The evaluation of growth characteristics, biomass yield, and chemical composition of two cultivars of Panicum maximum (Mombaca and Gatton) and Brachiaria brizantha (Marandu) at different harvesting stages
- Authors: Sokupa, Mihle Inga https://orcid.org/0000-0002-3918-1393
- Date: 2020-11
- Subjects: Pastures
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21433 , vital:48621
- Description: The objective of this study was to carry out a comparative assessment of growth characteristics, biomass yield and chemical composition of Panicum maximum and Brachiaria brizantha cultivars at different harvesting stages. The field experiment was conducted at the University of Fort Hare research farm in Alice, South Africa. The main factors were three cultivars: Mombaca, Gatton (Panicum maximum) and Marandu (Brachiaria brizantha) and three harvesting stages (6, 10 and 14 weeks after planting). This study was a 3 × 3 factorial set up in a randomized complete block design with three replicates. Characteristics which included plant height, number of leaves and number of tillers were measured in five plants per plot at 2-week intervals from 4 to 14 weeks after planting (WAP). The fresh yield was weighed then oven dried at 65oC for 72 hours then dry matter yield was calculated after drying. The chemical composition (Ash, Fat, ADF, ADL, NDF, CP, Ca, Mg, Na, P, K, Cu, Fe, Zn and Mn) was determined on forage harvested at 6, 10 and 14WAP. Data was analysed using the Statistical Analysis Software in a 3x3 factorial to compute the ANOVA and all means of all treatments were calculated and the difference was tested for significance using the Least Significant Difference (LSD) test at P=0.05. The results showed variations (P<0.05) in plant height, but the number of leaves did not differ (P > 0.05) between the cultivars. The number of tillers were significantly different (P<0.05), the highest number of tillers was observed in Mombaca. Fresh yield showed significant differences at 10 and 14WAP, with Marandu producing the highest Fresh yield. The moisture content was different (P<0.05) across all the three harvests. Varying (P< 0.05) results were also observed in the dry matter yield of the cultivars with Mombaca producing the highest dry matter yield. There were no significant differences (P>0.05) in the ash content of the cultivars. The fat content also showed no significant differences. Variations (P<0.05) occured in the ADF of the cultivars, Marandu had the lowest ADF. The cultivar × WAP interactive effect was significant for ADL content. NDF significantly varied across the cultivars at 6WAP. There were no similarities (P<0.05) in the crude protein during the three harvesting intervals, Mombaca produced the highest CP and the lowest was obtained from Gatton. There was a significant interaction (P<0.05) between the cultivars and harvesting intervals for Calcium (Ca), Magnesium (Mg), Sodium (Na), Potassium (K), K/Ca+Mg, Copper (Cu), Iron (Fe), Zinc (Zn) and Manganese (Mn) contents of the cultivars. However, Phosphorus (P) showed no significant interaction (P>0.05) between the cultivars and harvesting intervals. The results obtained in this study showed that as the grasses grow, the biomass yield produced increases according to the genetic makeup and the factors affecting growth and biomass yield. However, the chemical composition decreased between cultivars. Mombaca showed superior traits in terms of growth biomass yield and chemical composition. Mombaca, which is a Panicum maximum cultivar can be used as a choice in forage production and chemical composition as it can supply both quality and quantity. It can be concluded that there are significant differences in growth characteristics, biomass yield and chemical composition of Panicum maximum and Brachiaria brizantha cultivars at different harvesting stages. It can also be recommended that the best harvesting stage is at 10 WAP, this is because both biomass yield and chemical composition are both satisfactory. , Thesis (MSc) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-11
Production potential of lucerne (Medicago sativa) over-sown into kikuyu (Pennisetum clandestinum) based pasture
- Authors: Fourie, Ilze
- Date: 2015-12
- Subjects: Kikuyu grass , Dairy cattle -- Feeding and feeds , Pastures
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/73554 , vital:79469
- Description: Dairy farming in the southern Cape region of South Africa is based on irrigated kikuyu (Pennisetum clandestinum) over-sown with different ryegrass species (Lolium spp.). Although this system can be highly productive, sustainable production of kikuyu is dependent on expensive nitrogen (N) fertiliser inputs and irrigation due to a high water requirement to maintain production. The introduction of lucerne (Medicago sativa) into pasture systems can lower the risk of high input cost and droughts. Lucerne has a high nutritive value, is able to fix atmospheric N, has high water-use efficiency and is adapted to local climatic conditions. The aim of this study was to determine the DM production potential of lucerne cultivars from various dormancy groups when over-sown into an existing kikuyu pasture base on soils that are suitable for lucerne cultivation, without any N fertiliser application. The study was carried out on the Outeniqua Research Farm near George, Western Cape. Two cultivars were selected from each of the four lucerne dormancy groups and sown into an