Effect of LEPR,ABCG2 and SCD1 Gene Polymorphisms on Reproductive Traits in the Iranian Holstein Cattle

During the last decades, genetic selection for milk production traits has led to increased fertility and health problems in dairy cattle. The aim of this study was to investigate the impact of three polymorphisms located in the ATP‐binding cassette superfamily G member 2 transporter (ABCG2), stearoyl‐CoA desaturase 1 (SCD1) and leptin receptor (LEPR) genes on reproductive traits and somatic cell count (SCC). The analysis was conducted on 408 randomly selected cows. The SNPs within the genes (LEPR, ABCG2 and SCD1) were genotyped using the PCR‐RFLP method. All three possible genotypes were observed for SCD1‐T878C and LEPR‐T945M SNPs, but not for ABCG2‐Y581S SNP. LEPR‐T945M and ABCG2‐Y581S SNPs had no statistically significant effect on the studied reproductive traits and SCC. However, SCD1‐T878C SNP were negatively and significantly related to pregnancy length, dry days and open days (p < 0.05), which lead to decreased profitability in dairy herds. The results suggest that the T878C SNP of SCD1 might be useful as a DNA marker to decrease reproductive problems and improve production traits in Iranian Holstein dairy cows.     

Involvement of breast cancer resistance protein (BCRP/ABCG2) in the secretion of danofloxacin into milk: interaction with ivermectin

Danofloxacin, a veterinary fluoroquinolone antimicrobial drug, is actively secreted into milk by an as yet unknown mechanism. One of the main determinants of active drug secretion into milk is the transporter (BCRP/ABCG2). The main purpose was to determine whether danofloxacin is an in vitro substrate for Bcrp1/BCRP and to assess its involvement in danofloxacin secretion into milk. In addition, the role of potential drug-drug interactions in this process was assessed using ivermectin. Danofloxacin was transported in vitro by Bcrp1/BCRP, and ivermectin efficiently blocked this transport. Experiments with Bcrp1(-/-) mice showed no evidence of the involvement of Bcrp1 in plasma pharmacokinetics of danofloxacin. However, the milk concentration and milk-to-plasma ratio of danofloxacin were almost twofold higher in wild-type compared with Bcrp1(-/-) mice. The in vivo interaction with ivermectin was studied in sheep after co-administration of danofloxacin (1.25 mg/kg, i.m.) and ivermectin (0.2 mg/kg, s.c.). Ivermectin had no significant effect on the plasma levels of danofloxacin but significantly decreased danofloxacin concentrations in milk by almost 40%. Concomitant administration of multiple drugs, often used in veterinary therapy, may not only affect their pharmacological activity but also their secretion into milk, because of potential drug-drug interactions mediated by BCRP.     

Identification of the variant C of β-lactoglobulin in sheep using a polymerase chain reaction-restriction fragment length polymorphism method

β-Lactoglobulin (β-LG) is the major whey protein in the milk of ruminants and is able to bind and transport small hydrophobic molecules. However, its biological role is mainly unknown (G odovac -Z immermann 1988). Previously three genetic variants have been found in sheep: A, B and C. The genetic variants A and B differ at amino acid position 20, where variant A has a His and variant B has a Thr (K olde and B raunitzer 1983). The variant C is a subtype of variant A with a single amino acid exchange of Arg→Glu at position 148 (E rhardt et al. 1989). The genotype β-LG BB was found to be associated with higher milk yield, whereas genotypes AA and AB had a higher milk protein and casein content as well as yielding more curd (G arzon and M artinez 1992). No data is available concerning the relationship between the β-LG C allele and production traits or milk properties. Since DNA-based genotyping has already been performed for alleles A and B (S chlee et al. 1993), the aim of the present study was to develop a DNA-based method for identifying the β-LG C variant. However polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) typing has been established (P rinzenberg and E rhardt 1999) recently, and this study shows an alternative method to detect β-LG C.     

