The Effect of Five Different Wetting Treatments on the Nutrient Content and Microbial Concentration in Hay for Horses

Abstract

Five different hays were used to determine the effect of 5 different soaking and steaming treatments on the water soluble carbohydrate and microbial (bacteria and mould) contents of UK hay. Hays were subjected to the following 5 treatments: 1. Dry; 2. Steamed for 50 minutes in the Haygain- 600 steamer; 3. Soaked in water at 16°C for 9 hours; 4. Steamed then soaked and 5. Soaked then steamed. Post treatment hays were tested for water soluble carbohydrates, bacteria and mould contents. Differences between means were determined using ANOVA and least significant difference with hay (5), bale (3) and treatment (5) as fixed factors, thus n = 75. Protein and ash proportions were unaltered in any of the treatments. Soaked, steamed then soaked and soaked then steamed treatments were all equally effective at reducing water soluble carbohydrates, with significantly (P<0.05) lower mean contents (79–83 g/kg DM) compared with 126 and 122 g/kg dry matter (DM) for dry and steamed respectively. Steamed and soaked then steamed had significantly (P<0.05) less bacteria (1.04×103 and 4.9×102 CFU/g DM) compared with soaked which increased CFU/g DM from 6.0×104 in dry hay up to 3.5×105. Mould contents CFU/g DM were significantly (P<0.05) reduced by steaming (2) and soaking then steaming (1.9) but no difference was seen between dry (1148), soaked (692) or steamed then soaked (501). Soaking for 9 hours followed by steaming for 50 minutes in the Haygain steamer was the most effective method for reducing water soluble carbohydrates and microbial contamination in hay. Soaking or steaming+soaking lowered water soluble carbohydrates but significantly reduced the hygienic quality of the hay which could potentially compromise the health of the horse.

Mapping the bacterial ecology on the phyllosphere of grass hay and the potential hazards of soaking fodder for horse gut health

“…The range of WSC in the three hays of 125 to 242 g/kg DM is typical of UK hay and agrees with previously published values [11,33]. MC and PRG hays contained 100 to 140g/kg DM more WSC than is currently recommended for forages intended to be fed to equids with a pre-disposition to laminitis and such levels stimulate horse owners to reduce the level of WSC by soaking for extended periods.…”

“…While the practice has been previously shown to be effective in both of these endeavours [9,10,11,12,13] soaking hay has some well-documented disadvantages such as nutrient and mineral leaching [9,10,11] production of post-soak liquor that is a biological hazard [14,15] and recorded increases of 1.5 to 5 fold of bacteria in post soaked hay samples [16,17]. To date there is no published information on the resident bacterial profile (s) of hays nor what influence soaking might have on such profiles.…”

Examination of the hygienic status of selected organic enrichment materials used in pig farming with special emphasis on pathogenic bacteria

“…The hay from the farm had the highest mould count of all materials. Different hays can vary widely in their hygienic status, and a TVC of up to log 10 6.47 cfu/g and a mould count of up to log 10 6.67 have previously been reported [31]. The contamination in the present study is comparable to these studies, but to the authors’ knowledge, there is no evidence that this kind of contamination poses a health risk for pigs.…”

Nutritional tips for veterinarians

“…An effective reduction in total viable count and reduction in respirable particles has been reported when hay is steamed appropriately (James and Moore‐Colyer ), whereas prolonged soaking of hay significantly increases the mould and bacterial counts (Moore‐Colyer et al . ).…”