Relationship between body condition score , body weight , some nutritional metabolites changes in blood and reproduction in Algerian Montbeliad cows

The objective of this study was to investigate through a nutritional and biochemical approach the variability of reproductive performance in dairy cows of semi arid area herds. Seventy four multiparous females reared in four farms were tracked from one month before calving to the third month postpartum. Information about reproductive events were taken once a month, and the body condition score evaluated on a 1 to 5 scale according to the EDMONSON method (1989). Blood samples were taken on a sample of 23 cows chosen according to body condition score before calving for biochemical analysis of energy, nitrogen and minerals parameters. Maximum concentrations depended to physiological stage. Blood glucose and calcium are stable at around 0.60g / l and 0.76 g / l respectively (p>0.05). Uremia (0.27g/l vs 0.16g/l) and triglycerides (0.74g/l vs 0.48g/l) are higher in the first month of lactation (p <0.05). Cholesterol (1.42g/l vs 1.03g/l) is higher in the 3rd month post-partum. The results show also that best performances are recorded in cows with BC before calving around 3 and 3.5 (p<0.05) and for those loosing less BC in the first months postpartum. The nutritional and metabolic profiles of females were used to characterize high female performance which has a reduces format and losses of BC in post-partum are minimal and late; They express the moderate concentration of glucose (0.60g / l), elevated cholesterol (> 1.20 g / l) and low triglycerides (about 0.60 g / l). Great format Cows with early and significant loss of BC after calving. They express a poor reproductive performance with high triglycerides concentration (1.02 g / l) in the 1st month of lactation.


Introduction
during the first period of lactation.For Baumgard et al. (2006), most dairy cows come in negative energy The body condition (BC) of dairy cows in pre balance after parturition, which is a normal adaptation and post-partum modulate reproductive performance to lactation.This situation is independent of the genetic (Castaneda-Guti´errez et al. 2009) and milk production potential of milk yield.Bukley et al. (2003) reported (Jilek et al. 2008).The effects of nutrition on reproductive that it is the severe energy balance which causes metabolic efficiency of females were clearly demonstrated by disorders and impaired fertility.Contrariwise, Grimard et several studies.Short et al. (1990) reported that lactating al. (2003) observed an improvement in fertility by cows reduced feed intake before calving is reflected by equilibration of energy balance even if the body condition lowest body condition at calving accompanied to long score remains low.postpartum anoestrus.Also, it was demonstrated that The estimation of body condition scoring by undernutrition and low body condition score during notation though is simple and subjective it allows an the first phase of lactation is accompanied by disorders indirect measure of the energy status of females.However, in plasma concentrations of reproductive hormones it can be enhanced by objective measure-ments such as (Westwood et al. 2002), low follicle development biochemical analysis of blood parameters to understand (Fassi Fihri et al. 2005) and poor oocytes quality and explain biologically loss or recovery in BC and its (Jorritsma et al. 2003).
impact on reproduction (synthesis and secretion of sex A distinction has been made by researchers hormones, toxicity, etc.).between body condition score and energy balance This study aims to clarify through a nutritional and metabolic approach the effects of body condition -Calving to conception interval (CI); before calving and its evolution dynamics in post partum -First service to conception interval; on the changes of blood biochemical parameters related -Number of services per conception; to food energy, nitrogen and mineral and reproductive -Conception rate at 60, 90 and 120 day after calving behaviour of cows.In addition, the accuracy of best (CR) BC and evolution type adapted to a good reproductive Statistical analysis: All data are then subjected to rate and dietary recommendations needed to establish several statistical analyses to study the relation the ideal BC when desired. between body condition and the variability of blood metabolites and its impact on reproduction.

Materials and methods
The data were presented as least square means Animal material: (LS mean ±S.E.).A two step classification was used to The study was done in four larges separate classes with different BC before calving.farms in eastern semi arid area of Algeria.Seventy Class distribution is only accepted if the cohesion and four Montbeliard cows of different ages are followedth separation index is greater than 0.5.PCA follows a up around one month before calving to the 4 months hierarchical classification of reproductive parameters of lactation.Twenty three of them are chosen for blood is performed to identify the different types of sampling.
Body condition score and body weight measure-performances.The analysis of variance single factor ment: The body condition score (BCS) was estimated (SPSS Procedure 18) was used to analyse the effect of monthly on a 1-5 scale (Edmonson et al. 1989).A tape age and season on reproductive parameters.The measure for cattle is used to estimate the body weight evolution of the BC, BW and nutritional metabolites (BW) by measuring the girth.
was subjected to analysis of variance with repeated Nutritional parameters in blood: A sample (23 measures (LGM procedure) indicating the variability cows) of the initial population was chosen to perform between physiological stage.blood tests to make determinations of energy, nitrogen Given the small size of the sample, the Kruskaland mineral metabolites.The choice was made so as to Wallis nonparametric analysis was conducted to cover all classes of body condition before calving describe the variability of reproductive parameters (Table -1).
and blood metabolites by BC classes.The significance The samples were taken in the last month of level was set at 0.05.When the effect of class was gestation, 30, 60 and 90 days of lactation.For each significant, regression test were established to animal a sample of 10ml of blood was taken from determine the type of evolution.All analysis were coccygeal vessels on a Vacutainer ® tube without performed by SPSS (18).anticoagulant.Then 5ml of the sample is poured

