Mentoring Graduate Students for Academic Careers in Grassland Science

Effective mentorship enhances student productivity and career achievements, yet faculty generally do not receive mentorship training, nor does mentorship receive focused attention, evaluation, and recognition. The objectives of this paper are to 1) define mentorship and identify roles of a mentor, 2) highlight qualities and outcomes of effective mentoring, and 3) elaborate best mentoring practices, metrics for assessing mentoring, and challenges for mentoring the next generation of grassland scientists. Mentoring is a professional alliance where individuals work together to support the personal and professional growth, development, and success of the relational partners. Mentors should be altruistic discipline experts, have substantial mentorship training or experience, be accessible and giving of their time, and capable of identifying mentee strengths and weaknesses. Metrics of effective mentoring include being sought after by prospective mentees, providing mentor-mentee interaction leading to successful educational outcomes, mentees receiving awards and recognition while mastering critical career skills, developing a track record of mentee success in the job market and sustained mentee enthusiasm for their career, and finally, sustaining long-term personal and professional mentor-mentee engagement. Specific to training the next generation of academics in grassland science, there is need to maintain, or regain, a critical mass of grassland faculty who are trained mentors and capable of developing novel, creative, and impactful research questions. These combined skills attract funding and create exciting opportunities for mentees. By addressing important research questions, mentor-mentee teams advance grassland science, but importantly, they also serve end-users. When value is perceived by consumers of our science, it sets in motion a chain of events required to maintain a critical mass of grassland scientists and confirms the value and relevance of our discipline

Rotational Stocking and Soil Nutrient Distribution on Hawaiian Grasslands

A naturalized kikuyu (Pennisetum clandestinum Hochst. ex Chiov.) grassland was grazed by heifers (Bos taurus) for 2 years to determine the effects of two rotational stocking methods (short vs. long grazing periods) on soil N, P, K, Ca, Mg, and S distribution in paddocks with natural shade. Additionally, kikuyugrass-greenleaf desmodium (Desmodium intortum Urb.) paddocks were used to evaluate soil nutrient distribution in rotationally stocked paddocks (long grazing periods) without shade. In the study with shade, soil N, P, and K distribution did not differ between stocking methods. These nutrients accumulated within 15 m of shade, but did not accumulate significantly around waterers. In the study without shade, soil P, K, and Mg accumulated within 15 m of the waterer. It is suggested that the magnitude of excretal N, P, and K accumulation is greater around shade than waterers, and that in pastures without shade substantial amounts of P and K accumulate near the waterer

Intensive Rotational Grazing Systems for Dairying in a Subtropical Environment: Animal, Plant, and Soil Responses

Forage species, stocking rate, and supplementation rate effects upon performance of lactating dairy cows were studied. Forage mass and nutritive value and nutrient concentration in shallow groundwater also were measured. Cows (n = 44) grazed bermudagrass (Cynodon dactylon) or rhizoma peanut (Arachis glabrata), stocked at 4.9 or 7.4 cows ha-1, and 2.5 or 4.9 cows ha-1, respectively. Pelleted concentrate:whole cottonseed (80:20) was offered twice daily post milking at 1 kg per 2 or 3 kg of daily milk production. Cows grazing rhizoma peanut produced more (P = .076) milk per day but had greater (P = .028) loss of body condition. Higher stocking rates caused greater (P \u3e .070) weight loss. Greater supplementation increased (P \u3c .05) production of milk, fat and protein, but also increased (P \u3c .044) weight and body condition losses. Higher stocking rates and lower supplementation reduced pasture (P \u3c .001) herbage mass. Rhizoma peanut herbage was higher in nutritive value than bermudagrass. Nutrient concentrations in shallow groundwater were not affected by treatments. Use of pasture for lactating cows has potential in Florida, but low milk production and loss of body condition during summer pose management challenges

Selection of morphological traits to improve forage characteristics of Setaria sphacelata grown in Florida.

