Effect of Rice Bran Quality and Protein Supplement, Base Mix, and/or Soybean Meal on Growing Pig Performance in Cambodia

The objective of this study was to evaluate the effect of rice bran quality and dietary supplement source on growing pig performance. A total of 60 castrated male pigs (Yorkshire × Duroc, initially 16.1 kg) were used for 52-day trial. Pigs were allotted to pens in a completely randomized design (4 pigs per pen) and assigned to four dietary treatments in a 2 × 2 factorial with factors being rice bran source (high or low-quality) and source of protein, vitamins, and minerals (supplement or soybean meal and base mix). Analyzed protein and fat level for the high- and low-quality rice bran was 11.07% and 5.86% and 11.20% and 4.50%, respectively. Crude fiber content for high- and low-quality rice bran was 13.44% and 27.79%. Diets were formulated in two phases (phase 1: 16 to 27 and phase 2: 27 to 48 kg) to adjust to the pig’s nutrient requirements. There was no evidence for an interaction (P > 0.05) between rice bran quality × supplement type or main effect of supplement type (soybean meal + base mix vs protein supplement) for final body weight, average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (F/G). However, pigs fed high-quality rice bran had improved (P < 0.001) ADG and F/G and lower ADFI compared to pigs fed low protein rice bran. In conclusion, rice bran quality as measured by protein, crude fiber, and fat influenced growing pig performance, while the type of dietary protein supplement did not. Additionally, rice bran with high protein, fat, and low fiber improved ADG and F/G.

Evaluation of nutritive value and in vitro rumen fermentation gas accumulation of de-oiled algal residues

Background：Algae are widely recognized for their high oil content and for exponentially accumulating biomass with particular potential to provide single cell protein for human consumption or animal feed.It is believed that along with biodiesel from algae,the high protein de-oiled algal residue may become an alternative feed supplement option in the future.This study was conducted to investigate de-oiled algal residue obtained from the common Chlorella species,Thalassiosira weissflogii,Selenarstrum capricornutum,Scenedesmus sp.,and Scenedesmus dimorphus for assessment as potential feed supplements for ruminants by comparing with soybean（Glycine max） meal and alfalfa（Medicago sativa） hay.Results：With the exception of T.weissflogii,algal residue had higher concentrations of Cu,Zn,and Mn and lower concentration of Ca,Mg,and K than soybean meal and alfalfa hay.The algal residue CP（crude protein）concentrations ranged from 140 to 445 g/kg DM and varied among the de-oiled residues.In vitro rumen fermentation gas accumulation curves indicated that algal biomass degradation potential was less than that of soybean meal or alfalfa hay by up to 41.7%.The gas production curve,interpreted with a dual pool logistic model,confirmed that the fraction sizes for fast fermenting and slow fermenting of de-oiled algal residues were smaller than those in soybean meal and alfalfa hay,and the fermenting rate of the fractions was also low.Conclusions：Inferior in vitro rumen gas accumulation from the five de-oiled algal residues suggests that these algal byproducts are less degradable in the rumen.

Effects of temperature and particle size on the thermophysical properties of six plant-origin protein supplements

Reasonable design of the parameters of thermal processing such as conditioning and cooling according to formula changes of pelleted feeds has always been a serious challenge for Chinese feed mills and feed equipment manufacturers. Studying the thermophysical properties of different protein feeds under different temperatures and particle sizes will facilitate the equipment design, parameter optimization, and simulation for the thermal processing of pelleted feeds. In this study, the specific heat (Cp), thermal conductivity (kb), and thermal diffusivity (α) of six plant protein supplements with three particle sizes were determined over a temperature range of 25℃-100℃. The differences in Cp, kb, and α among different feedstuffs and particle sizes were analyzed and the influences of temperature and particle size on these properties were evaluated. Results showed that the Cp, kb, and α of all the feedstuffs increased with increasing temperature and varied from 1.622 to 2.417 kJ/(kg∙℃), 0.080 to 0.362 W/(m∙℃), 6.379×10^(-8) to 21.984×10^(-8) m^(2)/s, respectively. To rise to the same temperature, the distiller’s dried grain with solubles (DDGS) needed to absorb 3% more heat than that required for soybean meal (SBM), while the rest four feedstuffs just needed to absorb 93%-98% heat for SBM. Particle size had no significant effect on Cp for all the feedstuffs (p>0.05). However, descending trends in kb and α were observed with increasing particle size for a certain feedstuff at the same bulk density. In addition, regression equations with only statistically significant terms were developed to describe Cp, kb, and α as a function of temperature and particle size for six feedstuffs. The results can provide basic theory and data for the optimization of thermal processing parameters required for the plant-protein ingredient change in compound feed formulations.