Effect of dietary cobalt supplementation during late gestation and early lactation of Friesian cows on: 1. milk production, some blood parameters and reproductive performance

تأثير اضافة الكوبلت المعدنى الى العليقة اثناء فترة الحمل المتأخر و بداية فترة الحليب لابقار الفريزيان على 1- انتاج اللبن و بعض قياسات الدم و الكفاءة التناسلية

Abstract: Aim of this study was to evaluate the effect of dietary cobalt (Co) supplementation at different levels during pre- (50-60 days) and post-partum (120 days) on milk production, some blood parameters and reproductive performance of Friesian cows and growth performance of their offsprings. Twenty lactating multiparous cows were divided into four groups, 5 in each. Cows in the 1st group (G 1) were fed a control diet; while those in G2, G3 and G4 were fed the control diet supplemented with 0.19, 0.57 and 0.93 mg Co /kg diet on DM of concentrate feed mixture, respectively. Average daily (ADMY) and total milk yield (TMY) as well as composition of milk was individually recorded. Blood samples were individually taken pre-partum and 30 and 60 day-postpartum for determination of Co, Fe, Cu and Zn contents and total cholesterol (CHO); IgG and estradiol concentrations in blood serum. Postpartum first estrous interval (PPFEI), conception rate (CR) after artificial insemination, number of services per conception (NSC), and days open (DO) were recorded. After calving, live body weight (LBW) of calves was recorded and average daily gain (ADG) was calculated during the suckling period. Results show that ADMY for 35 lactation weeks was not affected significantly by dietary Co. ADMY and TMY were the highest (P<0.05) in G3 (1l.76 and 4034.3 kg) with the longest (P<0.05) lactation period. Milk in G3 showed lower (P<0.05) fat content (4.90%) than in Gl (5.78%), G2 (5.63%) and G4 (5.67%) With the highest (P>0.05) protein and lactose contents (4.55. and 6.83%) as compared to other groups (4.44-4.50 and 6.65-6.75%), respectively. Prepartum Zn content increased (P<0.05) in G3 and G4 as compared to Gland G2. The effect of Co on mineral contents and on CRO and IgG concentrations was not significant within 30 day-postpartum. Within 60 day-postpartum, Cu content and IgG concentrations decreased (P<0.05) in Co supplemented groups than in GI, while Fe decreased (P<0.05) only in G3. Cows in G3 showed the shortest (P<0.05) PPFEI (40 d) and DO (78.7 d) and decreased (P<0.05) NSC (2.5 serv.). CR within 120 day-postpartum was 80% in GI and G3, and 60% in G2 and G4.
LBW and ADG of calves were higher (P<0.05) in G2 and G3 than in G4 and G1. In conclusion, there was tendency of increasing milk production and reproductive performance of dairy cows fed diet supplemented with 0.57 mg/kg diet as well as improving LBW and weight gain of their offsprings from birth up to 16 wk of age.
Keywords: Cows, Cobalt, milk yield and composition, blood parameters, reproduction.

Publication year

2013

Pages

151-161

Availability location

معهد بحوث الانتاج الحيوانى-شارع نادى الصيد- الدقى- الجيزة

Availability number

Organization Name

Animal Production Research Institute (APRI)

serial title

The 4th Scientific Conference of Animal Production Research Institute (APRI)

Author(s) from ARC