The manipulation of grass swards for summer‐calving dairy cows

Fisher, G. E. J.; Roberts, David J.; Dowdeswell, A. M.

doi:10.1111/j.1365-2494.1995.tb02337.x

Cited by 7 publications

(7 citation statements)

References 16 publications

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“…However, where there is a low probability of ‘tall’ patches being eaten, a bimodal distribution emerges (Parsons and Dumont, 2003). Bimodal distributions have been reported, mainly for cattle (Gibb and Ridout, 1986, 1988; Fisher et al. , 1995; Gibb et al.…”

Section: Grazing Modelsmentioning

confidence: 99%

“…Gibb and Ridout (1986; 1988) found that the frequencies of height in swards continuously stocked by cattle had a skewed distribution that was better described by a double‐normal distribution than by the more common normal distribution. Since the five‐parameter double‐normal distribution consists of a mixture of two overlapping normal distributions, and an estimate of the proportion of the data belonging to each distribution, this distribution has been used as a tool to quantify the proportion of swards that are occupied by ‘tall’ and ‘short’ vegetation and to characterize these fractions (Fisher et al. , 1995; Gibb et al.…”

Section: Introductionmentioning

confidence: 99%

“…Gibb and Ridout (1986;1988) found that the frequencies of height in swards continuously stocked by cattle had a skewed distribution that was better described by a double-normal distribution than by the more common normal distribution. Since the five-parameter doublenormal distribution consists of a mixture of two overlapping normal distributions, and an estimate of the proportion of the data belonging to each distribution, this distribution has been used as a tool to quantify the proportion of swards that are occupied by 'tall' and 'short' vegetation and to characterize these fractions (Fisher et al, 1995;Gibb et al, 1999;Morris et al, 1999). However, evidence of bimodality is not always strong and the gamma distribution has also been suggested as a good descriptor of frequency distributions of herbage mass under rotational cattle grazing (Shiyomi et al, 1983;1984;1998;Tsutsumi et al, 2002;Sanders et al, 2003) and for herbage height under rotational cattle grazing (Sanders et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

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Frequency distributions of sward height under sheep grazing

Barthram¹,

Duff

Elston

et al. 2005

Grass and Forage Science

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Cattle and sheep can create and maintain a mixture of relatively tall and short patches in grass swards through selective grazing. In swards that are grazed by cattle this heterogeneous structure can result in the frequencies of height measurements having a skewed distribution that has variously been better described by the doublenormal distribution the gamma distribution and the Weibull distribution than by the more common normal distribution. The fit of these statistical distributions, and the adequacy of the potentially useful log-normal distribution, to sward height frequencies were tested in sown temperate swards grazed by sheep and compared within a single sward. It was concluded that the single-normal and Weibull distributions were inadequate and that overall the log-normal and gamma distributions had the best fit to the measurements.

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Section: Grazing Modelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Frequency distributions of sward height under sheep grazing

Barthram¹,

Duff

Elston

et al. 2005

Grass and Forage Science

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“…This unfavourable effect on the nutritive value of the offered herbage caused by the reduction of the stocking rate has already been well described in the literature. Laxely grazed swards are characterised by a deterioration of sward quality during the grazing season because of an increase in stem and dead tissue content and a reduced leaf content [15,23,30,40].…”

Section: The Effect Of the Grazing Systemmentioning

confidence: 99%

The effect of two contrasting grazing managements and level of concentrate supplementation on the performance of grazing dairy cows

Delaby

Peyraud

Foucher³

et al. 2003

Anim. Res.

