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1.
The aim of this study was to measure changes in biochemical markers in the peripartum period of primiparous Holstein cows diagnosed with subclinical and clinical mastitis. In this study, 37 dairy cows were monitored daily during milking until 60 days postpartum and were categorized according to the occurrence of clinical mastitis (group mastitis (GM), n?=?9) or subclinical mastitis (group subclinical mastitis (GSUB), n?=?10) or absence of symptoms (control group (CG), n?=?18). Blood samples were collected weekly from ?30 to 60 days from calving. Samples were grouped for prepartum (?30 to 0 days from calving), early postpartum (0 to 30 days from calving), and late postpartum (30 to 60 days from calving) periods. Prepartum serum non-esterified fatty acid (NEFA) concentration was higher in GM than in CG (P?<?0.01). In addition, CG had higher prepartum serum glucose concentration than GM (P?=?0.03). In the early postpartum period, aspartate aminotransferase (AST) activity was lower in CG than in GSUB (P?<?0.05), and in the late postpartum period, AST activity was lower in CG than GSUB and GM (P?=?0.01). Somatic cell count was higher during the early and late postpartum periods for GM and GSUB when compared to CG (P?<?0.01). In this study, primiparous cows with low glucose and higher NEFA in the prepartum were more susceptible for mastitis in the early postpartum, probably due to low immune function associated to a more negative energy balance. In sum, increased prepartum serum NEFA concentration and decreased glucose in primiparous cows were associated with clinical mastitis incidence in the postpartum period.  相似文献   

2.
This study determined the effects of feed supplementation during the postpartum period on the weight gain, milk yield, blood profiles and reproductive performance of Sanga and Friesian-Sanga cows grazing on natural pasture. 20 Sanga and 20 Friesian-Sanga cows were randomly allocated either to serve as a control on grazing only or to be supplemented with 2.5 kg of concentrate a day for 10 weeks during the dry season. Each week, all cows were weighed and scored for body condition. Partial milk yield of cows was determined daily. Plasma concentrations of blood metabolites were assessed fortnightly from weeks 1 to 10 postpartum. Resumption of postpartum ovarian activity was determined by measuring progesterone concentration in the plasma from weeks 1 to 10. Supplemented cows had a better body condition score (6.2 versus 5.8; P?<?0.05) and higher partial milk yield (1.94 versus 1.55 L/day; P?<?0.01) than non-supplemented cows. Sanga cows had a better body condition score (6.2 versus 5.8; P?<?0.05) but lower milk yield (1.58 versus 1.92 L/day; P?<?0.01) than the Friesian-Sanga crossbreds. Total protein (P?<?0.05) and albumin (P?<?0.01) concentrations were higher in the supplemented than in the non-supplemented cows. Sanga cows recorded higher globulin (P?<?0.05) and total cholesterol (P?<?0.01) but lower albumin (P?<?0.01) concentrations than Friesian-Sanga crossbred cows. Feed supplementation did not affect (P?<?0.05) the interval from calving to resumption of ovarian activity, and the days to resumption of ovarian activity in the Sanga and Friesian-Sanga cows were also similar (P?>?0.05). The results demonstrate the beneficial effects of feed supplementation in terms of improved body condition and metabolic status and increased milk yield.  相似文献   

3.
We determined the effects of dietary supplementation with folate and vitamin B12 on lipid metabolism and the deposition of these vitamins in eggs of laying hens (age 64–72 weeks). Four levels of folate (0, 0.5, 4 and 10 mg/kg) and three levels of vitamin B12 (0, 0.01 and 0.08 mg/kg) were added to the basal diet for 8 weeks in a 4 × 3 factorial completely randomized design study. No significant physiological interaction between folate and vitamin B12 was evident under our experimental conditions. There was no effect of vitamins supplementation on egg production or feed intake. Supplementation with folate significantly elevated serum (p < 0.01) and yolk (p < 0.05) folate levels. Supplementation with vitamin B12 did not significantly affect serum or egg yolk vitamin B12 levels. Supplementation with folate or vitamin B12 did not significantly affect triglyceride or total phospholipid levels in serum or egg yolk although a positive relationship was observed between dietary folate supplementation and total serum phospholipid (r 2  = 0.68, p < 0.05). The study showed that it is possible to produce folate-enriched eggs. An increase in serum total phospholipids due to dietary supplementation with folate may provide physiological benefits to hens, although we did not observe any strong effects of these vitamins on lipid composition.  相似文献   

