Diet mixing and condensed tannins help explain foraging preferences by Creole goats facing the physical and chemical diversity of native woody plants in the central Monte desert (Argentina)

Comparing the Effects of a Pine (Pinus radiata D. Don) Bark Extract with a Quebracho (Schinopsis balansae Engl.) Extract on Methane Production and In Vitro Rumen Fermentation Parameters

The aim of this study was to compare the effects of a pine (Pinus radiata D. Don) bark extract (PBE) with a quebracho (Schinopsis balansae Engl.) extract (QTE) on methane (CH4) production and in vitro rumen fermentation parameters. A forage diet supplemented with PBE or QTE (0, 2 and 4% dry matter (DM) basis) was incubated for 24 h to determine in vitro DM disappearance (IVDMD), CH4, volatile fatty acids (VFA), and ammonia nitrogen (NH3-N) production. Differences were analyzed using Tukey’s test, orthogonal contrasts, hierarchical clustering heatmap (HCH), and principal component analysis (PCA). Both extracts (4% DM) decreased butyrate (Bu; p = 0.001), CH4 (p = 0.005), total VFA (p < 0.001), and NH3-N (p = 0.006) production and increased acetate (Ac; p = 0.003) without affecting the partitioning factor (p = 0.095). Propionate (Pr; p = 0.016) was increased, whereas IVDMD (p = 0.041) was decreased with QTE (4% DM). The inclusion of QTE (2% DM) decreased CH4 production (p = 0.005) and the (Ac + Bu)/Pr ratio (p = 0.003), whereas PBE (2% DM) decreased the NH3-N (p = 0.006) and total VFA production (p < 0.001). The HCH and PCA indicate a negative correlation (r = −0.93; p < 0.001) between CH4 production and tannins. In conclusion, PBE shares many of the effects generated by QTE on ruminal fermentation, although the magnitude of these effects depends on concentration. The PBE could be used as an additive in ruminant diets to reduce CH4 and NH3-N production without reducing IVDMD or increasing propionate, but further in vivo studies are required to clarify its effects on animal production.

Mineral status of soil, sea water, and mangrove (Avicennia marina) forages in several coastal areas of West Sumatra

Background and Aim

The availability of minerals in the soil affect the mineral content of mangrove leaves. This study aimed to determine the macro- and micromineral contents in the environment and mangrove leaves (Avicennia marina) as animal feed in the coastal areas of West Sumatra, Indonesia.

Materials and Methods

In this study, soil, water, and mangrove leaves were extracted from the mangrove plant's environment. The mineral contents were determined using the atomic absorption spectrophotometer of Beijing Rayleigh Analytical Instrument Corporation (make and country of origin). The total phenol and tannin contents were determined using the Folin-Ciocalteu and hide-powder methods, respectively.

Results

The mineral content of the soil affected the mineral content of the plants. The soil and leaves of A. marina in the Pariaman area were richer in terms of macro- and microminerals. The soil had pH value, organic carbon content, leaf nitrogen content, phosphorus, calcium, and potassium of 5.65, 4.21%, 3.39%, 0.17%, 1.99%, and 0.54%, respectively. A. marina leaves had a total phenol and tannin contents of 24.51 mg GAE/g check the unit and 4.09%, respectively.

Conclusion

This research showed that the mineral content in the soil in several mangrove areas in West Sumatra has a positive correlation with the mineral content in the leaves of A. marina, which have a complete mineral content. Therefore, A. marina leaves could be recommended as a mineral source for ruminants.

Preference of Boer goats for Namibian native forage legumes and Lucerne (Medicago sativa)

The objective of this study was to determine the relative palatability of four native forage legumes (Otoptera burchellii, Crotalaria argyraea, Crotalaria podocarpa and Vigna lobatifolia) in comparison with each other and with Lucerne (Medicago sativa). Eight weaned Boer goats aged 6 months and weighing 25.2 ± 4.9 kg were grouped by sex, and then randomly allocated to individual pens. Goats were simultaneously offered 100 g of each of the four native legumes and 600 g of M. sativa (as-is basis) over a 10-day period. Grass hay (Cenchrus ciliaris), fresh water and mineralised salt licks were available at all times. Grass hay was given to allow diet mixing and possibly ameliorate any undesirable effects, such as bloat, due to feeding on legumes alone. The percentage of each species consumed of that offered was associated (P &lt; 0.001) with legume species, day and legume × day interaction. Over 95% of the O. burchellii, V. lobatifolia and Lucerne offered were consumed from Days 1 to 10. The amounts of Crotalaria spp. consumed fluctuated widely in the first 4 days, but increased thereafter to &gt;95% of that offered. This study demonstrated that hay of all the four native forage legume hays were palatable to Boer goats, with the inferred ranking being: (Lucerne, V. lobatifolia) &gt; O. burchellii &gt; Crotalaria spp. Further studies are required to investigate the productivity of goats feeding on these native forage legumes, which have potential for use in marginal lands.

Dietary selection by goats and the implications for range management in the Chihuahuan Desert: a review

Field studies characterising the forage resources of mixed-breed goats on Chihuahuan Desert rangelands were reviewed and the principal sources of variation in their diet choices discussed. Goats eat a varied diet comprising at least 126 plant species in this landscape. Goats are highly selective feeders, changing their diet from predominantly forbs (8–64%) to browse (35–88%). Graminoids make up only ~5% of the diet, but grasses could be important dietary components on rangelands in good condition. Feed intakes range between 0.8% and 3.4% of bodyweight, depending on the season. DM digestibility of forage selected by goats ranges between 44% and 65%. Annual crude protein (CP) in forages selected by goats varies from 80 to 160 g CP kg–1 DM. Overall, pregnant and lactating goats manage to ingest food that contains higher amounts of CP and lower amounts of cell wall than non-pregnant, non-lactating goats. Goats not adapted to severe shortage of forage select a diet that does not match their nutritional requirements and fetal losses occur. Goat kids select higher quality diets than do mature goats (94.5 vs 88.5 g CP kg–1 DM). Granadina goats eat ~20% more shrubs, including 3-fold more Larrea tridentata (DC) Cav., than Nubian goats. Goats with severely eroded incisors avoid grasses, focusing on tender-leaved shrubs. During the rainy season, bucks select mainly shrubs (78% of the diet) and avoid grasses (1.7% of the diet), whereas does rely heavily on forbs (about one-third of their diet). Alternating use of grazing grounds increases shrub ingestion by 25%. No evidence exists indicating that food choice by goats in this arid environment is biased towards forages with lower secondary compounds. It is concluded that the flexible, broad-scale and opportunistic feeding behaviour of goats make them an effective animal to sustainably exploit the forage resources of the Chihuahuan Desert.