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Hamilton, New Zealand

Sondergaard E.,University of Aarhus | Jago J.,DairyNZ
Applied Animal Behaviour Science | Year: 2010

The natural behaviour of horses in response to danger is to take flight, and consequently human handlers can be injured. Reducing the flight response and general reactivity of horses is therefore likely to reduce the incidence of injuries to handlers. In this experiment we investigated the effect of handling foals in the first 2 days after birth on their subsequent response to handling, humans and novelty, and the foal-mare relationship. Standardbred foals were assigned to one of two groups, handled (H) (N = 22, 12 colts, 10 fillies) and control (C) (N = 22, 11 colts, 11 fillies). Handling took place 3 times/day on days 1 and 2 after birth for 10 min/session. Individual foals were gently restrained and stroked all over their body using bare hands and then a plastic bag and each leg was lifted once. C foals received no handling. C and H foals did not differ in their reaction to freeze branding at a mean age of 14 days. The approach and leave behaviour of mare-foal pairs were observed at pasture during week 5 to evaluate their relationship. Mares of H foals were less active in keeping the pair together than mares of C foals (GLM: F1,33 = 6.81; P < 0.05). At 6 weeks of age all colts were introduced to an arena, together with their mare, and their reaction to a novel object and an unknown human were tested. Treatment did not affect heart rate of foals or in mares. C foals initiated more suckling bouts than H when no human was present (Wilcoxon: Z = 2.44, N = 22, P < 0.05) indicating that they responded differently to the novel arena than H foals. However, there was no difference between H and C foals in their exploratory behaviour in the arena. When a human was present in the arena, H foals had a shorter flight distance than C foals (Z = -1.98, N = 22, P < 0.05) and tended to move further away from the mare (Z = -1.80, N = 22, P = 0.07). Handling of foals in the first 2 days after birth appeared to affect the foal-mare relationship and alter their perception of humans at a later age but did not alter their response to novelty or to handling. The effects of early handling of foals on the foal-mare relationship require further investigation. © 2010 Elsevier B.V. All rights reserved. Source

Gregorini P.,DairyNZ
Animal Production Science | Year: 2012

Within a day, grazing decisions such as 'when' to begin, 'which' frequency and 'how' to distribute grazing events determine ruminants' diurnal grazing pattern. Ruminants can have between three and five daily grazing events. The major grazing events occur in the early morning and late afternoon/early evening; the later grazing event is the longest and most significant in terms of herbage intake. This review first attempts to answer 'why does this happen?' and then to examine evidence for managing this pattern to improve animal production. Due to photosynthesis and transpiration during the day, herbage accumulates DM, sugars and essential fatty acids, which dilute fibre and protein contents and facilitate herbage particle breakdown during ingestion. Diurnal fluctuations in light intensity stimulate circadian release of neuropetides and hormones, providing the cue to start grazing and modulating ingestive-digestive behaviours that interact with the diurnal fluctuation in herbage feeding value. Grazing decisions depend on grazing environments, the current state of the animal, and on past and anticipated states of the animal. The dusk grazing event seems to be an adaptative feeding strategy to maximise daily energy acquisition, providing a steady release of nutrients over night. Hunger deceives ruminants and makes them graze at dawn, when herbage presents the lowest feeding value. Hunger, however, can be used to concentrate and intensify grazing events. Strategic management of these interactions emerges as the tool to alter the frequency, intensity and temporal distribution of diurnal grazing events, and thereby to increase and modulate nutrient supply to and productivity of grazing ruminants. © 2012 CSIRO. Source

Doole G.J.,University of Western Australia | Doole G.J.,University of Waikato | Romera A.J.,DairyNZ
Agricultural Systems | Year: 2013