existing kikuyu pasture based on soils suited for lucerne cultivation. Three establishment methods namely glyphosate/planter (Gly/Plant), glyphosate/rotavator (Gly/Rot) and rotavator (Rot) were used. The statistical design was a randomised block design with three replicates. The botanical composition (lucerne-, kikuyu-, clover-, grass- and weed content), growth rate (kg DM ha-1 day-1), total DM production (kg DM ha-1) and DM content of the treatments were determined before every grazing. The nutritional value (CP-, ME-, NDF-, Ca-, and P content) of the treatments was determined seasonally. Establishing lucerne into kikuyu with the glyphosate/rotavator (Gly/Rot) and rotavator (Rot) method yielded an overall higher percentage of established seedlings compared to the glyphosate/planter (Gly/Plant) establishment method. The establishment method used affected the botanical composition. Lucerne established with the Gly/Plant or Gly/Rot establishment method into kikuyu had a higher lucerne content than the Rot establishment method. The seasonal growth rates of the kikuyu-lucerne pasture varied between 14.8 kg DM ha-1 day-1 during winter to 84.1 kg DM ha-1 day-1 during summer. The establishment method and cultivar influenced the seasonal growth rate and total seasonal production. The cultivar WL 711 established with Gly/Plant establishment method had the highest or did not differ significantly from the highest lucerne content, seasonal growth rate and total seasonal production within seasons. The total annual production ranged between 13805 to 19975 kg DM ha-1 year-1 with the Gly/Plant establishment method yielding the highest or did not differ significantly from the highest annual production when compared with the other establishment methods. The botanical composition affects the nutritive value of the kikuyu-lucerne pasture. The ME content of kikuyu and kikuyu-lucerne pasture did not meet the daily ME requirements for a lactating dairy cow to maintain milk production throughout both years. The CP and Ca content decreased as the lucerne content decreased and the kikuyu content increased. The P content of kikuyu-lucerne and kikuyu pasture met the daily P requirement of a lactating dairy cow. The dormancy groups D2 and D5 were the only dormancy groups that could meet the recommended Ca:P ratio for dairy cows over all the seasons. Lucerne can be successfully established into kikuyu with the use of herbicide as part of the establishment method. Kikuyu-lucerne pasture has a higher DM production with an improved quality compared to kikuyu pasture. By establishing lucerne into kikuyu the cost of N fertiliser application could be lowered as no N needs to be applied. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2015
- Full Text:
- Date Issued: 2015-12
Manure production and nutrient management in pasture-based dairy production systems
- Authors: Svinurai, Walter
- Date: 2010
- Subjects: Manures , Nitrogen -- Metabolism , Aloe -- South Africa , Pine bark , Pastures , Dairy cattle -- Nutrition , Dairy cattle -- Management , Dairy cattle -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11812 , http://hdl.handle.net/10353/475 , Manures , Nitrogen -- Metabolism , Aloe -- South Africa , Pine bark , Pastures , Dairy cattle -- Nutrition , Dairy cattle -- Management , Dairy cattle -- Feeding and feeds
- Description: Manure production and nutrient management in pasture-based dairy production systems by Walter Svinurai The effect of dietary treatments on nutrient excretion was determined and an attempt to improving the retention of excreted nitrogen in stored manure using Aloe ferox leaf gel (AFLG) and pine bark was conducted at a pasture-based dairy farm. The animal mass-balance method was used to determine nutrient excretion by cows fed on three dietary treatments, Lolium perrene-based treatment (LP), Lolium multiforium-based treatment (LM) and Lolium perenne- Trifolium repens -based treatment (LTF). In separate experiments, slurry from dairy cows fed LM was amended with AFLG and pine bark at concentrations of 25, 50, 75 and 100 g/l and stored under anaerobic conditions for 16 days. The highest and lowest excretions of N, P and K were observed in LM and LP treatments, respectively. Increasing dietary N improved K and N retention in milk and, consequently increased milk urea nitrogen (MUN) and N excretion (P < 0.05). The concentrations of AFLG affected N and P retention in manure (P < 0.05). The highest retention in total Kjeldahl nitrogen (TKN) of the initial was 42% AFLG at 25g/l inclusion rate. Ammonium nitrogen (AMN) concentration increased significantly due to the interactive effect of AFLG inclusion rate and time. Pine bark powder significantly improved N and P retention in manure at all concentrations. The retention in TKN was higher (P < 0.05) at 25g/l pine bark powder than other concentrations. The interaction effect of inclusion rate and time increased iii AMN (P < 0.05). Dietary treatments significantly affected nutrient excretion, and AFLG and pine bark considerably improved N retention in stored slurry. Findings from the filed trial suggest the need for more attention on managing dietary nutrients in the post-rainy and cool-dry season when growth of pasture influenced choice of dietary treatments that led to high nutrient excretion. Field simulation of the additives to determine their efficacy and environmental hazards was recommended.
- Full Text:
- Date Issued: 2010