1. Four experiments were performed to study the effects on the growth of lambs of extending natural daylength to 20 h with dim artificial light, under management conditions similar to those on commercial farms.

2. Thirty-six female lambs aged 6 months were given a concentrate ration at a restricted level in groups of nine; there was significantly faster live-weight gain in the two groups that received extra light but no effect on carcass weight or linear measurements.

3. Forty-eight castrated male lambs were fed either ad libitum or at a restricted level on a concentrate diet; half were given additional light. Feeding ad libitum gave faster growth than restricted feeding but there were no significant effects of daylength.

4. One hundred and fourteen lambs of mixed sex were offered silage ad libitum plus one of three concentrate supplements at an average of 0·25 kg per head per day. Half were exposed to 20·h daylength from mid-October until slaughter in mid-January. There were no effects of light treatment on growth or carcass weights.

5. The fourth experiment was a repeat of the third and again there were no effects of extended daylength.

6. It is concluded that this method of controlling daylength is not appropriate for commercial use.

Six groups of eight 2-day-old calves were placed successively in a controlled environment chamber. Three groups were exposed to air temperatures of 10° and 25°C. A liquid diet of skimmed-milk substitute and 4 I/day of drinking (free) water was offered to each calf. Within each group, calves were allocated to either a low (<0·2 m/s) or a high (>3 m/s) air velocity and to either a low (30 g dry matter (DM) per kg M0·75 per day) or a high (40 g DM per kg M0·75 per day) feeding level. At 8 days of age the apparent digestibilities of DM at air temperatures of 10° and 25°C were 0·77 (s.e. 0·126) and 0·82 (s.e. 0·126) respectively (P > 0·05). The apparent digestibilities of DM were greater at the low feeding level with low air velocity than for either this feeding level with high air velocity or the high feeding level at both air velocities (P < 0·05) between which there was no significant difference (P > 0·05). At 8 days of age there were significant air temperature × air velocity (P < 001) and air velocity × feeding level interactions in the intake of free water (P < 005). There was a significant air temperature × feeding level interaction for total water intake (P < 0·05). Urinary water loss relative to total water intake was significantly greater at the low air velocity than at the high air velocity (P < 0·05).

In a further two groups of eight calves given 30 g DM per kg M 75 per day at 8 days of age, the apparent digestibilities of DM at air temperatures of 10° and 25°C were 0·71 (s.e. 0·020) and 0·90 (s.e. 0·013) respectively (P < 0·01). In the same calves given 40 g DM per kg M0·75 per day at 20 days of age, the apparent digestibilities of DM at air temperatures of 10° and 25°C were 0·89 (s.e. 0·009) and 0·93 (s.e. 0·011) respectively (P < 0·05). The free and total water intakes, the ratios of (total water intake-faecal water loss): total water intake and the urinary losses of water were significantly greater at the air temperature of 25°C than at 10°C (P < 0·05). Live-weight gains were lower at 10°C than at 25°C (P < 0·01).

The results suggested that air temperature, air velocity and feeding level can affect the health and growth of calves less than 4 weeks of age.

Nineteen pluriparous buffaloes of Nili-Ravi breed which calved during the months of October and November 1983 were studied for the effects of sucking stimulus on the uterine involution, post-partum ovarian functions and fertility. On the day of calving, buffaloes were assigned to either a limited-suckling (LS) or non-suckling (NS) group. Changes in reproductive organs were monitored by rectal palpations at weekly intervals. Buffaloes were observed for oestrus twice daily (04.00 and 18.00 h) with the help of a teaser bull, and were artificially inseminated at the first post-partum and each subsequent oestrus. LS buffaloes had a shorter period to uterine involution (20 days) than NS buffaloes (28 days). Intervals to regression of the corpora lutea of pregnancy and to resumption of post-partum follicular development did not differ in the two groups. LS buffaloes had longer intervals to first post-partum oestrus and conception (54 and 88 days respectively) than NS buffaloes (39 and 68 days respectively). However, the difference in services per conception of LS and NS buffaloes was non-significant (2-05 v. 1·62). These limited data reveal that the suckling stimulus has a negative effect on the post-partum resumption of oestrous activity, and that conception is delayed. Further studies are indicated to verify these observations in a larger sample size and during all seasons of the year.

