Transmission of Mycoplasma bovis infection in bovine in vitro embryo production

Mycoplasma bovis (M. bovis) causes several costly diseases in cattle and has a negative effect on cattle welfare. There is no effective commercial vaccine, and antimicrobial resistance is common. Maintaining a closed herd is the best method to minimize the risk of introduction of M. bovis. Assisted reproduction is crucial in a closed herd to make genetic improvements. M. bovis has been found in commercial semen, and contaminated semen has been the source of disease in naïve dairy herds. The objective of this study was to evaluate M. bovis transmission in bovine in vitro embryo production (IVP) using several possible exposure routes. We used a wild-type M. bovis strain isolated from semen at a final concentration of 106 CFU/mL to infect cumulus–oocyte complexes, spermatozoa, and 5-day-old embryos. We also used naturally contaminated semen in fertilization. Blastocysts were collected on day 7–8 and zona pellucida (ZP)-intact embryos were either washed 12 times, including trypsin washes as recommended by the International Embryo Technology Society (IETS), or left unwashed. Washed and unwashed embryos, follicular fluids, maturation medium, cumulus cells, fertilization medium, and G1 and G2 culture media, as well as all wash media were analyzed using enrichment culture followed by real-time PCR detection of M. bovis. Altogether, 76 pools containing 363 unwashed embryos and 52 pools containing 261 IETS washed embryos were analyzed after oocytes, spermatozoa, or 5-day-old embryos were infected with M. bovis or naturally contaminated semen was used in fertilization. We could not detect M. bovis in any of the embryo pools. M. bovis was not found in any of 12 wash media from different exposure experiments. M. bovis did not affect the blastocyst rate, except when using experimentally infected semen. Contrary to an earlier study, which used a cell co-culture system, we could not demonstrate M. bovis in embryo wash media or tight adherence of M. bovis to ZP-intact embryos. Naturally infected semen did not transmit M. bovis to embryos. We conclude that by using our IVP system, the risk of M. bovis transmission via IVP embryos to recipient cows is very low

Dietary supplement of conjugated linoleic acids or polyunsaturated fatty acids suppressed the mobilization of body fat reserves in dairy cows at early lactation through different pathways

To investigate the metabolic (.11, !I:2.es in the adipose tissue (AT) of dairy cows under milk fat depression (MFD), 30 cows were randomly allocated to a control diet, a conjugated linoleic acid (CLA)-supplemented diet, or a high-starch diet supplemented with a mixture of sunflower and fish oil (2:1; as HSO diet) from 1 to 112 d in milk. Performance of animals, milk yield, milk composition, energy balance, and blood metabolites were measured during lactation. Quantitative PCR analyses were conducted on the AT samples collected at wk 3 and 15 of lactation. The CLA and HSO diets considerably depressed milk fat yield and milk fat content at both wk 3 and 15 in the absence of significant changes in milk protein and lactose contents. In addition, the HSO diet lowered milk yield at wk 15 and decreased dry matter intake of cows from wk 3 to 15. Compared with the control, both CLA and HSO groups showed reduced body weight loss, improved energy balance, and decreased plasma concentrations of nonesterified fatty acids and beta-hydroxybutyrate at early lactation. The gene expression analyses reflected suppressed lipolysis in AT of the CLA and HSO groups compared with the control at wk 3, as suggested by the downregulation of hormone-sensitive lipase and fatty acid binding protein 4 and the upregulation of perilipin 2. In addition, the HSO diet promoted lipogenesis in AT at wk 15 through the upregulation of 1-acylglycerol-3-phosphate O-acyltransferase 2, mitochondria' glycerol-3-phosphate acyltransferase, perilipin 2, and peroxisome proliferator-activated receptor gamma. The CLA diet likely regulated insulin sensitivity in AT as it upregulated the transcription of various genes involved in insulin signaling, inflammatory responses, and ceramide metabolism, including protein kinase B2, nuclear factor kappa B1, toll-like receptor 4, caveolin 1, serine palmitoyltransferase long chain base subunit 1, and N-acylsphingosine amidohydrolase 1. In contrast, the HSO diet resulted in little or no change in the pathways relevant to insulin sensitivity. In conclusion, the CLA and HSO diets induced a shift in energy partitioning toward AT instead of mammary gland during lactation through the regulation of different pathways.Peer reviewe

The effect of chilling on the viability of in vitro produced bovine embyos

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Suomen ensimmäiset lampaan koeputkialkiot kehittyivät Luonnonvarakeskuksen laboratoriossa

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Suomen ensimmäiset lampaan koeputkialkiot kehittyivät Luonnonvarakeskuksen laboratoriossa

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Endometrial expression of progesterone, estrogen, and oxytocin receptors and of 20α-hydroxysteroid dehydrogenase and cyclooxygenase II 2 and 5 days after ovulation in induced short and normal estrous cycles in dairy cows

