Methane (CH4) emission traits were previously found to be heritable and repeatable in sheep fed alfalfa pellets in respiration chambers (RC). More rapid screening methods are, however, required to increase genetic progress and to provide a cost-effective method to the farming industry for maintaining the generation of breeding values in the future. The objective of the current study was to determine CH4 and carbon dioxide (CO2) emissions using several 1-h portable accumulation chamber (PAC) measurements from lambs and again as ewes while grazing ryegrass-based pasture. Many animals with PAC measurements were also measured in RC while fed alfalfa pellets at 2.0 × maintenance metabolizable energy requirements (MEm). Heritability estimates from mixed models for CH4 and CO2 production (g/d) were 0.19 and 0.16, respectively, when measured using PAC with lambs; 0.20 and 0.27, respectively, when measured using PAC with ewes; and 0.23 and 0.34, respectively, when measured using RC with lambs. For measured gas traits, repeatabilities of measurements collected 14 d apart ranged from 0.33 to 0.55 for PAC (combined lambs and ewes) and were greater at 0.65 to 0.76 for the same traits measured using RC. Genetic correlations (rg) between PAC in lambs and ewes were 0.99 for CH4, 0.93 for CH4 + CO2, and 0.85 for CH4/(CH4 + CO2), suggesting that CH4 emissions in lambs and ewes are the same trait. Genetic correlations between PAC and RC measurements were lower, at 0.62 to 0.67 for CH4 and 0.41 to 0.42 for CH4 + CO2, likely reflecting different environmental conditions associated with the protocols used with the 2 measurement methods. The CH4/(CH4 + CO2) ratio was the most similar genetic trait measured using PAC (both lambs and ewes, 63% and 66% selection efficiency, respectively) compared with CH4 yield (g/kg DMI) measured using RC. These results suggest that PAC measurements have considerable value as a rapid low-cost method to estimate breeding values for CH4 emissions in sheep.

Ewes heterozygous (I+) for the Inverdale prolificacy gene (FecX1) located on the X chromosome have ovulation rates approximately 1.0 times higher than noncarriers (++). The aims of this study were to examine, in I+ and ++ ewes, the peripheral plasma concentrations and/or ovarian secretion rates of FSH, LH, inhibin, estradiol, and progesterone during anestrus and the estrous cycle and after ovariectomy. Also examined were aspects of ovarian morphology and functions of granulosa cells in vitro. No FecX1-specific differences were noted for the ovarian hormones or for FSH or LH. However, I+ animals contained significantly more ovarian antral follicles (p < 0.05) and their granulosa cells had a higher mean LH responsiveness in vitro with respect to cAMP synthesis at smaller follicular diameters relative to ++ ewes (I+ = > 2.5 mm; ++ = > 4.5 mm). Moreover, nonatretic follicles in I+ animals compared to the ++ genotype contained fewer granulosa cells and smaller CL. Although the I+ animals had a higher ovulation rate than the controls (p < 0.05), the total weight of CL was not different between the genotypes. These findings suggest that the FecX1 gene affects ovarian function without altering ovarian hormone secretion. The findings also suggest that there are no FecX1-specific differences in the mean concentrations of gonadotropins, although further studies on temporal changes in gonadotropin secretion are warranted.

Six experiments involving the artificial insemination (AI) of a total of 300 female red deer (hinds) with frozen-thawed red deer semen (collected by electro-ejaculation) were conducted over 3 years. Insemination took place at fixed times following various oestrous synchronization procedures using progesterone withdrawal and treatment with pregnant mare's serum gonadotropin (PMSG). In the 1st year, the experiments evaluated basic AI techniques in which pregnancy rates were 45% in 20 hinds receiving two inseminations per vaginam (PV) and 56% in 27 hinds inseminated by the laparoscopic intrauterine method (IU). In the 2nd year, the experiments involved comparisons of the progesterone regime, one or two PV inseminations, and the timing of a single PV insemination. There was no effect of replacement of the progesterone device after 9 days and withdrawal 3 days later compared with the use of one device for the whole period in two experiments. The pregnancy rate for a double PV insemination was significantly higher than for a single PV insemination (58 and 34%; P < 0·05) and there was also a small effect of timing of insemination relative to the synchronization treatment. In the 3rd year all hinds were inseminated by the IU method. The experiments involved a comparison of various times of AI following progesterone withdrawal and a comparison of the progesterone regime. The overall pregnancy rate for 63 hinds inseminated was 56% with no difference between three times of insemination (48, 52 and 55 h). In the second experiment, the difference in pregnancy rate between treatment with progesterone for 15 days and 12 days (44 and 72% for 18 hinds per group) was not significant, but the interaction between the length of progesterone treatment and insemination time was significant (P < 0·05), with the 12-day progesterone/55 h insemination giving a much higher pregnancy rate than the 15-day/55 h insemination (89 and 20% respectively). Although no experiments involved direct comparisons of the routes of insemination, overall pregnancy rates were 56% for IU, 53% for double PV and 35% for single PV inseminations.

Traceability of meat and meat products is a major issue in the meat industry with the two main drivers being food safety ⁄ risk management and authentication. Increasingly, the world marketplace is indicating that traceability systems for food products derived from individual animals (e.g. steak, chops etc.) is required now or will be required in the near future. Traceability requirements for compound products, such as ground beef, are usually less strict and are frequently limited to date and place of manufacture. As global competition increases it is imperative that technologies are available that protect against, and deter, fraudulent labelling of inferior product. Traceability offers more than marketing advantages. It can be applied at every stage of the meat production continuum and can be just as valuable to farmers and processors as it is to marketers and consumers.

The common method for synchronizing oestrus in brushtail possums is by removal of their pouch young (RPY)