1. Seventy-two individually fed, virus pneumonia-free Large White weaners were used to determine the effect of supplementing diets containing either some animal protein or only vegetable protein with either 0·1% CuSO4.5H2O or 2½% E.C. Feed (molasses distillers dried solubles).

2. The marked growth-promoting effect of supplementing a diet containing animal protein with Cu was again confirmed. The response when Cu was added to the all-vegetable diet was significantly less than that on the diet containing some animal protein, the significant improvement in growth rate on the two types of diet being respectively 5·1% and 14·5%.

3. The addition of 2½% E.C. Feed to the diet containing some animal protein significantly increased growth rate by 5·1%. This response was significantly less than that obtained from Cu supplementation. The 3·6% increase in mean growth rate when E.C. Feed was added to the all-vegetable diet was not statistically significant.

4. Whereas Cu improved the efficiency of food utilisation of the pigs, particularly when added to the diet containing animal protein (a significant improvement of 5·2%), E.C. Feed did not on either type of diet. Both Cu and E.C. Feed similarly increased the rate of food consumption of the pigs on both types of diet.

5. There were no differences in the performance of the control pigs given either the unsupplemented diets with animal protein or the corresponding all-vegetable diets.

Young stock survival is a trait of crucial importance in cattle breeding as calf mortality leads to economic losses and represents an animal welfare issue. The aim of this study was to estimate genetic parameters and sire breeding values for young stock survival in beef x dairy crossbred calves. Two traits were analysed with a univariate animal model: young stock survival between 1 to 30 days and 31 to 200 days after birth. Breed combinations with Belgian Blue sires outperformed all other sire breeds. The lowest survival rates were found for breed combinations with Jersey dams or Blonde d’Aquitaine sires. The results showed low but significant heritabilities (0.045 to 0.075) for both survival traits. Differences in breeding values between sires ranged from −2.5% to 3.5% and from −5.4% to 4.7% survival from 1 to 30 days and 31 to 200 days, respectively. Based on these findings, we concluded that it is feasible to breed for improved young stock survival in beef x dairy crossbred calves. This will hopefully contribute to increasing the survival rate of the calves and reduce economic losses for the farmers.

Heritability is a central element in quantitative genetics. New molecular markers to assess genetic variance and heritability are continually under development. The availability of molecular single nucleotide polymorphism (SNP) markers can be applied for estimation of variance components and heritability on population, where relationship information is unknown. In this study, we evaluated the capabilities of two Bayesian genomic models to estimate heritability in simulated populations. The populations comprised different family structures of either no or a limited number of relatives, a single quantitative trait, and with one of two densities of SNP markers. All individuals were both genotyped and phenotyped. Results illustrated that the two models were capable of estimating heritability, when true heritability was 0.15 or higher and populations had a sample size of 400 or higher. For heritabilities of 0.05, all models had difficulties in estimating the true heritability. The two Bayesian models were compared with a restricted maximum likelihood (REML) approach using a genomic relationship matrix. The comparison showed that the Bayesian approaches performed equally well as the REML approach. Differences in family structure were in general not found to influence the estimation of the heritability. For the sample sizes used in this study, a 10-fold increase of SNP density did not improve precision estimates compared with set-ups with a less dense distribution of SNPs. The methods used in this study showed that it was possible to estimate heritabilities on the basis of SNPs in animals with direct measurements. This conclusion is valuable in cases when quantitative traits are either difficult or expensive to measure.

