Nutritional quality of massai grass fertilized with phosphorus and nitrogen and its influence on intake and weight gain of sheep under rotational grazing on quartzipsamment soil

Abstract

The effects of phosphate and nitrogen fertilization on aspects of forage composition and ruminal fermentation were separately evaluated pre- and post-grazing, in addition to the dry matter intake and weight gain of sheep grazing Panicum maximum cv. Massai under a rotational system on Quartzipsamment soil. The aim was to evaluate the effect of fertilization with different levels of phosphorous (50 and 200 kg P2O5/ha) and nitrogen (100 and 400 kg N/ha) compared to unfertilized control soil. The experiment was conducted at the School of Veterinary Medicine and Animal Science at Universidade Federal do Tocantins – UFT, in a randomized complete block design with four replicates in a factorial 2 × 2 design. The study area consisted of 32 paddocks (301 m²), each of which had previously been sown with Panicum maximum cv. Massai. The experimental area was managed under intermittent stocking with a variable stocking rate. Twenty-eight crossbreed sheep were used for grazing management. Evaluations were made before and after grazing, including forage evaluation and measurement of ruminal degradability and intake (using titanium dioxide as the external marker). Regarding the forage composition, a significant difference (P < 0.05) was observed between the control and fertilizer treatments for neutral detergent fiber (NDF), acid detergent fiber, crude protein, lignin and phosphorous content. Fertilization was found to alter the nutritional quality of Panicum maximum cv. Massai grass. Among the nutritional aspects evaluated, fertilization influenced NDF, grass digestibility and dry matter intake. The forage composition of Massai grass is improved by fertilization with nitrogen at 100 kg N/ha and phosphate up to 50 kg P2O5/ha, which represents a relevant management practice for increasing quantity and quality.

Classification of Megathyrsus Maximus Accessions Grown in the Colombian Dry Tropical Forest by Nutritional Assessment During Contrasting Seasons

“…Some studies suggest that in vitro and in vivo digestibility of organic matter increases with the rainy season (Vargas Junior et al, 2013;Silva et al, 2017), and others show that water stress did not significantly affect organic matter digestibility (OMD), (Fariaszewska et al, 2020). The findings in this research suggested that ADF decreased similar to that reported by Larsen et al (2021) and IVDMD increased slightly during the dry season vis-à-vis the rainy season.…”

“…09, 6.24, 6.13, 6.72, 7.82, and 8.30%, respectively. These values were higher than those found in commercial cultivars in important tropical livestock areas (dos Costa et al, 2017;Silva et al, 2017;da Silva et al, 2018). However, in the same research location where this experiment took place, and with a similar number of regrowing days and average height in Massai, Ruiz et al (2015) showed 14.20% CP.…”

WITHDRAWN: Classification of Megathyrsus maximus Accessions Grown in The Colombian Dry Tropical Forest by Nutritional Assessment during contrasting seasons

“…Several factors such as management, regrowth age, fertilization, cut height, phenological aspects, growth under shade and seasons might have a signi cant effect in the nutritional value of forages (Van Soest, 1982Velásquez et al, 2010, Santiago-Hernández et al, 2016, Silva et al, 2017, Coêlho et al, 2018, Vasconcelos et al, 2019, Schnellmann et al, 2020and Tesk et al, 2020 which affects digestibility in animals (Valente et al, 2010). Variability in structural carbohydrates (NDF, ADF) composition of the M. maximus collection may be in uenced by characteristics related to accession own physiological and metabolic aspects as the conversion e ciency of nitrogen and the rate of owering (Costa et al, 2017) which might generate a wide range of available accessions and could be used in plant breeding programs (Deo et al, 2020) to generate or select materials with the best IVDMD (Barahona & Sánchez-Pinzón, 2005) Protein content reduction during low precipitation periods might be caused by the lack of production of new leaves and tillers during dry season.…”

Performance supplementation and ingestive behavior of sheep finished in continuous pasture in the period of water restriction

“…Gurgel et al (2017) observed even lower values (5.5%) in Massai grass in times of water restriction, according to these authors this makes the supplementation necessary for a better productive performance. Silva et al (2017) evaluating doses of up to 100 kg ha -1 and 50 kg ha -1 of N and P2O5 respectively, in the same area of Massai grass where this experiment was carried out, found CP values of 7.06% in the water period, close to the 7.03% observed by Costa et al (2017) The production and structure of the pasture did not present difference for the evaluated treatments, indicating that the management adopted in the pasture was the same in the used area. Managing Massai grass height at 35.58 cm, the dry mass production was 5512.41 kg ha -1 (Table 4), a value lower than the forage mass production obtained in this same area in the water period (6600 kg ha -1 ) with similar management and fertilization height (Cardoso et al, 2019), which was expected due to the low precipitation of this time (Table 1).…”