Plasma leptin in growing lambs as a potential predictor for carcass composition and daily gain.

Leptin is an adipocyte derived hormone and correlates highly to the extent of body fat tissue. The aim of this study was to determine if leptin could serve as an early predictor for carcass composition and final growth rate in lambs with special emphasis on size and cellularity of the different body fat depots. Thirty intact male ad libitum fed lambs were blood sampled at 20, 25, 30, 35, and 40kg live weight.

The relationships between leptin concentrations and body fat reserves in lambs are reduced by short-term fasting.

Feed deprivation decreases plasma leptin concentrations depending on the amount of body fat reserves. While a greater response was observed in lean than in fat humans and rats, a few results for ruminants are inconsistent. The objective of this study was to determine the influence of feed deprivation on plasma leptin concentration in growing lambs with different body fat reserves and on the relationship between leptin and fatness.

Identification and analysis of putative regulatory sequences for the MYF5/MYF6 locus in different vertebrate species.

The myogenic factors (MYF) 5 and 6 are integral to the initiation and development of skeletal muscle and to the maintenance of its phenotype. Thus, they are candidate genes for growth- and meat quality-related traits. We performed a comparative sequence analysis of the MYF5/MYF6 locus in swine, cattle, dog, chicken and zebrafish on the basis of structural and functional information from human and mouse.

Prediction of intramuscular fat by impedance spectroscopy.

Multiple multi-frequency impedance measurements during the computer controlled passage of a probe through the M. longissimus dorsi in pork and beef were applied. It was expected that the variability in impedance would correlate with the intramuscular fat (IMF) due to the inhomogeneous distribution of electrolytes and fat.

Relationship between plasma leptin concentrations and carcass composition in fattening mutton: a comparison with ultrasound results.

Positive relationships between circulating leptin concentrations and body fat content have been established in sheep when covering a rather broad range of age and/or body weight. The usefulness of leptin measurements for predicting carcass fat has yet to be evaluated specifically in fattening lambs. We therefore measured plasma leptin concentrations in 56 male lambs half and half Merino Mutton and Blackheaded Mutton.

Prediction of carcass composition by impedance spectroscopy in lambs of similar weight.

Previous research on impedance measurements for the prediction of carcass composition was predominantly carried out on animals that varied widely in body weight, breed, or sex. The high accuracy for the estimated lean or fat mass was mainly obtained by including the body weight in the regression equations. The objective of this study was the prediction of carcass composition in lambs of similar weight.

Outdoor use, tonic immobility, heterophil/lymphocyte ratio and feather condition in free-range laying hens of different genotype.

1. Movement (frequency of changes) between inside and outside housing areas, time spent in each area, tonic immobility (TI) and differential blood cell counts were studied in relation to feather condition in laying hens of two genotypes, white (LSL) and brown (LT). 2.

Prediction of lamb carcass composition by impedance spectroscopy.

The objective of this study was to compare impedance spectroscopy with resistance measurements at a single frequency (50 kHz) for the prediction of lamb carcass composition. The impedance spectrum is usually recorded by measuring the complex impedance at various frequencies (frequency domain); however, in this study, we also applied the faster and simpler measurement in the time domain (application of a current step and measurement of the voltage response). The study was carried out on 24 male, German Black-headed Mutton lambs with an average BW of 45 kg.

Characterization of the porcine CDKN3 gene as a potential candidate for congenital splay leg in piglets.

Congenital splay leg is a hereditary disease observed in newborn piglets. The etiology and pathogenetic mechanism of the disorder are still unknown. The gene for cyclin-dependent protein kinase inhibitor 3 (CDKN3) was identified as a potential candidate gene in a differential display experiment.

The influence of the ovulation rate on ultrasonically determined ovine corpus luteum morphometry and progesterone concentrations in cyclic and early pregnant sheep.

The objective of the present study was to describe morphology and function of the Corpora lutea (CL) during the oestrous cycle and early pregnancy in sheep with different ovulation rates. In total 40 Booroola. Mutton Merino crosses [heterozygous carriers (FecBFec+) and non-carriers (Fec+Fec+) of the Booroola-fecundity gene (FecB)] with ovulation rates 1 to 4 were examined.

Effect of long-term heat exposure on peripheral concentrations of heat shock protein 70 (Hsp70) and hormones in laying hens with different genotypes.

1. The effect of long-term, moderate heat stress (30 to 32 degrees C) on heat shock protein 70 (Hsp70) concentration in mononuclear blood cells and plasma concentrations of 3,5,3'-triiodothyronine (T3) and corticosterone in laying hens was investigated. 2.

Isolation of expressed sequence tags of skeletal muscle of neonatal healthy and splay leg piglets and mapping by somatic cell hybrid analysis.

We have isolated 14 differentially displayed and 10 further expressed sequence tags (ESTs) from Musculus biceps femoris of newborn healthy and splay leg piglets. By comparison with EMBL/GenBank data we could identify nine porcine homologues to human genes (TATA box binding protein associated factor B TAF1B; B-cell CLL/lymphoma 7B BCL7B; pyruvate dehydrogenase kinase, isoenzyme 4 PDK4; ribosomal protein S10 RPS10; SPARC-like 1 SPARCL1; epithelial protein lost in neoplasm beta EPLIN; N-myc downstream-regulated gene 2 NDRG2; pleiomorphic adenoma gene like 2 PLAGL and, BCL-2 associated transcription factor short form BTFS). Eight fragments correspond to uncharacterized ESTs and 7 ESTs had no significant match with database sequences.