• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.4
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• pp.268-275
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• 2005

Early predictions of crop yields call provide information to producers to take advantages of opportunities into market places, to assess national food security, and to provide early food shortage warning. The objectives of this study were to identify the most useful parameters for estimating yields and to compare two model selection methods for finding the 'best' model developed by multiple linear regression. This research was conducted in two 65ha corn/soybean rotation fields located in east central South Dakota. Data used to develop models were small temporal variability information (STVI: elevation, apparent electrical conductivity $(EC_a)$, slope), large temporal variability information (LTVI : inorganic N, Olsen P, soil moisture), and remote sensing information (green, red, and NIR bands and normalized difference vegetation index (NDVI), green normalized difference vegetation index (GDVI)). Second order Akaike's Information Criterion (AICc) and Stepwise multiple regression were used to develop the best-fitting equations in each system (information groups). The models with $\Delta_i\leq2$ were selected and 22 and 37 models were selected at Moody and Brookings, respectively. Based on the results, the most useful variables to estimate corn yield were different in each field. Elevation and $EC_a$ were consistently the most useful variables in both fields and most of the systems. Model selection was different in each field. Different number of variables were selected in different fields. These results might be contributed to different landscapes and management histories of the study fields. The most common variables selected by AICc and Stepwise were different. In validation, Stepwise was slightly better than AICc at Moody and at Brookings AICc was slightly better than Stepwise. Results suggest that the Alec approach can be used to identify the most useful information and select the 'best' yield models for production fields.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.5
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• pp.660-664
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• 2003

An attempt was made to evaluate the effects of total mixed rations (TMR) containing 17.5% forage neutral detergent fiber (NDF) from paragrass, paragrass+cassava chips and corn silages on the performance of dairy cows in the tropics. Experimental dietary treatments contained a similar content of total NDF, total non-fiber carbohydrates, crude protein and energy. Maximum and minimum temperature humidity index during the experimental period were 79.1-80.6 and 66.8-68.6, respectively. Among silage sources, there were no differences (p>0.05) in concentrations of acetic and propionic acids and butyric acid was undetectable. Concentration of lactic acid was higher (p<0.01) in corn silage but its pH was lower (p<0.01) than in paragrass and paragrass+cassava silages. Dairy cows on TMR containing corn silage not only gained more weight (161 and 46 vs. -189 g/d) but also consumed more feed (18.47, 15.84 and 14.49 kg/d), and produced more milk (23.89, 22.03 and 20.83 kg/d), 4% fat corrected milk (25.47, 24.05 and 22.02 kg/d), solids-not-fat (1.99, 18.3 and 1.73 kg/d) and total solid (3.10, 2.85 and 2.64 kg/d) compared with those on TMR containing paragrass+cassava and paragrass silages, respectively (p<0.01). Dairy cows on TMR containing paragrass+cassava silage were better in these respects (p<0.01). These results suggest that in formulating diets on an equal NDF basis for different forage qualities, diets higher in forage quality can stimulate higher DMI for dairy cows in the tropics and thus improve productivity.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.7
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• pp.1014-1019
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• 2015

The purpose of this study was to determine the effect of ${\beta}$-mannanase supplementation on digestible energy (DE) and metabolizable energy (ME) contents of copra expellers (CE) and palm kernel expellers (PKE) fed to pigs. Six barrows with an initial body weight of 38.0 kg (standard deviation = 1.5) were randomly allotted to a $6{\times}6$ Latin square design with 6 dietary treatments and 6 periods. Six experimental diets were prepared in a $3{\times}2$ factorial treatment arrangement with 3 diets of a corn-soybean meal-based diet, a CE 30% diet, and a PKE 30% diet and with 2 concentrations of supplemental ${\beta}$-mannanase at 0 or 2,400 U/kg. All diets had the same proportion of corn:soybean meal ratio at 2.88:1. The marker-to-marker procedure was used for fecal and urine collection with 4-d adaptation and 5-d collection periods. No interactive effects were observed between diet and ${\beta}$-mannanase on energy digestibility and DE and ME contents of experimental diets. However, diets containing CE or PKE had less (p<0.05) DE and ME contents compared with the corn-soybean meal-based diet. The DE and ME contents in CE and PKE were not affected by supplemental ${\beta}$-mannanase. Taken together, we failed to find the effect of ${\beta}$-mannanase supplementation on energy utilization in CE and PKE fed to pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.4
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• pp.470-473
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• 2000