A genetically diverse population of Setaria sphacelata was developed at Gainesville, Florida by intercrossing the cultivars ?Narok?, ?Kazungula? and ?Solander? and a local persistent population. To determine heritability of traits that may improve setaria as a forage plant in Florida, progeny of the intercrossed population underwent two cycles of selection for inflorescence number and one cycle for leaf width. The selected populations, together with cultivars and introductions, were evaluated for morphological characters, yield and forage quality in field experiments with close- and wide-spaced plants. Increase of inflorescence number was not obtained by selection but resulted in decreased plant height, inflorescence length, yield, leaf width, and leafiness. Leaf width was increased by selection and was associated with increased leafiness and whole-plant crude protein content. The results suggest good prospects for selection of setaria cultivars suited to Florida with improved yield and quality providing they tolerate winter cold and reliably produce seed

Is There a Need for Tailored Graduate Programs for International Students?

International studies often present opportunities for capacity development and mentorship for students to equip them with the knowledge and skills to address the challenges in their home countries. Typically, international graduate students are drawn from diverse educational and cultural backgrounds different from those in their host countries. Adjusting to these changes might be challenging and time-consuming, thus influencing their academic journey. Understanding these challenges might provide international students the opportunity to address them in time and, where possible, seek help. In this paper, we discuss some graduate program-related challenges international students face and provide potential recommendations that might result in tailored programs. It is anticipated that such programs will effectively prepare international graduate students to adapt quickly to new conditions in their host countries and optimize the learning process while acquiring the appropriate tools for their future careers. We conducted a literature search that focused mainly on articles related to international graduate students in the US. Five challenges were explored: Cultural and language barriers, technological literacy and competency, mentorship, career development, and course structure and research priority areas. Graduate programs need to help students identify these challenges while helping them create an ideal environment for excellence. Such programs need to provide adequate support structures, making them known to students at the beginning of their programs. Although it is not feasible to change an entire educational program to accommodate all the needs of international graduate students, pressing concerns need to be identified for action

Forage Quality Determinants of Mott Elephantgrass and Pennisetum Hybrids

Daily gains of cattle grazing Mott elephantgrass (MB; Pennisteum purpureIum Schum.) arc approximately twice those obtained on other warm-season perennial grasses grown in Florida, USA, but plant characteristics responsible for the high forage quality of MB have not been identified. Three experiments were conducted during 1987- 1991 to determine factors that explain the high forage quality of MB and to assess the quality potential of P. purpureum x P. glaucum (L.) [R.Br.J x clephantgrass hybrids. Higher organic matter (OM) digestibility and intake of MB than Pensacola bahiagrass (PB; Paspalum nonatum Flugge) were associated with a lesser percentage of sclercnchyma (1.6 v. 5.4%) and a greater percentage of epidermis (32.8 v. 25.9%) in the leaf cross-sectional area of MB than PB. Leaf lamina percentage, crude protein (CP), and in vitro OM digestibility (IVOMD) of MB herbage were 65, 8,7 and 66% when harvested every 12 weeks to a 10-cm stubble, and percentages increased with more frequent cutting and taller stubble heights. Three Pennistum hybrids had lower leaf/stem ratio than MB but IVOMD and chemical composition of the hybrids and MB varied little. We conclude that 1) high forage quality of ME is due to a high leaf/stem ratio and to the proportion and distribution of tissues in the leaf lamina, and 2) nutritive value of Pennisetum hybrids is comparable to that of ME

Herbage Accumulation, Nutritive Value and Persistence of Mulato II in Florida

Grasses in the Brachiaria genus are the most widely grown forages in tropical America, occupying over 80 Mha (Boddey et al. 2004). Mulato II is apomictic and a vigorous, semi-erect cultivar resulting from 3 generations of crosses including original crosses between ruzigrass and signal-grass (cv. Basilisk, apomictic tetrapliod). According to Peters et al. (2003), Mulato produced 25% more herbage mass than palisadegrass (Brachiaria brizantha) and koroni-viagrass (Brachiaria humidicola) under similar management practices. Although Mulato II shows promise as a forage in tropical regions, herbage accumulation and persistence in subtropical areas is unknown. This publication summarises results of the research with Mulato II conducted in Florida in the last 5 years

Cattle Weight Gain and Sward-Animal Nitrogen Relationships in Grazed Hemarthria altissima Pastures