Physically effective fiber is needed by dairy cattle to prevent ruminal acidosis. This study aimed to examine the effects of different sources of physically effective fiber on the populations of fibrolytic bacteria and methanogens. Five ruminally cannulated Holstein cows were each fed five diets differing in physically effective fiber sources over 15 weeks (21 days/period) in a Latin Square design: (1) 44.1% corn silage, (2) 34.0% corn silage plus 11.5% alfalfa hay, (3) 34.0% corn silage plus 5.1% wheat straw, (4) 36.1% corn silage plus 10.1% wheat straw, and (5) 34.0% corn silage plus 5.5% corn stover. The impact of the physically effective fiber sources on total bacteria and archaea were examined using denaturing gradient gel electrophoresis. Specific real-time PCR assays were used to quantify total bacteria, total archaea, the genus Butyrivibrio, Fibrobacter succinogenes, Ruminococcus albus, Ruminococcus flavefaciens and three uncultured rumen bacteria that were identified from adhering ruminal fractions in a previous study. No significant differences were observed among the different sources of physical effective fiber with respect to the microbial populations quantified. Any of the physically effective fiber sources may be fed to dairy cattle without negative impact on the ruminal microbial community.

The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) is an essential enzyme in cholesterol biosynthesis. To study the expression of HMGR and corresponding cholesterol content in liver, adipose and muscle, six Chinese local breed (Huai pig) and Landrace pigs were selected. The results indicated that significant differences of cholesterol content in adipose (P < 0.01), liver (P < 0.05) and muscle (P < 0.01) tissues were detected between pigs of differing genetic backgrounds. HMGR mRNA expression were noted for adipose, liver and muscle of the two vastly differing genetics. Moreover cholesterol content differed (P < 0.01) among tissues across breed. Likewise, HMGR mRNA expression was different between adipose and liver tissues, muscle and liver tissues in both breeds; however, no difference was noted between adipose and muscle tissues. Results from this study indicate that cholesterol content and HMGR mRNA expression are higher in Huai pig tissues suggesting this gene is expressed in a breed- and tissue-dependent manner in pigs. Understanding the causes of variation in HMGR gene expression may provide crucial information about cholesterol biosynthesis.

The improvement in porcine embryo preservation and non-surgical embryo transfer (ET) procedures achieved in recent years represents essential progress for the practical use of ET in the pig industry. This study aimed to evaluate the effects of parity, weaning-to-estrus interval (WEI) and season on reproductive and embryonic parameters at day 6 after insemination of donor sows superovulated after weaning. The selection of donor sows was based on their reproductive history, body condition and parity. The effects of parity at weaning (2 to 3, 4 to 5 or 6 to 7 litters), season (fall, winter and spring), and WEI (estrus within 3 to 4 days), and their interactions on the number of corpus luteum, cysts in sows with cysts, number and quality of viable and transferable embryos, embryo developmental stage and recovery and fertilization rates were evaluated using linear mixed effects models. The analyses showed a lack of significant effects of parity, season, WEI or their interactions on any of the reproductive and embryonic parameters examined. In conclusion, these results demonstrate that fertilization rates and numbers of viable and transferable embryos collected at day 6 of the cycle from superovulated donor sows are not affected by their parity, regardless of the time of the year (from fall to spring) and WEI (3 or 4 days).