4.
The spent mushroom substrate of Ganoderma balabacense cultivation (SMSGB) contains a large amount of bioactive substances. However, the potentials of SMSGB for improving milk production in dairy cows have not been thoroughly studied. In this study, the effects of hot water extract (HWE) from spent mushroom substrate after G. balabacense cultivated with JUNCAO, the herbaceous plants long‐known to be suitable for cultivating edible and medicinal fungi, on production performance and hematology parameters of dairy cows, were determined. Holstein dairy cows were fed different doses of HWE. After a 60‐day administration period with 100 g/day of HWE, milk yield, milk protein and triglyceride (TG) levels increased by 4.02% (P < 0.01), 4.49% (P < 0.05) and 32.65% (P < 0.05), respectively; somatic cell count (SCC) and alanine aminotransferase (ALT) were significantly decreased (P < 0.05). The production performance of dairy cows suggests that HWE with SMSGB treatment is effective in improving milk yield (P < 0.01) and hematology parameters of dairy cows, and may be useful as a functional feed additive.  相似文献   

5.
Seventy multiparous healthy lactating Holstein cows (fat-corrected milk yield = 7,561.8 kg) were monitored from 14 days before to 70 days after calving. Transrectal ultrasound scanning was performed twice weekly from 7 to 65 days postpartum. Blood samples were also collected twice weekly to measure serum P4 and biweekly to detect serum β-hydroxybutyrate (βHB) and nonesterified fatty acid (NEFA) concentrations. Body condition score (BCS) was taken biweekly after calving. Based on the serum P4 profile of 59 cows (11 cows were excluded due to the occurrence of postpartum diseases) studied, 27 (45.8%) had normal ovarian activity, while 21 (35.6%), six (10.1%), three (5.1%), and two (3.4%) had delayed ovulation (DOV), prolonged luteal phase (PLP), short luteal phase (SLP), and cessation of ovarian activity, respectively. Cows with PLP had an earlier ovulation compared to that of cows with normal ovarian activity (23.16 ± 4.02 vs 31.9 ± 8.35 days; P < 0.05). PLP cows also had a greater mean ± standard deviation peak milk yield (44.2 ± 5.8 vs 37.2 ± 5.7 kg/day, 75 days postpartum; P < 0.05) than cows with normal postpartum ovarian activity. The PLP group also had greater milk production in the previous lactation period. Logistic regression analysis indicated that cows with P4 concentration ≥1 ng/ml on day 24 after calving were more at risk for PLP by 1.1 for each 1 kg increase in mean peak milk yield during 75 days after calving. BCS was lower in cows with DOV compared to that of cows with normal ovarian activity at any time after calving (P < 0.05). Serum βHB concentrations in DOV cows were significantly higher than that of normal cows on day 42 after calving (0.69 ± 0.29 vs 0.54 ± 0.12 mmol/L, P < 0.05). No significant difference was found in the mean concentrations of NEFA between cows in different groups at any time after calving (P > 0.05). The concentrations of P4 on days 28 and 31 were negatively correlated with βHB concentration on day 42 after calving in cows with normal ovarian activity (R = −0.44, P = 0.02). In conclusion, these findings suggest that early ovulation and hence early postpartum P4 rise in addition to the high milk production could partly be responsible for the occurrence of PLP in dairy cows.  相似文献   

