One-generation divergent selection on large and small yolk proportions in a White Leghorn line

1. A striking change in egg consumption from shell eggs toward egg products is taking place. Consequently, internal egg quality traits must be seen in a different light, as they may affect the profitability of the egg processing industry. In order to study the possibility of using breeding as a means to alter yolk production, a one-generation divergent selection experiment was set up. The trait was yolk proportion. The effect of hen's age on egg composition was also studied. Genetic parameters for yolk proportion, yolk weight, egg weight and albumen weight were estimated, using a multiple trait animal model, and restricted maximum likelihood. 2. Selection response was obtained for yolk proportion and correlated selection responses for yolk weight and albumen weight. In the 'high line' a decrease in egg weight and an increase in yolk weight was established, whereas in the 'low line', egg weight remained more or less the same and yolk weight decreased slightly 3. Yolk proportion, yolk weight, egg weight and albumen weight all increased with increasing age of the hen in both selection lines. The difference between selection lines in yolk proportion, yolk weight and albumen weight persisted throughout the laying period. 4. Estimated heritabilities for yolk proportion, yolk weight, egg weight and albumen weight were 0.38, 0.22, 0.34 and 0.41 respectively. The genetic correlation between yolk proportion and yolk weight was 0.52, whereas the genetic correlations with egg weight and albumen weight were -0.51 and -0.74 respectively. 5. We conclude that selection can be used to alter yolk production. Selection can be at an early age with a sustained effect throughout the laying period.     

A retrospective study of pathologic findings in the Amazon and Orinoco river dolphin (Inia geoffrensis) in captivity.

River dolphins are especially susceptible to negative human impacts. For their conservation, attempts of relocation or procreation ex situ may become important in the future to avoid their extinction. Additional knowledge and medical experiences of river dolphin management in captivity may aid such conservation efforts. The medical records and necropsy and histopathology reports on 123 captive Amazon River dolphins (Inia geoffrensis) were re-viewed. Of these 123 animals, 105 were necropsied and 70 necropsies were supported with histopathology. Eighteen animals were not necropsied. Among wild-born animals, mortality was highest in the first 2 mo immediately postcapture and transport, accounting for 32 of 123 deaths. Pneumonia and skin lesions (cutaneous and subcutaneous ulcerations and abscesses) were the most common findings, found in 44 of 105 (42%) and 38 of 105 (36%) of gross diagnoses, respectively. At least 10 of 44 cases of pneumonia diagnosed grossly included a verminous component. Cachexia, from a variety of causes, was a major gross finding in 21 animals. Fifteen animals had histologic evidence of significant renal pathology, and this was the primary cause of death in 13 cases. Hepatic pathology was found in 18 cases, and bacterial sepsis was confirmed via histology in 16 cases. Based on these findings, it may be concluded that keys to successful maintenance of this species include 1) prophylactic anthelminthic and antibiotic therapy immediately post-capture; 2) maintenance of animals in larger enclosures than in past attempts, in compatible groups, and in facilities capable of separating aggressive animals; 3) maintenance in microbiologically hygienic water quality at all times; and 4) a proactive program of preventive medicine during the immediate postcapture, quarantine, and maintenance period of captivity.     

Breeding for resistance: breeding for Plum pox virus resistant plums (Prunus domestica L.) in Germany

In German plum breeding programmes new varieties tolerant to Plum pox virus (PPV) were initially obtained by selecting hybrids originating from crossings between tolerant old varieties while, later on, sharka tolerant varieties bred in Čačak, Serbia were used as crossing partners. Varieties released from these programmes replaced the sensitive ones in all sharka infected regions in Germany. While all the new tolerant varieties can be infected by the virus, PPV symptoms on the fruits are acceptable. However, environmental factors can weaken the plant, causing them to suffer more from PPV infections and to display worse symptoms on fruits, as did occur during some recent very dry and warm years. A breeding programme at the University of Hohenheim is tackling this problem with genotypes that show a hypersensitive response after infection. These genotypes are completely field resistant to PPV, remaining virus free in the field since they cannot be infected via aphid transmission. They are able to isolate the virus after infection. The first hypersensitive variety was 'Jojo'. Many seedlings originating from crossings with at least one hypersensitive parent are under evaluation. Since the inheritance of the trait 'hypersensitivity against PPV' is very good, combining hypersensitivity with excellent fruit quality and good cropping capacity will be possible soon. In 2005, a breeding programme for hypersensitive Prunus genotypes began at the Technical University of Munich.     