The study examined the effects of harvest time of red and white clover silage on eating and ruminating activity and particle size distribution in feed boli, rumen content and faeces in cows. The clover crops were harvested at two stages of growth and ensiled in bales. Red clover crops had 36% and 45% NDF in dry matter (DM) at early (ER) and late (LR) harvest, respectively, and the white clover crops had 19% and 29% NDF in DM at the early (EW) and late (LW) harvest, respectively. The silages were fed restrictively (80% of ad libitum intake) twice daily to four rumen cannulated non-lactating Jersey cows (588 ± 52 kg) in a 4 × 4 Latin square design. Jaw movements (JM) were recorded for 96 h continuously. Swallowed boli, rumen mat, rumen fluid and faeces samples were collected, washed in nylon bags (0.01 mm pore size) and freeze-dried before dry sieving through 4.750, 2.360, 1.000, 0.500, 0.212 and 0.106 mm into seven fractions. The length (PL) and width (PW) values of rumen and faeces particles within each fraction were measured by use of image analysis. The eating activity (min/kg DM intake; P < 0.05) was higher in LR compared with the other treatments. The eating activity (min/kg NDF intake; P < 0.05) was affected by clover type with highest values for white clover silage. The mean ruminating time (min/kg DM), daily ruminating cycles (P < 0.001) and JM during ruminating (P < 0.05) were affected by treatment with increasing values at later harvest time. The proportion of washed particle DM of total DM in boli (P < 0.001), rumen mat (P < 0.001), rumen fluid (P < 0.01) and faeces was (P < 0.001) highest by feeding LR. There were identified two peaks (modes 1 and 2) on the probability density distribution (PDF) of PW values of rumen mat and faeces, but only one peak (mode 1) for PL values. There was no difference in the mean and mode 1 PW and PL value in rumen mat between the four treatments. The mean PL, mode PL, mode 2 PW and mean PW in faeces were highest for LR (P < 0.05). The mean particle size in boli measured by sieving was higher at white clover compared with red clover treatments (P < 0.001) and the highest value in faeces was found in LR (P < 0.01). The two peaks on PDF for width values of rumen mat and faeces particles are most likely related to the leaves and the stems/petioles. In conclusion, the mean total chewing activity per kg DM was lowest for the white clover silage and increased for both silages due to later harvest time. The mean particle size in boli was smallest for LR, whereas the mean PL and PW in faeces were highest for the LR.

Pregnancy-associated glycoproteins (PAGs) are a large grouping of placental proteins that belong to the aspartic peptidase gene family. Although useful to detect pregnancy in ruminant species, the function of these molecules is unclear. Several PAGs expressed by trophoblast binucleate cells can enter the maternal circulation, suggesting that they could have a systemic role in altering maternal physiology. The objective of this work was to examine whether these circulating placental antigens were important in pregnancy by actively immunizing ewes against them. PAGs were purified by pepstatin-affinity chromatography and conjugated to the immunogenic protein, keyhole limpet hemocyanin (KLH). Ewes were immunized with PAG–KLH conjugate (n = 22) or with KLH alone (n = 9), and bred to intact rams. Blood samples, collected on Day 0 (day of estrus), Day 10, Days 15 to 25 and weekly throughout pregnancy, were analyzed for PAG by an ELISA. On Day 30, pregnancy was confirmed by ultrasound. Ewes immunized against PAG–KLH produced a range of reactive anti-PAG titers, whereas all immunized ewes had high anti-KLH immunoreactivity. PAGs became detectable in the anti-KLH (control) ewes at Day 21.6 ± 2.2 of pregnancy. Those ewes immunized against PAGs (n = 7), that had very low immunoreactivity toward PAGs, had measurable PAG by Day 22.9 ± 1.3, and their PAG serum profiles throughout pregnancy did not differ from the controls. Those exhibiting moderate to high anti-PAG immunoreactivity (n = 15), had significantly lower PAG concentrations than controls, with antigen not becoming detectable until Day 48.1 ± 15.6. The decrease in circulating PAG in the immunized animals did not correlate with changes in pregnancy rates, lamb number or lamb birth weight. These results suggest that while PAGs may play a role in maintaining pregnancy, their major contribution is likely to be at the fetal–maternal interface. Their actions at extra-placental sites are presumably of more secondary importance.

This study comprises two trials that investigated the effects of feeding time and time-restricted feeding on the fattening traits and plasma metabolite levels of White Roman geese. In Trial I, 24 geese aged 8 weeks of each sex were allowed free access to a fattening diet for 1 h either in the morning (morning-feeding group) or afternoon (afternoon-feeding group). At 12 weeks of age, blood samples were collected hourly for 4 h, beginning 1 h after feeding to determine the plasma levels of glucose, triacylglycerols and uric acid. The results showed a lower (P<0.05) daily feed intake (DFI) and daily gain (DG) and higher (P<0.05) feed efficiency (FE) for the morning-feeding group compared with those of the afternoon-feeding group. In addition, the postprandial plasma levels of glucose, triacylglycerols and uric acid did not differ (P>0.05) between groups. In Trial II, 12 geese aged 8 weeks of each sex were randomly assigned to either the ad libitum feeding group (control group) or time-restricted feeding group (restricted group). The geese in the control group were fed a fattening diet ad libitum, whereas those in the restricted group were allowed access to the diet for 2 h every morning. All geese were killed at 13 weeks of age and their carcass traits were evaluated. The results showed a lower DFI and DG and higher FE for the restricted group compared with those of the control group (P<0.05). In addition, the restricted group exhibited lower visceral and abdominal fat and higher empty digestive tract and liver weights than those of the control group (P<0.05). The results showed that time-restricted feeding in the morning resulted in superior DG and FE compared with feeding in the afternoon. Moreover, time-restricted feeding implemented in the morning during the fattening period reduced DFI and increased FE in geese compared with ad libitum feeding.