The experiment was carried out to evaluate the effect of varying levels of flaked com abomasally infused on energy metabolism and nitrogen metabolism in fattening steers. The starch levels of flaked corn of abomasally infused were 0, 300, 600 and 900 g/d. Four mature fattening steers fitted with permanent abomasum cannulas were allocated to a $4{\times}4$ Latin square design were fed at 1.2 maintenance requirement a basal diet of Chinese wildrye (Aneurolepidium Chinense). Compared with 0 g/d (control group), digestible nitrogen, retention nitrogen (RN, g/d) and the efficiency of digestible nitrogen converted into retention nitrogen (RN/DN, %) of 300, 600 and 900 g/d groups were higher (p<0.05). The post-ruminal starch digestion of flaked corn were 71.36, 80.27 and 64.71 % when the amounts abomasally infused were 300, 600 and 900 g/d, respectively. When the amount of starch abomasally infused was more than 600 g/d, the post-ruminal digestion of starch decreased. 300, 600 and 900 g/d starch infusion groups showed higher metabolizable energy intake (ME) and net energy gains (NEg, MJ/d) than the control group, and the efficiencies of metabolizable energy converted into body weight (Kf, %) of these groups were higher than the control group by 38.31, 73.18 and 67.06% (p<0.05). Kf (Y, %) had a positive curved relation to starch of flaked com abomasally infused (X, g/d), $Y=36.1605X^{0.0760}$ (n=16, r=0.9308).

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.5
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• pp.643-648
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• 2005

Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid, accurate method of evaluating some chemical constituents in cereal grains and forages. If samples could be analyzed without drying and grinding, then sample preparation time and costs may be reduced. This study was conducted to develop robust NIRS equations to predict fermentation quality of corn (Zea mays) silage and to select acceptable sample preparation methods for prediction of fermentation products in corn silage by NIRS. Prior to analysis, samples (n = 112) were either oven-dried and ground (OD), frozen in liquid nitrogen and ground (LN) and intact fresh (IF). Samples were scanned from 400 to 2,500 nm with an NIRS 6,500 monochromator. The samples were divided into calibration and validation sets. The spectral data were regressed on a range of dry matter (DM), pH and short chain organic acids using modified multivariate partial least squares (MPLS) analysis that used first and second order derivatives. All chemical analyses were conducted with fresh samples. From these treatments, calibration equations were developed successfully for concentrations of all constituents except butyric acid. Prediction accuracy, represented by standard error of prediction (SEP) and $R^2_{v}$ (variance accounted for in validation set), was slightly better with the LN treatment ($R^2$ 0.75-0.90) than for OD ($R^2$ 0.43-0.81) or IF ($R^2$ 0.62-0.79) treatments. Fermentation characteristics could be successfully predicted by NIRS analysis either with dry or fresh silage. Although statistical results for the OD and IF treatments were the lower than those of LN treatment, intact fresh (IF) treatment may be acceptable when processing is costly or when possible component alterations are expected.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.6
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• pp.725-731
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• 1998

Nine crossbred female pigs fitted with the bladder catheters were used to investigate the effects of dietary protein form on the efficiency of absorbed nitrogen for nitrogen retention in growing pigs. Combinations of the main protein sources were corn-soybean meal (CSM; slow + slow absorption rate form), corn-hydrolyzed casein (CAS; slow + rapid absorption rate form) and corn-porcine plasma (CPL; slow + intermediate absorption rate form). All experimental diets were formulated to be isonitrogenous (CP 11%) and isocaloric (3.5 Mcal/kg) and synthetic amino acids were added to the diet as required to maintain an equivalent amino acid profile among diets. Fecal digestibility of nitrogen was not different among treatments (p > 0.10). Ingested nitrogen was absorbed with an apparent efficiency of 82% to 84%. Mean nitrogen retention in pigs fed the CSM diet was as high as for pigs fed the CPL diet (0.74 g N/kg $BW^{0.75}$ per d), which was higher than the N retention rate in pigs fed CAS diet (0.68 g/kg $BW^{0.75}$ per d; P < 0.05). Apparent biological values (ABV = 100 ${\times}$ N retention/absorbed nitrogen) were 63.3%, 58.0% and 61.6% for CSM, CAS, and CPL groups, respectively (p < 0.05). There was no difference in mean energy digestibility among treatments. The efficiency of absorbed lysine utilization was significantly different among treatments (p < 0.05). Pigs fed the CAS diet were inferior to counterparts on the other diets in utilizing absorbed lysine. The ratios of free (and small peptide-bound) to protein-bound amino acids in CSM diet differed considerably from the CAS diet. This may affect the efficiency of amino acids utilization for nitrogen retention if hydrolyzed and intact amino acid pools reach the blood at different times.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1309-1313
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• 2016