ABCG2 transporter: therapeutic and physiologic implications in veterinary species

Drug transporters significantly influence drug pharmacokinetics and pharmacodynamics. While P-glycoprotein, the product of the MDR1 (ABCB1) gene, is the most well-characterized ABC transporter, the pharmacological importance of a related transporter, ABCG2, is starting to be realized in veterinary medicine. Based primarily on human and rodent studies, a number of clinically relevant, structurally and functionally unrelated drugs are substrates for ABCG2. ABCG2 is expressed by a variety of normal tissues including the intestines, renal tubular cells, brain and retinal capillary endothelial cells, biliary canalicular cells, and others, where it functions to actively extrude substrate drugs. In this capacity, ABCG2 limits oral absorption of substrate drugs and restricts their distribution to privileged sites such as the brain and retina. ABCG2 is also expressed by tumor cells where it functions to limit the intracellular accumulation of cytotoxic agents, contributing to multidrug resistance. Several ABCG2 polymorphisms have been described in human patients, some of which result in altered drug disposition, increasing susceptibility to adverse drug reactions. Additionally, ABCG2 polymorphisms in humans have been associated with disease states such as gout. Feline ABCG2 has recently been demonstrated to have several amino acid differences at conserved sites compared with 10 other mammalian species. These amino acid differences adversely affect transport function of feline ABCG2 relative to that of human ABCG2. Furthermore, these differences appear to be responsible for fluoroquinolone-induced retinal toxicity in cats and may play a role in acetaminophen toxicity as well. Studies in rodents and sheep have determined that ABCG2 expressed in mammary tissue is responsible for the secretion of many compounds (both therapeutic and toxic) into milk. Finally, data in rodent models suggest that ABCG2 may play an important role in regulating a number of physiologic pathways involved in protecting erythrocytes from oxidative damage.     

Comparative quantification of the in vitro activity of veterinary fluoroquinolones

The aim of this study was to compare the in vitro antimicrobial activity of the veterinary fluoroquinolones against a panel of recently isolated porcine and bovine bacterial pathogens. The study used enrofloxacin as a benchmark against which other agents were compared, being the most common fluoroquinolone used in treatment of bovine and porcine infections. The activity of ciprofloxacin was also assessed as it is the main metabolite of enrofloxacin in cattle. Enrofloxacin and ciprofloxacin generally showed higher antibacterial activity, in terms of MIC(50) values, for most pathogen species when compared with marbofloxacin, difloxacin, danofloxacin and norfloxacin. Ciprofloxacin showed significantly greater in vitro antibacterial activity than enrofloxacin against M. haemolytica, P. multocida and E. coli, whereas enrofloxacin showed greater activity than ciprofloxacin against S. aureus. Marbofloxacin was significantly more active than enrofloxacin against M. haemolytica, E. coli and B. bronchiseptica but less active against P. multocida, S. aureus, coagulase negative Staphylococci, S. dysgalactiae, S. uberis, A. pleuropneumoniae and S. suis. Danofloxacin was significantly less active than enrofloxacin against P. multocida, E. coli, S. uberis, A. pleuropneumoniae and S. suis. Enrofloxacin and its metabolite ciprofloxacin showed the highest in vitro activities against most bovine pathogens tested and the porcine pathogens also showed a high degree of sensitivity to enrofloxacin. These data facilitate further pharmacokinetic/pharmacodynamic comparison of fluoroquinolones currently used in veterinary medicine.     

Interaction of mammary bovine ABCG2 with AFB1 and its metabolites and regulation by PCB 126 in a MDCKII in vitro model

The ATP‐binding cassette efflux transporter ABCG2 plays a key role in the mammary excretion of drugs and toxins in humans and animals. Aflatoxins (AF) are worldwide contaminants of food and feed commodities, while PCB 126 is a dioxin‐like PCB which may contaminate milk and dairy products. Both compounds are known human carcinogens. The interactions between AF and bovine ABCG2 (bABCG2) as well as the effects of PCB 126 on its efflux activity have been investigated by means of the Hoechst H33342 transport assay in MDCKII cells stably expressing mammary bABCG2. Both AFB1 and its main milk metabolite AFM1 showed interaction with bABCG2 even at concentrations approaching the legal limits in feed and food commodities. Moreover, PCB 126 significantly enhanced bABCG2 functional activity. Specific inhibitors of either AhR (CH233191) or ABCG2 (Ko143) were able to reverse the PCB 126‐induced increase in bABCG2 transport activity, showing the specific upregulation of the efflux protein by the AhR pathway. The incubation of PCB 126‐pretreated cells with AFM1 was able to substantially reverse such effect, with still unknown mechanism(s). Overall, results from this study point to AFB1 and AFM1 as likely bABCG2 substrates. The PCB 126‐dependent increased activity of the transporter could enhance the ABCG2‐mediated excretion into dairy milk of chemicals (i.e., drugs and toxins) potentially harmful to neonates and consumers.     

