Effect of concentrate supplementation level on production, health and efficiency in an organic dairy herd

Abstract

The proportions of organic feed and roughage in the feed ration for organic dairy cows have to reach 100 and 60%, respectively, in 2005. The aim of this study was to elucidate the long-term effects of reducing or omitting concentrate supplementation to high genetic merit dairy cows on a basal ad libitum diet of clover-grass (silage and grazing). Three concentrate levels, N, L and L 1 (38, 0 and 19% of dry matter (DM) intake, respectively) were investigated in a herd of 60 cows during 3 years. The production in group N was 6723 kg energy corrected milk (ECM) per cow year, based on an intake of 6226 kg DM of which 38% was concentrates. In group L the omission of concentrates reduced intake to 4770 kg DM, and milk production to 5090 kg ECM per cow year. Milk protein content was reduced and milk free fatty acid content was increased, and the first calving interval was significantly increased, as compared to group N. The intake in group L 1 was 5226 kg DM per cow year of which 19% was concentrates. Milk production in group L 1 was reduced by only 493 kg ECM per cow year as compared to group N, primarily due to a significantly improved feed conversion ratio (12%). There were no indications of health problems associated with the reduced feeding levels. 

Reproductive performance, general health, and longevity of dairy cows at a Swedish research farm with both organic and conventional production

“…Reksen et al (1999) speculated that the reason for the impaired RP was due to deficient energy supply. This concept was supported by Sehested et al (2003) who showed that lower concentrate supplementation causes prolongation of both CFI and CI in organically managed dairy cows. In our study, the animals were managed by professional personnel at a research herd, thus with small risk of malnutrition, and well-suited for high-quality comparisons.…”

The importance of nutrient balance, cropping strategy and quality of dairy cow diets in sustainable organic systems

“…5 While these results suggest that, when very-high-forage diets are being fed, a breed of lower genetic potential may be better suited to the system, the results from another study with the Holstein-Friesian breed have shown that a diet with only 126 kg of concentrates per cow and high-quality forage led to no adverse health effects, although the feed conversion into milk was lower than that for cows fed either 1024 or 2350 kg of concentrates. 28 In many organic herds, milk is primarily produced during the growing season when the herd grazes grass/clover leys, with minimal or no concentrates offered to supplement the herbage. 29 As stated previously, the high N content of the grazed grass/white clover leys from early summer onwards can lead to an excess of N in the diet of the dairy cow; this has been found to lead to increased blood urea levels, which may delay conception and impair embryo survival.…”

White or red clover-grass silage in organic dairy milk production: Grassland productivity and milk production responses with different levels of concentrate

“…Previous investigations have shown that it is harder to maintain the breeding efficiency in dairy cows bred during winter in organic than in conventional husbandry (Reksen et al, 1999), which is likely due to both lower concentrate levels and forage energy concentrations and thereby lower dietary energy supply for the organically than for the conventionally managed cows (Kristensen and Kristensen, 1998;Olesen et al, 1999;Sehested et al, 2003;Haas et al, 2007). More frequent cuts may be a strategy to improve the quality of farm-grown forages for winter feeding.…”