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Increasing pasture intake by allocating additional plantain pasture to cows before morning milking

The trend towards intensification in the dairy industry results in concentrates forming a larger proportion of pasture-based dairy cow diets, resulting in a less resilient system, dependent on the milk-to-feed price ratio. Milk production response to increased levels of concentrate feeding follows the law of diminishing return, meaning that once a certain level of concentrate is surpassed, each unit increase in concentrate will result in less than one unit increase in milk production, reducing the profit margins. To increase the profitability of pasture-based dairy farming, the focus should be placed on increasing dry matter intake (DMI) from pasture. Pasture DMI is affected by many factors such as the level of concentrate feeding and its effect on the substitution rate, animal and pasture characteristics including pasture allocation and quality. A possible alternative approach to increase DMI from pasture is the partial substitution of concentrate with a high-quality, fast-degradable pasture, such as the forage herb plantain (Plantago lanceolata). The lower neutral detergent fibre (NDF) content of plantain will allow higher intake as the NDF content and the digestibility of NDF of a forage determine the rumination time and potential DMI. The aim of the study is to determine if allocating additional plantain pasture into a ryegrass-dominant pasture-based production system will increase pasture DMI, increase milk production and allow the feeding of concentrate at a lower level without reducing milk production.


Sixty lactating Jersey cows were blocked according to 4% fat-corrected milk, days in milk, lactation number and live weight. Cows within blocks were then randomly allocated to one of four treatment groups. This study followed a 2 x 2 factorial design with two pasture treatments (ryegrass only and ryegrass with additional plantain pasture) and two levels of concentrate (4 kg/day and 6 kg/day) with 15 cows per treatment. Treatments were as follows: RGPL6 - Cows grazed ryegrass day and night and were moved to plantain pasture before morning milking. Cows were supplemented with 6 kg concentrate/cow/day. RG6 – Cows grazed ryegrass day and night and were supplemented with 6 kg concentrate/cow/day. RGPL4 - Cows grazed ryegrass day and night and were moved to plantain pasture before morning milking. Cows were supplemented with 4 kg concentrate/cow/day. RG4 - Cows grazed ryegrass day and night and were supplemented with 4 kg concentrate/cow/day.


The average daily milk yield of cows on RGPL6, RG6, RGPL4 and RG4 treatment was 20.1a, 19.2b, 19.1b and 17.5c kg, respectively. The milk fat and milk protein content did not differ between treatments, with milk fat content of 49.8, 50.6, 51.7 and 51.9 g/kg, respectively and milk protein of 39.1, 39.8, 39.3 and 39.3 g/kg, respectively. Through factorial analysis, it is clear that the addition of plantain pasture was more impactful to cows fed 4 kg concentrate/cow/day, with a 1.5 kg/day increase in milk production compared to the smaller impact of the addition of plantain pasture to cows receiving 6 kg concentrate/cow/day where the milk yield only increased by 0.88 kg/day. A similar average daily milk production between RGPL4 and RG6 indicates that it is plausible to partially substitute concentrate with a high-quality pasture such as plantain. Cows from all four treatments gained body weight during the 5-week trial period. The higher increase in body weight when plantain pasture was allocated to cows fed 4 kg concentrate/cow/day compared to cows allocated additional plantain pasture and fed 6 kg concentrate/cow/day highlights the larger contribution of allocating additional plantain pasture at a lower concentrate level. A trend towards an increase in eating time (21 vs 13.4 min/24 hours) was recorded when additional plantain pasture was allocated to cows receiving 4 kg concentrate/cow/day (+21 min/24 hours) compared to 6 kg concentrate/cow/day (+13.4 min/24 hours). An economic evaluation showed that profit could be increased by R 10.64/cow/day and R 4.37/cow/day when cows receive additional plantain pasture at 4 kg concentrate/cow/day and 6 kg concentrate/cow/day, respectively.


Cows allocated additional plantain pasture before morning milking tended to spend more time eating, possibly increasing DMI, which is evident in the higher milk production observed between cows receiving additional plantain and cows receiving ryegrass only. The benefit of additional plantain pasture was more pronounced when concentrates were fed at a lower level. It is thus plausible to partially substitute concentrate with plantain without causing a reduction in milk production. This resulted in a substantial increase in profit/cow/day.

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