6.
As a result of research conducted in the US, recommendations for dry cow vitamin E intakes have increased seven fold there, however there has been no change to recommendations in the UK. As part of a larger study comparing the impact of existing UK and new US recommended vitamin E intakes on the health and fertility of commercial dairy cows in the UK, a study was set up to investigate the effect of route of supplementation and stage of lactation, over a 21 day period, on the response to mega-supplementation of cattle receiving supposedly adequate vitamin E. The study assessed the response of dry, peak lactation and mid lactation cows to in-feed or parenteral vitamin E supplementation (7 animals per treatment/lactation stage group) by measuring plasma and milk vitamin E concentrations, blood glutathione peroxidase (GSH-Px) activity and milk yields over a 21 day period. Plasma vitamin E concentrations were significantly influenced by a time, stage and treatment interaction (P = 0.046). Both dry and lactating animals had significantly higher plasma vitamin E concentrations at some time points in the parenteral supplemented cows compared to the in-feed supplementated animals (P ≤ 0.011 and P < 0.01, respectively). Milk vitamin E concentrations did not significantly differ between lactation stages but treatment had a significant effect on concentrations (P < 0.008) when lactation stage was removed from the model. There was no significant difference in milk yield between treatment groups. A significant relationship between plasma and milk vitamin E concentrations was only found in the parenterally supplemented cows (r = 0.435, P < 0.001). In cattle with intakes greater than the ARC recommendations, measurement of plasma vitamin E concentration may be of limited value in determining whether there has been a response to supplementation. The relationship between plasma and milk vitamin E concentrations is too poor for milk vitamin E concentrations to be used as a proxy for plasma vitamin E.  相似文献   

7.
Data from six primiparous and nine multiparous Holstein cows were used to clarify the difference of Ca and P mobilization between primiparous and multiparous cows during early lactation. The dry matter intake (DMI) of primiparous cows was lower (P < 0.01) than those of multiparous cows. Milk yield was lower in primiparous cows at 7, 14, 21 (P < 0.01), and 28 days (P < 0.05) after parturition. There was no significant difference in milk Ca and P concentrations between primiparous and multiparous cows. There were no significant differences in plasma Ca and P concentrations between primiparous and multiparous cows. The plasma P level at 7 days postpartum in primiparous cows was lower (P < 0.05) than 28 days postpartum. The concentration of plasma osteocalcin (OC) measured as bone formation marker of primiparous cows was significantly higher than multiparous cows (P < 0.01) at 21 and 28 days postpartum. The urinary deoxypyridinoline (DPD) as bone resorption marker of primiparous cows tended to be higher (P < 0.10) than multiparous cows at 21 days after parturition and decreased to the same level as that of multiparae toward the peak lactation. These results show that Ca and P mobilization of primiparous cows are more active than multiparous cows.  相似文献   

8.
Eleven primiparous Holstein Friesian and their crossbred calves (F1, Japanese Black cattle × Holstein Friesian) and 10 multiparous Holstein Friesian and their Holstein Friesian calves were used to evaluate vitamin E status in periparturient period. Plasma α‐tocopherol (α‐toc) concentrations of the multiparous cows were significantly higher than those of the primiparous cows from 60 days before expected calving to 90 days of lactation (P < 0.05). The multiparous cows had a further decrease in the concentrations of α‐toc and total lipid in plasma to the calving than the primiparous cows. Colostrum α‐toc concentrations in multiparous cows were significantly higher than those of the primiparous cows (P < 0.05). Plasma α‐toc concentrations of calves borne by the multiparous cows were significantly higher than those of the primiparous cows at 5 days of age (P < 0.05). Plasma α‐toc concentrations of calves were highest at 5 and 15 days of age in the calves borne by the multiparous and primiparous cows, respectively, and decreased thereafter till 90 days of age. The higher vitamin E status of multiparous cows over primiparous cows might have reflected nutritional composition in the rations. Their calves afforded higher plasma α‐toc levels after birth because of more α‐toc transfer via placenta and more α‐toc secretion in the colostrums thereafter. Plasma α‐toc concentrations of the calves might have decreased as the calves became dependent upon the solid feed of low vitamin E content.  相似文献   

