Influence of sward characteristics on grazing behaviour and growth of Hereford steers grazing tropical grass pastures

1978 ◽  
Vol 29 (1) ◽  
pp. 89 ◽  
Author(s):  
EA Chacon ◽  
TH Stobbs ◽  
MB Dale

Relationships between sward characteristics, grazing behaviour and growth of Hereford steers were studied on nitrogen-fertilized (378 kg ha-1 yr-1) Setaria anceps cv. Nandi and Digitaria decumbens swards continuously stocked at 4.3, 6.2 and 8.0 beasts ha-1 during five periods over 2 years. Availability of herbage, as measured by bite size, and nitrogen content and in vitro digestibility of herbage in the top of the swards were the two most important factors influencing the performance of steers. The relative importance of these factors varied between seasons, between stocking rate treatments and to a lesser extent between pasture species. The highest growth rates were measured on the leniently stocked pastures because steers were able to harvest feed easily (a large bite size) and could more readily select the more nutritious plant parts from the top of the sward. The swards were highly heterogeneous, and numerical analysis of data showed that at the same herbage yield, spatial distribution of herbage (leaf bulk density and leaf to stem ratio) and the nutritive value (in vitro digestibility and nitrogen content) of herbage greatly influenced the growth of steers. Cattle were unable to satisfy their feed requirements on some high quality but low-yielding swards, despite increasing grazing time to compensate for the small bites prehended (up to 707 min in 24 hr in spring). Consequently nitrogen and digestibility contents of extrusa samples were at times poor indicators of performance.


1988 ◽  
Vol 10 (1) ◽  
pp. 60 ◽  
Author(s):  
AM Holm ◽  
RJ Allen

This study was undertaken to assess whether the nutritional quality of spinifex pasture lands is improved by buming to promote the growth of grasses other than spinifex. We selected two comparable sites in the Exmouth Gulf region of Western Australia; one had been bumt in late 1979 and the other had not been burnt for many years. On these sites we sampled the five grass species present, as well as Triodia pungens (soft spinifex) and Plectrachne >chinzii (Oat eared spinifex) on 10 occasions from March 1980 to April 1982. Plant parts were analysed for nitrogen, phosphorus and sulphur content, and in vitro digestibility. None of the common grass species tested was more nutritious or more palatable than soft spinifex. It seems that little is gained from manipulating spinifex pastures through burning if the aim is to encourage alternative grass species. There is a need however for further studies into the importance of woody herbs and forbs in the nutrition of grazing animals on spinifex country and the effect of fire on these species.



1969 ◽  
Vol 11 (3) ◽  
pp. 369-378 ◽  
Author(s):  
J. P. Langlands

SUMMARYThe ability of two groups of six Merino wethers aged 6 and 66 months to digest a lucerne ration was examined in order to detect possible biases in the use of faecal nitrogen as a faecal index substance. Earlier work with this technique had indicated a difference in selectivity between young and older sheep. No difference in ability to digest the ration was observed and it was concluded that the earlier observation was not an artefact in the faecal nitrogen technique. Oesophageal fistulae were prepared in 120 sheep differing in breed, sex, age, strain and previous history. Determinations were made of the nitrogen content, and in one experiment of the in vitro digestibility of the diet selected by sheep grazing various pastures. Significant differences in the nitrogen content of the diet selected by sheep varying in breed, age and previous grazing history were recorded on some pastures on some occasions but not on others. No significant differences were observed between sheep varying in strain or sex. No reason could be suggested for the occasional differences between groups in the nitrogen content or digestibility of the diet selected, but it appeared unlikely that it would be a major source of variation in the productivity of the different groups at pasture.