An overview of aflatoxin B1 biotransformation and aflatoxin M1 secretion in lactating dairy cows

Milk is considered a perfect natural food for humans and animals. However, aflatoxin B1 (AFB1) contaminating the feeds fed to lactating dairy cows can introduce aflatoxin M1 (AFM1), the main toxic metabolite of aflatoxins into the milk, consequently posing a risk to human health. As a result of AFM1 monitoring in raw milk worldwide, it is evident that high AFM1 concentrations exist in raw milk in many countries. Thus, the incidence of AFM1 in milk from dairy cows should not be underestimated. To further optimize the intervention strategies, it is necessary to better understand the metabolism of AFB1 and its biotransformation into AFM1 and the specific secretion pathways in lactating dairy cows. The metabolism of AFB1 and its biotransformation into AFM1 in lactating dairy cows are drawn in this review. Furthermore, recent data provide evidence that in the mammary tissue of lactating dairy cows, aflatoxins significantly increase the activity of a protein, ATP-binding cassette super-family G member 2 (ABCG2), an efflux transporter known to facilitate the excretion of various xenobiotics and veterinary drugs into milk. Further research should focus on identifying and understanding the factors that affect the expression of ABCG2 in the mammary gland of cows.     

Milk secretion of nitrofurantoin,as a specific BCRP/ABCG2 substrate,in assaf sheep: modulation by isoflavones1

Studies on residues in milk used for human consumption have increased due to health concerns and priority interest in the control of potentially risky drugs. The protein BCRP/ABCG2, present in the mammary epithelia, actively extrudes drugs into milk and can be modulated by isoflavones. Nitrofurantoin is a specific BCRP substrate which is actively excreted into milk by this transporter. In this research, we studied nitrofurantoin transport into milk in four experimental groups: G1‐calves fed forage with isoflavones; G2‐calves fed forage with isoflavones and administered exogenous genistein and daidzein; G3‐calves fed forage without isoflavones; G4‐calves fed forage without isoflavones and administered exogenous genistein and daidzein. Results show increased levels of nitrofurantoin in milk from calves without isoflavones (G3) and decreased nitrofurantoin residues in milk when isoflavones were present, either by forage (G1 and G2) or by exogenous administration (G4). The values of C_max in milk were significantly lower in those groups with isoflavones in forage (G1, G2). Plasma levels were low and unmodified among the groups. Inter‐individual variation was high. All these results seem to point to a feasible control of drug secretion into milk through isoflavones in the diet when the drug is a good BCRP/ABCG2 substrate.     

中国荷斯坦奶牛ABCG2基因外显子9多态性研究

本研究旨在寻找ABCG2基因上与产乳性状相关的多态位点,为提高产乳性状提供理论依据。本研究采用PCR-SSCP技术分析了ABCG2基因exon9的多态性。使用SAS9.0对多态性与产乳性状之间的相关性进行方差分析。研究结果表明,在exon9中存在A→G突变,导致氨基酸由酪氨酸突变为半胱氨酸。A、B 2个等位基因的频率分别为0.86和0.14;存在3种基因型:AA、AB和BB型,基因型频率分别为:0.73、0.26、0.01;多态信息含量为0.22。方差分析结果显示,3种基因型间5种产乳性能的差异不显著。Y367C与产乳性状的相关性不明显,由于突变前后氨基酸性质发生了改变,可能会对蛋白质的结构产生一定的影响。     

Comparison of chemotherapeutic drug resistance in cells transfected with canine ABCG2 or feline ABCG2

