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The aim of this study was to investigate the role of acute-phase protein concentration and metabolic status in the establishment and resistance of clinical endometritis (CE) and subclinical endometritis (SE) in dairy cows. We also characterised the treatment-related changes in the concentration of acute-phase proteins and metabolic variables in dairy cows affected by CE and SE. Cows of the SE and CE groups presented a significantly higher β-hydroxybutyrate (BHB), haptoglobin and total sialic acid (TSA) concentrations compared with a healthy group of animals. A significantly lower serum calcium concentration, and a significantly higher serum aspartate aminotransferase activity in the CE group, were observed when compared with SE and healthy groups. The comparison of parameters before treatment indicated that cows suffering from CE or SE with lower concentrations of hepatic and inflammatory markers showed a better response to further treatment, and endometritis was not detected in the second examination. Moreover, decreased concentrations of BHB, acute-phase proteins and hepatic markers were observed after successful treatment for endometritis in CE and SE cows. The results obtained in this study suggest that improved liver function and a decrease in the acute-phase protein concentration might favour the resolution of endometritis after treatment.

The thyroid function and sexual development of eight 6-week-old Suffolk ram lambs were studied. The lambs were divided into either control or treatment groups and housed indoors. From 6 to 12 weeks of age, four lambs in the treatment group received 15 mg kg(-1) body weight per day of 6-propyl 2-thiouracil orally to suppress normal thyroid function. During the same period, thyroxine and tri-iodothyronine were injected s.c. at the rate of 8 and 16 microg kg(-1) body weight per day, respectively, to induce a hyperthyroid state. Four control lambs received sham injection and oral excipient. Concentrations of thyroxine, tri-iodothyronine, FSH, testosterone and insulin-like growth factor I were determined in blood collected by indwelling jugular catheters once a week, every 20 min from 09:00 to 15:20 h. Scrotal circumference was recorded each week. Semen collection was attempted by electro-ejaculation between weeks 17 and 36. Lambs were castrated at week 36 and testicular histology was examined. During the treatment period only, the concentration of thyroid hormones was higher in treated lambs than in controls (P < 0.05). From week 6 to week 9 only, concentrations of FSH in treated lambs were lower than in controls (P < 0.05). Insulin-like growth factor I concentrations were lower in treated lambs than in controls from week 10 to week 13 (P < 0.05). Frequency of testosterone pulses was higher (P < 0.01) in the treated lambs but concentrations were similar in the control and treated lambs throughout the experiment. Scrotal circumference was greater in treated lambs from week 26 to week 36 (P < 0.05). Treated lambs produced viable spermatozoa earlier than did control lambs. At week 36, sperm concentration in treated lambs was higher than in controls (P < 0.01) but semen volumes were similar (P > 0.1). Diameter of the seminiferous tubules in treated lambs was larger than in controls (P < 0.05). In conclusion, transient neonatal hyperthyroidism decreased FSH and insulin-like growth factor I concentrations temporarily, increased testosterone pulses and sperm production and advanced puberty in Suffolk ram lambs.

, M. L. 1999. Relationships of thyroid hormones, IGF-I and testosterone in breeds of ram lambs with low and high prolificacies. Can. J. Anim. Sci. 79: 441-448. Ten Suffolk (Sfk) and 10 Outaouais (Out) ram lambs were selected to study the relationship between testosterone, thyroid hormones (T 3 , T 4 ), IGF-I, glucose, semen production and testicular histology at the onset of puberty in lower prolific (Sfk) and higher prolific (Out) breeds. SC, BW, ADG, RG and DM consumption were recorded weekly. Semen was collected by electro-ejaculation from 32 to 35 wk of age and evaluated. Blood was collected weekly by indwelling jugular catheters, every 20 minutes from 0900 to 1520 h to measure the concentration of glucose, T 4 , T 3 , IGF-I and testosterone. At wk 35, histological sections of testes were evaluated. Number of spermatozoa in the semen of Out was higher than Sfk (P < 0.01). Average BW, ADG, RG, SC, DM consumption and blood glucose of the two breeds were not different throughout the experiment (P > 0.1). However, there were negative correlations between levels of glucose, T 4 , T 3 and age of the lambs. Testosterone concentrations and pulse frequencies were higher in Out than Sfk (P < 0.05). There were positive correlations between testosterone concentration, testosterone pulse frequencies and age of the lambs in the two breeds. Moreover, level of T 4 , T 3 and IGF-I were higher in Out than Sfk throughout the sampling period (P < 0.01). Although there were fluctuations in the level of IGF-I in the blood, no pulses were detected. Higher levels of testosterone, T 4 , T 3 , IGF-I and testosterone pulses in Out may be associated with greater prolificacy in this breed. Dix jeunes béliers Suffolk (Sfk) et dix béliers Outaouais (Out) ont été utilisés dans une étude du rapport entre les concentrations de la testostérone, des hormones thyroïdiennes, T 3 et T 4 , d'IGF-1, et du glucose, la production séminale et l'histologie testiculaire au déclenchement de la puberté chez une race peu prolifique (Sfk) et chez une race prolifique (Out). La circonférence scrotale (CS), le poids corporel (PC), le GMQ, le taux de croissance relatif (CR) et la consommation de m.s. étaient consignés une fois par semaine. La semence était prélevée par électroéjaculation entre les âges de 32 et 35 semaines. Les prises de sang hebdomadaires étaient faites au moyen de cathéters permanents implantés dans la veine jugulaire, toutes les 20 minutes de 9 h à 15 h 20, pour l'analyse des concentrations de glucose, de T 4 et T 3 , de IGF-1 et de testostérone. À l'âge de 35 semaines, on procédait à l'examen de coupes histologiques des testicules. Le nombre de spermatozoïdes dans la semence des béliers Out était plus important (P < 0,01) que dans celle des Sfk. Le PC, le GMQ, la CR, la CS, la consommation de m.s. et la teneur en glucose du sang n'affichaient pas de différences significatives (P > 0,01) entre les deux races. Toutefois, on relevait des corrélations négatives entre, d'une part, la teneur en glucose, en T 4 et en T 3 et, de l'autre, l'âge des ...