scholarly journals Effect of Hot and Humid Conditions on Cortisol Levels m Lactating Dairy Cows

1997 ◽  
Vol 2 ◽  
pp. 21
Author(s):  
M. Younas ◽  
J. W. Fuquayz ◽  
A.B. Moorez ◽  
S.M. I. Hussain
Keyword(s):  
Dairy Cows ◽  
Luteal Phase ◽  
Blood Sampling ◽  
Holstein Cows ◽  
Diurnal Pattern ◽  
Forced Ventilation ◽  
Blood Samples ◽  
Treatment Groups ◽  
Lactating Dairy Cows ◽  
Ambient Data

Fourteen lactating, non-pregnant Holstein cows were heat synchronized for estrus and assigned randomly to pens in a free stall barn with (Fan) or without (Control) a fan to observe the effect of forced ventilation on cortisol concentrations. After a 21-day adjustment period, Jugular cannulae were inserted for blood sampling before PGF2a injection. All animals were in their luteal phase at the time of injection as determined by previous observations for estrus and palpation. After PGFZa, blood samples were collected at 6-h intervals from 0 to 36h,  4-h intervals from 36 to 88h and 3 times weekly for three weeks thereafter. Blood samples were assayed for cortisol. Daily rectal temperatures and ambient data were recorded. Average daily rectal temperatures were lower (P<0.05) in the Fan (39.1“C) than in the Control (39.5“C). Cortisol did not show a diurnal pattern and the values did not differ (P >0.05) between treatment groups.

scholarly journals 141 Effect of induction of an ipsilateral vs. contralateral accessory corpus luteum (CL) on pregnancy per AI and pregnancy loss in lactating dairy cows

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 113-114
Author(s):  
Pedro L J Monteiro ◽  
Caio A Gamarra ◽  
Rodrigo S Genari ◽  
Alexandre B Prata ◽  
Rafael V Barletta ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Corpus Luteum ◽  
Pregnancy Loss ◽  
Statistical Analyses ◽  
Holstein Cows ◽  
Crown Rump Length ◽  
Blood Samples ◽  
Vesicle Size ◽  
Lactating Dairy Cows ◽  
In Pregnancy

Abstract Induction of accessory CL can increase circulating progesterone (P4) and potentially improve fertility; although, regression of accessory CL contralateral to the pregnancy can occur, potentially negating their benefit. In this study, primiparous (n = 377) and multiparous (n = 678) lactating Holstein cows (80.0 ± 3.3DIM, 43.2 ± 13.3 kg milk/d, and BCS = 2.85 ± 0.24) were enrolled in Presynch-Ovsynch (PGF-14d-PGF-12d-GnRH-7d-PGF-56h-GnRH-16h-AI) with AI at 81 ± 3 DIM. On d5 after AI, cows were randomly but unequally assigned as Control (n = 289) or GnRH (n = 641; 100 µg gonadorelin acetate). Blood samples were collected for P4 and ovaries evaluated by ultrasound on d5, d12, d19, d26, d33, d47, and d61. mRNA for ISGs (d19) and PSPB (d26) concentrations were evaluated and pregnancy diagnoses were done on d26, d33, d47 (also embryonic measurements), and d61. Statistical analyses were performed with PROC GLIMMIX of SAS 9.4. Ovulation to GnRH on d5 was 85.4% (577/676). Cows were designated as: Control (n = 289), Ipsilateral (n = 239), or Contralateral (n = 241). Overall P4 differed (P &lt; 0.01) within groups (Control = 7.90 ± 0.35c, Ipsilateral = 10.5 ± 0.34a, and Contralateral = 9.55 ± 0.26a). Interestingly, 52.7% (78/148) of contralateral pregnant cows had accessory CL regression by d61 with decreases in P4 after contralateral CL regression (P &lt; 0.001). There were no treatment differences for pregnant cows in ISG15 (P = 0.63) or Mx2 (P = 0.51) mRNA, circulating PSPB (P = 0.56), amniotic vesicle size (P = 0.89), or crown-rump length (P = 0.19) or in pregnancy/AI on d26 (P = 0.24), d33 (P = 0.67), d47 (P = 0.53), or d61 (P = 0.62; overall 50.3% [387/769]). Nevertheless, pregnancy losses between d26 and d61 were lower (P = 0.03) for ipsilateral (6.6 ± 2.3%) than contralateral (14.0 ± 3.0%) and from controls (P = 0.065; 13.7 ± 2.9%) With differences also from d26-33 (Control = 7.5 ± 2.1; Ipsilateral = 3.1 ± 1.5; Contralateral = 9.6 ± 2.5). Within contralateral group, early accessory CL regression was associated with greater pregnancy loss from d26-33 (P = 0.04) and d26-61 (P = 0.01). Thus, induction of accessory CL increases P4 and may reduce pregnancy loss, although these advantages are reduced for contralateral accessory CL, because many of these CL regress during pregnancy.

