The mouse represents the model of choice to study the biological function of mammalian genes through mutation of its genome. However, the biggest challenge of mouse geneticists remains the phenotypic analysis of mouse mutants. A survey of mouse mutant databases reveals a surprisingly high number of gene mutations leading to neonatal death. These genetically modified mouse mutants have been inst...

The relationships between cow nutrition, restricted suckling and milking patterns and their effect on milk yield, milk composition and calf growth were examined under tropical conditions in south east Mexico. Eleven Bos indicus 3 Bos taurus cows, 14 days postpartum, with calves weighing on average 37 kg were used in a change-over experimental design. All cows were fed Cynodon nlemfuensis hay ad...

The aim of this study was to investigate if a 2-step method of preventing suckling and cow-calf separation reduces the stress reaction in foster cows compared with a simultaneous separation method. Seven Swedish Holstein and 5 Swedish Red dairy cows were used as foster cows, each having a group of 4 calves. The foster cow-calf group was formed when calves were 1 wk old, and the calves were prev...

The endocannabinoid system, including its receptors (CB(1) and CB(2)), endogenous ligands ('endocannabinoids'), synthesising and degrading enzymes, as well as transporter molecules, has been detected from the earliest stages of embryonic development and throughout pre- and postnatal development. In addition, the endocannabinoids, notably 2-arachidonyl glycerol, are also present in maternal milk...

Background RFamide-related peptide-3 (RFRP-3) inhibits gonadotropin releasing hormone (GnRH) and luteinizing hormone (LH) secretion in rats. This study evaluates the effects of litter size and suckling intensity on RFRP mRNA expression in the dorsomedial hypothalamic nucleus (DMH) of rats. MaterialsAndMethods A total of 32 pregnant and 4 non-lactating ovariectomized (control group) Sprague-Dawl...

BACKGROUND Vanadium is an important environmental and industrial pollutant. It has a status of reproductive toxicant and is reported to cross placental barrier. OBJECTIVE The current study was performed to assess the therapeutic efficacy of Tiron and its combination with selenium against vanadium induced toxicity in lactating and suckling rats. MATERIALS AND METHODS Rats were exposed to van...

Transcriptome analyses were conducted on the ileal mucosa of 14- to 35-day-old piglets to investigate postnatal gut development during suckling and postweaning. The transcriptome profiles of 14-day-old suckling piglets showed a considerably higher number of differentially expressed genes than did those of 21-, 28-, and 35-day olds, indicating an intensive gut development during the first 14-21 ...

The form, function and fibre-type profiles of the ilio-marsupialis muscles, branches of which insert on to the skin of the nipples and pouch, have been investigated in the small dasyurid marsupial Sminthopsis douglasi. Single fibres from the branches of muscles associated with unsuckled nipples in non-lactating females and with both unsuckled and suckled nipples at four stages during the 70-day...

Care of offspring is a form of affiliative behavior that is fundamental to studies of animal social behavior. Insects do not figure prominently in this topic because Drosophila melanogaster and other traditional models show little if any paternal or maternal care. However, the eusocial honey bee exhibits cooperative brood care with larvae receiving intense and continuous care from their adult s...

Examination of yolk sac from a C3Hf and a C3H mouse with the electron microscope revealed the presence of C-type virus particles in the blood islands. Particles were observed budding from the plasma membrane of hemocytoblasts, from erythroblasts, and occasionally from reticulocytes. C-type particles were also found in similar cells in hematopoietic foci in the liver, spleen, and bone marrow of ...