ABCG2 (ATP binding cassette subfamily G, member 2) mediates resistance to a variety of cytotoxic agents. Although human ABCG2 is well characterized, the function of canine ABCG2 has not been studied previously. Feline ABCG2 has an amino acid substitution in the adenosine triphosphate‐binding domain that decreases its transport capacity relative to human ABCG2. Our goal was to compare canine ABCG2‐mediated chemotherapeutic drug resistance to feline ABCG2‐mediated chemotherapeutic drug resistance. HEK‐293 cells stably transfected with plasmid containing canine ABCG2, feline ABCG2 or no ABCG2 were exposed to carboplatin, doxorubicin, mitoxantrone, toceranib or vincristine, and cell survival was subsequently determined. Canine ABCG2 conferred a greater degree of chemotherapy resistance than feline ABCG2 for mitoxantrone. Neither canine nor feline ABCG2 conferred resistance to doxorubicin, vincristine or toceranib. Canine, but not feline, ABCG2 conferred resistance to carboplatin, a drug that is not reported to be a substrate for ABCG2 in other species.     

The livestock photosensitizer, phytoporphyrin (phylloerythrin), is a substrate of the ATP-binding cassette transporter ABCG2

Hepatogenous photosensitization occurs in livestock following damage to the liver or biliary apparatus that results in impaired excretion of phytoporphyrin (phylloerythrin), a photosensitizer. Based on earlier observations that porphyrin-based photosensitizers are substrates of the ATP-binding cassette transporter ABCG2, we examined the ability of the hepatic transporters ABCB1 (P-glycoprotein) and ABCG2 to transport phytoporphyrin. Transport of phytoporphyrin was blocked by the ABCG2-specific inhibitor fumitremorgin C (FTC) in human embryonic kidney cells transfected with full length human ABCG2, while no transport by cells transfected with human ABCB1 was noted. FTC-inhibited transport of phytoporphyrin was also demonstrated in ABCG2-expressing LLC-PK1 pig kidney cells, consistent with the idea that the pig orthologue, like human ABCG2, transports the photosensitizer. ABCG2 expression was confirmed by immunohistochemistry in the hepatocytes of cow, pig and sheep livers. We conclude that phytoporphyrin is a substrate for ABCG2 and that the transporter is likely responsible for its biliary excretion.     

Milk whey induction of agglutination in ovine and bovine mastitis Staphylococcus aureus

A total of 59 mastitis staphylococcic strains were tested for growth agglutination upon supplementation of growth media with ovine and bovine milk whey and mammary secretions from dry cows. Differences were observed when comparing bacterial species or origins (ovine vs. bovine) of bacteria and whey. All of the ovine and bovine S. aureus strains tested, but only 4 among 22 other ovine mastitis staphylococcic strains, showed growth agglutination in Todd Hewitt broth (THB) supplemented with greater than or equal to 30% (v/v) ovine milk whey. None of the strains agglutinated during growth in regular THB medium. Ovine whey had an agglutination induction capacity higher than bovine whey (P less than 0.005), concerning the number of responsive ovine and bovine S. aureus strains. There were no differences between whey samples from different ewes with regard to their capacity to induce agglutination. Ovine S. aureus strains were more responsive than bovine strains of this bacterial species, concerning the number of responsive strains (P less than 0.001) to bovine whey (greater than or equal to 30% in THB), the proportion of responsive strains at low (10%) ovine whey concentration (P less than 0.001), and the strength of reaction (precipitation timing and clump size). Secretions from dry cows systematically induced agglutination in all of the bovine and ovine S. aureus strains tested.     

Performance of a Johne's disease enzyme-linked immunosorbent assay adapted for milk samples from goats.

Antibody detection-based tests for paratuberculosis offer speed and economy, 2 diagnostic test attributes important to animal industries with narrow profit margins. Application of such tests to individual milk samples instead of serum samples can further improve testing efficiency and decrease testing cost. Accuracy of a commercial bovine paratuberculosis enzyme-linked immunosorbent assay (ELISA) adapted for use on goat serum and milk samples was determined. Fecal, blood, and milk samples were collected from 159 goats belonging to 2 Wisconsin goat herds with a prior history of paratuberculosis and 1 herd of 50 goats from a paratuberculosis-free Wisconsin herd. Fecal samples were cultured using the modified BACTEC 12B media. Sera were tested according to the manufacturer's instructions for bovine samples. Milk samples were centrifuged and mixed with the ELISA kit's Mycobacterium phlei-containing diluent at a ratio of 1:2. Using fecal culture as the "gold standard," the sensitivity of the ELISA on goat serum was 64% and the sensitivity of the ELISA on goat milk was 48%. The milk ELISA had higher agreement with fecal culture results (kappa = 0.525) than the serum ELISA (kappa = 0.425). ELISA specificity was 100% on both serum and milk. Regression analysis also showed good correlation between serum and milk S/P values (r2 = 0.67). Although less sensitive, the ELISA on goat milk samples appears to offer a useful, low-cost alternative for detection of goats with paratuberculosis that have progressed to the stage of shedding M. paratuberculosis in their feces.     