Associations between early lactation milk protein concentrations and the intervals to calving for Holstein cows of differing parity

2017 ◽  
Vol 57 (10) ◽  
pp. 2100 ◽  
Author(s):  
Jack Fahey ◽  
John M. Morton ◽  
Martin J. Auldist ◽  
Keith L. Macmillan
Keyword(s):  
Dairy Cows ◽  
Reproductive Performance ◽  
Milk Protein ◽  
Holstein Cows ◽  
Breeding Period ◽  
Gestation Length ◽  
Calving Interval ◽  
Early Lactation ◽  
Average Interval ◽  
Lactating Dairy Cows

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.

Effect of Metabolisable Protein on intake of grass silage and milk protein yield in dairy cows.

1994 ◽  
Vol 1994 ◽  
pp. 113-113 ◽  
Author(s):  
J.R. Newbold ◽  
B.R. Cottrill ◽  
R.M. Mansbridge ◽  
J.S. Blake
Keyword(s):  
Dairy Cows ◽  
Milk Protein ◽  
Live Weight ◽  
Protein Yield ◽  
Holstein Cows ◽  
Grass Silage ◽  
Lactating Dairy Cows ◽  
Ad Libitum ◽  
Few Data

Few data are available to evaluate the Metabolisable Protein (MP) System (AFRC, 1992) as an aid to ration formulation for dairy cows. Responses of lactating dairy cows to MP were evaluated in two experiments.In Experiment One, groups of 10 Holstein cows were offered grass silage ad libitum and 7kg DM/d of one of six (treatments 1-6) compound foods from 39d after calving, for eight weeks. All rations were isoenergetic, assuming silage intake of 11kg DM/d (typical for the herd). Ratios between MP supply (calculated from in situ protein degradability measurements) and requirement (calculated for a standard cow: 565kg live weight, 281 milk/d, 40g/kg butterfat, 33g/kg milk protein, liveweight change =0kg/d) were 1.00, 1.02, 1.06, 1.06, 1.1 and 1.17 for treatments 1-6, respectively.

160 CONCEPTION RATES FOLLOWING TREATMENT OF LACTATING HOLSTEIN RECIPIENTS WITH A GONADOTROPIN RELEASING HORMONE (GnRH) ANALOGUE AT THE TIME OF TRANSFER OF OVUM PICK-UP/IVF-DERIVED EMBRYOS

2013 ◽  
Vol 25 (1) ◽  
pp. 228
Author(s):  
T. L. C. Pinto ◽  
J. N. S. Sales ◽  
R. R. Carvalho ◽  
T. M. França ◽  
J. C. Souza
Keyword(s):  
Dairy Cows ◽  
Embryo Transfer ◽  
Management Tool ◽  
Gnrh Analogue ◽  
Gnrh Analogues ◽  
Treatment Groups ◽  
Lactating Dairy Cows ◽  
Conception Rates ◽  
Day Of Embryo Transfer

The use of lactating dairy cows as ovum pick-up (OPU)/IVF-derived embryo recipients in large-scale embryo transfer programs may be limited by the effects of low progesterone concentrations on the uterine environment and subsequent embryo development. It was hypothesized that the injection of a GnRH analogue on the day of embryo transfer would induce ovulation and formation of an accessory corpus luteum, increasing progesterone concentrations and, as a result, conception rates. An experiment was designed to evaluate the effects of two different GnRH analogues injected IM on the day of embryo transfer on conception rates of lactating Holstein recipients. Oestrus was not synchronized and was detected continuously by multiple observers during the day and in the evening until midnight. Recipient days in milk varied from 45 to 150, daily milk production ranged from 20 to 45 kg, body condition scores and age ranged from 2.5 to 4.5 and 2.5 to 5.5 years, respectively. Herd pregnancy rates after the first artificial insemination ranged from 15% to 70%, considering the period the experiment was conducted. Embryos were produced by standard in vitro techniques following OPU on Holstein donors. Lactating Holstein recipients (n = 224) were allocated randomly to one of three treatment groups 7 days after detected oestrus: Control (n = 77) = vehicle; Buserelin (Sincroforte®, Ouro Fino, Sao Paulo, Brazil; n = 75) = 10 µg; and Deslorelin (Sincrorrelin®, Ouro Fino; n = 72) = 750 µg. Embryos were transferred nonsurgically 6 to 8 days after observed oestrus. Pregnancy was detected by ultrasonography between 62 and 72 days after embryo transfer. Percent pregnant data were analyzed as a binomial distribution under the GENMOD procedure of SAS (SAS Institute Inc., Cary, NC, USA). Conception rates were similar (P = 0.13) between Control (28%, 22/77), Buserelin (24%, 18/75), and Deslorelin (38%, 28/72) treatment groups. These data demonstrate that conception rates from in vitro produced embryos transferred to lactating dairy cows are not improved by treatment with a GnRH analogue on the day of transfer. Although not critically tested, results indicate that adequate conception rates may be obtained in commercial dairy operations from OPU/IVF-derived embryos, adding an important management tool for reproduction and animal breeding enhancement.