9.
High‐yielding Holstein‐Friesian recipients (n = 43) were used in order to investigate the relation between energy balance status during the early postpartum period and subsequent embryonic mortality after transferring good‐quality frozen embryos. Blood samples were collected during the second, third, fourth, fifth, sixth and seventh weeks postpartum in order to measure energy status indicators. These indicators include β hydroxyl butyric acid (BHBA), non‐esterified fatty acid (NEFA), total cholesterol (T‐chol), glucose and blood urea nitrogen (BUN). Moreover, body condition scores (BCS) were assessed during the same period. Pregnancy diagnosis by ultrasonography at the 28th day postestrus and embryo viability was ascertained until 45 days postestrus in order to detect late embryonic mortality (LEM). The pregnancy rate on day 28 was 44.2% (19/43); however, five cows (11.6%) experienced LEM by day 45. Based on the non‐return rate at day 24, non‐pregnant animals, as diagnosed by ultrasonography, were allocated into animals with longer estrus intervals than 24 days (32.5%; mid‐embryonic mortality (MEM) group) and animals returning to estrus by day 24 postestrus (23.5%; early embryonic mortality (EEM) group). At week 5 postpartum, BCS was significantly (P < 0.05) lower in the LEM group than that of pregnant (PREG), EEM and MEM groups. NEFA was significantly higher in animals that experienced LEM (LEM group) at week 7 postpartum (289.6 ± 47.0 µEq/L; P < 0.01) than that of PREG (196.8 ± 16.0 µEq/L), EEM (157.2 ± 18.6 µEq/L) and MEM groups (191.5 ± 14.4 µEq/L). In conclusion, lower BCS at week 5 postpartum and higher NEFAs at week 7 postpartum may be associated with subsequent LEM in high‐yielding recipient cows.  相似文献   

10.
An experiment was conducted with 16 Japanese Black cows to determine the effects of different days on feed (89, 208, 271 and 341 days), inclusion levels of grain in concentrate (60% vs. 40%; dry matter (DM) basis) and roughage sources (hay vs. rice straw) on finishing performance. Additional four cows were slaughtered at 0 days on feed to obtain non‐fed carcass data. Maximum carcass weights were observed in cows fed for 271 days; an increase in carcass weight of only 14 kg was shown from 208 days to 271 days. The marbling score increased (P < 0.05) with days on feed. The percentage of fat in the subprimal rib linearly increased (P < 0.05) with days on feed. The percentage of lean meat was higher (P < 0.05) for cows fed rice straw than for cows fed hay as a roughage source. Increasing the days on feed decreased (P < 0.05) the yellowness of the fat. The effects of the inclusion levels of grain in concentrate on the finishing performance of cows were lower than the other two factors. In conclusion, feeding improves carcass values, but feeding over 208 days is an inefficient system of production in cows.  相似文献   

11.
The objective of this study was to clarify the effect of different milking frequencies under an automatic milking system (AMS) on milk yield, plasma metabolite profiles and mammary arterial‐venous (A‐V) differences of milk precursors by mammary tissues in early lactation cows. Twelve Holstein cows were divided into two and four times milking frequency treatments by AMS after calving to 50 days postpartum. Cows were given a partial mixed ration ad libitum and a concentrate diet at every milking. Dry matter intake increased similarly in both treatments with advancing postpartum days. Milk yield was greater (P < 0.001) by 25% with four times milking, but milk composition was not affected by milking frequency. Body weight change was also not affected by milking frequency. Arterial concentrations of glucose and glutamate were lower (P < 0.05) for four times milking frequency. However, arterial concentration of nonesterified fatty acids did not differ between treatments. Although mammary A‐V differences of plasma concentration for most milk precursors did not differ between treatments, estimated plasma flow was higher (P < 0.05) for four times milking frequency. These results indicate that higher milking frequency may increase mammary uptake of milk precursors, whereas may not affect the extent of fat mobilization of early lactating cows from day 20 postpartum onward.  相似文献   

12.
Heat stress decreases natural immunity making cows more vulnerable to diseases. A previous study reported that daidzein can enhance animal resistance to heat stress and regulate animal immunocompetence. However, it is unclear whether daidzein regulates the immune performance of late lactation cows under heat stress. In this study, late lactation cows in four groups were raised in hot weather and fed with basic diet, basic diet plus 200, 300, 400 mg/day daidzein, respectively, and the experimental period was 60 days. Blood was collected to examine the changes of serum total protein (TP), albumin (ALB), immunoglobulin G (IgG), interferon alpha (IFN‐α), and interleukin‐2 (IL‐2). We found the levels of serum IgG and INF‐α were significantly higher in late lactation cows after 300 and 400 mg/day daidzein treatment compared to those in the control group and 200 mg/day daidzein treatment (P < 0.05 or P < 0.01). Moreover, 300 and 400 mg/day daidzein treatment markedly increased serum IL‐2 (P < 0.01), while the levels of serum TP and ALB were not changed by any concentration of daidzein treatment (P > 0.05). Daidzein can enhance the immunocompetence of late lactation cows and strengthen cow resistance to heat stress.  相似文献   

