Relationships between botanical composition,yield and forage quality of permanent grasslands over the first growth cycle

This study examined the relationships between botanical composition and forage parameters (yield and forage quality variables) in 153 permanent grasslands located in the Massif Central of France. Grasslands were sampled at two vegetation stages in the first growth cycle. Botanical composition, yield, ash, crude protein, neutral detergent fibre, acid detergent fibre, acid detergent lignin, organic matter digestibility (OMD) and voluntary intake (VI) were estimated for each sample. Temporal variability in species–forage parameter relationships were accounted for using innovative multivariate analyses applied mainly in ecological science. Crude protein and OMD were weakly correlated when each harvest time was analysed separately. Species–forage parameter relationships remained stable during the first growth cycle. The stability of these relationships indicates that permanent grasslands dominated by competitive species were associated with high yield and forage quality values whereas permanent grasslands composed of conservative species and/or high proportions of senescent material were associated with high structural carbohydrate values and low yield, OMD and VI values. Based on these relationships, we propose a typology of permanent grasslands along with a set of indicator species enabling non‐specialist botanists to easily classify grasslands for grassland management purposes.     

Effects of ecological,landscape and management factors on plant species composition,biodiversity and forage value in Alpine meadows

Due to decades of loss of grassland diversity across Europe, there is a need to identify factors affecting species composition and diversity in managed meadows. The aim of the current study was to assess how ecological, landscape and management factors may affect plant species composition, biodiversity and forage value in Alpine hay meadows. Species composition, Shannon index and forage value were obtained from phytosociological relevés. Twenty explanatory variables were selected from a set of ecological, landscape and management factors. Their effects on plant species composition, Shannon index and forage value were analysed by applying the variation partitioning approach. Plant species composition was related to sixteen factors, explaining 35·6% of the variability. Shannon index and forage value were related to eleven factors, explaining 47·8 and 40·8% of their total variation respectively. Ecological factors were the main set explaining species composition and diversity, whereas none of the three individual groups of factors (ecological, landscape, management) significantly explained variability within forage value. Overall, the effects of the three groups of factors accounted for 70% of the total variability in plant species composition, but less than half that of Shannon index and of forage value.     

Proximate composition and antinutritional factors in rice bean (Vigna umbellata)

Thirteen promising strains of Rice bean (Vigna umbellata) were analysed for their proximate compositions and antinutritional factors. Protein content in these varieties ranged from 17.50 to 23.10 per cent, ash from 3.06 to 4.48 per cent, ether extract from 2.4 to 3.9 per cent and crude fibre from 1.70 to 4.25 per cent. Trypsin inhibitor activity ranged from 112.63 to 163.98 units/g and polyphenols ranged from 0.58 to 1.19 per cent. Phytohemagglutinating activity was present in all the strains, except one, RB-32. Oligosaccharides, viz., raffinose, stachyose and verbascose, ranged from 0.32 to 0.91, 0.95 to 1.98 and 1.40 to 2.58 per cent, respectively. Attempts have been made to compare the results with a standard variety each of cowpea (Vigna unguiculata), moong (Vigna radiata) and mash (Vigna mungo).     

Agronomic factors affecting the yield and quality of forage maize in Ireland: effect of sowing date and plastic film treatment

The objectives of these studies were to examine the effects of sowing date and plastic film on the yield and quality of forage maize ( Zea mays L.) in Ireland, a marginal maize-growing area. In 1989–95, comparisons were made of maize sown through clear plastic film (PP treatment), and maize sown in the conventional manner without plastic (NP treatment), in terms of dry-matter (DM) yield and quality (cob, grain and starch contents). The PP treatment significantly increased DM yields in five years, with a mean yield increase of 3·10 t ha⁻¹. Whole-plant DM content increased (significant in four years) by a mean of 0·15; cob content increased (significant in five years) by a mean of 0·32; grain content increased (significant in all of the three years examined) by 0·75; and starch content increased from 236 to 318 g kg⁻¹ DM ( P  < 0·01) in 1995 where the plastic film treatment was used. Organic matter digestibility values were similar for both treatments in 1995. Sowing date in the April-May period had no consistent effect on DM yields, but early sowings did increase cob (significant, except in 1994), grain (significant in one (1995) of the two years tested) and starch ( P  < 0·05) contents (only tested in 1995). Sowing on 11 April 1995 through perforated plastic gave lower yields than the NP treatment sown on the same date, due to severe frost damage in early May.     

