Insulin-like growth factor-I (IGF-I) and thioredoxin are differentially expressed along the reproductive tract of the ewe during the oestrous cycle and after ovariectomy

Insulin-like growth factor-I (IGF-I) and thioredoxin are regulated by gonadal steroids in the female reproductive tract of many species. Oestradiol regulates IGF-I and thioredoxin mRNA levels in the reproductive tract of prepubertal lambs. The physiological status (different endocrine environment) may affect the sensitivity of the reproductive tract to oestradiol and progesterone. We studied the effects of different endocrine milieus (late-follicular and luteal phases of the oestrous cycle, and ovariectomy before or after puberty) on the expression of IGF-I, thioredoxin, oestrogen receptor α (ERα) and progesterone receptor (PR) in sheep. The mRNA levels were determined by a solution hybridisation technique. In the uterus the levels of ERα, PR and thioredoxin mRNA were higher in the late-follicular phase group than in the other three groups, and IGF-I mRNA was high during both the late-follicular and the luteal phases. In the cervix only PR mRNA was significantly higher in the ewes in the late-follicular phase than in the other groups. In the oviducts the levels of thioredoxin and ERα mRNA were highest in the ovariectomised adult ewes, and thioredoxin mRNA was higher than the levels found in the ewes in the late-follicular phase. The IGF-I mRNA levels in the oviduct did not differ between any of the groups. The transcripts of IGF-I, thioredoxin, ERα and PR, varied according to the physiological status and also along the female reproductive tract, suggesting that the regulation of the mRNA levels of these factors by the steroid environment is tissue specific

Proliferation, angiogenesis and differentiation related markers in compact and follicular-compact thyroid carcinomas in dogs

Immunohistochemical markers (IGF-1, IGF-1R, VEGF, FGF-2, RARα and RXR) were evaluated in healthy canine thyroid glands (n=8) and in follicular-compact (n=8) and compact thyroid carcinomas (n=8). IGF-1, IGF-1R and VEGF expression was higher in fibroblasts and endothelial cells of compact carcinoma than in healthy glands (P < 0.05). Compared to follicular-compact carcinoma, compact carcinoma had higher IGF-1R expression in fibroblasts, and higher FGF-2 expression in endothelial cells (P < 0.05). RARα expression was higher in endothelial cells of compact carcinoma than in those of other groups (P < 0.05). The upregulation of these proliferation- and angiogenesis-related factors in endothelial cells and/or fibroblasts and not in follicular cells of compact carcinoma compared to healthy glands supports the relevance of stromal cells in cancer progression

Effect of pegbovigrastim on fertility and culling in grazing dairy cows and its association with prepartum nonesterified fatty acids

This randomized controlled trial on 4 commercial grazing dairy farms investigated whether treatment with pegbovigrastim (PEG) affected fertility and culling as measured during the full lactation. We also explored the effect of potential interactions of PEG treatment with parity, prepartum body condition score, prepartum nonesterified fatty acid concentration (pre-NEFA), and early-lactation clinical disease on these outcomes. Holstein cows were randomly assigned to 1 of 2 trial arms: a first PEG dose approximately 7 d before the expected calving date and a second dose within 24 h after calving (PEG: primiparous = 342; multiparous = 697) compared with untreated controls (control: primiparous = 391; multiparous = 723). Cox’s proportional hazards regression models were used to analyze rate of first insemination, rate of pregnancy [within 150 and 305 d in milk (DIM)], and hazard of culling. Additional analyses were performed on data that were stratified by parity group and pre-NEFA class (low ≤0.3; high >0.3 mM). In high pre-NEFA cows, PEG treatment increased the rate of first insemination [hazard ratio (HR) = 1.15]. Early-lactation clinical mastitis (CM) and uterine disease (UD: retained placenta, metritis, or both) were associated with a reduced rate of pregnancy within 150 DIM (HR = 0.49 and 0.78, respectively). Pegbovigrastim treatment in high pre-NEFA cows with CM and UD increased the rate of pregnancy within 150 DIM (HR = 1.75 and 1.46, respectively). In high pre-NEFA cows, PEG treatment resulted in a lower hazard of culling (HR = 0.79). No treatment effect was detected in low pre-NEFA cows. This study shows that the effect of PEG treatment on fertility and culling interacts with pre-NEFA. In high pre-NEFA cows, PEG treatment increased the rate of first insemination, counteracted the negative association of early-lactation CM and UD with the rate of pregnancy, and decreased the hazard of culling

Direct and carry-over effect of grassland herbage allowance on metabolic hormones and reproduction in primiparous beef cows undergoing temporary weaning and flushing

