Effet d’une Supplémentation de la Ration en Matière Grasse Additionnée de Méthionine Protégée sur les Performances Productives et Reproductives et sur la Composition du Lait des Vaches Laitières en Début de Lactation = Effect of Supplementation of the Diet with Fat with Added Protected Methionine on Productive and Reproductive Performance and Milk Composition of Dairy Cows in Early Lactation

2016 ◽  
Vol 89 (Numéro Spécial) ◽  
pp. 183-186
Author(s):  
Mondher Ben Salem ◽  
Hassen Marouani ◽  
Kamel Hawala
1996 ◽  
Vol 76 (2) ◽  
pp. 221-230 ◽  
Author(s):  
W. Z. Yang ◽  
D. N. Mowat ◽  
A. Subiyatno ◽  
R. M. Liptrap

Two experiments were conducted to evaluate the effects of chromium (Cr) supplementation on early lactation performance of Holstein cows. Experiment 1 involved 12 primiparous (PP) and 22 multiparous (MP) cows, while exp. 2 involved 18 PP and 22 MP cows. In each trial, cows were fed total mixed rations (TMR) and assigned to one of two treatments: control or 0.5 mg kg−1 supplemental chelated Cr from week 6 prepartum to week 16 postpartum The cortisol response to synthetic adrenocorticotropin (ACTH) intramuscular (i.m.) and the luteinizing hormone (LH) response to synthetic gonadotropin-releasing hormone (GnRH) i.m. were evaluated as well, during weeks 2 and 6 postpartum in exp. 2 During the first 16 wk of lactation, supplemental Cr tended to increase milk yields in PP cows by 13% (P = 0.06) and increased milk production by 7% (P < 0.05) in exps. 1 and 2, respectively, but had no effect in MP cows. Despite increased milk yield, Cr supplementation had no adverse effect on milk composition, reproductive performance, or health status. Furthermore, Cr supplementation tended to increase the milk lactose content in PP cows. Supplemental Cr reduced serum β-hydroxybutyrate levels and may reduce subclinical ketosis in MP cows. In addition, in overconditioned, aged cows, Cr supplementation may reduce the incidence of certain other metabolic disorders. Peak values and production rates of cortisol in Cr-supplemented cows tended to be greater (P < 0.10) than in control cows at week 6 Basal LH concentrations did not differ between the two treatments for either week However, the Cr-supplemented cows released less (P < 0.05) LH than did control cows at week 6. Results from hormonestimulation tests suggest that the Cr-supplemented cows may have experienced a greater stress with their increased milk production. However the time in postpartum anestrus and the time to conception were similar, suggesting that Cr supplementation may have mitigated the slower return to fertility usually seen in higher producing PP dairy cows. Further study is needed to determine the effects of Cr supplementation on reproductive performance, health status, and metabolic disorders in dairy cows. Key words: Chromium, milk production, luteinizing hormone, cortisol, reproduction, dairy cows


2017 ◽  
Vol 57 (10) ◽  
pp. 2100 ◽  
Author(s):  
Jack Fahey ◽  
John M. Morton ◽  
Martin J. Auldist ◽  
Keith L. Macmillan

High milk protein concentrations (MP%) have been positively associated with the reproductive performance of lactating dairy cows. No studies have measured the effects of this association on subsequent calving dates in multiparous cows, nor assessed whether the underlying causal mechanisms are present in nulliparous heifers. Holstein cows (primiparous = 918; multiparous = 4242) were selected from herds that had seasonally concentrated calving patterns resulting from seasonally restricted breeding periods. In seasonally calving herds, the date of a herd’s planned start of calving (PSC date) is the average gestation length of 282 days after the date that the preceding breeding period commenced, so that the interval from the herd’s PSC date to each cow’s actual calving date (PSC-to-calving interval) primarily reflects the time to conception from the start of the breeding period in the previous year. This measure was used to compare associations between the average MP% during the first 120 days of lactation and time to the calving that initiated that lactation in primiparous and multiparous cows. Early lactation MP% was negatively associated with PSC-to-calving interval. A 1% difference in MP% was associated with an 8-day difference in the average PSC-to-calving interval in primiparous cows and a 31–35-day difference in the average interval in multiparous cows. The observed associations between early lactation MP% and PSC-to-calving interval are likely to involve determinants present during a cow’s breeding period that affect the probability of conception. Some of these determinants are not restricted to early lactation as the association between MP% and PSC-to-calving interval in primiparous cows is a reflection of the reproductive performance in nulliparous heifers at ~15 months of age.


