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Maisons-Alfort, France

Kaewlamun W.,CNRS Developmental Biology Laboratory | Kaewlamun W.,National Veterinary School of Alfort | Kaewlamun W.,Chulalongkorn University | Okouyi M.,CNRS Developmental Biology Laboratory | And 9 more authors.
Animal Feed Science and Technology | Year: 2011

The objectives of the present study were to investigate whether a dietary supplement of β-carotene given to dairy cows during the dry period was able to: (1) increase their β-carotene status, (2) increase the amount of β-carotene in colostrum, (3) increase the concentrations of immunoglobulin G in colostrum and (4) modify metabolic hormone, enzyme and metabolite status in their calves at birth. Forty Holstein cows were allocated to one of two dietary treatments: a control diet (C, n= 20) or the same diet plus 1 g β-carotene/cow/day (BC, n= 20) starting on the day of drying-off. The β-carotene supplement was given individually to the cows throughout the dry period. From week 2 after the start of supplementation, blood concentrations of β-carotene were higher in BC compared to C cows (P<0.0001). The β-carotene concentrations of colostrum were higher in BC than in C cows (3.10 ± 0.23 mg/l vs.1.44 ± 0.24 mg/l, P<0.001). Colostrum production was not different between groups (BC, 11.11 ± 1.21 kg vs. C, 10.05 ± 2.25 kg). The content of IgG in colostrum was not affected by treatment (BC, 82.65 ± 8.79 mg/ml vs. C, 79.32 ± 9.02 mg/ml). Blood concentrations of β-carotene in calves at birth were unaffected by treatment (BC, 1.16 ± 0.21 mg/l vs. C, 1.27 ± 0.24 mg/l). A supplement of β-carotene given during the dry period to dairy cows did not affect metabolite and metabolic hormone concentrations and enzyme activities in newborn calves. The results of this study indicate that a dietary supplement of β-carotene given in late-gestation was able to increase β-carotene concentrations in dam blood and in colostrum but was unable to increase colostral IgG. In addition, hormone and metabolite status and enzyme activities in the neonatal calf were also unaffected. © 2011 Elsevier B.V. Source


Kaewlamun W.,CNRS Developmental Biology Laboratory | Kaewlamun W.,National Veterinary School of Alfort | Kaewlamun W.,Chulalongkorn University | Okouyi M.,CNRS Developmental Biology Laboratory | And 6 more authors.
Theriogenology | Year: 2011

β-carotene is the main natural precursor of vitamin A and plays an important role in reproductive efficiency and immune function in dairy cows. The objective of this study was to investigate whether a supplement of β-carotene given during the dry period is able to 1) increase blood concentrations of β-carotene postpartum, 2) improve ovarian function and progesterone production, and 3) enhance uterine involution and uterine health. This study was conducted using 40 Holstein cows. On the day of drying-off, cows were allocated to one of two dietary treatments: control diet (C, n = 20) or control diet plus 1g/d β-carotene (BC, n = 20). The β-carotene supplement was given individually to the cows until calving. Blood samples were obtained regularly before and after calving from the cows to measure the concentrations of β-carotene. The diameters of the cervix and uterine horns were measured regularly using ultrasonography. Endometrial cytology samples were acquired from the cervix and uterus to determine uterine health. Milk samples were obtained three times per week for progesterone assay. Additional blood samples were taken on the day of calving, 7 and 21 days postpartum to determine the plasma concentrations of amino acids. Blood concentrations of β-carotene were not different before the start of the experiment (C, 3.03 ± 0.22 mg/L vs BC, 3.12 ± 0.22 mg/L, P > 0.05). Blood concentrations of β-carotene in the BC group peaked (7.45 ± 0.24 mg/L) 1 month after drying-off while the concentrations in the C group remained constant β-carotene concentrations then decreased in both groups. The difference in blood concentrations of β-carotene between groups became significant 2 weeks after the start of the supplement until 2 weeks postpartum. There was no significant difference in the interval from calving to ovulation between groups (C, 27.8 ± 3.46 d vs BC, 35.8 ± 3.55 d, P > 0.05). The dietary supplement of β-carotene during the dry period had no effect on ovarian activity, progesterone production, cervix and uterine horn diameters. Plasma concentrations of hydroxyproline in the BC group were higher than in the C group on day 21 postpartum (BC, 20.8 ± 1.33 μmol/L vs C, 15.0 ± 1.33 μmol/L; P < 0.01). On day 28 postpartum the percentage of neutrophils in the BC group was lower than in the C group (cervical smear; C, 21.0 ± 3.22% vs BC, 9.7 ± 3.14%, P < 0.05 and uterine smear; C, 32.0 ± 3.86% vs BC, 20.9 ± 3.76%, P < 0.05). In the present experiment a dietary supplement of β-carotene had no effect on ovarian activity. However, due to effects of β-carotene on hydroxyproline profiles and their potential relationship with uterine function we speculate that uterine involution may have been more complete and that uterine inflammation may have been reduced in cows which received the β-carotene compared to controls. © 2011 Elsevier Inc. Source


Barbat A.,French National Institute for Agricultural Research | le Mezec P.,University Paris Est Creteil | Ducrocq V.,French National Institute for Agricultural Research | Mattalia S.,University Paris Est Creteil | And 4 more authors.
Journal of Reproduction and Development | Year: 2010

In most countries where genetic selection for milk production has been conducted, a continuous degradation of reproductive performances has been observed in dairy cattle. This paper describes the phenotypic evolution of fertility traits in France for the main 3 dairy breeds and the different actions undertaken to counteract this unfavourable evolution of reproductive performance. In 2001, functional traits (including conception rate as a fertility trait) have been included into the French total merit index ISU, to take these traits into account in the selection objective. In addition, a marker-assisted selection (MAS) program has been developed since 2001. Through this approach, a set of QTL related to fertility traits were identified using the phenotypic information for fertility collected on a national basis. Fine mapping of these QTL let to their introduction in 2008 in genomic evaluation and the routine selection for fertility traits in breeding schemes. This approach will evolve in the near future through the inclusion of results of several genomic research programs that were conducted either in station or under field conditions aiming at identifying genes and pathways controlling cattle fertility (based on genomics, transcriptomics and proteomics) and at enhancing phenotyping for reproductive performance. The paper describes the general approach behind these evolutions, the expected benefits of genomic selection and first results. Information on the potential use of reproductive technologies that may improve the efficiency of multiple trait genomic selection are also presented. Source

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