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Crossbred pigs (384) used in three trials were assigned to one of three grouping treatments when moved to 1.4 X 1.6 m nursery pens 4 h postweaning at 28 d of age. Treatments included eight pigs from the same litter (8-1), four pigs from each of two different litters (4-2) and one pig from each of eight different litters (1-8). A commercial odor masking agent (OMA) commonly used to reduce tail biting and fighting was sprayed on one-half of the replicates of each treatment 20 min after (trial 1) or immediately before (trials 2 and 3) the pigs were moved to the nursery. Agonistic behavior was quantified (trials 2 and 3) by direct observation for the first 3 h and again for 2 h at 24 and 48 h post-grouping. Application of OMA 20 min post-mixing caused only a temporary (3 to 5 min) cessation of fighting. A slight increase in fighting in all three grouping treatments was observed when OMA was applied before mixing. Average daily gain for 0 to 4 and 0 to 28 d and feed intake for 0 to 7 and 0 to 28 d were not influenced by OMA or grouping treatments. Combining alien pigs resulted in a significant increase in fighting but did not affect long term performance.

The objective of this study was to evaluate the use of an electronic radio-frequency-identification-based system (GrowSafe System Ltd., Airdrie, Alberta, Canada) to measure feeding behavior traits in beef cattle fed a high-grain diet. Feeding behavior data were recorded by the GrowSafe system and time-lapse video using 10 heifers over a 6-d period. Observed bunk visit (BV) and meal event data (frequency and duration) were compared with electronic feeding behavior data generated by the GrowSafe system at 5 parameter settings (MPS; 30, 60, 100, 150, and 300 s), which are used to define the maximum duration between consecutive electronic identification recordings to initiate a subsequent BV event. A random coefficient model was used to compare video and electronic data using orthogonal contrasts. Video data were regressed on the electronic feeding behavior data to obtain an estimate of precision (r(2)) and other statistical estimates, including mean square error of prediction and concordance correlation coefficient, to access the adequacy of the electronic system predictions. The variation in MPS values affected BV data, but not meal event data. Electronic meal frequency and duration data were not different (P > 0.50) from observed values, and were not affected by electronic MPS values. The optimal MPS value for prediction of BV and meal event frequency and duration traits was 100 s. Our evaluation indicated the GrowSafe system 4000E was able to predict BV and meal event data when the 100-s MPS was used to analyze the feeding behavior data.

Cloning by somatic cell nuclear transfer can result in the birth of animals with phenotypic and gene expression abnormalities. We compared adult cloned pigs and adult pigs from naturally bred control females using a series of physiological and genetic parameters, including detailed methylation profiles of selected genomic regions. Phenotypic and genetic analyses indicated that there are two classes of traits, one in which the cloned pigs have less variation than controls and another characterized by variation that is equally high in cloned and control pigs. Although cloning creates animals within the normal phenotypic range, it increases the variability associated with some traits. This finding is contrary to the expectation that cloning can be used to reduce the size of groups involved in animal experimentation and to reproduce an animal, including a pet, with a homogenous set of desired traits.