The Effect of Levothyroxine Treatment on Resting Energy Expenditure of Hypothyroid Dogs

Thirty adult, client-owned dogs were diagnosed with hypothyroidism based on history, physical examination findings, hematologic and biochemical abnormalities, thyrotropin (TSH) response testing, endogenous canine thyrotropin (cTSH) concentration, or both, and total serum thryoxine concentration. All dogs received levothyroxine (L-thyroxine) at an initial dose of 22 μg/kg PO sid in either a tablet (13 dogs) or chewable form (17 dogs). Energy expenditure of each dog during apparent rest was estimated with an open-flow indirect calorimetry system by determining the rates of carbon dioxide production and oxygen consumption. Energy expenditure of apparent rest (EE) was lower in untreated hypothyroid dogs compared with reference values for EE. After treatment with L-thyroxine, EE of the hypothyroid dogs was significantly ( P < .05) higher than pretreatment values.     

Fungal decomposition of sapwood and heartwood of European aspen,Populus tremula L.

In contrast to the woodrotting fungi which can only attack Populus tremula after felling, Phellinus tremulae successfully invades the central part of the living tree. Possible causes for this difference were investigated. It was found that sterile wood samples were decomposed more rapidly by saprophytic fungi than by parasitic fungi. With both types of fungi, heartwood was more resistant to decay than sapwood. It is postulated that living sapwood inhibits infection by most woodrotting fungi, but that P. tremulae can successfully overcome this barrier. This postulate cannot be confirmed by experiments using sterilized wood samples.     

Isolation and determination of alpha-dicarbonyl compounds by RP-HPLC-DAD in green and roasted coffee

Glyoxal, methylglyoxal, and diacetyl formed as Maillard reaction products in heat-treated food were determined in coffee extracts (coffee brews) obtained from green beans and beans with different degrees of roast. The compounds have been reported to be mutagenic in vitro and genotoxic in experimental animals in a number of papers. More recently, alpha-dicarbonyl compounds have been implicated in the glycation process. Our data show that small amounts of glyoxal and methylglyoxal occur naturally in green coffee beans. Their concentrations increase in the early phases of the roasting process and then decline. Conversely, diacetyl is not found in green beans and forms later in the roasting process. Therefore, light and medium roasted coffees had the highest glyoxal and methylglyoxal content, whereas dark roasted coffee contained smaller amounts of glyoxal, methylglyoxal, and diacetyl. For the determination of coffee alpha-dicarbonyl compounds, a reversed-phase high performance liquid chromatography with a diode array detector (RP-HPLC-DAD) method was devised that involved the elimination of interfering compounds, such as chlorogenic acids, by solid phase extraction (SPE) and their derivatization with 1,2-diaminobenzene to give quinoxaline derivatives. Checks of SPE and derivatization conditions to verify recovery and yield, respectively, resulted in rates of 100%. The results of the validation procedure showed that the proposed method is selective, precise, accurate, and sensitive.     

Carbon dynamics and stability between native Masson pine and exotic slash pine plantations in subtropical China

Afforestation and ecological restoration have often been carried out with fast-growing exotic tree species because of their high apparent growth and yield. Moreover, fast-growing forest plantations have become an important component of mitigation measures to offset greenhouse gas emissions. However, information on the long-term performance of exotic and fast-growing species is often lacking especially with respect to their vulnerability to disturbance compared to native species. We compared carbon (C) storage and C accumulation rates in vegetation (above- and belowground) and soil in 21-year-old exotic slash pine (Pinus elliottii Engelm.) and native Masson pine (Pinus massoniana Lamb.) plantations, as well as their responses to a severe ice storm in 2008. Our results showed that mean C storage was 116.77 ± 7.49 t C ha^?1 in slash pine plantation and 117.89 ± 8.27 t C ha^?1 in Masson pine plantation. The aboveground C increased at a rate of 2.18 t C ha^?1 year^?1 in Masson pine and 2.23 t C ha^?1 year^?1 in slash pine plantation, and there was no significant difference in C storage accumulation between the two plantation types. However, we observed significant differences in ice storm damage with nearly 7.5 % of aboveground biomass loss in slash pine plantation compared with only 0.3 % loss in Masson pine plantation. Our findings indicated that the native pine species was more resistant to ice storm because of their adaptive biological traits (tree shape, crown structure, and leaf surface area). Overall, the native pine species might be a safer choice for both afforestation and ecological restoration in our study region.