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-The grazing management of dairy cows is characterised by practices that vary greatly in terms of stocking rate, nitrogen fertilisation and supplementation. The objective of this 6-year experiment was to establish the response by dairy cows to increasing amounts of concentrate supplement under two contrasted rotational grazing systems. Each year, 30 cows were assigned to a Severe grazing system aimed at maximising milk production per hectare with high annual nitrogen input (280 kg N·ha -1 ) and a high stocking rate. Another 30 cows were assigned to a Lax grazing system characterised by a lower input (120 kg N·ha -1 ) and stocking rate aimed at offering a greater quantity of grass per animal per day. From 1995 to 1997, four moderate levels of concentrate supplementation (0, 1.4, 2.8 and 4.0 kg) adjusted according to the milk yield of the cows at turnout were compared. From 1998 to 2000, higher quantities of concentrate (0, 2, 4 and 6 kg) maintained at a flat rate between cows were compared. The Lax grazing system led to a 0.8 to 1.0 kg increase in milk yield (P < 0.0001) per cow per day without any significant modification of milk fat and milk protein content, compared to the Severe grazing system. Compared with the Severe treatment, the Lax treatment reduced cow grazing days by 160 days per ha and milk production by 3225 kg per ha. In both systems, concentrate supplementation made it possible to increase milk yield, with an efficiency of close to 1 kg of milk per kg of concentrate, as well as increasing milk protein content and live weight gain. The milk fat content decreased only in the last three years of the experiment, following an increased concentrate supplementation. All these animal responses remained linear up to the maximum amount of concentrate offered; there was no variation between cows supplemented with the same concentrate level. This multi-annual experiment confirms the importance of making the best possible use of herbage produced by adapting the stocking rate to achieve a post grazing sward height of 5 to 6 cm during the grazing season. With an increased genetic potential of the dairy herd, high individual cow performance at grazing can be attained by the use of concentrate supplementation. dairy cows / grazing management / supplementation / milk production 437 * Corresponding author: luc.delaby@rennes.inra.fr Anim. Res. 52 (2003) 437-460  INRA, EDP Sciences, 2003 DOI: 10.1051/animres:2003030Résumé -Effets des conditions de pâturage et de l'apport de concentré sur les performances des vaches laitières. L'alimentation des vaches laitières au pâturage se caractérise par une grande diversité des pratiques à la fois en terme de chargement, de fertilisation azotée et de complémentation. L'objectif de cette expérience pluriannuelle est de décrire la réponse des vaches laitières à l'apport de doses croissantes de concentré dans deux situations contrastées de pâturage. Chaque année, la moitié des 60 vaches utilisées a été affectée soit à un scénario Severe visant à maximiser les performances...

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“…, 2000), and have a negative effect on herbage intake and livestock performance (Baker and Leaver, 1986; Stakelum and Dillon, 1990; Hoogendoorn et al. , 1992; Fisher et al. , 1995).…”

Section: Introductionmentioning

confidence: 99%

Effect of altering the grazing interval on growth and utilization of grass herbage and performance of dairy cows under rotational grazing

Dale

Mayne

Laidlaw

et al. 2008

Grass and Forage Science

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The effects of short grazing intervals in the early part of the grazing season on the growth and utilization of grass herbage, and the performance of grazing dairy cows, in a rotational grazing system were examined. Seventy-six cows were allocated to two grazing treatments: a normal rotation treatment (20-d rotations for the first 60 d) and a short rotation treatment (12-, 8-, 8-, 8-, 12-and 12-day rotations). Thereafter, both treatments had the same grazing interval and over the season as a whole both treatments received the same amount of nitrogen fertilizer and were stocked at the same rate. The short rotation treatment significantly reduced pre-and post-grazing sward heights and pre-

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The manipulation of grass swards for summer‐calving dairy cows

Abstract: Two experiments examined the effects of different defoliation treatments in spring on sward morphology and animal performance in mid-season and late season.

Cited by 7 publications

References 16 publications

Frequency distributions of sward height under sheep grazing

Frequency distributions of sward height under sheep grazing

The effect of two contrasting grazing managements and level of concentrate supplementation on the performance of grazing dairy cows

Effect of altering the grazing interval on growth and utilization of grass herbage and performance of dairy cows under rotational grazing

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