Soil Ingestion by Dairy Cattle

Abstract

Sets of 5 to 10 random fecal samples were obtained from animals of various management groups of nine dairy herds. Titanium content of feces and soils to which the animals had access was determined by x-ray fluorescence spectroscopy. Titanium of feces was the indicator of soil ingestion, which was calculated for 60% digestibility of the total ration dry matter. Mean soil ingestion +/- standard error as a percent of dry matter intake by groups of lactating cows ranged from .14 +/- .02 to .53 +/- .05 for those confined to concrete, .35 +/- .06 to .64 +/- .18 for those housed in freestall barns with soil bedding, and .60 +/- .07 to .96 +/- .22 for those with access to unpaved lots with no vegetation. Mean soil ingestion as a percent of dry matter intake by groups of yearling heifers and dry cows ranged from .52 +/- .11 to .81 +/- .19 for those confined to concrete, .25 +/- .04 to 2.41 +/- .26 for those with access to unpaved lots with no vegetation, 1.56 +/- .21 to 3.77 +/- 1.50 for those with access to unpaved lots with sparse vegetation, and 1.38 +/- .33 to 2.43 +/- .50 for those on pasture but receiving supplemental feed. Sensitivity of the method depended on the titanium content of the soils which was four to five times greater in clay than in sandy soils. Over all observations, the percent soil of feces was related to the percent ash of feces with the orthogonal linear regression equation, Soil = .69 Ash--5.1 (squared correlations, .62).

Soil intake of lactating dairy cows in intensive strip grazing systems

“…This is in accordance with previously reported values (Mayland et al, 1975;Fries et al, 1982;Thornton and Abrahams, 1983), generally classified as extreme and not relevant to current outdoor systems. Healy (1968) showed that soil intake increased with increasing stocking rate: soil intake had a yearly average of 0.5 kg/day at 1.2 cows/ha, increasing to 0.85 kg/day at 1.65 cows/ha and finally reaching 1.06 kg/day at 2.5 cows/ha, with 1.86 kg/day during the winter period.…”

“…He reported that these differences were mainly because of a strong increase in soil intake over the New Zealand winter and at high stocking density. Our average and extreme values seem close to those reported in previous studies focused on extensive ranching (Mayland et al, 1975;Fries et al, 1982;Thornton and Abrahams, 1983) even if higher soil intake can be hypothesised in the case of trampling or when cows graze under heavy rainfall (Healy, 1968).…”

“…Calculated least significant differences for dry soil intake were 0.14 and 0.15 kg/day in Trials 1 and 2, respectively. This indicates that a soil intake difference between treatments of less than 0.15 kg/day would not be detectable with this (Fries et al, 1982;Beyer et al, 1999). Soil intake within a given treatment 3 period group, that is, between triplets (Trial 1) or cows (Trial 2) in the same plot was analysed (Figure 1).…”

“…Mayland et al (1975) and Thornton and Abrahams (1983) estimated soil intake very roughly in herds in which heifers, suckler and dairy cows were mixed, that is, cattle with very different levels of dry matter (DM) intake. Fries et al (1982) reported a soil intake of less than 1% of total DM intake (i.e. ,0.2 kg/day) for dairy cows; however, data obtained for dairy heifers and dry cows suggest higher soil intakes when grazing conditions become worse (3% of DM).…”

“…Soil intake in wild animals (Beyer et al, 1994), in sheep (Healy et al, 1967) or in cattle (Healy 1968;Fries et al, 1982) can be estimated from marker techniques such as acidinsoluble ash (AIA). Available literature data on soil intake by cattle on pasture are often old and do not allow easy extrapolation to current grazing systems.…”