The relationship among parasitological parameters, abomasal size and body size measurements was investigated in lambs following an experimental infection with Haemonchus contortus. In total, 100 lambs from five different genotypes (German Merino (GM), Texel × GM, Suffolk × GM, German Blackhead Mutton × GM and Ile de France × GM) were experimentally infected with 5000 infective third stage larvae of H. contortus at the time of weaning at 12 weeks of age. Four and six weeks after infection, individual faecal samples were collected for estimation of faecal egg counts (FECs). Furthermore, wither height, shoulder width, heart girth, loin girth and body length were taken at 18 weeks of life. Lambs were slaughtered and necropsied 7 weeks post-infection, and worm counts, abomasal volume and surface area were determined. Positive correlations were found between different body size parameters, body weight and abomasal sizes. FEC and worm counts were not significantly correlated either with body size parameters or with abomasal size. The mean worm burden was higher in GM than in crossbred lambs. There was no significant difference in abomasal size between GM and crossbred lambs. The results suggest that the variations between animals in worm burden following an experimental infection with H. contortus (worm resistance) are not influenced by body size parameters or abomasal sizes. Therefore, other factors, including genetic-based differences in resistance, must cause these findings between and within breeds.

The use of culled potatoes was investigated in Belgian Blue double-muscled finishing cows, confined in tie stalls. The control diet (Treatment 1) consisted of concentrate and maize silage (50/50 on a dry matter (DM) basis). Potatoes either replaced 60% maize silage (Treatment 2) or 60% concentrate (Treatment 3). Diets were formulated to be isocaloric and isonitrogenous. They were fed ad libitum. Approximately 18 kg potatoes were fed daily in Treatments 2 and 3. Daily gain was not significantly altered; it decreased from 1.09 kg (Treatment 1) to 1.04 kg (Treatment 2) or increased to 1.20 kg (Treatment 3), although potatoes stimulated DM intake by 5% to 8% (P < 0.05). Feed conversion was unaffected in comparison with the control diet, when expressed in terms of DM, but energy efficiency (MJ/kg live weight gain) was substantially lower for Treatment 2 compared with Treatment 1 (89.9 v. 79.0; P = 0.046). Carcass weight, grading and composition were not affected by treatments, but potatoes increased dressing percentage (P = 0.009). Treatment had no significant effect on meat quality parameters. However, potatoes (Treatments 2 and 3) tended to decrease moisture content (P = 0.090) and tended to increase drip loss (P = 0.059) compared with Treatment 1. Because of a better animal performance and a lower feed cost, it is most appropriate to use potatoes as a replacement for concentrate. Feeding large amounts of potatoes besides concentrate may have an adverse effect on the fibrousness of the diet, resulting in a tendency (−5%) for a reduced daily gain and a lower energy efficiency (P < 0.05).

