Mid-infrared (MIR) spectroscopy of milk was used to predict dry matter intake (DMI) and net energy intake (NEI) in 160 lactating Norwegian Red dairy cows. A total of 857 observations were used in leave-one-out cross-validation and external validation to develop and validate prediction equations using 5 different models. Predictions were performed using (multiple) linear regression, partial least squares (PLS) regression, or best linear unbiased prediction (BLUP) methods. Linear regression was implemented using just milk yield (MY) or fat, protein, and lactose concentration in milk (Mcont) or using MY together with body weight (BW) as predictors of intake. The PLS and BLUP methods were implemented using just the MIR spectral information or using the MIR together with Mcont, MY, BW, or NEI from concentrate (NEIconc). When using BLUP, the MIR spectral wavelengths were always treated as random effects, whereas Mcont, MY, BW, and NEIconc were considered to be fixed effects. Accuracy of prediction (R) was defined as the correlation between the predicted and observed feed intake test-day records. When using the linear regression method, the greatest R of predicting DMI (0.54) and NEI (0.60) in the external validation was achieved when the model included both MY and BW. When using PLS, the greatest R of predicting DMI (0.54) and NEI (0.65) in the external validation data set was achieved when using both BW and MY as predictors in combination with the MIR spectra. When using BLUP, the greatest R of predicting DMI (0.54) in the external validation was when using MY together with the MIR spectra. The greatest R of predicting NEI (0.65) in the external validation using BLUP was achieved when the model included both BW and MY in combination with the MIR spectra or when the model included both NEIconc and MY in combination with MIR spectra. However, although the linear regression coefficients of actual on predicted values for DMI and NEI were not different from unity when using PLS, they were less than unity for some of the models developed using BLUP. This study shows that MIR spectral data can be used to predict NEI as a measure of feed intake in Norwegian Red dairy cattle and that the accuracy is augmented if additional, often available data are also included in the prediction model.

This is a review of factors affecting carotenogenesis by the order Mucorales which includes Phycomyces blakesleeanus, Choanephora cucurbitarum and Blakeslea trispora. The Mucorales have opposite sex types and when mated, beta-carotene production is increased 15 to 20 times. Trisporic acids are the substances produced upon mating which stimulate carotenogenesis. Structural analogs have been shown to mimic the actions of the trisporic acids. The common denominator of the stimulators is the ionone ring and the hydrocarbon side chain. Secondary metabolism is discussed as well as the use of food byproducts to stimulate, specifically, the production of beta-carotene by B. trispora.

Alternative genomic selection and traditional BLUP breeding schemes were compared for the genetic improvement of feed efficiency in simulated Norwegian Red dairy cattle populations. The change in genetic gain over time and achievable selection accuracy were studied for milk yield and residual feed intake, as a measure of feed efficiency. When including feed efficiency in genomic BLUP schemes, it was possible to achieve high selection accuracies for genomic selection, and all genomic BLUP schemes gave better genetic gain for feed efficiency than BLUP using a pedigree relationship matrix. However, introducing a second trait in the breeding goal caused a reduction in the genetic gain for milk yield. When using contracted test herds with genotyped and feed efficiency recorded cows as a reference population, adding an additional 4,000 new heifers per year to the reference population gave accuracies that were comparable to a male reference population that used progeny testing with 250 daughters per sire. When the test herd consisted of 500 or 1,000 cows, lower genetic gain was found than using progeny test records to update the reference population. It was concluded that to improve difficult to record traits, the use of contracted test herds that had additional recording (e.g., measurements required to calculate feed efficiency) is a viable option, possibly through international collaborations.

The effects of different media, length of time of incubation, media constituents and pH on recovery of spores of Bacillus subtilis var. niger exposed to hydrogen peroxide were examined. As the time of exposure of spores to hydrogen peroxide increased, the incubation time req'uired for colony formation increased. A medium consisting of 7.5 g/L of yeast extract, 2.5g of glucose/L, 6.Og of vitamin-free casamino acids/L, 15.Og of agar/L, O.lg of ferrous sulfate/L, and O.lg of manganous sulfate/L gave the best recovery. The presence of glucose and yeast extract in the medium was important Autoclaving of ferrous sulfate and manganous sulfate apart from the rest of the medium improved recovery and allowed for pH adjustment of the medium before autoclaving. Maximal recovery occurred between pH 6.8 and 7.0. The results of these experiments indicate that the sporitidal action of hydrogen peroxide may not be as great as previously observed and that careful attention should be paid to the procedures used to evaluate the safety of food processes that utilize hydrogen peroxide as a bactericide.