Results
immediately into a lithium heparin tube.All blood samples were carried early in the morning before the Dynamic changes of BCS and BW: Similar distribution of concentrate.At laboratory, blood was evolution shape of BC and BW in pre and post partum centrifuged at 3000rpm for 5 minutes.The plasma and was observed.The best records are stored in dry serum are passed directly back to a multi autoanalyzer periods (3.46 and 638kg of BC and BW respectively).for determination of glucose, cholesterol, triglycerides, Both parameters undergo a decrease equivalent to 5 to urea, creatinine and calcium concentration using 6% in post-partum to reach a minimum in the 2nd enzymatic reactions with commercial kits (Spainreact month of lactation (p < 0.001).The recovery status is ®) for metabolites considered.
established from the 3rd month when BC and BW Reproduction parameters: Five reproductive traits represent 96% and 98% of initial situation.were analyzed:

Dynamic changes of metabolite profile
Energetic metabolites: Changes in blood -Calving to first service interval (FSI); concentrations of energy metabolites revealed three between these parameters.The BC before caving is profiles.Glucose variability is low and stagnant at a strongly correlated with FSI (p = 0.012, r = 0.61) and concentration of 0.6 g / l.However, the blood concen-relatively correlated with CI (p = 0.097, r = 0.47).The best performances were recorded in females with tration of cholesterol shows low around calving 1g / l, medium BCS (2.75 to 3.50) whose reproductive but increases rapidly and significantly (p <0.05) from intervals were shorter (54 and 81days of FSI and CI the 2nd month to be higher than 1.4 g / l.Triglycerides respectively), obese cows show average performance are moving in the opposite direction.This rate is (71 and 85days).However, lowest performances were relatively moderate in dry (0.62g/l) increases rapidly observed in thins cows (131 and 150 days).and significantly (p <0.05) after calving and then For the biochemical parameters of energy decreases in the 2nd month to stabilize around 0.50 g / l.
metabolism, the Kruskal Wallis test shows that the BC Nitrogen metabolites: Uraemia average in dry is before calving has little effect that manifests only in approximately 0.17g/l , then increases (p<0.05) in the st one stage.Regression confirms the significant effect 1 months of lactation (0.27 g / l) and begins to decline nd of the BC before calving on blood glucose of dry cows from 2 month 2 (0.24 g / l) to return to the dry value in rd for obese cows (0.67 g / l vs. 0.52 g / l).Cholesterol in 3 month of lactation (0.19 g / l).
the first months of lactation is higher in cows with However, the variability of creatinine is low medium BCS (1.18 g / l) compared to obese cows with a high relative value before calving (0.20g/l) and (0.89 g/l).However, the level of triglyceride in serum a low in post partum (0.16g/l).
is greater in thins cows (0.91g / L vs 0.51g / l).Mineral metabolites: The calcium concentration Uraemia in dry evolves linearly according to the does not vary significantly (p>0.05)around calving BCS before calving, it is lower in thins cows (0.09 g / l) and the differences between stages are less than 0.08 g / l.
and higher among those obese (0.23g / l).Reproductive parameters: The reproductive Nutritional and Metabolic Characteristics of performances of cows are summarized in the table-2.