Fat metabolism is an important and complex biochemical reaction in vivo and is regulated by many factors. Recently, the findings on high expression of fibroblast growth factor-16 (FGF16) in brown adipose tissue have led to an interest in exploring its role in lipogenesis and lipid metabolism. The study cloned the goat’s FGF16 gene 624 bp long, including the complete open reading frame that encodes 207 amino acids. We found that FGF16 expression is highest in goat kidneys and hearts, followed by subcutaneous fat and triceps. Moreover, the expression of FGF16 reached its peak on the 2nd day of adipocyte differentiation (P < 0.01) and then decreased significantly. We used overexpression and interference to study the function of FGF16 gene in goat intramuscular preadipocytes. Silencing of FGF16 decreased adipocytes lipid droplet aggregation and triglyceride synthesis. This is in contrast to the situation where FGF16 is overexpressed. Furthermore, knockdown of FGF16 also caused down-regulated expression of genes associated with adipocyte differentiation including CCAAT enhancer-binding protein beta (P < 0.01), fatty acid-binding protein-2 (P < 0.01) and sterol regulatory element binding protein-1 (P < 0.05), but the preadipocyte factor-1 was up-regulated. At the same time, the genes adipose triglyceride lipase (P < 0.01) and hormone-sensitive lipase (P < 0.05) associated with triglyceride breakdown were highly expressed. Next, we locked the fibroblast growth factor receptor-4 (FGFR4) through the protein interaction network and interfering with FGF16 to significantly reduce FGFR4 expression. It was found that the expression profile of FGFR4 in adipocyte differentiation was highly similar to that of FGF16. Overexpression and interference methods confirmed that FGFR4 and FGF16 have the same promoting function in adipocyte differentiation. Finally, using co-transfection technology, pc-FGF16 and siRNA-FGFR4, siRNA2-FGF16 and siRNA-FGFR4 were combined to treat adipocytes separately. It was found that in the case of overexpression of FGF16, cell lipid secretion and triglyceride synthesis showed a trend of first increase and then decrease with increasing interference concentration. In the case of interference with FGF16, lipid secretion and triglyceride synthesis showed a downward trend with the increase of interference concentration. These findings illustrated that FGF16 mediates adipocyte differentiation via receptor FGFR4 expression and contributed to further study of the functional role of FGF16 in goat fat formation.

Before slaughter, lambs may experience several stressors such as feed and water deprivation, handling and transport that have the potential to negatively impact welfare and meat quality. The objective of this study was to evaluate the effect of pre-slaughter handling, exercise and the presence of a dog on the behaviour and physiology of lambs and meat quality at slaughter. At 6 months of age, 60 lambs (n=20 lambs/replicate; three replicates) were allocated to one of the two treatment groups (n=30 lambs/treatment): low (LOW) intensive handling or high (HIGH) intensive handling. LOW lambs were moved short distances, quietly and without the use of a dog before transport. HIGH lambs were moved quickly, long distances and with a dog present before transport. Lamb behaviour (standing, lying, rumination and panting) was recorded for 1 h before (post-treatment) and after transport (post-transport), and for 30 min before slaughter (pre-slaughter). Blood samples were collected before (baseline), after transport (post-transport) and at exsanguination (at slaughter) to assess cortisol, lactate and non-esterified fatty acid (NEFA) concentrations. At slaughter, lamb carcases (M. longissimus lumborum) were evaluated for pH levels, drip and cook loss, and tenderness. HIGH lambs spent more time standing (P<0.001) and panting (P<0.001) and less time lying (P<0.001) and ruminating (P<0.001) post-treatment than LOW lambs, but more (P<0.001) time ruminating post-transport. All lambs spent more time standing (P<0.001) and less time lying (P<0.001) and panting (P<0.001) post-transport and pre-slaughter than post-treatment. Cortisol concentrations were greater (P<0.001) in lambs post-transport and at slaughter compared with baseline values. Lactate concentrations were lower (P=0.002) in HIGH than LOW lambs. In addition, NEFA concentrations were higher (P<0.001) post-transport and at slaughter in HIGH compared with LOW lambs. Ultimate pH was higher (P<0.001) in HIGH than LOW lambs and pH declined quicker (P=0.012) in LOW than HIGH lambs. Cook loss, drip loss and shear force were lower (P⩽0.05) in HIGH than LOW lambs. The HIGH intensive pre-slaughter handling regime used in the present study caused stress in lambs and increased ultimate pH that could potentially negatively impact welfare, product quality and consistency.