Limpograss (Hemarthria altissima [Poir.] Stapf et C.E. Hubb.) in vitro digestion is greater than most perennial grasses adapted to Florida. Weight gain of cattle grazing limpograss has been lower than expected due in part to low herbage N concentration. Experiments were conducted on limpograss pastures to assess N fertilization, overseeding of the legume aeschynomene (Aeschynomene americana L), and feeding of N supplements to cattle as means of overcoming this limitation. Greater N fertilization, overseeding aeschynomene, and supplementation (corn-urea mixtures) increased weight gain 0.30, 0.23, and 0.24-0.35 kg d-1, respectively, over control treatments. Herbage digestible organic matter:crude protein ratio and cattle blood urea N concentration showed potential as predictors of response to N supplementation. Limpograss leaf blade crude protein (90-130 g kg-1) was two to three times greater than stem plus sheath. Stem plus sheath:leaf ratio was more than three times as great in the bottom as in the top half of the canopy, suggesting that lower stocking rates that allow greater diet selection may increase protein concentration of herbage consumed and increase gain

Diurnal Variation in Forage Nutrient Composition and Metabolic Parameters of Horses Grazing Warm-Season, Perennial Grass-Legume Mixed Pastures

Although warm-season, grass-legume mixed pastures have improved nutritive value and may reduce negative environmental impacts relative to nitrogen-fertilized grass monocultures, no study has been done to evaluate their effect on diurnal variation of non-structural carbohydrates (NSC) and other nutrients, and on the metabolic responses observed in horses’ blood and fecal samples. This 2-yr study aimed to investigate the circadian variation in nutrient composition and the fecal and blood metabolic responses in horses grazing these pastures. Forage, fecal, and blood samples were collected every 28 days at 0600, 1200, 1800, and 0000 h, in two years, for measurement of diurnal variation in forage nutrient composition and fecal and blood metabolites. Forage nutrient composition was affected by time of the day, with digestible energy (DE) and NSC increasing at 1800 h, crude protein decreasing after 1200 h and the fiber components increasing at 1200 h. Fecal lactate and blood insulin were also affected by time of the day. Fecal lactate increased from 0600 to 1200 h. Insulin levels were greater at 1800 than at 0600 h. The increased insulin level followed the increased concentration of NSC in the forage. In conclusion, warm-season, grass-legume mixed pastures show a diurnal pattern in forage nutrient composition, with increased NSC later in the afternoon. However, the metabolic responses observed in this study were not sufficient to predispose horses to metabolic dysregulation. The results also indicate that restricting grazing to the morning may reduce the forage nutritive value, with decreased concentration of DE and increased concentrations of the fiber components, which may decrease diet digestibility

Herbage Responses and Performance of Mature Horses Grazing Warm-Season Perennial Grass-Legume Mixed Pastures

Legume-grass mixtures may be a useful alternative to nitrogen-fertilized grass monocultures, but pasture and animal responses have not been assessed for pastures grazed by horses in Florida. This 2-yr study compared pasture and horse responses of continuously stocked, mixed pastures of rhizoma peanut (RP, Arachis glabrata Benth) and bahiagrass (BG, Paspalum notatum Flüggé) receiving 30 kg nitrogen (N)/ha (RP-BG) compared with BG pastures fertilized with 120 kg/N ha (BG-N) or with no N (BG-No N). Herbage mass was similar among treatments in 2020 and for most evaluation days in 2019. In 2019, stocking rate (AU/ha) was greater in BG-N (3.9) than in RP-BG (3.7) and BG-No N (3.1). In 2020, BG-No N (2.6) had the lesser stocking rate compared with BG-N (2.9) and RP-BG (2.9), with RP-BG not differing from BG-N. Herbage crude protein (CP) and digestible energy were similar across treatments in 2020, but they were greater for BG-N and RP-BG than BG-No N at some evaluation days in 2019. Except for CP, treatment did not affect nutrient digestibility by horses. Digestibility of CP was greatest for RP-BG in the late season. In the RP-BG treatment, proportion of RP in the pasture (~29%) was not affected by sampling date, and RP comprised 18.4% of the diet. Nonetheless, no differences were observed among treatments for body weight and condition score. The results indicate that intercropping legumes into warm-season perennial pastures can improve some measures of nutritive value and maintain horses’ body condition with similar stocking rate as N-fertilized bahiagrass pastures, while contributing to development of sustainable grazing systems for horses with reduced off-farm nitrogen inputs