Vision for Livestock Data Analytics Koltes et al.
Grazing warm‐season grass pastures with stocker cattle (Bos taurus) is an important economic activity in the southern Great Plains, and substantial increases in the price of N fertilizer have negatively affected profitability of forage producers. The goal of the study was to determine if bermudagrass [Cynodon dactylon (L.) Pers.] pastures interseeded with either annual or perennial legumes are more profitable than the conventional method of fertilizing with 112 kg N ha−1 commercial fertilizer. A completely randomized design grazing study was conducted in south‐central Oklahoma during the spring and summer months of 2008, 2009, and 2010. Preconditioned stocker cattle (260 ± 47 kg head−1) were randomly assigned to pastures (1.42 ± 0.10 ha; three replicates per system) at 2.32 ± 0.40 animals ha−1, beginning when measured standing forage reached 2000 kg ha−1 and grazing continuously until forage mass declined to 1000 kg ha−1. Results of the 3‐yr grazing study show that under continuous stocking for the growing conditions common to the south‐central Great Plains, the legume systems could not compete economically with the common practice of fertilizing bermudagrass pastures with synthetic inorganic N fertilizer. Results are most sensitive to number of grazing days, price of N, and prices of legume seed.
Use of cool‐season perennial grasses may decrease annual establishment cost and improve returns to stocker cattle producers. The objective of this 5‐yr field study was to compare the performance of two stocker cattle grazing forage systems: cool‐season annual (rye [Secale cereale L.]–annual ryegrass [Lolium multiflorum Lam.]) vs. cool‐season perennial tall fescue [Schedonorus arundinaceus (Schreb.) Dumort; formerly Festuca arundinacea Schreb., ‘Texoma’], with a nontoxic endophyte (MaxQ II). Paddocks of four replicates consisted of a cereal rye and annual ryegrass mixture that was planted annually in early September 2005 through 2009, whereas tall fescue was planted once in late September 2005. Steers (273 ± 55 kg initial body weight) were weighed every 28 d of each grazing season, and stocking rates were adjusted with put‐and‐take steers based on forage mass. In each 28‐d grazing period, forage mass, forage nutritive value, and stocker average daily gain (ADG) and total gain (TG) were measured. Animals performed well in both systems with ADG of 1.05 and 0.93 kg d−1, and TG of 491 and 349 kg ha−1 for rye–annual ryegrass and tall fescue, respectively. The 5‐yr average annual production cost was less for the tall fescue system ($336 ha−1) than for the rye–annual ryegrass system ($455 ha−1). The assumed amortization of the tall fescue was especially influential on net return; with a 5‐yr amortization, net return was greater for the rye–annual ryegrass ($279 ha−1) than for the tall fescue ($217 ha−1) system, but with 12‐yr amortization, the net return of these two systems was identical.
This paper describes the identification of 6-(pyrimidin-4-yloxy)-naphthalene-1-carboxamides as a new class of potent and selective human vascular endothelial growth factor receptor 2 (VEGFR2) tyrosine kinase inhibitors. In biochemical and cellular assays, the compounds exhibit single-digit nanomolar potency toward VEGFR2. Compounds of this series show good exposure in rodents when dosed orally. They potently inhibit VEGF-driven angiogenesis in a chamber model and rodent tumor models at daily doses of less than 3 mg/kg by targeting the tumor vasculature as demonstrated by ELISA for TIE-2 in lysates or by immunohistochemical analysis. This novel series of compounds shows a potential for the treatment of solid tumors and other diseases where angiogenesis plays an important role.
Live weight gains of light and heavy calves grazing Plains Old World bluestem at three stocking rates were evaluated during the summers of 1997 and 1998. Initial weights of mixed-breed light-weight steers (LHT) were 141 SD = 17 kg (n = 214) in 1997 and 160 SD = 23 kg (n = 193) in 1998. Initial weights of mixed-breed heavy steers (HWT) were 265 SD = 17 kg (n = 115) in 1997 and 248 SD = 13 kg (n = 126) in 1998. Initial stocking rates for both sizes of steers were as follows: light, 392 kg of live weight/ha; moderate, 504 kg of live weight/ha (increased to 616 kg live weight/ha in 1998); and heavy, 840 kg of live weight/ ha. Averaged gain and gain/hectare are reported as stocking rate by steer type within year. Heavy steers had greater ADG than LHT steers during both years. Forage intake, expressed as a percentage of BW, was greater (P = 0.05) for LHT (3.1%) than for HWT (2.8%) calves. Grazing time (min/d; 1998 only) was greater (P = 0.05) for LHT (665) than for HWT (624) steers. Forage CP and in vivo digestible organic matter (DOM) were slightly greater (P < 0.05) in pastures grazed by HWT vs LHT cattle. Gain/hectare was greater (P < 0.05) for LHT than for HWT calves at all three stocking rates during both years. A linear decline in ADG was observed (P < 0.07) as stocking rates increased for HWT steers in 1997 and LHT steers in 1998. However, ADG did not decline with increasing stocking rate for LHT calves during 1997 or HWT calves during 1998. Forage intake was not different among stocking rates in either 1997 or 1998. Grazing time was greatest (P < 0.05) for steers in the moderate and heavy stocking rates. Forage in vivo DOM decreased (P < 0.05) as stocking rate increased. Both LHT and HWT steers had lower (P < 0.05) ADG at all three stocking rates during 1998 compared with 1997. Despite lower ADG, LHT steers had greater gain/hectare than HWT steers during both 1997 and 1998.
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