13.
Relationship between rumen fermentation parameters, blood biochemical profiles and milk production traits in different yielding dairy cows during early lactation was investigated. Twelve dairy cows were divided into two groups based on their milk yield, that is low‐yield (LY) and high‐yield (HY) groups. Rumen fluid and blood were collected at 3 weeks prepartum and 4, 8 and 12 weeks postpartum. Results showed that proportions of acetate, propionate to total short chain fatty acids and acetate : propionate ratio were changed (P < 0.05) in both groups during the peripartum period, whereas butyrate and acetate : butyrate ratio were only altered in the HY group. Blood cholesterol, beta‐hydroxybutyric acid (BHBA) and glutamic oxaloacetic transaminase in the HY group were higher (P < 0.01) than those in the LY group. Principal component analysis revealed that milk yield and milk compositions were differently clustered between groups. These parameters showed similar direction with dry matter intake in the HY group and adverse direction in the LY group. Linear regression analysis indicated that butyrate was positively correlated with BHBA (P < 0.05) in the HY group. This study suggests that cows in the HY group seem to accommodate appropriately to negative energy balance in early lactation through rumen fermentation.  相似文献   

14.
母牛补饲维生素E和硒对新生犊牛生长和免疫的影响   总被引：1，自引：0，他引：1  
本试验选择年龄、胎次、体况评分、顸产期相近的中国荷斯坦奶牛40头,随机分成2组,一组自由舔饲维生素E富硒舔砖,一组不补饲舔砖,研究维生素E(VE)和硒对新生犊牛生长和免疫的影响.试验期90 d,从预产前60 d到产后30 d.结果表明,试验组母牛血清中VE的含量在产后12 h显著高于对照组(P<0.05),血清中硒的含量在产前30 d和产后12 h高于对照组,差异极显著(P<0.01).试验组母牛分娩后12 h,血清中IgG、IgM的含量,初乳中IgM、IgG、IgA的含量都显著高于对照组(P<0.05).试验组犊牛出生后12 h,血清中VE和硒含量极显著高于对照组(P<0.01),IgG、IgA的含量高于对照组,差异显著(P<0.05).试验组犊牛初生体质量和体尺显著高于对照组(P<0.05),30日龄体质量和体尺高于对照组,差异极显著(P<0.01).试验组犊牛的发病率比对照组降低了50%.  相似文献   

15.
AIM: To investigate ovarian follicular and luteal activity during the postpartum period of cows genetically selected for high or low mature bodyweight, in relation to metabolic and reproductive endocrine parameters, to determine whether there are differences between strains that could affect fertility outcomes.

METHODS: The presence of follicles ≥5 mm diameter and luteal structures was mapped in the ovaries of 12 high (heavystrain) and 12 low (light-strain) mature bodyweight cows by daily trans-rectal ultrasonography from Day 7 postpartum until the end of their first normal oestrous cycle. Blood samples were collected daily, for measurement of concentrations of follicle stimulating hormone (FSH), progesterone, growth hormone (GH), insulin-like growth factor-1 (IGF-1), and insulin. Intervals to first ovulation were calculated from ultrasonography data.

RESULTS: Heavy-strain cows had shorter intervals than light-strain cows from calving to the emergence of the first (9.0 (SE 0.9) vs 12.4 (SE 1.3) days) and second (16.4 (SE 1.8) vs 20.6 (SE 1.6) days) dominant follicles (p<0.05). Concentrations of FSH in heavy-strain cows prior to the emergence of the second, third and fourth dominant follicles were higher than in light-strain cows (p<0.05). Heavy-strain cows were more likely to have a large (>15 mm diameter) follicle earlier than light-strain cows (p<0.01). Concentrations of insulin and IGF-1, but not those of GH, were higher in heavy- than light-strain cows during the postpartum period (p=0.01 and p=0.02, respectively), and concentrations of both on Day 6 were inversely related to the time of emergence of the first dominant follicle (p>0.01).