Somatostatin (SS) is a hormone that inhibits the secretion of growth hormone. Immunization against SS can promote the growth of animals. A novel SS-VP22 fused vaccine, pEGS2SS-V, was constructed from pEGS2SS plasmid with a VP22 gene fragment. Two times of immunization with pEGS2SS-V-induced anti-SS antibodies in mice. Compared with mice immunized with pEGS2SS and 0.85% saline, the growth performance of mice immunized with pEGS2SS-V was increased by 14.1% (P < 0.05) and 48.4% (P < 0.01) on the 2nd week after the first vaccination, respectively. The results indicated that the effects of the somatostatin DNA vaccine could be improved effectively by VP22 gene adjuvant.

Breeding programmes for livestock require economic weights for traits that reflect the most profitable animal in a given production system, which affect the response in each trait after selection. The profitability of sheep production systems is affected by changes in pasture growth as well as grain, meat and wool prices between seasons and across years. Annual pasture growth varies between regions within Australia’s Mediterranean climate zone from low growth with long periods of drought to high growth with shorter periods of drought. Therefore, the objective of this study was to assess whether breeding objectives need to be adapted for regions, depending on how reliable the pasture growth is across years. We modelled farms with Merino sheep bred for wool and meat in 10 regions in Western Australia. Across these 10 regions, mean annual pasture growth decreased, and the CV of annual pasture growth increased as pasture growth for regions became less reliable. We calculated economic values for nine traits, optimising management across 11 years, including variation for pasture growth and wool, meat and grain prices between and within years from 2002 to 2012. These economic values were used to calculate responses to selection for each trait for the 10 regions. We identified two potential breeding objectives, one for regions with low or high reliability and the other for regions with medium reliability of pasture growth. Breeding objectives for high or low pasture growth reliability had more emphasis on live weight traits and number of lambs weaned. Breeding objectives for medium reliability of pasture growth had more emphasis on decreasing fibre diameter. Relative economic weights for fleece weight did not change across the regions. Regions with low or high pasture reliability had similar breeding objectives and response to selection, because the relationship between the economic values and CV of pasture growth were not linear for live weight traits and the number of lambs weaned. This non-linearity was caused by differences in distribution of pasture growth between regions, particularly during summer and autumn, when ewes were pregnant, with increases in energy requirements affecting the value of lambs weaned. In addition, increasing live weight increased the intake capacity of sheep, which meant that more poor quality pasture could be consumed during summer and autumn, which had more value in regions with low and high pasture reliability. We concluded that breeding values for sheep production systems should be customised depending on the reliability of pasture growth between years.

This study investigated the effects of various stunning methods on the quality of French ‘foie gras’ in ducks and geese. The ducks (n = 30 per group) were stunned with one of the following techniques: electrical stunning in a water bath (50 Hz AC, 130 mA, 4 s), head-only electrical stunning (50 Hz AC, 600 mA, 4 s), mechanical stunning (captive bolt) and controlled atmosphere stunning (CAS: phase 1, CO2 (40%)–O2 (30%)–N2 (30%), for 2 min followed by phase 2, CO2 >85% in air, for 2 min). The same methods (except head-only stunning which was not applied) were used in geese (n = 40 per group). The weight of the liver at slaughter was not affected by the stunning techniques, neither was its colour (L*, a*, b* coordinates), despite the differences in bleeding rate between the stunning treatments. The loss of fat during the cooking of canned fatty liver did not depend upon stunning treatment. Some appearance defects of raw fatty livers were significantly affected by the treatment: mechanical and head-only stunning induced higher incidence of petechial haemorrhages in duck liver, whereas in geese, incidence of superficial haemorrhages was significantly higher after CAS and water-bath stunning. The calculation of an overall score based on the incidence and severity of the different appearance defects observed in the present experiment showed that CAS was associated with the least favourable position in ducks as well as in geese, compared to the other treatments. The commercial grading of ducks and geese fatty livers, carried out by an expert from the industry, clearly showed the detrimental effect of CAS on the commercial value of raw livers. CAS, under the conditions applied in the present work cannot be recommended, because of its drastic effect on liver quality. The underlying mechanisms deserve further investigations.