The use of milk Fourier transform midinfrared spectra and milk yield to estimate heat production as a measure of efficiency of dairy cows

Background:Transformation of feed energy ingested by ruminants into milk is accompanied by energy losses via fecal and urine excretions,fermentation gases and heat.Heat production may differ among dairy cows despite comparable milk yield and body weight.Therefore,heat production can be considered an indicator of metabolic efficiency and directly measured in respiration chambers.The latter is an accurate but time-consuming technique.In contrast,milk Fourier transform mid-infrared(FTIR)spectroscopy is an inexpensive high-throughput method and used to estimate different physiological traits in cows.Thus,this study aimed to develop a heat production prediction model using heat production measurements in respiration chambers,milk FTIR spectra and milk yield measurements from dairy cows.Methods:Heat production was computed based on the animal’s consumed oxygen,and produced carbon dioxide and methane in respiration chambers.Heat production data included 16824-h-observations from 64 German Holstein and 20 dual-purpose Simmental cows.Animals were milked twice daily at 07:00 and 16:30 h in the respiration chambers.Milk yield was determined to predict heat production using a linear regression.Milk samples were collected from each milking and FTIR spectra were obtained with MilkoScan FT 6000.The average or milk yield-weighted average of the absorption spectra from the morning and afternoon milking were calculated to obtain a computed spectrum.A total of 288 wavenumbers per spectrum and the corresponding milk yield were used to develop the heat production model using partial least squares(PLS)regression.Results:Measured heat production of studied animals ranged between 712 and 1470 kJ/kg BW0.75.The coefficient of determination for the linear regression between milk yield and heat production was 0.46,whereas it was 0.23 for the FTIR spectra-based PLS model.The PLS prediction model using weighted average spectra and milk yield resulted in a cross-validation variance of 57%and a root mean square error of prediction of 86.5 kJ/kg BW0.75.The ratio of performance to deviation(RPD)was 1.56.Conclusion:The PLS model using weighted average FTIR spectra and milk yield has higher potential to predict heat production of dairy cows than models applying FTIR spectra or milk yield only.

A 314-bp SINE insertion in the ZNF2 promoter region may act as a repressor related to regulation of fat deposition in pigs

Retrotransposons,a type of DNA fragment that can mobilize itself on genome,can generate genetic variations and develop for molecular markers based on the insertion polymorphism.Zinc finger proteins(ZNFs)are among the most abundant proteins in eukaryotic animals,and their functions are extraordinarily diverse and particularly important in gene regulation.In the current study,bioinformatic prediction was performed to screen for retrotransposon insertion polymorphisms(RIPs)in six ZNF genes(ZNF2,ZNF3,ZNF7,ZNF8,ZNF10 and ZNF12).Six RIPs in these ZNFs,including one short interspersed nuclear element(SINE)RIP in intron 1 and one long interspersed nuclear element 1(L1)RIP in intron 3 of ZNF2,one SINE RIP in 5′flanking region and one SINE RIP in intron 2 of ZNF3,one SINE RIP in 3′UTR of ZNF7 and one L1 RIP in intron 2 of ZNF12,were discovered and their presence was confirmed by PCR.The impact of the SINE RIP in the first intron of ZNF2,which is close to the core promoter of ZNF2,on the gene activity was investigated by dual-luciferase assay in three cell lines.Our results showed that the SINE insertion in the intron 1 of ZNF2 repressed the core promoter activity extremely significantly(P<0.01)in cervical cancer cells and porcine primary embryonic fibroblasts(HeLa and PEF),thus SINE may act as a repressor.This SINE RIP also significantly(P<0.05)affected the corrected back fat thickness in Yorkshire pigs.The corrected back fat thickness of individuals with SINE insertion in the first intron of ZNF2 was significantly(P<0.05)higher than that of individuals without SINE insertion.In summary,our data suggested that RIPs play important roles in the genetic variations of these ZNF genes and SINE RIP in the intron 1 of ZNF2 may provide a useful molecular marker for the screening of fat deposition in the pig breeding.

