On the effects of the concentrate proportion of dairy cow rations in the presence and absence of aFusariumtoxin-contaminated triticale on cow performance

Abstract

The aim of the present study was to investigate the effects of a deoxynivalenol (DON) contaminated ration with a concentrate proportion of 50%, on the performance of dairy cows (Period 1), and to examine the effects when the concentrate proportion was elevated to 60% compared to a ration with 30% concentrates (Period 2). In Period 1, 13 lactating German Holstein cows (Myco group, on average 29 days in milk) were fed the experimental diet (on average 5.3 mg DON/kg DM) as total mixed ration over 11 weeks, while another 14 cows (on average 33 days in milk) received a control diet. Both rations contained 50% concentrates (on DM basis). In Period 2 (18 weeks), the same 27 cows plus five additional cows were divided into four groups: Control-30 (30% concentrates), Myco-30 (30% concentrates, 4.4 mg DON/kg DM), Control-60 (60% concentrates), Myco-60 (60% concentrates, 4.6 mg DON/kg DM). The overall performance level was characterised by a mean daily DM intake of 17.9 kg and a mean daily milk production of 26.7 kg fat corrected milk (FCM) in Period 1 and 17.3 kg DM intake and 24.5 kg FCM in Period 2, respectively. In both periods cows fed the Fusarium toxin-contaminated diets consumed more DM (in Period 2 only significant for group Myco-30) resulting from stimulating effects on the ingesta passage rate of the natural contaminated Fusarium-infected triticale. In Period 1, cows fed the Fusarium toxin-contaminated diet had a significantly higher milk yield, milk urea and somatic cell count, whereas milk fat and protein concentration and fat-to-protein-ratio (FPR) were significantly lower. In Period 2, on a low concentrate level, FCM was significantly higher in group Myco-30. On a high concentrate level, group Myco-60 produced significantly more milk, but milk fat and protein concentration, FPR and milk urea were significantly lower. A concentrate proportion of 60% had a depressing effect on milk fat concentration but was significantly more pronounced in the presence of Fusarium toxin-contaminated and Fusarium damaged-triticale.

Isoflavone concentration of soybean meal from various origins and transfer of isoflavones into milk of dairy cows

“…The daily dry matter intake amounted to 17.4 kg DM and varied between 16.1 and 18.3 kg/day. The feed intake was consistent with a previous experiment carried out at the experimental station of the FLI (Keese et al 2008). The mean energy intake in the present study was 119 MJ NEL/day, which indicates an adequate energy supply of the animals during the entire experiment (GfE 2001).…”

No carry over of unmetabolised deoxynivalenol in milk of dairy cows fed high concentrate proportions

“…The slightly fluctuant DOM-1 concentrations in the serum of the control cows reflected the variability in the DON concentrations in the used maize silages. Furthermore the time-dependent course corresponds to the time-dependent course of the total DM intake (shown at Keese et al [22]). …”

“…During the 29 wk of the current trial we observed some cases of clinical mastitis in individual cows but we could not detect an obvious relation between the occurrence of clinical signs of an udder infection and elevated DOM-1 concentrations in milk samples of the affected cows. Anyway it has to be stressed that cows showing clinical signs of mastitis were treated immediately and that the determination of the somatic cell count was just adequate to get an impression about the udder health of the animals in this study for the reasons discussed by Keese et al [22].…”

“…The experimental design is described in more detail by Keese et al [22]. In brief, in Period 1, 27 lactating German Holstein cows (mean BW = 522 l 56 kg, mean days in milk (DIM) = 31 at the beginning of the trial) were divided into two groups for a duration of 11 wk.…”

“…This paper is a part of a comprehensive study in which Fusarium toxin-contaminated triticale was fed to lactating dairy cows in rations with 30, 50 and 60% concentrate. In this paper, the focus is on the carry over of DON and DOM-1 in milk and the DON residues in serum and bile in Fusarium toxin-exposed lactating cows, while effects on performance parameters, ruminal fermentation and parameters of the acid -base metabolism are discussed at Keese et al [22,23].…”