Effects of growth-promoting agents and season on blood metabolites and body temperature in heifers.

نویسندگان

  • T L Mader
  • W M Kreikemeier
چکیده

To assess the efficacy of growth-promoting agents among seasons, triiodothyronine (T3), thyroxine (T4), plasma urea nitrogen (PUN), IGF-I, and tympanic temperature (TT) were measured in summer and winter studies. Heifers (n = 9/pen) were allotted to 12 pens in both December and June. Pens were assigned to 1 of 6 growth promotant treatments: control (no growth promotant), estrogenic implant (E), trenbolone acetate implant (TBA), E + TBA (ET), melengestrol acetate (MGA), and ET + MGA (ETM). Blood samples were collected from 4 heifers per pen per study on d 0, 28, 56, and 84 via jugular puncture. Near the midpoint of both studies, TT were obtained from the heifers. There was a season by sample day interaction for all blood metabolites (P < 0.05). During the winter, IGF-I levels peaked on d 28, whereas T3, T4, and PUN peaked on d 56. In the summer, IGF-I levels increased from d 0 to 28 and remained elevated throughout the study. Season by growth promotant interactions (P < 0.05) indicated that in the winter ET increased T3, whereas TBA alone decreased both T3 and T4, compared with control, or ET, and ETM treatment groups. Across seasons, treatments ET and ETM increased (P < 0.05) IGF-I and decreased (P < 0.05) PUN. However, E, TBA, and MGA alone had no effect on IGF-I or PUN concentrations. The maximum TT was greater (P < 0.01) in the summer than in the winter, whereas the minimum TT was lower (P < 0.01) in the summer. Mean TT did not differ among growth-promoting treatments. However, in the summer and over both seasons, the maximum TT was lower (P < 0.05) in E-, MGA-, and ETM-treated heifers. Although limited growth promotant by season interactions existed, changes in blood metabolite levels resulting from the use of growth promotants do not appear to influence seasonal changes in body temperature as measured by TT.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Growth Promoting Agents and Season Effects on Blood Metabolite and Body Temperature Measures

متن کامل

EFFECTS OF DIFFERENT TEMPERATURE AND FEEDING RATE ON GROWTH PERFORMANCE, BODY COMPOSITION AND BLOOD PARAMETERS OF ASIAN SEA BASS (LATES CALCARIFER)

This study aimed to investigate the effects of different temperatures (20, 27 and 33 °C) and two feeding rates (2.5 % biomass per day and satiation) on growth performance, body composition, hematology and blood biochemistry of Asian sea bass (Lates calcarifer). For this purpose, 8 fish with an average initial weight of 99.55 ± 0.24 g were randomly transported to 200 liters tanks (6 treatments w...

متن کامل

Effects of Dietary Crude Protein Level and Stocking Density on Growth Performance, Nutrient Retention, Blood Profiles, and Carcass Weight of Growing-Meat Quails

Two experiments were conducted to evaluate the effect of stocking density on growing-meat quail performance (experiment I) and the effect of dietary crude protein (CP) levels and stocking density on growth performance, nutrient retention, blood metabolites, and carcass weight of growing-meat quails under high ambient temperature (experiment II). Three hundred and eighty male growing-meat quails...

متن کامل

Performance of Holstein Calves, Heifers and First-Lactating Cows Fed Starter Diets with Different Protein Levels and Types of Soybean Meal

Holstein calves were fed pelleted starter diets with crude protein (CP) concentrations of 18%, 22% and 24% per dry matter (DM) containing soybean meal (SBM) (SBM18, SBM20 and SBM24), respectively, for 10 weeks from 14 days of age. Another diet with a CP concentration of 18% per DM was tested using commercial xylose-soybean meal (XSB; Yasminomax) instead of SBM. Each diet was fed to 24 calves an...

متن کامل

Effects of Oregano (Origanum vulgare) and Thyme (Thymus vulgaris) Oils on Growth Performance and Blood Parameters in Holstein Suckling Calves

This experiment was conducted to compare the effect of supplementation of milk with thyme (THY) and oregano (ORE) essences separately or a mixture of THY and ORE essences on growth performance, haematological parameters and some blood metabolites of Holstein suckling calves. Forty-eight Holstein calves (48.31±5.82 kg) were randomly allocated to four treatments including (1) control without esse...

متن کامل

ذخیره در منابع من

ذخیره در منابع من قبلا به منابع من ذحیره شده

{@ msg_add @}


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Journal of animal science

دوره 84 4  شماره 

صفحات  -

تاریخ انتشار 2006