Grazing systems constitute the most extensive land use worldwide. However, economic analysis of these systems has mainly involved the use of linear optimisation methods that provide a general description of the complex processes contained therein. This paper describes a nonlinear optimisation model of a New Zealand dairy farm that incorporates a detailed depiction of key biophysical processes present within grazing systems. The capacity of this optimisation model to provide rich insight into the effects of higher stocking rates within grazing systems is demonstrated in an empirical application. In accordance with system trials, this application shows that higher stocking rates on pasture-based New Zealand dairy farms generally increase pre-grazing pasture biomass, decrease post-grazing pasture biomass, increase pasture utilisation, decrease herbage allowance, decrease intake and energy consumption per cow, decrease milk production per cow, increase milk production per ha, and reduce conception rate. Nevertheless, an intermediate stocking rate is optimal, as greater milk production with a higher stocking rate is not sufficient to offset the associated costs. © 2013 Elsevier Ltd. Source

Vogeler I.,Agresearch Ltd. | Beukes P.,DairyNZ | Burggraaf V.,Agresearch Ltd.
Agricultural Systems | Year: 2013

Dairy farms are under pressure to increase productivity while reducing environmental impacts. We used the DairyNZ Whole Farm Model (WFM) and APSIM to evaluate the effect of mitigation strategies within an efficient farm (EF) in the Waikato region, NZ, on these targets. Mitigation strategies compared with the baseline farm (BF) included the use of fewer more efficient cows, low nitrogen (N) feed supplements, loafing pads, less N fertiliser and nitrification inhibitor (DCD). To encompass climate affects three different years with average, high and low annual rainfall were modelled. The WFM predicted number of urinations and urinary N loads deposited during individual grazing events were used as an input for APSIM to simulate N leaching from urine patches, as well as from non-urinated areas. Results were aggregated to obtain total N leached on a paddock and farm scale. For all 3. years, farm averaged N leaching was lower, by 20-55%, in the EF compared with the BF farm. DCD reduced leaching in two of the 3. years by 12% and 15%. N leaching was lowest for N deposited in the wet year and highest for the dry year. Milk production was consistently greater for the EF compared to the BF, with an increase in milksolids (MS)/ha ranging from 8% in the wet, to 17% in the dry year. © 2012 Elsevier Ltd. Source

Dairy herd size is expected to increase in many European countries, given the recent policy changes within the European Union. Managing more cows may have implications for herd performance in the post-quota era. The objective of this study was to characterise spring-calving herds according to size and rate of expansion, and to determine trends in breeding policy, reproduction and production performance, which will inform industry of the likely implications of herd expansion. Performance data from milk recording herds comprising 775 795 lactations from 2555 herds for the years 2004 to 2008 inclusive were available from the Irish Cattle Breeding Federation. Herds were classified into Small (average of 37 cows), Medium (average of 54 cows) and Large (average of 87 cows) and separately into herds that were not expanding (Nil expansion), herds expanding on average by three cows per year (Slow expansion) and herds expanding on average by eight cows per year (Rapid expansion). There was no association between rate of expansion and 305-day fat and protein yield. However, 305-day milk yield decreased and milk protein and fat percentage increased with increasing rate of expansion. There were no associations between herd size and milk production except for protein and fat percentage, which increased with increasing herd size. Average parity number of the cows decreased as rate of expansion increased and tended to decrease as herd size increased. In rapidly expanding herds, cow numbers were increased by purchasing more cattle. The proportion of dairy sires relative to beef sires used in the breeding programme of expanding herds increased and there was more dairy crossbreeding, albeit at a low rate. Similarly, large herds were using more dairy sires and fewer beef sires. Expanding herds and large herds had superior reproductive performance relative to non-expanding and small herds. Animals in expanding herds calved for the first time at a younger age, had a shorter calving interval and were submitted for breeding by artificial insemination at a higher rate. The results give confidence to dairy producers likely to undergo significant expansion post-quota such that, despite managing more cows, production and reproductive performance need not decline. The management skills required to achieve these performance levels need investigation. © 2011 The Animal Consortium. Source

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