The effect of feedborne Fusarium mycotoxins on dry matter intake, milk production and blood metabolites of early lactation dairy cows

2019 ◽  
Vol 253 ◽  
pp. 39-44 ◽  
Author(s):  
Z.C. McKay ◽  
O. Averkieva ◽  
G. Rajauria ◽  
K.M. Pierce
1990 ◽  
Vol 30 (4) ◽  
pp. 495 ◽  
Author(s):  
C Grainger

Three separate experiments were carried out to determine the effects of stage of lactation and feeding level on marginal production response by dairy cows to change in feeding level. In each experiment cows were individually offered cut pasture in stalls, ad libitum initially for 10 days, and for a further 28-day period when feeding treatments were imposed. In experiment 1, a total of 37 cows in early or late lactation were offered the same high quality pasture diet either ad libitum or at 0.60 x ad libitum intake. In experiments 2 and 3, 35 and 31 cows which were in early (experiment 2) or late lactation (experiment 3) were offered pasture at 1 of 3 feeding levels: ad libitum, 0.75 x ad libitum. 0.50 x ad libitum intake. In experiment 1 the marginal response was similar, 23.5 and 25.0 g milk fat/kg change in dry matter intake, for cows offered the same diet in early or late lactation. In experiment 2, cows in early lactation showed marginal responses which ranged from 0 to 80 g milk fat/kg dry matter intake and were greater at lower feeding levels and for cows with greater initial milk production. In experiment 3, the marginal response for cows in late lactation was similar to that in experiment 1 (24.4 g milk fat/kg change in DM intake) and was not significantly affected by the level of feeding or by the initial milk production of the cow. Reduced levels of feeding in late lactation appeared to accelerate the changes in milk composition which occur normally in late lactation: increases in the concentration of milk fat and protein; a decrease in lactose concentration. It is concluded that in early lactation, much of the published variation in marginal response can be explained by differences between experiments in levels of feeding studied and in the initial milk yield of the cows. In late lactation there was much less variation in the reported magnitude of the marginal response, and the variation which did exist can be explained by experimental error.


1999 ◽  
Vol 133 (4) ◽  
pp. 419-425 ◽  
Author(s):  
Y. UNAL ◽  
P. C. GARNSWORTHY

Dry matter intake is one of the major factors limiting milk production in dairy cows, although the quantity of food consumed by an individual cow when housed and fed as part of a group is rarely known. Such information would permit more precise ration formulation, concentrate allocation and selection of cows according to efficiency of milk production. Alkanes have been used with sheep and cattle to estimate feed intake under grazing conditions and could provide a technique for measuring intake in housed dairy cows. The purpose of this study was to examine alkanes C32 and C36, in combination with alkane C33, as indigestible markers for estimating intake of housed dairy cows fed on different diets under experimental and commercial conditions. Three experiments were conducted with hay-based diets (Expt 1), silage only diets (Expt 2) and a diet consisting of a silage-based basal ration plus concentrates (Expt 3). Animals were dosed once daily with C32 and C36, either on filter papers (Expts 1 and 2) or as part of a specially prepared concentrate (Expt 3). Faecal recoveries of alkanes ranged from 0·88 to 0·99. Over the range of intakes found in the three experiments (6–24 kg DM/d), the r2 values for estimated versus actual dry matter intakes ranged from 0·81 to 0·99. It is concluded that alkanes could provide a useful technique for estimating intake in dairy cows housed and fed in groups.


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