Emphasizes the judgemental elements of interpretation in clinical pathology, hematology, clinical chemistry, and cytology. Features over 100 case histories covering all species. Each chapter, exclusive of those on technique, has a brief introduction followed by case discussions. Cases presented exemplify laboratory alterations associated with the disease affecting the system under review, and some cases can be used for self-evaluation.

Veterinary clinical pathology

The major goals of the poultry industry are to increase the carcass yield and to reduce carcass fatness, mainly the abdominal fat pad. The increase in poultry meat consumption has guided the selection process toward fast-growing broilers with a reduced feed conversion ratio. Intensive selection has led to great improvements in economic traits such as body weight gain, feed efficiency, and breast yield to meet the demands of consumers, but modern commercial chickens exhibit excessive fat accumulation in the abdomen area. However, dietary composition and feeding strategies may offer practical and efficient solutions for reducing body fat deposition in modern poultry strains. Thus, the regulation of lipid metabolism to reduce the abdominal fat content based on dietary composition and feeding strategy, as well as elucidating their effects on the key enzymes associated with lipid metabolism, could facilitate the production of lean meat and help to understand the fat-lowering effects of diet and different feeding strategies.

https://e-sc.org/upload/ajas/pdf/ajas-27-7-1057-20.pdf

Nutritional Factors Affecting Abdominal Fat Deposition in Poultry: A Review

Marks Basic Medical Biochemistry, A Clinical Approach

During last decades there has been a growing interest in the potential uses of L-carnitine (LC) as a medicinal agent as well as a nutritional/dietary supplement. In addition to a great interest from medical sciences, carnitine received a substantial attention from pig and poultry industry.The molecular mechanisms accounting for the positive effect of LC on many physiological parameters in farm animals and poultry are not yet fully understood but many protective effects of LC reported in literature, have been postulated to be related to its antioxidant action. However, by the time of writing no comprehensive review on this subject has appeared.Based on the analysis of the recent publications it could be concluded that antioxidant action of carnitine is related to: 1. Its direct scavenging free radicals; 2. Chelating catalytic metals-promoters of reactive oxidative species (ROS), such as Fe and Cu; 3. Maintaining mitochondria integrity in stress conditions and preventing ROS formation; 4. Inhibiting ROS-generating enzymes, such as XO and- NAPDH oxidases; 5. Affecting redox-signaling via activation of Nrf2 and PPARα and inhibition of NF-κB with additional synthesis of antioxidant enzymes (SOD, GSH-Px, GR, GST, CAT, etc.) and small antioxidant molecules (GSH); 6. Regulating vitagenes and synthesis of HSPs, sirtuins, thioredoxins and other antioxidant molecules. It seems likely that in biological system in vivo all the aforementioned mechanisms are involved and their interactions provide an important place for carnitine to be a crucial part of the integrated antioxidant systems of the animal and human body. Therefore, carnitine participation in redox signaling and affecting transcription factors (Nrf2, PPARα, NF-κB, etc.) as well as activating the vitagene network are main mechanisms responsible for antioxidant action of LC and its derivatives. Taking into account low carnitine content in grains and poultry and pig diet formulations with limited amounts of animal proteins, carnitine requirement and possible inadequacy in commercial poultry and pig nutrition should receive more attention. Furthermore, protective roles of carnitine in stress conditions of commercial poultry and pig production are difficult to overestimate. Therefore, a development of carnitine-containing antioxidant compositions supplying via drinking water seems to be an important way forward in decreasing the detrimental consequence of various stresses in poultry and pig production.

https://www.ecronicon.com/ecve/pdf/ECVE-02-000010.pdf

Antioxidant Action of Carnitine: Molecular Mechanisms and Practical Applications

National Basic Research Program of China (973 program 2014CB138603), National Natural Science Fund (31472290 and 31772859) and Fundamental Research Funds for the Central Universities

