Utilities

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Technical Support for the NIRS/NUTBAL Nutritional Management System - Publication intended to assist NRCS employees, consultants, and livestock producers in making decisions about nutritional needs of livestock when using NUTBAL software.

TRAINING and Example NUTBAL Report

Training Presentation of NIRS/NUTBAL

COWSCORE

COWSCORE determines either weight, frame score or body condition score for cattle, given age, gender, and the other 2 parameters (for weight, enter frame score and body condition score, for frame score, enter weight and body condition score etc.)

PKMILK

This program accepts input of calf age, calf weight at the specified age in days and the frame score of the cow to estimate peak milk. The program was adapted from Fox et al. (1988). The values are reasonable for calves greater than 120 days. To overcome this problem another program was developed for descreet calf age groups.

NEWPMILK

Peak milk yield is estimate by requesting calf age in discreet age groups of 1,2,3,4,5,6 and 7 months of age. Calf weight for that age and frame score of the cow are requested then to compute peak milk yield of the cow. This method has a lower standard error of estimate of peak milk yield. The method was derived from Fox et al. (1988).

CALFWT

This program requires users to input the cows frame score and peak milk yield along with age of the calf in question. Calf weight for the specified age is then computed. Equations were derived from data provided in Fox et al. (1988).

TDNCALC

Because feed tags only provide estimates of crude protein (natural and urea), fiber, ash, moisture, and in the case of liquid feeds, total inverted sugars, it is difficult for users to input TDN values of feeds without requesting TDN values of a particular lot sold to a producer. In many cases feed representatives cannot or will not provide the information. To facilitate this process, TDN requests ingredient composition and provides default digestibility of each component. The user can modify the default digestibility values to derive an "as fed" TDN value (%) and a dry matter TDN (%) value. Entries of feedstuff values in NUTBAL are reflected on a dry matter basis, requiring computation of CP and ASH values on a dry matter basis from tag values as well.

FORAGE

Because NUTBAL adjust intake based on standing crop of available forage, there are instances where animals are subjected to high, short duration grazing pressures where current standing crop rapidly declines. FORAGE is a utility program designed to help adjust intake for these types of situations. An intake adjustment factor is computed based on input of current standing crop, pasture size, animal numbers, average body weight, expected duration of stay in the pasture, percent harvestable forage, non-harvestable standing crop,and growth rate of forage. The user sets the available standing crop to >2300 lb/ac in NUTBAL and then inputs the intake adjustment factor computed by FORAGE if a negative intake factor is computed. Typically, stock densities must be less than 5 ac/au and standing crops less than 2000 lb/ac before negative impacts are noted. After extensive review of the behavior of NUTBAL's standing crop algorithm, we suggest setting the value of 2300 lb/ac in the program and running FORAGE if stocking density is less than 5 ac/au.

GRAIN

Currently, NUTBAL cannot represent negative associative effects of high-starch grains without first running the GRAIN utility distributed with NUTBAL. Grain requests from a NUTBAL case without grain represented in the situation to be analyzed. The body condition score 5 weight and estimated fecal output from the NUTBAL balance report are input into GRAIN along with information on the diet quality value of the forage (CP, DOM derived from NIRS fecal analysis). The amount of grain fed and analysis value for dry matter (%), ash (%), crude protein (%), and metabolizable energy concentration (mcal/lb). GRAIN outputs a recommended intake adjustment factor which actually reduced fecal output of the animal, adjusted DOM value of the forage on offer and the amount of grain fed expressed as percent of body weight on an as-fed basis.

Experimental Utilities

PROTEIN

Assessment of DIP and DUP Balance in Beef Cattle (Under development by Scott Schowers)