Effects of calcium salts of medium-chain fatty acids on plasma metabolite and hormone concentrations in early lactating dairy cows

2014 ◽  
Vol 54 (10) ◽  
pp. 1699
Author(s):  
T. Sugino ◽  
A. Tateno ◽  
G. Ueno ◽  
K. Kawashima ◽  
T. Okimura ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Dairy Cows ◽  
Control Group ◽  
Calcium Salts ◽  
Treatment Groups ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Lactating Dairy Cows ◽  
Plasma Metabolite ◽  
Chain Fatty Acids

To elucidate the effects of medium-chain fatty acids (MCFA) on milk production and plasma metabolite and hormone concentrations in early lactating dairy cows, 10 multiparous Holstein dairy cows were randomly assigned to two dietary treatment groups after parturition. One group was fed a diet supplemented with calcium salts of MCFA (MCFA-Ca) for 8 weeks after parturition, while the other group was fed the same diet without the supplement (control). MCFA-Ca, containing 60% caprylic acid and 40% capric acid, was added to a total mixed ration (TMR) at 1.5% of the dietary dry matter (DM). Cows were offered the TMR ad libitum. DM intake, daily gain in bodyweight, milk yield, milk fat content and milk protein content did not differ between the two treatment groups. The MCFA-Ca diet decreased plasma glucose and triglyceride concentrations (P < 0.05), while plasma concentrations of total and free cholesterols tended to increase (P < 0.10). Plasma ghrelin was maintained at a higher concentration (P < 0.05) in cows fed the MCFA-Ca diet than in the control group. Relative to the control diet, the MCFA-Ca diet decreased plasma insulin concentration (P < 0.05) and numerically increased plasma glucagon concentration, resulting in a lower insulin : glucagon ratio (P < 0.05). In conclusion, plasma metabolite and hormone concentrations were affected by the MCFA-Ca diet, suggesting that MCFA-Ca supplementation may change endocrine functions and nutrient metabolism in early lactating cows, ultimately resulting in an enhanced catabolic state.

scholarly journals The Association of Calcium Profiles at Calving with Health and Performance of Holstein Cows and Their Calves

2021 ◽  
Vol 3 (4) ◽  
pp. p1
Author(s):  
Constantin Gavan ◽  
Mihaela Riza
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Holstein Cows ◽  
Fetal Membranes ◽  
Health Implications ◽  
Lactating Dairy Cows ◽  
Holstein Friesian ◽  
And Performance ◽  
Significant Health ◽  
Friesian Cows

The aim of this study was to assess the association of hypocalcemia at calving with health and performance of Holstein cows and their calves. Data were collected January 1st 2017 to December 31st 2020. A total of 431 lactating Holstein Friesian cows (118 primiparous and 313 multiparous) from a research of hypocalcemia was 2 groups (hypo and non-hypo). The overall prevalence of hypocalcemia was 3.4% for first-lactation cows and 18% for multiparous cows. Lactating dairy cows with hypocalcemia had greater proportion of cows with Retained Fetal Membranes (RFM) metritis and culling within 60 days in milk (DIM), compared with non-hypocalcemia respectively. For the first 2 official milk tests milk yield and components (% fat, % protein on SCC) did not differ between hypo and non-hypo cows. The days in milk at first service, mastitis, dystocia and pregnancy at first service were not different between hypo and non-hypo groups. The proportion of stillbirth, survival at 60 days of age in calves did not differ between calves born from hypo or non-hypo cows. Calves born from Hypo cows had greater incidence of diarrhea (38.3%) than calves born (22.3%) from non-hypo cows. The results of this study show that hypocalcemia in calving has significant health implications for both dams and their calves.  

scholarly journals Effect of Two Cooling Frequencies on Respiration Rate in Lactating Dairy Cows Under Hot and Humid Climate Conditions

2019 ◽  
Vol 19 (3) ◽  
pp. 821-834 ◽  
Author(s):  
Severino Pinto ◽  
Gundula Hoffmann ◽  
Christian Ammon ◽  
Wolfgang Heuwieser ◽  
Harel Levit ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Respiration Rate ◽  
Coat Color ◽  
Humid Climate ◽  
Related Factors ◽  
Digital Photograph ◽  
Stress Assessment ◽  
Climate Conditions ◽  
Treatment Groups ◽  
Lactating Dairy Cows