Agronomic factors affecting the yield and quality of forage maize in Ireland: effect of plastic film system and seeding rate

The objectives were to compare the effects of two plastic film systems [perforated (PP) and complete‐cover (CC) systems] on the yield and quality of forage maize, and to study the effects of seeding rate on maize grown with, and without, plastic film. Between 1995 and 1998 (Experiments 1 and 2), comparisons were made of maize without plastic film systems (NP), sown through clear plastic film (PP) and covered with clear plastic film (CC). In the CC system, the plastic was removed manually from the crop. Two dates of removal (CC1 and CC2) were compared in 1995, while four removal dates (CC1, CC2, CC3 and CC4) were examined in 1996–98. In 1996–98, three sowing dates (early, mid‐April; mid, early‐May; late, mid‐May) were also examined. Four seeding rates (78 200, 93 900, 107 000 and 126 000 seeds ha^?1) were examined in two experiments (Experiment 3 in 1996 and Experiment 4 in 1996–98). No plastic was used in Experiment 3, while three plastic treatments (NP, PP and CC) were examined in Experiment 4. In the CC treatment, the plastic film was removed at the six‐ to eight‐leaf stage. In Experiment 1, the PP treatment gave lower DM yields than the NP treatment due to frost damage which killed 0·30 of the plants in the PP treatment. Plants were undamaged by frost in both CC treatments, and the CC2 treatment (plastic removal at the six‐leaf stage) gave significant increases in DM and grain yields. In Experiment 2, averaged over years and sowing dates, DM yields were significantly increased by all plastic film treatments except CC4. All plastic film treatments gave significantly earlier tassel emergence than the NP treatment, and significantly increased grain yields and contents of DM and grain. The highest yields of DM and grain were obtained from the PP system. Within the CC treatments, leaving the plastic film intact until the ten‐leaf stage (CC4) gave lower yields of DM and grain than removing the plastic film at an earlier stage. Averaged over years, the largest DM yields were obtained from the CC system with early‐sown material, while the yield differences between treatments with late‐sown crops under this system were not significant. Highest DM and grain yields were obtained with early sowing, while late sowing gave lower contents of DM and grain, and later tassel emergence. In Experiments 3 and 4, DM and grain yields increased as seeding rate increased up to 126 000 seeds ha^?1 with NP and CC plastic treatments. With the PP treatment, DM yield reached a plateau at 107 000 seeds ha^?1. Seeding rate did not significantly affect DM content in either experiments but grain content declined in both experiments as seeding rate increased.     

Seed yield variation in plains rough fescue (Festuca hallii (Vasey) Piper) populations and its relation with phenotypic characteristics and environmental factors

Plains rough fescue (Festuca hallii (Vasey) Piper) is a dominant grass in the endangered Fescue Prairie of North America. Infrequent and unpredictable seed production presents a challenge for the use of this species in restoration and rangeland seeding. The objective of this study was to compare seed yield of different plains rough fescue populations and to determine the dependence of seed yield on phenotypic characteristics. Effect of weather conditions during the floral induction and initiation period of different years of the study was also compared. In 2007, a completely randomized field plot experiment was established from eleven populations of plains rough fescue at Swift Current, SK, Canada. In 2007, 2010 and 2011, individual plant seed yield, reproductive tillers, above‐ground biomass, plant height and crown diameter were measured, and plant vigour was scored. All measured variables differed significantly (P ≤ 0·05) among populations. Four populations were identified as having higher seed yield potential. Plants in these four populations also had characteristics of good plant vigour, taller stems, more reproductive tillers and greater biomass. Seed yield increased linearly with increasing plant height, crown diameter, above‐ground biomass and number of reproductive tillers (r² ranged 0·17–0·67, P < 0·001), but number of reproductive tillers (r² = 0·53–0·67, P < 0·001) was a better predictor for selection of lines with higher seed yield. Although seed yield varied among years, populations with higher seed yield tended to produce greater amounts of seed over the period of the study.     

