The aim of this study was to evaluate the performance of various boar taint detection methods, measure the relationship between them and identify possible points of improvement for boar taint detection. The methods used to evaluate boar taint in the carcasses of 448 entire male pigs and 17 barrows were the hot iron method (n = 442), a standardised (n = 323) and home (n = 58) consumer meat-evaluation panel, an expert panel assessment of meat and fat (n = 464) and laboratory analysis of skatole, androstenone and indole in fat (n = 464). The axillary odour of a number of slaughtered entire male pigs was also investigated (n = 231). As correlation coefficients were generally weak, a positive result for one of these detection methods did not per se result in a positive result for all other methods. Results of one detection method could not be generalised. The choice to use one or more detection methods deserves consideration depending on the aim of the study. In this paper, we suggest some possible improvements for evaluating boar taint with a consumer panel based on our results and experience. The home consumer evaluation was correlated with the concentration of indole (r = 0.27) but not with skatole or androstenone. We therefore recommend that lab analyses include indole testing. The hot iron method seems to be an easy and fast detection method, which yields comparable or better correlation coefficients with the other detection methods than an expert panel evaluating fat samples. However, the reliability of the hot iron method depends on the training and reliability of one or two assessors. Efforts should be made to further optimise this method by evaluating the effect of testing conditions. The axillary odour score was moderately correlated with the other detection methods (up to 0.32). More research is needed to evaluate the possibilities of axillary odour as a boar taint detection method.

The objective of this study was to investigate the effects of a flaxseed-supplemented diet on archaeal abundance and gene expression of methanogens in the rumen of dairy cows. In all, 11 non-lactating dairy cows were randomly divided into two groups: group A (five cows) and B (six cows). The two diets fed were: (1) the control diet, a conventional dry cow ration; and (2) the flaxseed-supplemented diet, the conventional dry cow ration adjusted with 12.16% ground flaxseed incorporated into the total mixed ration. A cross-over experiment was performed with the two groups of cows fed the two different diets for five 21-day periods, which included the first adaptation period followed by two treatment and two wash out periods. At the end of each feeding period, rumen fluid samples were collected via rumenocentesis and DNA was extracted. Quantitative PCR was utilized to analyze the gene abundance of 16S ribosomal RNA (16S rRNA) targeting the ruminal archaea population and the mcrA gene coding for methyl coenzyme-M reductase subunit A, a terminal enzyme in the methanogenesis pathway. Results demonstrated a 49% reduction of 16S rRNA and 50% reduction of mcrA gene abundances in the rumen of dairy cows fed the flaxseed-supplemented diet in comparison with those fed the control diet. This shows flaxseed supplementation effectively decreases the methanogenic population in the rumen. Future studies will focus on the mechanisms for such reduction in the rumen of dairy cattle, as well as the relationship between methanogenic gene expression and methane production.

A flock of 117, 10-month-old Egyptian geese consisting of 90 females and 27 males were utilized in this investigation. Birds were randomly divided into three equal groups, each made up of three replicates of 10 females and 3 males each. The first group was kept under a pasture system (PS) and allowed to swim in water ducts during the daytime (PS) and kept inside the house during the night. The second group of birds were kept in confinement in a house and fed ad libitum on a commercial feed (intensive system (IS)). Birds in the third group (semi-intensive system (SIS)) were released from the house for 6 h a day and given access to the pasture and water ducts. Each group was housed in three pens (replicates) in the SIS. They were given ad libitum access to the commercial feed when in the house. Each pen measured (2 × 3 m2). Natural mating was practiced during the period from November to the end of May. BW of geese under ISS was significantly (P ⩽ 0.05) higher than those under PS and SIS. Egg number, weight and mass of geese in the SIS system were significantly (P ⩽ 0.05) greater than those of geese in the PS and IS systems. Fertility and hatchability percentages were significantly (P ⩽ 0.05) greater in the PS (84.2% and 88.6%) than in the IS (77.5% and 82.8%) and SIS systems (80.7% and 85.5%). Shell weight and thickness were significantly (P ⩽ 0.05) better in the IS and SIS systems than in the PS system. Geese in the PS and SIS systems exhibited significantly higher plasma estradiol-17 and progesterone than those in the IS. Testosterone was significantly higher in IS than in the other systems. Semen quality factor was significantly higher in the PS and SIS systems than in the IS system. Carcass weight was significantly greater in IS and SIS geese than in PS geese, but the PS system resulted in a decreased percentage skin, abdominal fat and liver. Total amount of meat produced per geese was significantly greater in the SIS than in the IS system and greater in the IS than in the PS system.