2007 ◽  
Vol 90 (3) ◽  
pp. 1467-1476 ◽  
Author(s):  
A.T.M. van Knegsel ◽  
H. van den Brand ◽  
J. Dijkstra ◽  
W.M. van Straalen ◽  
M.J.W. Heetkamp ◽  
...  

2009 ◽  
Vol 2009 ◽  
pp. 12-12
Author(s):  
H S Gilmore ◽  
F J Young ◽  
R A Law ◽  
A R G Wylie ◽  
D C Patterson ◽  
...  

Poor fertility is a major problem on dairy farms. On-farm studies indicate than pregnancy rates to first service have declined from approximately 55% between 1975 and 1982 to 39% between 1995 and 1998 (Royal et al., 2000), illustrating a decline of approximately 1% per year during this period. The cause is multifactorial and influenced by many factors including genetics, management and nutrition. Previous studies have reported improved fertility through nutritional modification in early lactation (Gong et al., 2002). The aim of this study was to evaluate the effect of nutritional strategy in early lactation on reproductive performance.


2016 ◽  
Vol 16 (1) ◽  
pp. 129-143 ◽  
Author(s):  
Barbara Stefańska ◽  
Włodzimierz Nowak ◽  
Ewa Pruszyńska-Oszmałek ◽  
Robert Mikuła ◽  
Daniel Stanisławski ◽  
...  

Abstract The aim of the study was to investigate the effect of BCS (Body Condition Score) on the calving day and its decrease during early lactation on the biochemical blood indices and reproductive performance. One hundred and thirty-one Polish Holstein-Friesian cows were divided into three groups according to the North-American body condition score on the calving day (AC≤3.5 point BCS; MID 3.51-3.75 point BCS; FAT>3.75 point BCS) and according to the decrease in BCS during early lactation (HG >0.49 point BCS; WEL 0.49-0.25 point BCS, L<0.25 point BCS). In current study, significant interaction between change of BCS during early lactation and time of blood sampling on BHBA concentration was observed. In the AC group (≤3.5 BCS), the highest concentrations of glucose on 3 and 5 d of lactation compared to the MID and FAT groups and of insulin on 28 d and also IGF-I on 5 and 28 d of lactation compared to the FAT group were recorded. In the FAT group, the highest concentration of NEFA on 3 and 5 d compared to the AC group and of BHBA on 28 d of lactation compared to the MID group was recorded. The body condition score on the parturition day affected the reproductive performance; in the FAT group (>3.75 BCS) the lowest conception rate of the first insemination, insemination index and thereby the longest days open were observed. The highest decreases in BCS (HG >0.49 points) resulted in increased concentrations of NEFA on 3 d and of BHBA on 3 and 5 d. Moreover, in the HG group, the lowest concentration of T3 on 3, 5 and 28 d as compared to the WEL group was recorded. We concluded that the BCS (>3.5 points) on the calving day had a significantly negative effect on the metabolic status of dairy cows in the postpartum period estimated by the concentration of biochemical blood indices characterising carbohydrates (IGF-I, insulin) and lipid (NEFA, BHBA) metabolism and also the reproductive performance such as the conception rate of the first insemination, insemination index, days open. We suggested that the blood serum concentrations of IGF-I and NEFA were the most sensitive biochemical markers of the metabolic status of dairy cows in our study.


Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1054
Author(s):  
Zelmar Rodriguez ◽  
Elise Shepley ◽  
Pedro P. C. Ferro ◽  
Nilon L. Moraes ◽  
Acir M. Antunes ◽  
...  