Concentrations of progesterone were similar in both strains of cow until Day 10 of the first oestrous cycle, but thereafter were higher in light- than heavy-strain cows until Day 16. Progesterone concentrations in heavy-strain cows declined earlier and more rapidly than in their lighter counterparts.

CONCLUSION: These results indicate that there is a rapid postpartum resumption of follicular activity in both heavy-and light-strain cows, but that there is an earlier emergence of dominant follicles and ovulation in the former. Differences in luteal function, in terms of lower dioestrus progesterone concentrations and an earlier onset of luteolysis, in heavy- than light-strain cows might be sufficient to impair the fertility of the former.  相似文献   

16.
Two experiments were conducted to evaluate feedlot performance, lactational characteristics, and carcass composition and quality of heifers and the performance of their calves in a single-calf heifer (SCH) system. In Exp. 1, 13 [10 lactating (L) and 3 nonlactating (NL)] prenatally androgenized (PA) heifers, born to cows implanted with testosterone propionate (TP) and 19 (13 L and 6 NL) control (C) heifers, born to nonimplanted cows, were used. Heifers were calved and the pairs were placed in feedlot pens to evaluate the effects of PA on feedlot performance and lactation. Heifers were fed an 85% concentrate diet and fed to a compositional endpoint of 1.1 cm of subcutaneous fat cover, at which point calves were weaned and heifers slaughtered approximately 12 h later. The NL heifers consumed 17.0% less (P<0.01) dry matter and were 30.8% more (P<0.01) efficient in feed conversion. When calf performance was included, overall feed efficiency of L heifers was 26.9% greater (P<0.05; 0.151 vs 0.119) than that of the NL feedlot heifers. Prenatal androgenization had no effect on heifer performance. Four percent fat-corrected milk yield averaged 7.79 and 5.62 kg/d for PA and C heifers, respectively. The NL heifers had 11.0% greater (P<0.01) marbling score and yield grades were 3.77 and 3.03 (P<0.05) for NL and L heifers, respectively. Livers (P<0.01) and kidneys (P<0.05) as a percentage of shrunk weight were heavier for L heifers than for NL heifers. Two carcasses were classified as hard-boned (C-maturity) and 74% received a USDA Choice grade. The L heifers tended (P<0.10) to have lower taste panel tenderness scores; however, shearforce was similar (P=0.81) for L and NL heifers. In Exp. 2, 24 Angus × Holstein heifers were utilized in the single-calf heifer system, similar to Exp. 1. Calves were weaned from their dam between d 64 and 89 postpartum. Heifers that had their calves early weaned (EW) gained 44.2% faster (P<0.01) and consumed 10.8% less (P<0.05) DM than L heifers. The EW heifers were 60.0% more (P<0.01) efficient than L heifers. However, when calf performance was included with heifer performance, L heifers were 23.7% more (P<0.05) efficient than EW heifers. The EW heifers had 18.9% heavier (P<0.01) hot carcasses than L heifers. Backfat thickness was 1.07 and 0.66 cm (P<0.01) for the EW and L heifers.  相似文献   

17.
Two experiments were conducted to clarify the effect of water‐soluble carbohydrate (WSC) content in orchardgrass pasture on the diurnal distribution of grazing time. Six ruminally cannulated, non‐lactating dairy cows were grazed on either of two pastures with different orchardgrass cultivars containing low WSC (LWSC; cultivar: ‘Hokkai 28’) or high WSC (HWSC; cultivar: ‘Harunemidori’). The cows were grazed in morning and evening sessions in experiment 1, whereas the cows were grazed throughout the day in experiment 2. In experiment 1, grazing time of the cows on HWSC was longer than that of the cows on LWSC (P < 0.01). This difference was larger in the morning session than in the evening session (pasture × grazing session: P < 0.05). Effects on herbage intake were similar to those on grazing time. In experiment 2, daily total grazing time was longer for the cows on HWSC than for those on LWSC (P < 0.05). The cows on HWSC spent a longer time grazing than those on LWSC in the morning between 03.00 and 09.00 hours (P < 0.01). The results indicated that prolonged grazing time in the period between dawn and early morning could increase daily herbage intake in cows grazed on pastures of orchardgrass cultivars with high‐WSC content.  相似文献   