Grazing management significantly contributes to low beef production in cow-calf systems within the Rio de la Plata native grasslands. An herbage allowance (HA) of 4 kg DM/kg BW increased the productive response of primiparous cows grazing shallow soils compared to 2.5. However, the impact of HA on metabolic changes and its association with productive response were not studied. We studied two levels of native grassland HA from -150 days relative to calving (DC) to weaning (195 DC) in spring-calving primiparous beef cows undergoing temporary weaning (TW) and flushing at 86 ± 12 DC on herbage intake (HI), body condition score (BCS), BW, milk yield, calf weight, concentrations of metabolic hormones, and the probability of ovulation and pregnancy. Thirty-one heifers were assigned to HA treatments that fluctuated throughout seasons: autumn (-150 to -90 DC) at 5 and 3 kg DM/kg BW, winter (-90 to 0 DC) at 3 and 3 kg DM/kg BW, and spring-summer (0 to 195 DC) at 4 and 2 kg DM/kg BW for High and Low HA, respectively. Data were analysed using linear models and generalised linear models for continuous and categorical variables, respectively. During the autumn period, HI, insulin, IGF-I, BCS, and BW were higher in High HA than Low, despite small differences in herbage mass between HA. Throughout the winter, spring, and summer, HI, insulin, leptin, and BCS changes did not differ between HA. However, IGF-I concentrations were greater at 65 and 40 DC (84 vs 55 ± 8.6 ng/mL; P < 0.05) and tended to be greater after TW in High HA than Low. The probability of ovulation did not reach significance (0.94 vs 0.75 ± 0.11 for High and Low HA, respectively; P = 0.125), while the probability of pregnancy was greater in High HA than in Low HA (0.9 vs 0.61 ± 0.10; P = 0.07). Ovulation probability exhibited a positive association with IGF-I concentrations at -90 and -40 DC (P < 0.05), but not postpartum. Milk yield did not differ between treatments, while calf weight was heavier at weaning in High HA cows (194 vs 178 ± 3.3 kg; P < 0.05). High HA enhances autumn HI and BCS and generates a carry-over effect on IGFI concentrations throughout winter and after TW (‘‘metabolic memory”), explaining the better reproductive response. Moderate changes in cows’ nutrition during autumn contribute to changes in metabolic status and reproductive outcomes in primiparous cows grazing moderate herbage production native grasslands

Post competition recovery of hydroelectrolytic and acid–base variables under distinct comfort indexes in equines participating in 90 km Federate RAID

Background: The recovery of acid-base and hydro electrolytic balance at medical discharge after Raid races and its association with comfort index (CI) is unknown. Aim: To determine hydroelectrolytic and acid–base variations before and at the time of clinical discharge in horses that completed 90 km Raid competitions. Methods: Hematocrit, total protein, sodium, potassium, chloride, calcium, and serum pH were determined in samples before and after the race and after hydration in 276 horses and were analyzed using a mixed procedure, including the time of the race, the CI and its interaction. Results: The hematocrit and total protein values after hydration showed a correction to normal values, however, while for total protein no differences were observed between this sample and before the race, the hematocrit at medical discharge was still higher than the sample before the race. The pH values after the race were higher than before the race and after hydration. Sodium concentrations before and after the race were higher than after hydration. Chloride and calcium concentrations before the race were higher than after the race and hydration. Potassium concentration was affected by the interaction between CI and sampling, as only in worse climate conditions, potassium concentrations after the race and hydration were lower than before the race. Conclusion: Most hydroelectrolytic and acid-base variables at the medical discharge did not reach the values before the race, but they were within the normal values. The CI was a non-explanatory source of variability for most variables in this study

Metabolic hormones, grazing behaviour, offspring physical distance and productive response of beef cow grazing at two herbage allowances