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The effect of diet on fatty acid composition of elongated bovine conceptuses

AbstraktiConceptus elongation is crucial for establishment of pregnancy in ruminants. During the elongation step, endometrium secreted lipids are required as a source of energy and for the remodeling and proliferation of cellular membranes (Ribeiro et al., Reprod 2016;152:R115-R126). The present study investigated the effects of diets designed to cause 15 % reduction in milk fat synthesis (milk fat depression) on fatty acid (FA) composition of elongated bovine conceptuses. The day-14 conceptuses were collected from 22 Nordic Red multiparous dairy cows during two sequential indoor housing periods. Treatments comprised a grass silage based basal diet (CO; 10 cows), basal diet supplemented with 12 g/d of rumen protected trans-10, cis-12 CLA (Lutrell Pure, BASF, Germany) (CLA; 8 cows), and grass silage based diet containing high-starch concentrate components and supplemented with 26.7 g/kg diet dry matter of sunflower oil and 13.3 g/kg diet dry matter of fish oil (MFD; 4 cows). CLA supplement was mixed in total mixed ration and administered in two equal proportions per day. Oil supplements replaced concentrate ingredients. Cows were randomly allocated to the treatments immediately after parturitions. The diets were total mixed rations with 55:45 forage:concentrate ratio on dry matter basis. In total of 45, 35 and 13 conceptuses having visible embryonic discs were used after recovery from the superovulated CO, CLA and MFD donors 130 days after parturitions, respectively. Lipids were extracted separately from each cryopreserved conceptus using a mixture of hexane and 2-propanol (3:2, vol/vol). FA were transesterified to methyl esters using methanolic sodium methoxide and analyzed with a gas chromatograph equipped with a flame ionization detector (Shingfield et al., Anim Sci 2003;77:165–179). Data were analyzed using linear mixed models with MIXED procedure in SAS 9.4. The proportions of the most abundant FA in conceptuses, cis-9 18:1 (30-32 g/100g FA, %), 16:0 (25-26 %), and 18:0 (12-14 %), did not differ between treatments (P > 0.10). In addition, total proportions of cis unsaturated FA (53-54 %) and saturated FA (43-45 %) and ratio of cis unsaturated FA to saturated FA was not different among treatments (P > 0.10). CLA had no effect on the conceptus’ FA composition compared with CO. However, MFD induced higher (P < 0.01) 22:6n-3, and lower (P < 0.05) 22:4n-6 and 22:5n-6 proportions compared with CLA and CO. The proportion of cis-12 18:1 and trans-9, cis-12 18:2, which are biohydrogenation products of 18:2n-6 found in rich amounts in sunflower oil, tended to be higher (P < 0.10) in MFD compared with other treatments. In conclusion, although CLA and MDF caused changes in lipogenesis in the mammary gland and milk fat depression, a substantial effect on the FA composition of conceptuses was not observed. However, unsaturated FA deriving from the MFD diet and metabolized in the rumen biohydrogenation processes had a specific impact on conceptus FA profiles during elongation stage.201

A splice donor variant in CCDC189 is associated with asthenospermia in Nordic Red dairy cattle

Background: Cattle populations are highly amenable to the genetic mapping of male reproductive traits because longitudinal data on ejaculate quality and dense microarray-derived genotypes are available for thousands of artificial insemination bulls. Two young Nordic Red bulls delivered sperm with low progressive motility (i.e., asthenospermia) during a semen collection period of more than four months. The bulls were related through a common ancestor on both their paternal and maternal ancestry. Thus, a recessive mode of inheritance of asthenospermia was suspected. Results: Both bulls were genotyped at 54,001 SNPs using the Illumina BovineSNP50 Bead chip. A scan for autozygosity revealed that they were identical by descent for a 2.98Mb segment located on bovine chromosome 25. This haplotype was not found in the homozygous state in 8557 fertile bulls although five homozygous haplotype carriers were expected (P=0.018). Whole genome-sequencing uncovered that both asthenospermic bulls were homozygous for a mutation that disrupts a canonical 5 splice donor site of CCDC189 encoding the coiled-coil domain containing protein 189. Transcription analysis showed that the derived allele activates a cryptic splice site resulting in a frameshift and premature termination of translation. The mutated CCDC189 protein is truncated by more than 40%, thus lacking the flagellar C1a complex subunit C1a-32 that is supposed to modulate the physiological movement of the sperm flagella. The mutant allele occurs at a frequency of 2.5% in Nordic Red cattle. Conclusions; Our study in cattle uncovered that CCDC189 is required for physiological movement of sperm flagella thus enabling active progression of spermatozoa and fertilization. A direct gene test may be implemented to monitor the asthenospermia-associated allele and prevent the birth of homozygous bulls that are infertile. Our results have been integrated in the Online Mendelian Inheritance in Animals (OMIA) database (https://omia.org/OMIA002167/9913/).Peer reviewe