Implication of pre-and postpartum energy intake with body condition to direct reproductive performance of friesian dairy cow

Twenty nine Friesian cows in their 1st to 5th lactation were used to study the interaction of prepartum and postpartum energy intake combinations with cow body condition on reproductive performance. Forty five days prior to calving [prepartum] cows were divided into two groups first group received low energy [LE] ration [70% of NRC prepartum energy requirement]. At parturition, cows of each group were divided within prepartum energy intake to either a low energy [70% of NCR post partum energy requirement] or high energy [HE] intake [130% of NRC postpartum energy requirement. High energy ration was achieved by addition of 7.2% dried fat. The designed treatments were: prepartum LE followed by postpartum LE; prepartum LE followed by postpartum HE; prepartum ME followed by postpartum LE and prepartum ME followed by postpartum HE. Prepartum LE intake had an adverse effect on calf birtg weight. No significant difference was obtained among calf weaning weight between treated groups except for cows fed pre-and postpartum LE rations. The results of postpartum interval [PPI], evaluation of postpartum cow and milk yield indicated that postpartum energy intake had an affective role over that of prepartum energy intake. Pregnancy rate and the number of cows in estrus within 60 days were dependent upon both pre-and postpartum energy intake. A negative relationship was exerted between cow body condition score [BCS] at parturition and length of PPI. Both thin and fatty cows had lower pregnancy percentage as compared with moderately BCS cow. Cow BCS had no effect on calf weaning weight and milk yield. Cow body weight change during postpartum was associated with the cow reproductive performance. Cows supplemented with dried fat in their postpartum ration showed marked elevation of serum total lipid and cholesterol levels. The present study has considered that pre and postpartum energy intake besides body condition performed an integrate system to exist the reproductive performance of dairy cows. However, it is worthy to mention that postpartrum energy intake has an effective role over prepartum nutrition to direct reproductive performance. The present study suggested that prepartum LE followed by postpartum HE is the most economic treatment for optimum productive performance of Friesian dairy cow

Relationship between body condition, milk yield and reproductive performance of dairy cows

To study the relationship between body condition, milk yield and reproductive perfomance of highly producing dairy cows under local conditions, a number of 287 Holstein-Friesian cows, in their 1[st] to 5[th] lactation were used. Animals were grouped according to their milk production and fed on a total mixed ration according to NRC 1989. All cows were evaluated subjectively for body condition score [BCS] at calving and at service. Linear regression coefficient of interval from calving to 1[st] estrus [Y1] on peak milk yield/kg/day [X1] was significant [P < 0.01]. The resulting equation was Y1=16.37+0.7X1. Cows with higher peak milk yield showed a significant long interval to 1[st] detected estrus. No significant linear regression was found between milk yield/kg during current lactation and reproductive traits. Linear regression coefficient of interval from parturition to 1[st] detected estrus [Y1] on BCS at calving up to score 4.0 [X2] was significant [P < 0.01]. The resulting equation was Y1=90.52-20.68 X2. Cows with high BCS at calving up to score 4.0 had significantly [P < 0.05] shorter interval to 1[st] detected estrus. Meanwhile, linear regression coefficient of days open [Y2] or number of services/conception [Y3] on BCS at service [up to score 3.5] [X3] was also significant. The resulting equations were Y2 = 293.59 - 66.47 X3 and Y3=5.13-1.056 x 3, respectively. Both days open and number of services/conception were significantly improved as BCS at service was increased up to 3.5. The present work revealed that, reduced fertility in highly producing cows is not directly related to increased milk yield but rather to loss of weight and body condition. It is worthy to mention that the equations used here are helpful to predict the reproductive perfomance of a given cow by means of peak milk yield and/or BCS