The Behaviour and Productivity of Mid-Lactation Dairy Cows Provided Daily Pasture Allowance over 2 or 7 Intensively Grazed Strips.

Megan Verdon,Pieter Raedts,Richard Rawnsley,Mark Freeman

doi:10.3390/ani8070115

Megan Verdon, Pieter Raedts + Show 2 more

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https://doi.org/10.3390/ani8070115

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Abstract

Simple SummaryRecent technological advances will soon allow pastoral dairy farmers to manage their cattle using increasingly intense and complex grazing regimes. Ensuring there is merit in the implementation of more intense grazing regimes will minimise the potential misuse of this technology and the associated consequences of misuse for animal welfare and productivity. Two groups of dairy cattle were provided with the same amount of fresh pasture over either 2 or 7 feeds per day. Cows that received pasture over 7 feeds produced less milk and spent less time ruminating, but more time resting, per day. However, feeding frequency did not affect the time cows spent feeding or estimated pasture consumption. Increasing the frequency of feeding restricts the amount of pasture available to cattle at any one time. In response, cattle adjust their ingestive behaviour (e.g., adopt high intake rates) which may negatively impact digestive processes. The success of more intensive pastoral dairy production requires grazing regimes that support the natural ingestive, digestive, and social behaviours of cattle, rather than necessitating cattle to substantially alter their behaviour in accordance with the grazing regime imposed upon them.Research into the effects of intense grazing regimes on cattle behaviour and productivity will support the ethical intensification of pastoral dairy production. Two treatments were applied to two herds of 30 mid-lactation cows over 28 days. Cows were offered an estimated 12 kg DM/cow (above 5 cm from ground level) of irrigated pasture per day. The control herd received their daily pasture allocation in two equal grazings while the experimental herd received theirs over seven smaller grazings. Backgrazing beyond the current allocation (morning or afternoon) was prevented. Individual records were taken daily for milk production and behaviour (MooMonitor+). Milk composition, energy corrected milk (ECM), and live weight were recorded weekly. Feeding mid-lactation dairy cows over seven smaller grazing allocations reduced the time cows spent ruminating (p < 0.001), milk yield (p < 0.001), and ECM (p < 0.05). However, milk composition, live weight, time feeding, and pasture consumption were not affected by feeding frequency (p > 0.05). Cattle may have adapted their ingestive behaviour in response to the more intensive strip-grazing regime utilised in this study, with negative consequences for digestive processes and consequently milk production. Intense grazing regimes need to support the ingestive, digestive, and social behaviours of cattle.

Highlights

The intensification of animal production is often associated with long periods of confinement and indoor housing [1], rather than with outdoor pastoral production systems
The more intensive strip-grazing regime utilised in the present study did not affect milk composition, pasture consumption, or the time cows spent feeding per day
Milk composition, the time cows spent feeding, and pasture consumption do not appear to be affected by feeding frequency

Summary

Introduction

The intensification of animal production is often associated with long periods of confinement and indoor housing [1], rather than with outdoor pastoral production systems. The Australian dairy industry has intensified considerably over the past 3 decades (i.e., by increasing stocking rate and the proportion of supplementary grain provided), the key profit driver of dairy production in Australia continues to be home grown feed consumption [2,3]. Intensive grazing regimes, such as the provision of pasture in single or half day allocations (i.e., strip-grazing), are commonly utilised by pastoral dairy farmers. Intense grazing regimes are likely to underpin the continued intensification of animal production in pasture-based systems [8]. The implementation of more intensive strip-grazing systems is limited by costs associated with increased labour and fencing requirements [9]

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