1982 ◽  
Vol 22 (119) ◽  
pp. 391
Author(s):  
CJ Gardener ◽  
RG Megarrity ◽  
MN McLeod

The distribution of dry matter between leaves, stems and inflorescences, and the nitrogen, phosphorus and sulfur concentration and in vitro digestibility of these parts were measured in uncut swards of nine accessions of seven Stylosanthes spp. grown in northern Queensland over 22 months. Despite above average rainfall in both dry seasons, which greatly reduced the normal moisture stress, only S. guianensis cv. Oxley retained a significant proportion of green leaf in the winter period. However, Oxley set little seed in either year. Plants of the three short-lived species S. hamata, S. humilis and S. subsericea died back to the crown at the end of each wet season, while adult plants of the strongly perennial shrubs S. viscosa, S. scabra and S. fruticosa shed most of their leaves by July. All accessions flowered in both years, and all, except Oxley, set a heavy seed crop by the second year. Some inflorescence was retained on the living stems of the perennial lines until October. This inflorescence had a nutritive value only just below that of young leaf, while the mature stem was low in nitrogen and digestibility in all accessions. The leaf and stem litter had a similar chemical composition to standing material but rapidly became mouldy. The two cultivars of S. humilis, Paterson and Gordon, and S. subsericea had significantly higher levels of nitrogen, phosphorus, sulfur and digestibility than the other accessions. S. viscosa had significantly lower levels of all four attributes. The utilization of the various accessions for improving cattle nutrition is discussed.



1982 ◽  
Vol 22 (119) ◽  
pp. 391 ◽  
Author(s):  
CJ Gardener ◽  
RG Megarrity ◽  
MN McLeod

The distribution of dry matter between leaves, stems and inflorescences, and the nitrogen, phosphorus and sulfur concentration and in vitro digestibility of these parts were measured in uncut swards of nine accessions of seven Stylosanthes spp. grown in northern Queensland over 22 months. Despite above average rainfall in both dry seasons, which greatly reduced the normal moisture stress, only S. guianensis cv. Oxley retained a significant proportion of green leaf in the winter period. However, Oxley set little seed in either year. Plants of the three short-lived species S. hamata, S. humilis and S. subsericea died back to the crown at the end of each wet season, while adult plants of the strongly perennial shrubs S. viscosa, S. scabra and S. fruticosa shed most of their leaves by July. All accessions flowered in both years, and all, except Oxley, set a heavy seed crop by the second year. Some inflorescence was retained on the living stems of the perennial lines until October. This inflorescence had a nutritive value only just below that of young leaf, while the mature stem was low in nitrogen and digestibility in all accessions. The leaf and stem litter had a similar chemical composition to standing material but rapidly became mouldy. The two cultivars of S. humilis, Paterson and Gordon, and S. subsericea had significantly higher levels of nitrogen, phosphorus, sulfur and digestibility than the other accessions. S. viscosa had significantly lower levels of all four attributes. The utilization of the various accessions for improving cattle nutrition is discussed.



1993 ◽  
Vol 1 (1) ◽  
pp. 45-54 ◽  
Author(s):  
M. Meuret ◽  
P. Dardenne ◽  
R. Biston ◽  
O. Poty

To upgrade grazing management recommendations in the Mediterranean area, one needs to assess the nutritive value of woody foliages including their changes over time and with location. Using a wide range of native and cultivated foliages, our objective was to evaluate the potential of near infrared (NIR) reflectance spectroscopy to determine foliage chemistry and in vitro digestibility for ruminants. The samples, representative of small ruminant eating bites, were divided into the different plant parts. Samples were carefully conditioned, being air-dried at 60°C; drying times were individually varied to ensure complete dehydration without excessive heating. Samples were analysed for organic matter (OM), nitrogen (N), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and in vitro digestibility with a pepsin–cellulase method developed for forages (IVDMD). NIR scans were made with an NIRSystems 5000 instrument and data analysis was performed using ISI software. Partial least squares (PLS) regression equations were developed for IVDMD and each constituent. Nine mathematical treatments, with and without scatter correction, were compared. The database of woody foliage spectra and a reference fodder database were compared in two ways: the first involved a comparison of the spectral variation in each collection while the second measured the Mahalanobis distance of each spectrum in one database from the average spectrum in the other. In the case of N, a broad-based calibration was compared with others derived from various sample sub-sets; these latter were formed either according to sample type or following a proximity analysis of five spectral groups by principal component analysis. NIR predictions of IVDMD were applied to describe the effect of phenological changes in the edible parts of Quercus pubescens Willd. The foliage base is very heterogeneous and wider than the reference fodder base. The fodder base variation does not include the foliage samples. The lowest standard errors of calibration (SEC) and cross-validation (SECV) are comparable to literature results on forest leaves, but better for lignin (SECV of 1.5 compared to SEC values of 2.5–2.9). SECV for IVDMD is satisfactory at almost 2.0 because this value is similar to precision data normally reported for in vitro digestibility estimations on narrower sample sets than the current one. The broad-based calibration for N gave similar or lower standard errors to those obtained using sample sub-sets. One can show that IVDMD values for Quercus pubescens leaves decrease from 65 to 15% with increasing maturity; leaf IVDMD values are approximately 15% higher than the previous year's stem value from May until October. NIR spectroscopy appears to be an adequate technique for the prediction of the nutritive value of Mediterranean foliages from trees and shrubs, with a reliability similar to that obtained from classical fodder analysis procedures. This study shows that broad-based calibrations with PLS regression could be made on extremely diverse sets of data (IVDMD ranging from 28 to 94%), grouping distinct edible plant parts within the same data base.