Herbage allowance (HA) management during gestation–lactation cycle of cows grazing native grasslands improves pregnancy rates and calves’ weaning weight records. Those improvements were associated with greater herbage mass, and better body condition score (BCS) and metabolic status of the cows, which could affect grazing and maternal behaviour, particularly when temporary suckling restriction (TSR) and flushing (FL) is applied. The objective of this study was to evaluate the effect of HA during the gestation–lactation period on cows’ and calves’ liveweight (LW), BCS, milk yield, insulin, IGF-1 and leptin concentrations, as well as the proportion of diurnal grazing activities (grazing, ruminating, walking and idling), and maternal behaviour from −10 to 70 days relative to TSR (day 0 = initiation of TSR at 86 ± 10 days relative to calving). Thirty-three primiparous Hereford cows were allocated to HA treatments during gestation and lactation, which annually averaged 2.5 (low = LHA) and 4 kg DM/kg LW (high = HHA). The LW and BCS of cows did not differ during −10 to 50 days but were greater in HHA than LHA at the end of the study ( P < 0.05). Concentrations of IGF-1 were greater in HHA compared to LHA, while insulin and leptin did not differ. Grazing was lower in HHA than LHA, and the opposite occurred with ruminating and idling ( P < 0.05). Cow–calf physical distance was greater in LHA cows compared to HHA ( P < 0.05) and increased greatly in the former group after FL, while this increase was lower and later in HHA cows. Milk yield was greater in HHA ( P < 0.05), and calves’ weight did not differ between treatments from day −10 to 35, but was greater in HHA compared to LHA from 45 days until the end of the study. Thus, the HHA in a low herbage height and mass condition resulted in greater IGF-1 concentrations and milk yield, and induced changes in grazing and maternal behaviour that were associated with increased cows’ LW, BCS and calves’ weight at the end of the study

Transference of passive immunity and growth in dairy calves born to dams with high or low somatic cell counts at dry-off and fed colostrum from cows with high or low somatic cell counts at dry-off

The purpose of this experiment was to evaluate the transference of passive immunity (TPI) and growth achieved by calves born to dams with low or high SCC at dry-off and fed with colostrum from cows with low or high SCC at dry-off. Forty multiparous (3.2 lactations; SD = 1.1), dry, and pregnant Holstein cows were used. The cows were separated into 2 groups based on the SCC in the last 3 monthly records before dry-off. An SCC of 200,000 cells/mL was used as the cut-off point to categorize cows with or without mastitis at dry-off, and 2 groups of 20 cows each were formed: L-cow cows (last 3 SCC before dry-off less than 200,000 cells/mL) and H-cow cows (last 3 SCC before dry-off greater than 200,000 cells/mL). At calving, 40 calves were obtained (20 calves born to L-cow cows [L-calf], and 20 calves born to H-cow cows [H-calf]; females = 21 and males = 19), and 40 colostrum units (20 from L-cow cows [L-col]; and 20 from H-cow cows [H-col]). The experimental design was a 2 × 2 factorial, with 2 factors and 2 levels within each factor (type of calf: L-calf and H-calf, and type of colostrum: L-col and H-col), determining 4 treatments (n = 10 per treatment): L-calfxL-col (L-calf fed with L-col); L-calfxH-col (L-calf fed with H-col); H-calfxL-col (H-calf fed with L-col); and H-calfxH-col (H-calf fed with H-col). Male and female calves were homogeneously distributed within each treatment. All calves received 4 L of colostrum, L-col or H-col depending on the assigned treatment, with an oro-esophageal tube within 3 h after birth. Yield, chemical composition and IgG were determined. The TPI and the apparent efficiency of IgG absorption (AEA) were also determined. Nutrient intake and body growth and development traits of the calves (BW, heart girth, and withers height) were determined in the first 30 d of life. The colostrum produced by L-cow presented a lower SCC compared with H-cow. Colostrum protein yield of L-cow was 0.21 kg higher than H-cow, and colostrum of L-cow had 24% higher IgG concentration. The TPI was not affected by the interaction calf type × colostrum type, and there was no effect of the colostrum type on the level TPI and AEA achieved by calves. However, an effect of calf type on TPI and AEA achieved was observed, as L-calf achieved greater TPI than H-calf (28.8 and 22.8 g IgG/L, respectively; SEM = 1.5), and L-calf presented a higher AEA than H-calf (30.0% and 24.5%, respectively; SEM = 1.4). The BW, heart girth, and withers height were not affected by calf type, colostrum type, or by the interaction calf type × colostrum type. We concluded that cows with high SCC at dry-off produced colostrum with higher SCC and lower IgG concentrations, but when ingested by calves it did not affect TPI, feed intake, growth, or development. Calves born to cows with high SCC at dry-off presented a lower AEA of IgG, which translated into a lower serum concentration of IgG, irrespective of type of colostrum that was fed

Regulation by Gonadal Steroids of Estrogen and Progesterone Receptors Along the Reproductive Tract in Female Lambs

