Effect of dietary conjugated linoleic acid and monounsaturated fatty acids on productive, carcass and meat quality traits of pigs

Three levels (0, 1 and 2%) of conjugated linoleic acid (CLA) were combined with two levels (low and high) of monounsaturated fatty acids (MUFA) for pig feeding. Productive, carcass and meat quality traits were studied. Large White ♂ × Landrace × Large White ♀ gilts (n = 288) weighting 70 kg were randomly allotted to 6 different feeding treatments and fed to a final average weight of 107 kg. Loins were taken from 48 animals (8 animals randomly selected from each treatment). No differences due to dietary CLA, MUFA or CLA × MUFA interaction were found on average daily gain, average daily consumption, feed conversion ratio, carcass yield, backfat thickness, loin weight, loin pH and loin colour. A significant increase in intramuscular fat content (p = 0.010) and in saturated fatty acids (SFA) (p < 0.001), and a decrease in MUFA (p = 0.001) and desaturase indices were found as consequence of dietary CLA, regardless the MUFA level. Therefore, dietary CLA, MUFA and their interaction did not influence productive and carcass traits of pigs. However, the use of CLA for swine feeding increased the intramuscular fat content and modified the fatty acid profile, regardless the MUFA level of the diets.     

Pyometra and unilateral uterine horn torsion in a sheep

A 13‐year‐old Romanov sheep presented for evaluation of vaginal discharge, depression and anorexia. Blood work demonstrated mature neutrophilia and marked hyperlactatemia. Transrectal and transabdominal ultrasound revealed echogenic fluid (pus) within the uterus. Purulent uterine fluid culture yield Escherichia coli. A diagnosis of pyometra was made. After medical treatment without clinical improvement, an exploratory laparotomy was performed, and a 360‐degree uterine left horn torsion was identified with the pyometra and multiple corpora lutea on both ovaries. Ovariohysterectomy was performed and the ewe recovered uneventfully.     

Rust resistance in Salix induced by inoculations with avirulent and virulent isolates of Melampsora larici‐epitea

Six Salix clones and four Melampsora larici‐epitea isolates were used in two leaf‐disc inoculation experiments to determine whether disease severity was affected by the presence of both virulent and avirulent rust genotypes. In the first experiment, an equal amount of urediniospores of a virulent isolate and an avirulent isolate was applied simultaneously using four levels of spore suspension. In the second, the willows were inoculated with one isolate first and then, after 3 days, with another using two spore concentrations. In the first experiment, overall rust spore production was reduced by 48.6% in inoculations with mixed inocula compared with that in the inoculations with single virulent isolates. In the second experiment, 20 of the 36 combinations involving pre‐inoculations with avirulent isolates showed significant reduction in spore production. The suppressive effects on rust sporulation were more obvious at the higher inoculum densities and on the clones S. × calodendron and S. × mollissima‘Q83’.     

Nursery fertilisation affects the frost-tolerance and plant quality of Eucalyptus globulus Labill. cuttings

Eucalyptus globulus is widely used in productive exotic plantations but the expansion of these plantations is limited by low temperatures, as its cold hardening capacity is limited (0.5 to 3.0 °C). It is not well understood how nursery fertilisation affects the field performance of plants. This led us to study the effect of three mineral nutrients (N, P and K) on both plant quality and frost tolerance. The experiment comprised eight growth treatments in which a high dose (H-) or a low dose (L-) of each nutrient was applied. Nitrogen was the nutrient that determined shoot growth, new root growth after transplanting (root egress), frost tolerance and field performance. Performance was better with treatment H-N than with treatment L-N, leaf nitrogen contents being 1.53 and 0.89% respectively. The effects of phosphorus and potassium were not significant between treatments for any parameter. The exception was P which, when interacting with N, favoured root egress for the H-N treatment. It was concluded that nursery fertilisation offers a management tool for eucalyptus growers concerned with plant stock quality.     

Identification of ISSR markers linked to flowering traits in a representative sample of <Emphasis Type="Italic">Eucalyptus cladocalyx</Emphasis>

Early flowering and flower abundance have long been considered desirable traits in eucalypt breeding programs. In particular, flowers of Eucalyptus cladocalyx provide a nectar source for the production of honey in arid ecosystems. To identify inter-simple sequence repeat (ISSR) markers that are associated with early flowering and flower abundance in the southern Atacama Desert, we used a sample of 47 trees, representing five Australian provenances of E. cladocalyx. A unified mixed linear model (which considered the effect of genetic structure and the kinship relationship among trees) revealed that three loci were significantly associated with early flowering, which accounted for 10–16 % of the phenotypic variation, while two loci accounted for 11–13 % in flowering intensity. Locus ISO_{1–500 bp} was associated with both flowering traits. This result is consistent with our previous findings indicating that marker-assisted selection on early flowering should have significant and positive impact on flowering intensity. The application of marker-assisted selection to identify trees that flower early and intensively may increase honey production, a resource that generates additional income for the local farmers of the southern Atacama Desert.     

Changes in the fatty acid profile of the subcutaneous fat of swine throughout fattening as affected by dietary conjugated linoleic acid and monounsaturated fatty acids

The fatty acid profile of the subcutaneous fat of pigs and its evolution throughout fattening as affected by dietary conjugated linoleic acid (CLA), monounsaturated fatty acids (MUFA), and their interaction (CLAxMUFA) were studied. Three levels (0, 1, and 2%) of an enriched CLA oil (28% cis-9, trans-11 and 28% trans-10, cis-12 CLA) were combined with two levels of MUFA (low, 19% average; and high, 39% average) for pig feeding (288 gilts). Subcutaneous shot-biopsies were taken from 48 animals at the beginning of the trial (S1, 70 kg), 14 days later (S2, 80 kg), and at slaughter (S3, 107 kg). Inclusion of CLA in the diet caused an increase during fattening in cis-9, trans-11 CLA, trans-10, cis-12 CLA, and saturated fatty acids (SFA) contents of pig backfat and a decrease in MUFA and polyunsaturated fatty acids (PUFA). MUFA supplementation also led to a MUFA enrichment of backfat. The interaction CLAxMUFA affected the SFA content. The rates of accumulation of CLA isomers, SFA, and MUFA throughout the trial did not follow a linear behavior, such rates being higher from S1 to S2 than from S2 to S3. These rates were also influenced by dietary CLA and MUFA levels. The increase in the ratio of saturated to unsaturated fatty acids of backfat caused by dietary CLA might be balanced by supplementation of pig diets with MUFA.