18.
In present study production performance of 96 lame cows was compared with 67 healthy cows. No significant effect of parity and year of calving on milk yield were observed but the effect of season of calving was significant (P < 0.01). Effect of lameness on milk yield at the second, third and fourth months and 305 days was highly significant (P < 0.01), and was also significant (P < 0.05) on lactation yield of the fifth and tenth months. The effect of lameness on monthly and 305‐day milk yield was significant (P < 0.01) only for those cows diagnosed lame before calving and during the first month of lactation. The differences in mean monthly yield were highly significant (P < 0.01) at the second, third and fourth months; and significant (P < 0.05) in the first and fifth months. The loss in the first lactation month of cows which were diagnosed as lame in the second month, was found to be significant (P < 0.05). Thus the yield of the month previous to the diagnosis (sub‐clinical stage) was also affected. A significant (P < 0.01) total loss of 498.95 kg of milk yield was observed during a period of 305 days.  相似文献   

19.
This study aimed to clarify diurnal fluctuations of herbage intake, ruminal fermentation of herbage carbohydrates and proteins, and digesta particulate weight in the rumen of grazing dairy cows. Six ruminally cannulated, non‐lactating dairy cows were grazed on perennial ryegrass/white clover pasture either in the morning (04.00 to 08.00 hours) or the evening (16.00 to 20.00 hours). Cows grazed in the evening spent more time (P < 0.01) and consumed more herbage (P < 0.01) compared with cows grazed in the morning. Higher (P < 0.05) daily mean concentrations of total volatile fatty acid, propionate and n‐butyrate in rumen fluid were observed for cows grazed in the evening compared with cows grazed in the morning. Although cows grazed in the evening ingested more crude protein compared with cows grazed in the morning, no significant difference in NH3‐N concentration in rumen fluid was observed between them. The ratio of purine‐derivative concentration to creatinine concentrations was higher (P < 0.01) in the urine of cows grazed in the evening than in cows grazed in the morning. These results clearly indicated that evening grazing was advantageous for dairy cows compared with morning grazing, in terms of ruminal fermentable energy intake and nitrogen utilization efficiency.  相似文献   

20.
To study the effect of vitamin E (VE), copper (Cu) and zinc (Zn) supplementation on the in vitro phagocytic activity (PA) and lymphocyte proliferation response (LPR) of blood neutrophils and lymphocytes, thirty Sahiwal pregnant cows (six in each group) in their late gestation at 30 days before the expected date of calving were selected from the NDRI experimental herd and supplemented with various micronutrients from 30 days before calving to 45 days after calving. Cows were supplemented individually with VE (1000 IU/cow/day), Cu (20 ppm/cow/day) and Zn (80 ppm/cow/day) and also with a combination of VE, Cu and Zn to study cumulative effect of all micronutrients. One group without any supplementation acted as a control. Blood neutrophils and lymphocytes were isolated and studied for their PA and LPR. Supplementation of micronutrients like VE, Cu, Zn and a combination of all these nutrients significantly (p < 0.01) increased the PA of experimental cows as compared to control (unsupplemented) cows during the pre‐partum period. During post‐partum, all the micronutrients (VE, Cu, Zn and their combination) showed a significant (p < 0.01) increase in the PA of experimental cows as compared to control cows. Of all the groups, significant (p < 0.01) and maximum PA was observed in the combination group followed by Zn‐supplemented group during both the pre‐ and post‐partum period. A significant (p < 0.01) increase in LPR of B lymphocytes was observed in combination‐supplemented group during the pre‐partum period and during both the pre‐ and post‐partum period in the Cu‐supplemented group.  相似文献   

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