Potential of Cistus ladanifer L. (rockrose) in small ruminant diets – effect of season and plant age on chemical composition,in vitro digestibility and antioxidant activity

Shrubs can provide an important contribution to the fodder resources for small ruminants in Mediterranean areas, but there is limited information on their feed value, including secondary metabolites and their seasonal differences. This study evaluated the effect of seasonal variation in chemical composition, in vitro digestibility and antioxidant activity of the aerial parts of plants of Cistus ladanifer of two age groups [young plants vs. older ones (2–6 years old)]. Aerial parts of C. ladanifer plants of both age groups were characterized by moderate cell‐wall content [321–410 g NDF kg^?1 dry matter (DM)], high levels of phenolic compounds (55·1–106 g gallic acid equivalents per kg DM) and condensed tannins (CT) (32·1–161 g kg^?1 DM), low protein content (55–100 g kg^?1 DM) and low digestibility (249–315 g of digestible organic matter per kg DM). During autumn and winter, C. ladanifer showed higher protein levels and lower cell‐wall content than in the other seasons. The highest values of phenolic compounds, CT and antioxidant activity were achieved during summer. Young plants showed higher levels of phenolic compounds during spring, summer and winter, and higher CT contents in summer (more than 54 g kg^?1 DM) compared to old plants. Aerial parts of C. ladanifer of both age groups may be used as a component of ruminant nutrition, but only as a supplement and associated with other feeding resources to complement its nutritional imbalances.     

Effect of plant spacing and nitrogen fertilizer levels on the growth,dry‐matter yield and nutritive quality of Columbus grass (Sorghum almum stapf) in southwest Nigeria

A field experiment was conducted in 2006 and 2007 to determine the agronomic performance and nutritive value of Sorghum almum for introduction in the derived savannah area of Nigeria. The experiment was arranged in a 2 × 4 factorial design with 2 plant spacings (0·5 × 0·5 m and 1·0 × 1·0 m) and 4 nitrogen (N) fertilizer levels (0, 60, 120 and 180 kg N ha^?1). Plant height, tiller number, leaf proportion, biomass yield and nutritive value of the herbage were evaluated as part of the search for alternatives (especially drought tolerant) to local forages for dry season feeding of ruminants. Herbage yield data were tested for linear, quadratic and cubic trends to identify the optimal fertilizer levels for both spacings. Spacing × N interactions (P < 0·05) were observed for plant height and tiller number in both years. Agronomic performance was marginally better in 2007 compared with 2006. The maximum dry‐matter (DM) yield of 3500 and 3740 kg ha^?1 for the more dense row spacing (0·5 × 0·5 m) was achieved at N fertilizer levels of 144 and 149 kg N ha^?1 for 2006 and 2007 respectively. For the less dense (1·0 × 1·0 m) row spacing, the maximum DM yield of 3020 and 3240 kg ha^?1 was achieved at 51 and 97 kg N ha^?1 for 2006 and 2007 respectively. The crude protein content of the grass ranged from 61 to 89 g kg^?1 DM, while the neutral detergent fibre (NDF) content ranged from 700 to 734 g kg^?1 DM. The ability of S. almum to persist into the second year in this region is seen as a promising index as persistence is one of the characteristics of a good forage plant. Considering the exorbitant price of N fertilizer, less dense row spacing with N fertilizer rate in the range of 50–100 kg N ha^?1 is hereby recommended for this region.