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Extruded Corn Meal as a Partial Replacement for Steam Flaked Corn in Finishing Diets for feedlot Cattle: Growth Performance and Digestive Function of feedlot Cattle

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Open Journal of Animal Sciences 2019年第2期9卷 196-206页

作者： L. Buenabad A. Y. Jacinto M. Montano R. A. Zinn Department of Nutrition and Biotechnology of Ruminats Instituto de Investigaciones en Ciencias Veterinarias Universidad Autónoma de Baja California Mexicali Mexico Department of Animal Science University of California Davis USA

Sixty-four Holstein steers (247 ± 4 kg) were used in a 70-d experiment to evaluate the effects of partial replacement of steam flake corn (SFC) with extruded corn meal (EC) on growth performance and dietary net energy. Treatments consisted of a steam flaked corn-based finishing diet containing 0%, 10%, 20%, or 30% EC, where EC replaced 0%, 15%, 30%, or 45% of SFC (DM basis). Replacement of SFC with increasing levels of EC did not affect (P > 0.10) ADG, DMI, and gain efficiency. When EC replaced 15% to 30% of SFC, observed dietary NE was 99% of expected. Whereas, when EC replaced 45% of SFC, observed dietary NE was 94% of expected. Four Holstein steers (210 ± 7 kg) with cannulas in the rumen and proximal duodenum were used in a 4 × 4 Latin square experiment to evaluate treatment effects on characteristics of digestion. Partial replacement of SFC with EC did not affect (P > 0.10) flow of undegraded feed N and microbial N and to the small intestine, and ruminal microbial N efficiency (g microbial N/kg OM fermented). Likewise, there were no treatment effects (P > 0.10) on ruminal digestion of OM, NDF, starch and feed N. As expected, total tract digestion of starch for all treatments exceeded 99%. However, partial replacement of SFC with EC decreased total tract digestion of DM and OM (linear effect, P = 0.02), and dietary DE (linear effect, P = 0.03). These effects were more pronounced where EC replaced 45% of SFC. Partial replacement of SFC with EC did not affect (P > 0.10) ruminal pH, total VFA concentration, molar proportions of acetate, propionate, and butyrate, and estimated methane production. It is concluded that partial replacement of SFC with EC does not have a beneficial effect on ruminal microbial efficiency and digestive function. The feeding value of extruded corn for feedlot cattle is comparable to that of steam flaked corn provided the inclusion rate does not exceed 20% of diet dry matter.

关键词： Corn Grain Extruded Steam Flaked feedlot Cattle

Effect of Supplemental Calcium Levels on feedlot Growth Performance and Dietary Net Energy Utilization during the Receiving Feeding Period of Calf-Fed Holstein Steers

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Open Journal of Animal Sciences 2020年第1期10卷 1-9页

作者： L. Buenabad B. C. Latack R. A. Zinn Instituto de Ciencias Agrícolas Universidad Autónoma de Baja California Mexicali México University of California Cooperative Extension Holtville USA Department of Animal Science University of California Davis CA USA.

Ninety-six calf-fed Holstein steer (127 kg) were used to evaluate the influence of supplemental dietary calcium (Ca) on growth-performance, and dietary net energy (NE) utilization during the initial 112-d of receiving period. Treatments consisted of steam flake corn-based growing-finishing diets supplemented with limestone to achieve 0.60%, 0.70%, 0.80%, or 0.90% dietary Ca (DM basis). Morbidity was low (6.3%) and it was not affected (P > 0.87) by dietary treatments. During the initial 84-d period (181 kg average BW), increasing dietary Ca did not influence (P > 0.10) DMI, ADG, gain efficiency or observed/expected DMI. Observed DMI was 19% greater than expected based on diet formulation and growth. Estimated metabolizable protein and methionine supply during the initial 84-d period averaged 92% and 79% of the required, respectively. The apparent decrease in efficiency of energy utilization in the present study is in close agreement with previous studies involving calf-fed Holstein steers in the early growing phase fed conventional growing-finishing diet that is otherwise deficient in metabolizable amino acids. Thus, it is considered that the anticipated growth-performance responses to dietary Ca treatments may have been masked by expected inefficiencies due to metabolizable amino acid deficiency. During the final 28-d period (256 kg of average BW), increasing supplemental Ca reduced feed intake (linear effect, P = 0.04) and enhanced gain efficiency (linear effect, P = 0.03). During this period, predicted ([1] Level 1) metabolizable protein and methionine supply were 110% and 94% of the required, respectively. Nevertheless, improvements in gain efficiency during the final 28-d period with increasing levels of supplemental Ca were not sufficient to influence (P > 0.10) overall 112-d growth-performance. It is concluded dietary Ca requirements of calf-fed Holstein steers during the initial 112-d feeding period appear to be secondary to deficiencies of conventional steam