Two new SINE insertion polymorphisms in pig Vertnin(VRTN)gene revealed by comparative genomic alignment

Despite one SINE retrotransposon insertion polymorphism(sRTIP)in the vertebrae development-associated(VRTN)gene was identified in pigs,the structural variations(SVs)in VRTN gene and its proximal flank regions were largely unknown.VRTN genic and flanking sequences from 14 breeds were assembled or downloaded from whole genome shotgun contings(WGS)database,and aligned to identify the SVs with Clustalx,and retrotransposons in VRTN gene were annotated by RepeatMasker,the splicing patterns of VRTN gene were predicted by Genescan,and large SVs were evaluated by PCR.A total of 12 small SVs and three large SVs in intron of VRTN,derived from SINE insertion polymorphisms.were identifed,and two of them(VRTN-sRTIP2 and VRTN-sRTIP3)were not reported before.These VRTN-sRTIPs may affect the splicing patterns of VRTN.They displayed polymorphisms in most detected eight breeds.VRTN-sRTIP2 and VRTN-sRTIP3 showed Hardy-Weinberg equilibrium distributions in most populations except the Chinese local Erhualian pigs,while VRTN-sRTIP1 showed genetic equilbrium in Erhualian pigs.Three VRTN-sRTIPs were identified,and displayed polymorphisms in pigs,and two of them were not reported before.These SVs provide a useful molecular markers for genetic analysis in pigs,and offer new information to facilitate the understanding the SVs of VRTN gene and their putative roles in the variation of vertebral number.

Assessing animal individuality:links between personality and laterality in pigs

Animal individuality is challenging to explain because individual differences are regulated by multiple selective forces that lead to unique combinations of characteristics.For instance,the study of personality,a core aspect of individuality,may benefit from integrating other factors underlying individual differences,such as lateralized cerebral processing.Indeed,the approach-withdrawal hypothesis(the left hemisphere controls approach behavior,the right hemisphere controls withdrawal behavior),may account for differences in boldness or exploration between left and right hemispheric dominant individuals.To analyze the relationships between personality and laterality we tested 80 male piglets with established laterality patterns for 2 motor functions(tail curling direction and the side of the snout used for manipulation)and a combined classification integrating both motor functions using cluster analysis.We analyzed basal salivary testosterone and cortisol along with their behavior in standardized tests as pre-established indicators of different personality traits(Boldness,Exploration,Activity,Sociability,and Coping).We found that the direction of the single motor biases showed significant associations with few personality traits.However,the combined laterality classification showed more,and more robust,significant associations with different personality traits compared with the single motor biases.These results supported the approachwithdrawal hypothesis because right-biased pigs were bolder and more explorative in a context of novelty.Additionally,right-biased pigs were more sociable than left-biased pigs.Therefore,the present study indicates that personality is indeed related to lateralized cerebral processing and provides insight into the multifactorial nature of individuality.

Endogenously increased n-3 PUFA levels in fat-1 transgenic mice do not protect from non-alcoholic steatohepatitis

Background:Non-alcoholic fatty liver disease(NAFLD)is the most common chronic liver diseaseworldwide,ranging from simple steatosis to non-alcoholic steatohepatitis(NASH)and fibrosis.Possiblereasons for the NAFLD epidemic in industrialized countries are the high intake of pro-inflammatory n-6polyunsaturated fatty acids(n-6 PUFAs)and low consumption of healthy n-3 PUFAs.Due to their antiinflammatoryproperties,n-3 PUFAs may have the potential to alleviate chronic liver disease.Herein,weexamined the therapeutic effect of increased n-3 PUFA tissue levels in fat-1 transgenic mice on progressiveNASH.Methods:Disease was induced in mice by streptozotocin and high fat diet(STZ/HFD)resulting in NASH.NAFLD in 6 and 8 weeks old wild type and fat-1 transgenic STZ/HFD treated mice was analyzed.Unlikeall other mammals,fat-1 transgenic mice ubiquitously express an n-3 fatty acid desaturase,which converts n-6to n-3 PUFAs,leading to increased n-3 and decreased n-6 PUFA tissue contents.Results:Liver damage,NAFLD activity score(NAS),hepatic lipid accumulation and inflammation weresignificantly reduced in fat-1 transgenic STZ/HFD treated mice in the early(6 weeks)but not late(8 weeks)phase of NASH.Simultaneously,mRNA expression of genes involved in fatty acid uptake and storage(Cd36and Plin3,respectively)was significantly down-regulated in 6 week old but not 8 week old fat-1 transgenicSTZ/HFD treated mice.Conclusions:Endogenously elevated n-3 PUFA levels in fat-1 transgenic mice transiently delay the onsetof STZ/HFD induced NASH but failed to efficiently protect from NASH development.