L.).
Eight collaborating farmers (different dairy units,
see Table 1) allowed temporary installation of a single
LoRaWAN ‘gateway’ on their farm to enable grazing
behaviour to be monitored remotely. Dairy units were
initially selected by phone interview on the basis of
their grazing infrastructure, i.e., rotational paddock
grazing systems, good water supply and trough pro
vision, temporary fencing within paddocks, little or no
buffer feeding, regular plate meter readings and milk
recording of individual cow’s yield. Each unit
operated separate day’ and ‘night’ grazing allocations
with twicedaily milking. Day fields were grazed
between the end of morning milking and the start of
evening milking and night fields were grazed between
the end of evening milking, and the start of morning
milking (Sheahan et al., 2013).
The ‘Control’ treatment consisted of the usual pas
ture allocation for the farm, herd and stage of the
grazing season as determined by the farm
management. To test hypothesis 2, an additional area
of pasture for the ‘GrazeMore’ treatment was allocated
daily during the day grazing period, at the start of the
herd’s second major grazing period (usually mid
morning), calculated as a percentage of the initially
allocated amount; the percentage increase varied
between trials (Table 1). The timing for the allocation
of the new ‘GrazeMore’ area was not set at a fixed time
of the day (see section 2.4.). Both treatments were
applied to the same grou