Yeast culture supplement during nursing and transport affects immunity and intestinal microbial ecology of weanling pigs

The objectives of this study were to determine the influence of a Saccharomyces cerevisiae fermentation product on innate immunity and intestinal microbial ecology after weaning and transport stress. In a randomized complete block design, before weaning and in a split-plot analysis of a 2 × 2 factorial arrangement of yeast culture (YY) and transport (TT) after weaning, 3-d-old pigs (n = 108) were randomly assigned within litter (block) to either a control (NY, milk only) or yeast culture diet (YY; delivered in milk to provide 0.1 g of yeast culture product/kg of BW) from d 4 to 21. At weaning (d 21), randomly, one-half of the NY and YY pigs were assigned to a 6-h transport (NY-TT and YY-TT) before being moved to nursery housing, and the other one-half were moved directly to nursery housing (NY-NT and YY-NT, where NT is no transport). The yeast treatment was a 0.2% S. cerevisiae fermentation product and the control treatment was a 0.2% grain blank in feed for 2 wk. On d 1 before transport and on d 1, 4, 7, and 14 after transport, blood was collected for leukocyte assays, and mesenteric lymph node, jejunal, and ileal tissue, and jejunal, ileal, and cecal contents were collected for Toll-like receptor expression (TLR); enumeration of Escherichia coli, total coliforms, and lactobacilli; detection of Salmonella; and microbial analysis. After weaning, a yeast × transport interaction for ADG was seen (P = 0.05). Transport affected (P = 0.09) ADFI after weaning. Yeast treatment decreased hematocrit (P = 0.04). A yeast × transport interaction was found for counts of white blood cells (P = 0.01) and neutrophils (P = 0.02) and for the neutrophil-to-lymphocyte ratio (P = 0.02). Monocyte counts revealed a transport (P = 0.01) effect. Interactions of yeast × transport (P = 0.001) and yeast × transport × day (P = 0.09) for TLR2 and yeast × transport (P = 0.08) for TLR4 expression in the mesenteric lymph node were detected. Day affected lactobacilli, total coliform, and E. coli counts. More pigs were positive for Salmonella on d 7 and 14 than on d 4, and more YY-TT pigs were positive (P = 0.07) on d 4. The number of bands for microbial amplicons in the ileum was greater for pigs in the control treatment than in the yeast treatment on d 0, and this number tended to decrease (P = 0.066) between d 1 and 14 for all pigs. Similarity coefficients for jejunal contents were greater (P = 0.03) for pigs fed NY than for those fed YY, but pigs fed YY had greater similarity coefficients for ileal (P = 0.001) and cecal (P = 0.058) contents. The number of yeast × transport × day interactions demonstrates the complexity of the stress and dietary relationship.     

三河牛ABCG2基因Y367C位点与产奶性状的关联分析

[目的]旨在检测三磷酸腺苷结合转运蛋白G超家族成员2（ABCG2）基因Y367C位点此在三河牛群体中的多态性,并分析了其与产奶性状之间的关系。[方法]利用Sequen—ornMassARRAYGenotype分析技术对该位点进行检测,通过SAS软件（9．1）对6个产奶性状与该位点的关联程度进行了统计分析。[结果]表明,Y367C位点在三河牛中均处于Hardy-Weinberg平衡状态（P〈0．05）;ABCG2基因Y367C位点的YY基因型个体体细胞评分最低,CC个体产奶量、乳脂量、乳蛋白量最高;Y等位基因降低体细胞评分,提高乳蛋白率;而C等位基因则有助于提高产奶量、乳脂率、乳脂量和乳蛋白量,但三种基因型之间差异不显著（P〈0．05）。[结论]该位点可以为三河牛的分子育种提供参考。     

