Intake, digestion, and nitrogen and sulfur retention in Angora goats and Merino sheep fed herbage diets

Abstract

The voluntary intake and digestion of three pasture hays of varying quality by Angora goats was compared with that by Merino sheep. The excretion and retention of nitrogen and sulfur were also measured. When a high quality hay was given, there were no differences between goats and sheep in the intake of organic matter (68 vs 61 g/kg0.75.d) or in organic matter digestibility (digestible organic matter intake) (72 vs 7 1 %). However, the goats appeared to utilize nitrogen less efficiently than the sheep as evidenced by nitrogen retention (673 vs 794 mg/100 g digestible organic matter intake.d), and there was a tendency for sheep to use absorbed energy more efficiently for body tissue synthesis. The apparent digestion of organic matter (65 vs 57%), plant cell wall constituents (67 vs 59%), nitrogen (29 vs 19%) and sulfur (40 vs 33%) in a medium quality hay low in nitrogen was greater in goats than in sheep. There were no differences in intake, but the goats were more efficient at conserving nitrogen (nitrogen retention -87 vs -200 mg/ 100 g digestible organic matter intake.d). Similar trends occurred when a poor quality hay with a higher nitrogen content was given. Goats have apparent advantages over sheep in their ability to digest fibrous feeds and conserve limiting nutrients from such feeds. Consequently, they may require less supplementary feeding than sheep in temperate areas during late summer and autumn when animals graze mature pastures.

A comparative study of the effect of two-stage olive cake added to alfalfa on digestion and nitrogen losses in sheep and goats

“…Nú ñ ez-Herná ndez et al (1991) reported a higher N digestibility in goats than in lambs when fed mountain mahogany (Cercocarpus montanus) leaves treated or untreated with PEG. Several nutritional studies comparing sheep and goats reported no differences in nutrient digestibility when moderate-or good-quality forages were fed (Isac et al, 1994;Molina Alcaide et al, 2000) but fibre digestibility of low-quality forages was greater in goats than in sheep (Doyle et al, 1984). In our work only ADF digestibility of AHCO and AHCOP diets differed between goats and wethers, being higher for goats, while values for AH diet remained similar for both animal species.…”

“…Bohra (1980) found that goats had lower N losses than sheep when fed the same diet. Doyle et al (1984) reported similar N losses when goats and sheep were fed subterranean clover hay or grass clover hay. However, with a ryegrass diet, goats lost less N than sheep did.…”

“…In our work only ADF digestibility of AHCO and AHCOP diets differed between goats and wethers, being higher for goats, while values for AH diet remained similar for both animal species. In other studies involving low dietary N availability, goats also showed greater N digestibility than sheep (Bohra, 1980;Doyle et al, 1984).…”

Voluntary intake and in vivo digestibility of different date-palm fractions by Murciano-Granadina (Capra hircus)

“…However, Wilson (1977) suggested that digestibility of high quality forages is similar between goats and sheep but goats are better at digesting low quality forage. In fact, a higher digestible capacity has been found in goats in comparison with sheep when consuming forages with low nitrogen and high lignin contents (Gihad et al, 1980;Doyle et al, 1984;Howe & Barry, 1988;Molina-Alcaide et al, 1997). These differences have been ascribed to a greater retention time of the digesta in the rumen of goats (Watson & Norton, 1982;Domingue et al, 1991) and to interspecies differences in the rumen environment, such as a higher production of microbial protein in goals (Hadjipanayiotou & Antoniou, 1983) or a higher number of cellulolytic bacteria in goats than in the sheep (Gihad et al, 1980).…”

Policy or poverty trap? Attitude of goat farmers towards the conservation rule on goat rearing in Bhutan

“…A large number of plant species are palatable to goats, and they have an ability to browse and graze in inaccessible areas (Henzell 1993;Parkes et al 1996). Goats also survive under adverse environmental conditions due to their ability to survive on low-nutrient fibrous vegetation (Wilson and Mulham 1980;Doyle et al 1984). These characteristics make goats a potential threat to vegetation and the environment.…”