The grazing preferences of cattle and sheep

Abstract

Factors affecting the grazing habits of ruminants are discussed in relation to the attractiveness and nutritive value of herbages and the observed preferences of cattle and sheep at different times.Methods of measuring stock preferences are considered and it is concluded that, while frequent eye estimates of the quantity of each species appear to provide an adequate method, continuous observations and herbage sampling are useful adjuncts to it.The results of five experiments are given. Four were carried out in 3 years' winter grazing and one on spring, summer and autumn grazing over 2 years. In the latter experiment herbage samples were chemically analysed and a relationship with the observed preferences was calculated.In the winter grazing trials the greener grasses tended to be selected first, i.e. timothy, white clover, rough-stalked meadow grass, perennial and Italian rye-grass. Cocksfoot, Phalaris, red fescue and meadow fescue were not generally relished. Meadow foxtail, smooth-stalked meadow grass, tall fescue and sometimes the different varieties of rye-grass and timothy varied in rank from year to year as a result of differential frost damage and fungal attacks.In the summer grazing trials lucerne and white clover were found palatable in all the 1956 trials; in 1957 lucerne remained so, but white clover was less well liked, especially in June and July. The amount of grass growing with the clover seemed to affect attractiveness, mixtures being preferred to either species by itself. Meadow fescue and timothy were always ranked high, perennial rye-grass and cocksfoot usually next. Agrostis and red fescue were lowest. For the grasses, preference rank was positively correlated in 1957 with water-soluble dry matter, water-soluble ash, water-soluble carbohydrate and negatively correlated with lignin content.Results are compared with those of other investigators and they show a marked degree of similarity. Variability in the data for sheep is possibly due to limitations in technique. The results for sheep and for cattle are compared; and it was generally found that cattle were fonder of meadow fescue than sheep, and less fond of cocksfoot.Stock appear to graze those plants which will most readily supply their requirements for salts and energy (carbohydrates). Factors like dung, fungal attack, accessibility, density and toughness may interfere with this relationship.

Non‐volatile organic acids of grasses

“…9 In the samples cut on 22 July 1957, the correlation coefficients between 'preference ranking' and shikimic acid, quinic acid and citric acid were approximately the same as that for water-soluble dry matter, the correlation coefficient of which was better than those of the other components measured. 9 In the samples cut on 22 July 1957, the correlation coefficients between 'preference ranking' and shikimic acid, quinic acid and citric acid were approximately the same as that for water-soluble dry matter, the correlation coefficient of which was better than those of the other components measured.…”

A comparison of voluntary intake and in vivo digestion in guanacos (Lama guanicoe) and sheep given fresh grass

“…Grazing animals generally select green leaf in preference to dead material and leaf in preference to stem (Arnold and Dudzinski, 1978), and similar responses would be expected during the current trial. Selection of particular plant parts generally leads to the material eaten being higher in nitrogen and gross energy and lower in fibre than the material offered and rejected (Arnold, 1960;Cowlishaw and Alder, 1960;Domingue et al, 1991). In contrast, the El and MI grass offered the animals a choice of plant parts from which to select and consequently food choice on these food types was quantified.…”

Rangelands in Arid Ecosystem

“…Cook, 1972;Dicko-Toure, 1980;Le Houéou, 1980b) refer to the relationship between palatability of a given species or taxon, its stage of development (phenology), its relative abundance on the rangeland, and its chemical composition. Cowlishow and Alder (1960) assert that palatability of a given species changes because of changing characteristics that an animal can recognize by its senses of sight, taste and smell. Table 2 shows a list of plant species and their palatability in Omayed Biosphere Reserve.…”