AbstractThe aim of this study was to evaluate the effects of evaporative cooling at two different frequencies per day on the respiration rate (RR) of lactating dairy cows, considering cow-related factors. Twenty multiparous Israeli Holstein dairy cows housed in a naturally ventilated cowshed were divided randomly into two treatment groups. The cows of both groups were exposed to 3 or 8 cooling sessions per day (3xcool vs. 8xcool, respectively). The RR was observed hourly, with a maximum of 12 measurements per day. Body posture (standing vs. lying) was simultaneously documented. Milk yield was recorded daily. Coat color was determined from a digital photograph. The RR of standing and lying cows was lower in the 8xcool group (60.2 and 51.6 breaths per min (bpm), respectively) than in the 3xcool group (73.1 and 65.6 bpm, respectively). For each increment of five kilograms of milk produced, RR increased by one bpm, and the RR of cows in early days in milk (DIM) was 12.3 bpm higher than that of cows in late DIM. In conclusion, eight cooling sessions per day instead of three lead to a RR abatement in heat-stressed cows under hot conditions, and cow-related factors directly impact the RR during heat stress assessment.

scholarly journals Effect of supplementation of rumen protected choline and methionine on milk yield and composition of early lactating dairy cows

2021 ◽  
Vol 52 (2) ◽  
Author(s):  
Jayaraj Neelima ◽  
Purushothaman Sajith ◽  
K. Ally ◽  
Ananth Deepa ◽  
Simon Shibu
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Milk Fat ◽  
Milk Composition ◽  
Treatment Groups ◽  
Nitrogen Levels ◽  
Lactating Dairy Cows ◽  
Significant Difference ◽  
Milk Urea ◽  
Dietary Treatments

An experiment was conducted on early lactating dairy cows to study the effect of rumen protected choline (RPC) and methionine (RPM) on milk yield and composition. Fifteen crossbred dairy cows in early lactation (within 10 days of calving) were selected and randomly allotted to any one of the following three dietary treatments, T1 (Control)- with compound feed mixture containing CP- 20% and TDN- 68% , T2- T1+20g RPM and 20g RPC, T3- with compound fed mixture containing CP- 17%, TDN- 68% + 20g RPM and 20g RPC. All the experimental animals were fed as per ICAR feeding standards (ICAR, 2013). Results revealed no significant difference (p>0.05) in milk yield and 4 per cent fat corrected milk (FCM) yield between the three treatment groups. Among the milk constituents, animals in T3 had significantly higher milk fat (p<0.05), SNF (p<0.05), protein (p<0.05) and total solids (p<0.01) compared to those in T1 and T2. Milk urea nitrogen levels did not differ significantly among the three treatments and were within the normal range. The study showed that milk composition could be effectively improved by supplementing feed with rumen protected forms of choline and methionine in combination at lower dietary protein level without any reduction in milk yield.

Circadian and ultradian rhythms of plasma thyroid hormone concentrations in lactating dairy cows

1994 ◽  
Vol 266 (6) ◽  
pp. R1797-R1803 ◽  
Author(s):  
J. Bitman ◽  
S. Kahl ◽  
D. L. Wood ◽  
A. M. Lefcourt
Keyword(s):  
Circadian Rhythm ◽  
Thyroid Hormone ◽  
Dairy Cows ◽  
Ultradian Rhythms ◽  
Blood Samples ◽  
Lactating Dairy Cows ◽  
Temperature Rhythm ◽  
Body Temperature Rhythm ◽  
The Mean ◽  
Plasma Triiodothyronine

Circadian and ultradian rhythms of thyroxine and triiodothyronine were analyzed by radioimmunoassay on integrated 15-min blood samples collected for 48 h from six lactating dairy cows. Body temperatures were recorded every 1.4 min using radiotelemetry. The cows were housed in an environmental chamber at 19.0 +/- 0.5 degrees C (lights on between 0700 and 2300 h), fed daily at 0900 h, and milked at 0800 and 2000 h. Mean concentrations of plasma triiodothyronine and thyroxine exhibited similar circadian rhythms with minima (0500-1300 h) and maxima (1700-0200 h) separated by 12 h. Triiodothyronine peaked 2 h before thyroxine. The thyroxine circadian rhythm preceded a circadian body temperature rhythm by 2 h. Superimposed on the circadian rhythm was an ultradian rhythm with a 90-min period that was 15-20% of the mean thyroid hormone concentrations. Peak thyroxine and triiodothyronine concentrations were 50 +/- 2 and 1.58 +/- 0.17 ng/ml, and minimal concentrations were 42 +/- 2 and 0.94 +/- 0.17 ng/ml, respectively. Our data indicate that peripheral triiodothyronine is regulated independently of peripheral thyroxine concentration.

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