high, medium and low cow performance
The averages FSI, CI, FSCI and NSC are 58, 86, 28 The principal component analysis (PCA) followed and 1.85 respectively.Indeed, 45% of cows are seen by hierarchical cluster analysis of reproductive pregnant at 60 days and 79% to 120jours.These parameters data allowed us to identify three classes of performances are related to calving season (p <0.001) cows whose performances are distinguished (table-3).but are independent at the age of females (p> 0.05).
However, there are also differences in dynamics The best performances were recorded in summer.change of body condition and blood concentrations of BC, metabolites and reproduction triglycerides, cholesterol and urea.The first class Impact of BCS before calving: According to the includes adult cows (older than 5 years).Their classes previously identified by two step classification reproductive performance is better; FSI and CI are it was found that BCS before calving affects equivalent to 43 and 56 respectively.Body condition is reproductive parameters mainly FSI and CI (p <0.05).
characterized by a good rating in dry, a low and early Regression analysis shows a strong relationship loss and significant recovery.The concentration of Contrwise, other authors reported that the calving glucose is constant around 0.60 g / l but cholesterol season had no effect on reproductive performance appears very high compared to other groups with a (Mouffok et al 2007;Resken et al. 1999). rd In our case improvement is observed from max at 3 months.In contrast, the plasma triglyceride concentration is low.Changes in blood urea concen-winter to summer.This variability can be explained by animal level of body reserves recovered during spring tration are low and stagnant in 0.20g / l level.
Class 2 contains cows with bad performances.(period of high forage potential) and its effects on post The FSI and CI are 115 days and 123 days respectively.partum energy balance (EB).The relationship of EB They were thin cows who suffer loss continues until with reproductive performance has been well nd the 2 month of lactation, the recovery is tardy.Blood documented.For BANOS et al. 2004, the negative glucose of cows is stable at around 0.58g/l.energy balance is associated with difficulties Cholesterol is low in dry and early lactation and encountered by the cow to receive and maintain the increases thereafter.Triglycerides are higher fetus.These problems are more noticeable in highly compared to the first.Uraemia is low before calving productive cows' milk.Royal et al. (2002) reported increases and stabilizes around 0.25 g/l after 1st month that in dairy cows, negative EB is the result of strong of lactation.
activity of hormones that regulate metabolism through Class 3 includes repeat breeding cows.Making the mobilization of body reserves.This activation in breeding is early (44 days) but conception will occur promotes the alteration of reproductive hormones after 5 months.The FSCI is very long (113 days).flow.An adequate energy supplements before and Females of this class have a good body condition at after calving can correct this negative balance (Staples calving who suffers a significant loss in the first et al. 1998;Pruit, 2001).Cavestony et al (2009) months of lactation (24%).Cows in this group express reported the correction of EB is valid only in blood glucose concentrations relatively higher multiparous.Primiparous continues to lose, at all level compared to other groups.Cholesterol is low before of complementation.In this study reproductive nd calving increase continually until the 2 month and parameters are correlated to BC before calving.The decrease after.Triglycerides are low in dry and early best performances are expressed by cows with BCS lactation, increased significantly in the 2nd month post between 3 to 3.5 points.Shrestha et al. (2005)  practice.Blood concentrations of glucose and urea are good performance.Calving to first service interval and higher in obese dry cows thus confirming works of calving to conception interval evaluated at 58 and 86 Tillard et al (2007) in Holstein in Indian pacific days was similar to the performances in temperate conditions.From that, urea concentration increased countries (Gillund et al. 2001;Pryce et al. 2001; significantly in the first months in thins and declines Veerkamp et al. 2001) and are best compared to the then.However, urea evolution is regular in obese results in similar conditions (Madani and Mouffok cows.The energy deficit decrease insulin and IGF-I 2008; Sraïri and Baqasse, 2000;Van Sanh et al. 1997).
secretion and inhibits hypothalamic GnRH, pituitary The intra-annual variability is much documented, but LH and FSH secretion (Castaneda et al. 2009) and the differences are different in direction and value.
reducing maturity and production of estrogen by Pryce et al. (2000) showed that in the United States and in Ireland, females calving in the period from ovarian follicles (Butler 2000).January to May realize the longer intervals.However, However, triglycerides are moving in the Gillund et al. (2001), observed in the Scandinavian opposite direction.Thin cows have the highest country a better performances for summer calving concentrations at dry following an intense lipolysis resulted in a gain of 10 to 14 days compared to winter.(3c).In postpartum, triglycerides values increase to st In contrast, N'dama cow in Africa realize low the 1 month result mobilization of body reserve to nd performance in summer (Kang'mate et al. 2000).support milk production but will go down from the 2 month to be at low levels indicating that recovery of recorded by cows having BC before calving overweight between 3 and 3.5 and for those who lose body condition are established.According to Chillard less in the first months postpartum.The nutritional and (1998) triglycerides are produced by the liver from free fatty acids released from adipose tissue at the time metabolic profiles of females was used to characterize of mobilization of corporal reserves.In contrast, high female performance which has a reduces format average concentrations were observed in cows with and losses of BC in post-partum are minimal and late; higher BCS (> 3.5).
They express the moderate concentration of glucose In our study, cholesterol is negatively correlated (0.60g /l), elevated cholesterol (> 1.20 g / l) and low with protein intake.Its content is higher in cows with triglycerides (about 0.60 g / l).Great format Cows with medium BC at any stage result a better reproductive early and significant loss of BC after calving.They performance.Obese and thin cows reveal similar low express a poor reproductive performance with high st levels before calving and diverge from the 1 month of triglycerides concentration (1.02 g / l) in the 1st month lactation when we observe a decrease of cholesterol of lactation.concentration in obese cows and an increase in thin and Jilek partum and decrease later.Uraemia follows the same nd et al. (2008) observed that no significant effect of the profile of blood cholesterol with a peak in the 2 BCS at dry period resumption of luteal activity and rd month and minimum values for dry and 3 months of breeding in the Holstein and Fleckvieh breed.lactation.However, the authors report that cows that loses more Discussion express longest postpartum intervals (Escobedo-Amezcua et al. 2010).In addition the BC is positively The study of reproduction in Montbeliard race correlated with glucose and urea, a sign of good food reared in Algerian semi arid region shows relatively