Various combinations of cereal chaff and Pinus radiata needles were fed to penned sheep in three experiments. The in vivo digestibility of green needles was estimated to be 36%. Intakes of needles were variable and increased to more than 50% of the total dry matter intake if the chaff component of the diet was restricted to 25% of normal intake. Under these conditions, the needles made a useful contribution to the diet and reduced rates of liveweight loss.The feeding value of pine needles may decrease by about 30% as they age but that of fresh young needles can be greater than those of late summer pasture residues. Therefore, if kept ungrazed for in situ consumption in summer or during drought, when pasture residues are not able to maintain sheep, green pine needles can be valuable either as a substitute for pasture or as a partial supplement.
Tag: pastures
Pine needle consumption and bark stripping by sheep grazing annual pastures in young stands of widely spaced Pinus radiata and ppinaster.
The consumption of the pine needles and the stripping of bark by sheep grazing annual pastures in three open stands of P. radiata and one of P. pinaster were measured. The P. radiata were four years old and the densities were 250, 500 and 750 trees ha-1. The P. pinaster included two, three and four year-old trees and the density was 440 trees ha1. Needles were eaten immediately after the sheep were admitted and this continued throughout the year. Within ten weeks of the start of winter grazing, sheep stocked at 7–10 ha1 had eaten about half of the accessible needles on both species where densities were less than500 trees ha1. The estimated consumption was about 260 g sheep1 day1 for the P. radiata. Bark stripping then commenced and continued throughout spring and summer on most plots. In some plots at low tree density, bark was stripped from more than 35% of the trees. In denser stands, needle consumption per tree was less and bark was stripped from less than 5% of the trees. Bark damage was most common on the smaller trees, and severity of stripping was negatively correlated with tree size. Of all the trees with bark damage, 22% of the P. pinaster and 14% of the P. radiata had more than half of the stem circumference stripped. A number of these will probably suffer both stem distortion and growth retardation, and some may die. Methods of reducing the incidence of bark damage are discussed.
Nutrient intake and utilisation by goats fed dried leaves of the shrub legumes Acacia angustissima, Calliandra calothyrsus and Leucaena leucocephala as supplements to native pasture hay
Thirty-six indigenous goats were used to determine the potential of sun-dried leaves of the shrub legumes Acacia angustissima, Calliandra calothyrsus and Leucaena leucocephala as supplements to native pasture hay (NPH). The dried leaves were included at the rates of 80, 160 and 320 g/head/day. Cottonseed meal fed at the same levels, and NPH fed alone were included as controls. Among the browses, C. calothyrsus had the lowest N content of 19.0 g/kg dry matter (DM) and A. angustissima the highest of 35.0 g/kg DM. The leaves from the legumes had significantly less N and higher cell wall, neutral detergent insoluble N (NDIN) and acid detergent insoluble N (ADIN) contents than cottonseed meal. The values of NDIN as a fraction of total N were 19, 456, 526 and 816 g/kg for cottonseed meal, L. leucocephala, A. angustissima and C. calothyrsus, respectively.Proanthocyanidin contents were 33, 196 and 134 g/kg DM for A. angustissima, C. calothyrsus and L. leucocephala, respectively. Type of supplement did not affect (P>0.05) NPH, total and digestible DM intakes although NPH intake was depressed (P<0.05) at the highest level of supplementation compared to the first two levels. Animals fed legumes excreted significantly more (P<0.001) faecal N (g/kg N intake) than animals consuming cottonseed meal. The reverse was observed for urine N. Among the legumes, C. calothyrsus had significantly higher (P<0.001) N in faeces (958 g/kg N intake) than A. angustissima (630) and L. leucocephala (615). Significant (P<0.05) correlation coefficients were obtained between proanthocyanidins (PAs) intake and faecal N, NDIN and ADIN (0.535, 0.501 and 0.786, respectively). Regressing digestible N on N intake indicated that A. angustissima and C. calothyrsus tannins had significant effects on the digestion of dietary N. The animal responses were discussed in relation to PAs content. It was concluded that both the type and level of PAs were important determinants of the animal responses.