Seasonal Variations in Voluntary Intake and Apparent Digestibility of Forages in Goats Grazing on Introduced <i>Leymus chinensis</i> Pasture

Abstract

The nutrient composition of pasture, voluntary intake and digestibility of diet ingested by goats grazing on an introduced Leymus chinensis pasture were measured across spring (May), summer (July), autumn (October) and winter (March). In each season, 12 Inner Mongolian Cashmere goats (6 wethers and 6 does with an average live weight of 22.2±1.3 kg and 19.5±0.8 kg, respectively) were used to graze on a 2 hectares size paddock. Diet selection was observed and the plant parts selected by grazing goats and whole plant L. chinensis were sampled simultaneously. The alkane pair C32:C33 and C36 were used to estimate intake and digestibility, respectively. The results showed that the plant parts selected by goats had higher crude protein (CP) and lower acid detergent fiber (ADF) and neutral detergent fiber (NDF) than the whole plant, especially in the autumn and winter. The voluntary intake of dry matter (DM), CP, ADF, NDF, and metabolizable energy (ME) by goats was highest in summer (p<0.05). The goats ingested more CP, ME, and less ADF in spring than in autumn (p<0.05). The intakes of DM, CP, and ME were lowest in winter (p<0.05). There were significant differences in nutrient intake between wethers and does in each season, except for the ADF and ME intake per metabolic weight (LW0.75). The nutrient digestibilities were higher in spring and summer, and decreased significantly during the autumn and winter (p<0.05). Goats, especially wethers, had a relative constant NDF digestibility across seasons, however, the apparent digestibility of CP in both wethers and does, decreased to negative values in winter. The grazing goats experienced relatively sufficient nutrients supply in spring and summer, and a severe deficiency of CP and ME in winter.

Influence of graded levels of baobab oil seed cake on growth performance and enteric methane emissions in Savannah × Boer crossbreed yearling goats.

“…These effects could be largely due to differences in body size between male castrates and female kids. Contrary, a study conducted by [33] reported that sex of goats had no signi cant difference on dry matter intake (P>0.05), this could be attributed to the fact that feed intake on animals is more in uence by feed palatability, as well as appetite on an individual animal, which means that either male nor female, any animal that has high appetite is more likely to have higher feed intake, regardless of sex.…”

Pasture characteristics and productive performance of dairy cows under two grazing management strategies

“…The greater in vitro digestibility found in the management with a variable defoliation interval would allow for a better utilization of the herbage DM by the animals, since low digestibility implies a shorter retention time of the herbage in the rumen, causing physical limitations. Around 40 to 60% of the variations in intake between forage plants can be attributed to differences in digestibility (Sun Wang, Zhong, & Zhou, 2014).…”

Analysis of Nutrient Composition, Rumen Degradation Characteristics, and Feeding Value of Chinese Rye Grass, Barley Grass, and Naked Oat Straw

“…In contrast, a study reported that the content of CP was 14.3% in the BG [ 31 ], which might be due to the difference in the harvest season and the maturity period. Consequently, the content of CP in the BG gradually decreased from the heading stage to the milk stage [ 32 ]. There was limited information on the content of CP in NO.…”