Abstract

Abstract
The aim of this thesis is to evaluate the reproductive performance of 319 dairy cows through a retrospective survey of more than 18 small holder farms and 2 big farms. For analysis of body condition and biochemical profile of the plasma concentrations of major substrates (urea, albumin, total cholesterol, glucose) and minerals (calcium, phosphorus, magnesium) in relation to reproductive performance. Was conducted on two axes: first, blood sampled of 135 Montbeliard cows (75 primiparous and 60 multiparous) and in different physiological stages (early lactation, middle and dry). Secondly, studies the monitoring of transition period (prepartum and postpartum) of 74 Montbeliard cows and 25 Fleckvieh. In which, blood sampled and body condition assessment according to Edmonson's notation; a month before calving and 3 times at one month interval in postpartum period was achieved. The results of this work, it appears that the conduct of reproduction is often poorly controlled, resulting in performance below objectives. Indeed, the majority of the parameters relating to the reproduction is outside the accepted norms, the calving interval (CI) displays an average 400 days of which more than 50% of the cows further than 400d, the interval calving to the first service (C1stSI)) and to the conception (CCI) at means of 100 and 125 days, with more than 50% of cows expressing C1stSI and CCI greater than 80d and 110d respectively. The physiological stage and the season were the most important factors of variation of reproductive parameters and biochemical profile. Among other things, the results also showed a significant interaction between nutritional status with certain reproductive parameters during the postpartum period. Reduction in glucose, total cholesterol, and urea levels and increased calcium and albumin scores were significantly associated with cows having an elongated interval between calving to first service and to the conception. On the other hand, a reduction in blood levels of magnesium and phosphorus and an increase in calcium levels were recorded in cows requiring +3 inseminations. In addition, there was a negative influence of: glucose and total cholesterol on the reproductive parameters of cows fed in the cold season (winter), urea nitrogen in cows given birth in the spring season, and calcium and magnesium in cows calved in hot season (summer).These results suggest that postpartum nutrition in dairy cows estimated by body condition score and metabolic profiling provide a clear indication for monitoring reproduction. It helps to explain in part some factors of poor reproductive performance such as the conception rate at first insemination, the coital index and the calving conception interval.
Keywords: body condition score, dairy cows, fertility, biochemical profiling, postpartum, season.

Information

Item Type:	Thesis
Divisions:	» Production animales, biotechnologie et sante » Institute of Agricultural and Veterinary Sciences
ePrint ID:	2275
Date Deposited:	2020-08-30
Further Information:	Google Scholar
URI:	https://www.univ-soukahras.dz/en/publication/article/2275

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