Monitoring the body condition score (BCS) of dairy cows is a management strategy that can assist dairy producers in decision-making. The BCS and its variations reflect the level of body fat reserves and fat mobilization throughout the different stages of lactation. Cows that mobilize excessive amounts of fat reserves in response to the increased energy requirements of the transition period are more likely to have higher beta-hydroxybutyrate (BHB) concentration in blood, leading to a higher incidence of hyperketonemia postpartum. In this study, our main objective was to evaluate how both BCS (at 21 d prior to the expected calving date, −21 BCS) and change in BCS during the late dry period (−21 d to calving, ∆BCS) are associated with temporal patterns of blood BHB concentrations during the first two weeks of lactation. Our secondary objective was to characterize the relationship between the change in BCS in the late dry period, and milk yield and milk composition in the first milk test postpartum. In this retrospective cohort study, we assessed BCS at 21 (±3) days before the expected calving date and within three days after calving. Blood BHB concentration was measured at days 3 (±1), 7 (±1), and 14 (±1) postpartum. Hyperketonemia (HYK) was defined as blood BHB ≥ 1.2 mmol/L. To evaluate how −21 BCS and ∆BCS during the late dry period were associated with BHB in early lactation, linear mixed-effects regression models with an unstructured covariate matrix were performed. The association between ∆BCS and incidence of postpartum HYK were determined using a multivariable log-binomial model. A linear regression model was used to evaluate the association between ∆BCS and milk yield and milk composition in the first monthly test-day. Covariates used for model adjustment include parity, season, and baseline BCS. We observed that cows with BCS ≥ 4.0 at 21 d before their expected calving date had the highest BHB concentration postpartum, but no evidence that BCS ≥ 4.0 at 21 d was associated with fluctuations of BHB over time. Cows that experienced a large BCS loss (larger than 0.5 units) during the late dry period had a 61% (95% CI: 1.04, 2.50) higher risk of developing HYK in early lactation and had higher BHB concentrations during early lactation compared with cows with no ∆BCS prepartum. These associations were observed independently of the BCS at −21 d prepartum (baseline). In addition, cows that lost more than 0.5 BCS unit in the late dry period produced 3.3 kg less milk (95% CI: −7.06, 0.45) at the first milk test compared to cows that had no ∆BCS during the late dry period. No evidence of an association between −21 BCS and ∆BCS in the late dry period and milk composition was observed in our study. These results suggest that dynamic measures of BCS during the late dry period, such as ∆BCS, are better at evaluating blood BHB patterns in early lactation than BCS measured at a single time point. Cows with larger BCS loss during the late dry period and with greater parity are more likely to have higher concentrations of blood BHB postpartum, with the highest concentrations reported at 7 d post-calving.


2007 ◽  
Vol 90 (6) ◽  
pp. 2788-2796 ◽  
Author(s):  
R.B. Walsh ◽  
J.S. Walton ◽  
D.F. Kelton ◽  
S.J. LeBlanc ◽  
K.E. Leslie ◽  
...  

1958 ◽  
Vol 38 (2) ◽  
pp. 133-144 ◽  
Author(s):  
V. S. Logan ◽  
Vern Miles

Daily strip grazing was compared with free range grazing for dairy cows during three pasture seasons on replicated areas in a 5-year crop rotation. Seventy-two Holstein and Ayrshire cows in early lactation and twelve yearling heifers were used for the complete experiment.Pasture productivity was estimated by crediting the respective pasture plots with the T.D.N. required for the milk produced, for maintenance and gain, and for the estimated T.D.N. harvested as silage or hay. The T.D.N. fed in supplementary feed (silage, hay, and concentrate) and the T.D.N. equivalent of any body weight losses were deducted from the pasture production.Strip-grazing yields were 16.5 to 26.9 per cent higher than those from free range grazing. Surplus grass cut and supplement adjustment accounted for the major portion of these differences. While strip grazing appeared to maintain more persistent milk yields, total milk production did not differ significantly between the two systems. Milk composition (butterfat and solids-not-fat) did not differ significantly between the two systems of grazing and was not affected by the varying stages of pasture growth during strip-grazing cycles.


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