The regulation of estrogen and progesterone receptor (ER, PR) expression by estradiol (E2) and progesterone (P4) in the oviduct, uterus and cervix of female lambs was studied. The animals received three intramuscular injections of E2, P4 or vehicle with an interval of 24 h and they were slaugthered 24 h after the third injection. Determinations of ER and PR were performed by binding assays and mRNAs of ERα and PR by solution hybridization. High levels of ER and PR in both cervix and oviduct were found in the female lamb, differing from other mammalian species. No significant effects by either E2 or P4 treatment on ER and PR levels in the cervix and oviduct could be observed. E2 treatment increased the mRNA levels of ERa and PR more than 3-fold in the cervix, while P4 treatment increased the mRNA levels of ERa and PR in the uterus. The results show differential effects of gonadal steroids on sex steroid receptor expression along the reproductive tract in female lambs, suggesting that steroid target tissues can modulate responses to the same circulating levels of steroid hormones

Cortisol secretion after adrenocorticotrophin (ACTH) and Dexamethasone tests in healthy female and male dogs

Background: For the conclusive diagnosis of Cushing's Syndrome, a stimulating ACTH test or a low suppressive Dexamethasone test is used. Reports in other species than the dog indicate that plasma cortisol concentration after ACTH administration is affected by gender. We investigated the effect of gender on the cortisol response to ACTH and Dexamethasone tests in dogs. Methods: Seven healthy adult Cocker Spaniels (4 females and 3 males) were assigned to a two by two factorial design: 4 dogs (2 females and 2 males) received IV Dexamethasone 0.01 mg/kg, while the other 3 dogs received an IV saline solution (control group). Two weeks later the treatments were reversed. After one month, ACTH was given IV (250 μg/animal) to 4 dogs (2 female and 2 males) while the rest was treated with saline solution (control group). Cortisol concentrations were determined by a direct solid-phase radioimmunoassay and cholesterol and triglycerides by commercial kits. Results and Discussion: No effect of treatment was observed in metabolite concentrations, but females presented higher cholesterol concentrations. ACTH-treated dogs showed an increase in cortisol levels in the first hour after sampling until 3 hours post injection. Cortisol concentrations in Dexamethasone-treated dogs decreased one hour post injection and remained low for 3 hours, thereafter cortisol concentrations increased. The increase in cortisol levels from one to two hours post ACTH injection was significantly higher in females than males. In Dexamethasone-treated males cortisol levels decreased one hour post injection up to 3 hours; in females the decrease was more pronounced and prolonged, up to 5 hours post injection. Conclusion: We have demonstrated that cortisol response to ACTH and Dexamethasone treatment in dogs differs according to sex

Contrasting feeding management in the first 21 days postpartum in Holstein dairy cows: direct and residual milk responses

The transition period and its management affect how dairy cows face physiological challenges. Total mixed rations (TMR) have been shown as a strategy to address pasture-based system limitations and improve milk production, without consistent information about their use in short periods and residual responses. The study aimed to evaluate contrasting feeding management in the first 21 days postpartum on direct and residual milk production responses until 60 days in milk (DIM). Sixty-seven mixed parity Holstein dairy cows were used in a completely randomised block design in two treatments across two trials: MD-MD, cows fed a mixed diet (MD) with grazing and supplementation with mixed ration, from calving until 60 DIM, TMR-MD: confined cows with TMR provided ad libitum during the first 21 DIM in a compost-bedded pack barn and changed to MD at 22 until 60 DIM. During the first 21 DIM (direct response), cows fed TMR produced 11.7% more milk than those on MD-MD. Multiparous (M) TMR-MD obtained 18.6% higher milk yield than M MD-MD cows, but no significant differences were detected between primiparous (P) cows. After the switch at 22 DIM (residual response), no significant differences were detected between treatments in milk yield. However, the interaction between treatment and parity indicates that M TMR-MD cows exhibited 3.6% more milk than those in MD-MD, as a carryover effect. In contrast, P cows did not differ between treatments. In the first 21 DIM, TMR-MD cows achieved a higher fat concentration and protein yield than MD-MD. Fat yield tended to increase in TMR-MD compared to MD-MD, without treatment effect for lactose yield. In the residual period, TMR-MD cows had higher pro-tein concentrations and tended towards higher fat concentrations than MD-MD cows. The interaction between treatments and parity showed that P TMR-MD cows had higher protein and exhibited a trend towards higher fat concentration than P MD-MD cows. The differential feeding management during the first 21 DIM did not generate differences in body condition score (BCS), between treatments or par-ities. In the residual period, TMR-MD cows achieved a higher BCS than MD-MD cows without differences between parities. No differences were found between treatments in grazing and ruminating time, reflect-ing a successful adaptation of TMR-MD cows. In conclusion, feeding TMR during the first 21 DIM is an effective strategy for increasing milk yield and achieving short-term carryover effects in M, but not in P cows