关键词： Holstein feedlot Performance Calcium

Impact of feedlot on Soil Phosphorus Concentration

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Journal of Environmental Protection 2011年第3期2卷 280-286页

作者： Nicolás Wyngaard Liliana Picone Cecilia Videla Ester Zamuner Néstor Maceira Facultad de Ciencias Agrarias (U. N. M. P.) / Estacion Experimental Agropecuaria Balcarce (I. N. T. A.) Unidad Integrada Balcarce

Raising cattle in feedlots is becoming more common in Argentina, but there is little information available about the effects of this practice on soil phosphorus (P) dynamics. In this study, concentrations of water and Bray -1 extractable soil P were quantified in a feedlot (upper and lower slope positions in the feedlot pen), runoff area and pasture during 2006 - 2008. The feedlot showed higher P concentrations in all P forms, soluble reactive P, soluble nonreactive, total soluble P, and Bray-P1 when compared to runoff area and pasture. Most of the total soluble P was soluble reactive P from the soil in the feedlot and the runoff area, while soluble nonreactive P predominated in the pasture. Concentrations of total soluble P were elevated in the feedlot at the soil surface, ranging on average from 158.71 to 245.86 mg?P?kg?1, and had a rapid decrease within the first 20 cm and remained relatively low, about 25.53 - 27.33 mg?P?kg?1. The evidence that total soluble P concentration in the feedlot was significantly (p feedlot had a moderate increase of 23.05 to 24.55 mg?P?kg?1 from the background concentration, it may represent a long-term source of increased nutrient loading to groundwater. Soil extractable Bray-1 P in the top 0 - 2.5 cm fluctuated from 659.26 to 45.36 mg?P?kg?1 in the feedlot and pasture, respectively. The relationship between soil P extracted by test and TSP was linear, and correlation coefficient was r2 = 0.95.

关键词： feedlot Water Soluble P Bray -1 P Cattle Manure Phosphorus Runoff

The distribution of drinking water-to-cattle ratios in the summer across four feedlots in the Texas High Plains

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Agricultural Sciences 2013年第6期4卷 282-286页

作者： Raju Gautam Pablo J. Pinedo Sangshin Park Renata Ivanek Department of Veterinary Integrative Biosciences College of Veterinary Medicine and Biomedical Sciences Texas A&M University College Station USA Texas A&M AgriLife Research & Extension Center College of Veterinary Medicine and Biomedical Sciences Texas A&M Uni-versity Amarillo USA

In this short communication, we report the findings of a cross-sectional pilot study of the amount of water available per head of cattle (water-to-cattle ratio) and the associated feedlot and environmental factors across 26 pens in four Texas feedlots. The water-to-cattle ratio varied greatly among pens within and between feedlots. Mixed-effect linear regression modeling with feedlot as a random effect indicated that water in troughs with a higher water-to-cattle ratio was generally warmer when compared with water in troughs with a lower water-to-cattle ratio. This may have implications in the transmission and persistence of pathogens in feedlot cattle, such as Shiga toxin-producing Escherichia coli and Salmonella, because warmer water has been reported to favor the growth of these pathogens. Therefore, future field studies in feedlot cattle are warranted to assess whether the water-to-cattle ratio affects the prevalence of these pathogens in the water itself or in feces shed by the animals.

关键词： Water-Trough feedlot Water-to-Cattle Ratio