The metabolic regulation of dietary L-carnitine in aquaculture nutrition: present status and future research strategies

The present study was conducted to determine the effects of dietary metabolisable energy (ME) density and L-carnitine supplementation on the performance, carcass traits and blood parameters of broiler chickens. The experiment was designed with three levels of dietary energy (low, medium and high) and two levels of L-carnitine (0 and 100 mg/kg diet) in a 3x2 factorial arrangement. L-carnitine supplementation did not significantly affect body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR). However, FCR and BWG showed a significant improvement as dietary energy density increased. No significant interactions were observed between energy density and L-carnitine supplementation in the performance and carcass parameters studied in the study. Carcass yield and proportion of carcass sections were not affected significantly by any of the treatments. Chemical composition of the leg (thigh and drumstick) and breast muscle was not significantly influenced by dietary energy or carnitine, with the exception of the dry matter (DM) content of breast muscle. A low ME diet caused a significant increase in the DM content of chicken breast muscle. Furthermore, blood parameters did not show any differences between treatments. However, aspartate aminotransferase (AST) activity in blood was elevated in chickens fed a high ME diet compared to those on a low ME diet. The results of the investigation showed that L-carnitine supplementation produced no significant improvement in broiler performance and meat quality. Higher levels of diet ME increased broiler performance, though no significant interactions could be found between energy and carnitine levels. South African Journal of Animal Science Vol. 37 (2) 2007: pp. 65-73

/pdf/effects-of-dietary-energy-density-and-l-carnitine-3i1akkt44f.pdf

Effects of dietary energy density and L-carnitine supplementation on growth performance, carcass traits and blood parameters of broiler chickens

L-carnitine has indispensable functions in intermediary metabolism and is received by endogenous synthesis and from exogenous sources. It plays an obligate role in fatty acid metabolism by directing fatty acids into the mitochondrial oxidative pathway through the action of specialised acyltransferases. In poultry production, L-carnitine has a multi functional purpose, which includes: growth promotion, strengthening the immune system, antioxidant effects and improving semen quality. The concentration of L-carnitine in animals varies widely across species, tissue type, and nutritional status of the animal. It has been suggested that the L-carnitine requirement may be increased under certain circumstances such as via higher performance, various stress conditions and where the diet is deficient in animal protein sources. The review of L-carnitine functions uniquely includes the main aspects of this consequential feed supplementary inclusion in poultry nutrition.

L-carnitine and its functional effects in poultry nutrition

To test phytase efficiency, 4 dietary treatments including a positive control (T1), negative control (T2, containing 0.10% less total phosphorus than T1), negative control plus 500 FTU phytase (T3), and low-negative control plus 500 FTU phytase (T4, containing 0.13% less total phosphorus than T1) were used. Reducing the available phosphorus level of the broiler diet from 0.47% to 0.37% during the starter, and from 0.37% to 0.26% during the grower-finisher period significantly (P<0.01) depressed growth performance as compared with T1. Phytase supplementation significantly (P<0.01) improved the growth performance of the birds for both starter and grower periods. Tibia ash and phosphorus content in both the T3 and T4 groups were similar to T1 and higher (P<0.01) than in T2. Phytase supplementation of both negative control diets significantly (P<0.01) reduced the phosphorus level in excreta. It can be concluded that with phytase supplementation, the total phosphorus level in broiler diets can be decreased by 0.13%.

http://www.jafs.com.pl/pdf-66142-5636?filename=The effects of phytase.pdf

The effects of phytase supplementation and dietary phosphorus level on performance and on tibia ash and phosphorus contents in broilers fed maize-soya-based diets.

M. Corduk

Papers

Effects of dietary energy density and L-carnitine supplementation on growth performance, carcass traits and blood parameters of broiler chickens

L-carnitine and its functional effects in poultry nutrition

The effects of phytase supplementation and dietary phosphorus level on performance and on tibia ash and phosphorus contents in broilers fed maize-soya-based diets.