Metabolic signals and the state of energy reserves have been shown to play a crucial role in the regulation of reproductive function. This study was carried out to investigate the effects of dietary glucose levels on puberty onset in gilts. Weight-matched, landrace gilts (n = 36) $162{\pm}3days$ old, weighing about $71.05{\pm}4.53kg$, were randomly assigned to 3 dietary treatment groups of 12 gilts each. The trial lasted until the onset of puberty. Gilts in each group were supplied with diets containing different levels of glucose as follows: i) starch group (SG) was free of glucose, contained 64% corn derived starch; ii) low-dose group (LDG) contained 19.2% glucose and 44.8% corn derived starch; iii) high-dose group (HDG) contained 30% glucose and 30% corn derived starch. Results indicated: i) The growth performance of gilts were not affected by the addition of glucose, but the age of puberty onset was advanced significantly (p<0.05); ii) Compared with the SG, the concentration of insulin significantly increased before puberty in HDG (p<0.05); iii) There was no difference in serum progesterone (P) levels amongst the different feed groups, however, levels of estradiol ($E_2$), luteinizing hormone, and follicle-stimulating hormone were significantly higher at puberty onset in HDG (p<0.05). Overall, our findings indicate that glucose supplementation significantly advances puberty onset, which can have practical purposes for commercial breeding.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.1
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• pp.45-51
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• 1993

With the purpose to utilize cage layer manure (CLM), whole crop corn forage was ensiled with 30% CLM (MS silage) and without CLM (CS silage). MS silage was significantly (p < 0.05) higher in pH value, total VFA, propionic and butyric acids, and the ratio of ammonia nitrogen to total nitrogen, but lower (p < 0.05) in lactic acid and water soluble carbohydrate (WSC) contents than CS silage. Digestibility was evaluated using Shiba strain Japanese goats. Urea was supplemented to CS silage at feeding to adjust nitrogen intake to MS silage (US silage). There were no differences in digestibilities of dry matter (DM) and energy among the three silages. However, US silage showed higher (p < 0.05) digestibility of crude protein, but digestibilities of NDF, ADF, hemicellulose and cellulose were higher (p < 0.05) in MS silage. Nitrogen retention was positive in US and MS silages, but it was negative in CS silage. Voluntary feed intake of goats was 11.02, 12.03 and 13.34 g of DM per metabolic body weight ($kg^{0.75}$) for 10 minutes, for CS, US and MS silages, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.1
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• pp.53-59
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• 1993

In situ degradability and fermentation characteristics in the rumen of goats fed whole crop corn forage ensiled with (MS silage) or without (CS silage) 30% of cage layer manure (CLM) were investigated. The two silages were well preserved. To adjust nitrogen intake of CS silage to that of MS silage, the 3rd group of goats was given urea with CS silage at feeding time (US silage). Each goat was given a diet of 2% of the body weight (dry matter basis) daily. In situ degradability of dry matter (DM) and crude protein (CP) of MS silage in the rumen were higher than those of CS and US silages. Total potentially degradable portions of DM and CP in MS silage were also higher than those in CS and US silages. Blood urea nitrogen and rumen ammonia nitrogen concentration of goats fed US and MS silages were significantly (p<0.05) higher than those of goats fed CS silage. Acetic, propionic and butyric acids in ruminal fluids of goats fed MS silage were significantly (p<0.05) higher than those of goats fed CS and US silages.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.4
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• pp.564-568
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• 2018

Objective: This experiment was conducted to determine the effects of dietary ${\beta}$-mannanase on the additivity of true metabolizable energy (TME) and nitrogen-corrected true metabolizable energy ($TME_n$) for broiler diets. Methods: A total of 144 21-day-old broilers were randomly allotted to 12 dietary treatments with 6 replicates. Five treatments consisted of 5 ingredients of corn, wheat, soybean meal, corn distillers dried grains with solubles, or corn gluten meal. One mixed diet containing 200 g/kg of those 5 ingredients also was prepared. Additional 6 treatments were prepared by mixing 0.5 g/kg dietary ${\beta}$-mannanase with those 5 ingredients and the mixed diet. Based on a precision-fed chicken assay, TME and $TME_n$ values for 5 ingredients and the mixed diet as affected by dietary ${\beta}$-mannanase were determined. Results: Results indicated that when ${\beta}$-mannanase was not added to the diet, measured TME and $TME_n$ values for the diet did not differ from the predicted values for the diet, which validated the additivity. However, for the diet containing ${\beta}$-mannanase, measured $TME_n$ value was greater (p<0.05) than predicted $TME_n$ value, indicating that the additivity was not validated. Conclusion: In conclusion, the additivity of energy values for the mixed diet may not be guaranteed if the diet contains ${\beta}$-mannanase.