1986 ◽  
Vol 26 (5) ◽  
pp. 551 ◽  
Author(s):  
DJ Minson ◽  
JB Hacker

We compare the voluntary intake and digestibility of 6 genotypes selected from 3 F1 families of Digitaria milanjiana for high or low leaf digestibility, and D. decumbens (pangola grass). Swards were harvested on 6 occasions (4 by 4-week regrowths, 1 by 10-week and 1 by 14-week regrowth) and fed to sheep in metabolism cages. Averaged over families and regrowths, high digestibility selections were significantly superior to low digestibility selections in digestibility, voluntary dry matter intake and intake of metabolisable energy. There was a large range in leafiness of the genotypes. Correlations between leafiness and in vivo digestibility, dry matter (DM) intake and intake of metabolisable energy were positive and statistically significant. Comparison of full-sibs at the same percentage stem (80 and 100%) suggested a higher DM intake, digestibility and intake of metabolisable energy of stem from genotypes selected for high leaf digestibility. Averaged over harvests, none of the selected genotypes was significantly superior to pangola grass in digestibility but all were superior in DM intake and 5 in intake of metabolisable energy. The best selected genotype was 35% better than pangola grass in terms of intake of metabolisable energy. Differences in in vitro digestibility of young leaves from vegetative tillers of full sibs, the characteristic on which the genotypes had been selected, were maintained under sward conditions, although differences were reduced.



1973 ◽  
Vol 24 (6) ◽  
pp. 821 ◽  
Author(s):  
TH Stobbs

Bite size (organic matter content per bite) of cows grazing swards of Chloris gayana (rhodes) and Setaria anceps (setaria) regrown for 2, 4, 6, and 8 weeks was measured using oesophageal fistulated animals. Sward canopy structure was measured by stratification into five vertical layers, each 15 cm high; for each layer weights of leaf and stem components were estimated. Chemical composition and in vitro digestibility of plant fractions and oesophageal fistulae samples were determined. Cows grazing the 4 week regrowths of rhodes grass had a larger bite size (0.32 g OM/bite) than when grazing 2 week regrowths (0.27 g OM/bite) when the availability of herbage and leaf material was lowest. Despite a marked increase in herbage yield as the pastures matured (up to 8427 kg/ha) the mean bite size decreased to a mean of 0.15 g OM/bite at 6 and 8 weeks. The bite size of cows grazing setaria pastures was lower than on the rhodes grass pastures but followed a similar pattern. A high density of leaf within the sward (sward leaf density) as well as a low stem content were considered to be the main factors affecting bite size. Setaria and rhodes grass pastures had both low sward bulk densities (a range of 14–96 kg/ha cm) and low sward leaf bulk densities (a range of 12–43 kg/ha cm) compared with temperate pastures. Basal layers of the sward contained more dense herbage (up to 148 kg/ha cm), but sward leaf density was usually less than 80 kg/ha cm and apparently inaccessible. ___________________ *Part I, Aust. J. Agric. Res., 24: 809 (1973).



Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1441
Author(s):  
Youssef Chebli ◽  
Samira El Otmani ◽  
Mouad Chentouf ◽  
Jean-Luc Hornick ◽  
Jean-François Cabaraux

Forest rangelands contribute largely to goat diets in the Mediterranean area. Information about browsed plant quality is essential for adequate feeding management. The purpose of this study was to evaluate the temporal changes in chemical composition and in vitro digestibility of the main plant species selected by goats in the Southern Mediterranean forest rangeland during two consecutive years; these were very contrasted (dry and wet). The browsed species were composed of herbaceous, eleven shrubs, and four tree species. Overall, large variability in chemical composition, in vitro organic matter digestibility (IVOMD), and metabolizable energy (ME) was observed among species, grazing season (spring, summer, and autumn), and years within each species. Crude protein (CP) content varied from 60 to 240 g/kg dry matter (DM). The fiber fractions, except for Quercus suber, increased significantly by advancing maturity. Due to the water stress, the lignin level presented a higher value during the spring of the dry year. Condensed tannin (CT) content varied from 2 to 184 g/kg DM. CP, IVOMD, and ME showed a negative correlation with lignin and CT. Based on the results presented herein, it is concluded that the nutritive value of the browsed plant species was highest in the spring and lowest during the summer and autumn of both studied years. With a good grazing management strategy, the selected plant species by goats could guarantee high-quality feeding resources throughout the year.



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chatchai Kaewpila ◽  
Pongsatorn Gunun ◽  
Piyawit Kesorn ◽  
Sayan Subepang ◽  
Suwit Thip-uten ◽  
...  

AbstractImproving the nutrition of livestock is an important aspect of global food production sustainability. This study verified whether lactic acid bacteria (LAB) inoculant could promote ensiling characteristics, nutritive value, and in vitro enteric methane (CH4) mitigation of forage sorghum (FS) mixture silage in attacking malnutrition in Zebu beef cattle. The FS at the soft dough stage, Cavalcade hay (CH), and cassava chip (CC) were obtained. The treatments were designed as a 4 × 2 factorial arrangement in a completely randomized design. Factor A was FS prepared without or with CH, CC, and CH + CC. Factor B was untreated or treated with Lactobacillus casei TH14. The results showed that all FS mixture silages preserved well with lower pH values below 4.0 and higher lactic acid contents above 56.4 g/kg dry matter (DM). Adding LAB boosted the lactic acid content of silages. After 24 h and 48 h of in vitro rumen incubation, the CC-treated silage increased in vitro DM digestibility (IVDMD) with increased total gas production and CH4 production. The LAB-treated silage increased IVDMD but decreased CH4 production. Thus, the addition of L. casei TH14 inoculant could improve lactic acid fermentation, in vitro digestibility, and CH4 mitigation in the FS mixture silages.



Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 658
Author(s):  
Matthew F. Digman ◽  
Jerry H. Cherney ◽  
Debbie J. R. Cherney

Advanced manufacturing techniques have enabled low-cost, on-chip spectrometers. Little research exists, however, on their performance relative to the state of technology systems. The present study compares the utility of a benchtop FOSS NIRSystems 6500 (FOSS) to a handheld NeoSpectra-Scanner (NEO) to develop models that predict the composition of dried and ground grass, and alfalfa forages. Mixed-species prediction models were developed for several forage constituents, and performance was assessed using an independent dataset. Prediction models developed with spectra from the FOSS instrument had a standard error of prediction (SEP, % DM) of 1.4, 1.8, 3.3, 1.0, 0.42, and 1.3, for neutral detergent fiber (NDF), true in vitro digestibility (IVTD), neutral detergent fiber digestibility (NDFD), acid detergent fiber (ADF), acid detergent lignin (ADL), and crude protein (CP), respectively. The R2P for these models ranged from 0.90 to 0.97. Models developed with the NEO resulted in an average increase in SEP of 0.14 and an average decrease in R2P of 0.002.



Sign in / Sign up

Export Citation Format

Share Document