Direct measurement of progesterone in plasma and milk by a simple solid-phase radioimmunoassay

A rapid method for determination of progesterone in bovine, goat and porcine plasma as well as in bovine milk was evaluated. The method employed was a solid-phase (125)I radioimmunoassay equipped with progesterone standards in human serum and called the Coat-A-Count procedure. The dilution curves of bovine plasma samples with high progesterone content were parallel with the standard curve based on human serum. The relation between measurements of progesterone levels in bovine plasma using the reference extraction method and the direct Coat-A-Count procedure was highly significant, resulting in the linear regression equation Y = 1.06x-0.04. In case of goat and porcine plasma, the direct method yielded higher results than the reference extraction method (Y = 1.37x + 1.38 and Y = 1.69x - 6.47, respectively). Progesterone concentration in bovine whole milk was much higher when measured by the Coat-A-Count procedure than by the reference Farmos kit (Y = 1.59x + 1.51). However, when the same samples were assayed by a modified Coat-A- Count procedure, i.e. progesterone standards from Farmos kit, the values were more or less identical (Y = 0.88x - 0.21).     

含蛋氨酸二肽影响奶牛乳腺上皮细胞乳蛋白合成相关基因表达

本试验旨在研究含蛋氨酸(Met)二肽对奶牛乳腺上皮细胞(BMECs)内乳蛋白合成相关基因表达的影响。试验分3部分,均采用单因子完全随机试验设计,Met的添加浓度及培养时间分别为60μg/m L(0.402 mmol/L)、48 h。第1部分,培养液添加8种含Met二肽[蛋氨酸-蛋氨酸(P-Met-Met)、蛋氨酸-赖氨酸(P-Met-Lys)、蛋氨酸-色氨酸(P-Met-Trp)、蛋氨酸-苯丙氨酸(P-Met-Phe)、蛋氨酸-苏氨酸(P-Met-Thr)、蛋氨酸-异亮氨酸(P-Met-Ile)、蛋氨酸-亮氨酸(P-Met-Leu)、蛋氨酸-缬氨酸(P-Met-Val)],以不添加二肽为对照,测定BMECs乳蛋白合成相关基因(αs1-酪蛋白、β-酪蛋白、κ-酪蛋白、β-乳球蛋白、Ⅱ型小肽转运载体和氨肽酶氮)的表达量;第2部分,培养液添加8种与上述二肽对应的游离氨基酸(F-Met-Met、F-Met-Lys、F-MetTrp、F-M et-Phe、F-M et-Thr、F-M et-Ile、F-M et-Leu、F-M et-Val),以不添加游离氨基酸为对照,测定BM ECs乳蛋白合成相关基因的表达量;第3部分,用二肽等物质的量替代相应游离氨基酸,测定BMECs乳蛋白合成相关基因的表达量以及细胞内外氨肽酶含量。结果表明:P-Met-Met和P-M et-Lys组较对照组和其他二肽组上调了αs1-酪蛋白和β-酪蛋白基因的表达量,且P-M et-M et组优于P-Met-Lys组。F-Met-Met和F-Met-Lys组较对照组和其他游离氨基酸组显著提高了αs1-酪蛋白基因的表达量(P0.05)。除P-Met-Val和P-Met-Leu组外,其他二肽替代游离氨基酸后均不同程度地提高了乳蛋白和Ⅱ型小肽转运载体基因的表达量,其中P-Met-Met表现出较好的促进效果。总之,含Met二肽等量替代对应的游离氨基酸能够促进乳蛋白基因的表达,其中尤以P-Met-Met的效果最好。     

Assessment of veterinary practitioners in the British Isles' approaches towards the management of canine osteoarthritis

