Essential 10

4. Randomisation Describe the strategy used to minimise potential confounders such as the order of treatments and measurements, or animal/cage location. If confounders were not controlled, state this explicitly. examples

4a State whether randomisation was used to allocate experimental units to control and treatment groups. If done, provide the method used to generate the randomisation sequence.
4b Describe the strategy used to minimise potential confounders such as the order of treatments and measurements, or animal/cage location. If confounders were not controlled, state this explicitly.
Explanation
Examples

Example 1

“Randomisation was carried out as follows. On arrival from El-Nile Company, animals were assigned a group designation and weighed. A total number of 32 animals were divided into four different weight groups (eight animals per group). Each animal was assigned a temporary random number within the weight range group. On the basis of their position on the rack, cages were given a numerical designation. For each group, a cage was selected randomly from the pool of all cages. Two animals were removed from each weight range group and given their permanent numerical designation in the cages. Then, the cages were randomized within the exposure group.” [1] 

Example 2

“...test time was between 08.30am to 12.30pm and testing order was randomized daily, with each animal tested at a different time each test day.” [2] 

Example 3

“Bulls were blocked by BW into four blocks of 905 animals with similar BW and then within each block, bulls were randomly assigned to one of four experimental treatments in a completely randomized block design resulting in 905 animals per treatment. Animals were allocated to 20 pens (181 animals per pen and five pens per treatment).” [3] 

  1. El-Agroudy NN, El-Naga RN, El-Razeq RA and El-Demerdash E (2016). Forskolin, a hedgehog signalling inhibitor, attenuates carbon tetrachloride-induced liver fibrosis in rats. Br J Pharmacol. doi: 10.1111/bph.13611
  2. Carrillo M, Migliorati F, Bruls R, Han Y, Heinemans M, Pruis I, Gazzola V and Keysers C (2015). Repeated Witnessing of Conspecifics in Pain: Effects on Emotional Contagion. PLOS ONE. doi: 10.1371/journal.pone.0136979
  3. Del Bianco Benedeti P, Paulino PVR, Marcondes MI, Maciel IFS, da Silva MC and Faciola AP (2016). Partial Replacement of Ground Corn with Glycerol in Beef Cattle Diets: Intake, Digestibility, Performance, and Carcass Characteristics. PLOS ONE. doi: 10.1371/journal.pone.0148224