Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in feedlot cattle, caused by multiple pathogens that become more virulent in response to stress. As clinical signs often go undetected and various preventive strategies failed, identification of genes affecting BRD is essential for selection for resistance. Selective DNA pooling (SDP) was applied in a genome wide association study (GWAS) to map BRD QTLs in Israeli Holstein male calves. Kosher scoring of lung adhesions was used to allocate 122 and 62 animals to High (Glatt Kosher) and Low (Non-Kosher) resistant groups, respectively. Genotyping was performed using the Illumina BovineHD BeadChip according to the Infinium protocol. Moving average of -logP was used to map QTLs and Log drop was used to define their boundaries (QTLRs). The combined procedure was efficient for high resolution mapping. Nineteen QTLRs distributed over 13 autosomes were found, some overlapping previous studies. The QTLRs contain polymorphic functional and expression candidate genes to affect kosher status, with putative immunological and wound healing activities. Kosher phenotyping was shown to be a reliable means to map QTLs affecting BRD morbidity.

SUMMARY: Moringa oleifera is a rich source of antioxidants and a promising feed for livestock, due to significant amounts of protein, vitamins, carotenoids and polyphenols, and negligible amounts of anti-nutritional factors. The current study tested whether ensiling would preserve the antioxidant capacity of M. oleifera plants, and assessed whether Moringa silage, fed as a substitute for maize silage, would confer health-promoting traits and affect milk production in dairy cows. To this end, hand-harvested M. oleifera plants were ensiled, with or without molasses and inoculants, in anaerobic jars at room temperature (25 °C) for 37 days. At the end of the storage period the silages were analysed for pH, lactic acid and acetic acid concentrations, aerobic stability, antioxidant capacity, polyphenols and protein content, and tocopherols and carotenoids concentrations. Moringa silages exhibited higher antioxidant capacity compared with fresh and dried Moringa plants, not related to polyphenol content but presumably attributed to accumulation of amino acids and low molecular weight peptides. Based on these findings, a large-scale ensiling protocol was implemented, followed by a feeding trial for dairy cows, in which Moringa silage replaced 263 g maize silage/kg in the diet. Cows fed Moringa silage had higher milk yield and antioxidant capacity and lower milk somatic cell counts compared with controls, during some stages of lactation. These findings imply that ensiling M. oleifera is an appropriate practice by which health and production of dairy cows can be improved.

Bovine respiratory disease complex (BRD), a major economic concern to the beef cattle industry all over the world, is triggered by physical, biological and psychological stresses. It is becoming noticeable that the key to reducing BRD appears to be centered at reducing the response to stress. The aims of the present study were to detect individual variations in the stress response of newly received young calves through their leukocyte heat shock protein (Hsp) response, selected neutrophil-related gene expression and oxidative stress, and relate them to pulmonary adhesions at slaughter, an indicative sign of clinical and subclinical episodes of BRD at an early age. Differential expression patterns of Hsp60 and Hsp70A1A were revealed in newly received calves 1 h, 5 h and 1 day after arrival, distinguishing between stress-responsive and non-stress-responsive individuals. Plasma cortisol was also indicative of stress-responsive and non-stress-responsive individuals, 1 h and 5 h after arrival. At the longer term, β-glycan levels were highest 7 days after arrival and significantly correlated with an adhesion-free phenotype at slaughter. Oxidative stress responses, measured through the oxidation products of the exogenous linoleoyl tyrosine (LT) marker, revealed that hydroperoxidation and epoxidation of membranes may readily occur. Based on the LT oxidation products and levels of β-glycan, we present a discriminant analysis model, according to which vulnerable individuals may be predicted at near 100% probability 7 days after arrival. Since clinical signs of BRD may often go undetected in feedlot calves, such a model, after its examination in large-scale experiments, may be a reliable tool for an early prediction of subclinical signs of BRD.