The aim of this questionnaire-based retrospective study was to ascertain veterinary practitioners in the British Isles' approaches to osteoarthritis in dogs. The Mann-Whitney U test, Kruskal-Wallis test and multiple ordinal logistic regression were used to compare demographic data with treatment options. Questionnaires were returned by 228 practitioners (a response rate of 22.8 per cent). The majority of responses were from males (70 per cent). Eighty-six per cent (188 of 220) of the respondents had graduated from veterinary schools in the UK and Ireland. Veterinarians who had graduated less recently used exercise modulation less frequently (P<0.004, odds ratio [OR]=1.06) and ranked exercise modulation as less important (P=0.008, OR=1.04). Veterinarians who had graduated outside the UK or Ireland were less likely (P=0.033, OR=0.46) to use exercise modulation than those who had graduated in the UK or Ireland. Veterinarians who had graduated more recently were less likely (P=0.008, OR=0.95) to use medications. Female veterinary surgeons were less likely to rank medications as important (P<0.0001, OR=0.29) and less likely to rank corticosteroids as important (P=0.046, OR=0.42) than male veterinary surgeons. Practitioners who had graduated outside the UK or Ireland were less likely (P=0.01, OR=0.30) to rank corticosteroids as important. There was a significant mild negative correlation between the frequency of use of structure-modifying osteoarthritis drugs (SMOADs) and practitioners' opinions on rank importance (-0.32, P<0.0001). Medications such as SMOADs and nutraceuticals were ranked as not important but were used frequently. Overall, age, sex, the university of graduation and the number of canine consultations per day had an impact on the practitioners' treatment protocols.     

Nutritional plane and selenium supply during gestation affect yield and nutrient composition of colostrum and milk in primiparous ewes

The objectives were to investigate effects of nutritional plane and Se supply during gestation on yield and nutrient composition of colostrum and milk in first parity ewes. Rambouillet ewe lambs (n = 84, age = 240 ± 17 d, BW = 52.1 ± 6.2 kg) were allocated to 6 treatments in a 2 × 3 factorial array. Factors included Se [adequate Se (ASe, 11.5 μg/kg of BW) or high Se (HSe, 77.0 μg/kg of BW)] initiated at breeding, and nutritional plane [60 (RES), 100 (CON), or 140% (HIH) of requirements] initiated at d 40 of gestation. Ewes were fed individually from d 40, and lambs were removed at parturition. Colostrum was milked from all ewes at 3 h postpartum, and one-half of the ewes (n = 42) were transitioned to a common diet meeting lactation requirements and mechanically milked for 20 d. Colostrum yield was greater (P = 0.02) for HSe ewes than ASe, whereas CON had greater (P < 0.05) colostrum yield than RES and HIH. Colostrum Se (%) was greater (P < 0.01) for HSe than ASe. Colostrum from ewes fed HSe had less (P = 0.03) butterfat (%), but greater (P ≤ 0.05) total butterfat, solids-not-fat, lactose, protein, milk urea N, and Se than ASe. Colostrum from HIH ewes had greater (P ≤ 0.02) solids-not-fat (%) than RES, whereas RES had greater (P ≤ 0.04) butterfat (%) than CON and HIH. Colostrum from ewes fed the CON diet had greater (P = 0.01) total butterfat than HIH. Total solids-not-fat, lactose, and protein were greater (P < 0.05) in colostrum from CON than RES and HIH. Ewes fed HSe had greater (P < 0.01) milk yield (g/d and mL/d) than ASe, and CON and HIH had greater (P < 0.01) yield than RES. Milk protein (%) was greater (P ≤ 0.01) in RES compared with CON or HIH. Ewes fed HSe had greater (P < 0.01) milk Se (μg/g and mg/d) than ASe on each sampling day. Milk from CON and HIH ewes had greater (P < 0.01) total solids-not-fat, lactose, protein, and milk urea N than RES. Total Se was greater (P = 0.02) in milk from ewes fed the CON diet compared with RES. Somatic cell count and total somatic cells were greater (P ≤ 0.05) in milk from CON than RES. A cubic effect of day (P ≥ 0.01) was observed for milk yield (g and mL). Butterfat, solids-not-fat, lactose, milk urea N, and Se concentration responded quadratically (P ≤ 0.01) to day. Protein (%), total butterfat, and total Se, and somatic cells (cells/mL and cells/d) decreased linearly (P < 0.01) with day. Results indicate that gestational nutrition affects colostrum and milk yield and nutrient content, even when lactational nutrient requirements are met.