| 1. |
- Andrée O´ Hara, Elisabeth, et al.
(författare)
-
Naturbetets näringsinnehåll och avkastning i relation till nötkreaturens val av plats vid bete, vila, gödsling och urinering
- 2011
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Det som har redovisats i denna rapport är en grundläggande kartläggning av nötkreaturens betesbeteende på naturbetesmarker i Svealand samt omfattande data rörande näringsinnehåll och avkastning på olika vegetationstyper i naturbetesmarker. Följande vegetationstyper identifierades och kartlades i beteshagarna: torr (T), frisk (F), blöt/fuktig (B), skuggpåverkad (S) samt vegetation som växte på näringsrik (N) gödselpåverkad mark. Syftet med studien var: • att få en karakterisering av de olika vegetationstypernas avkastning och näringsinnehåll • att studera nötkreaturens preferens för olika vegetationstyper i naturbetesmarker • att se om det fanns indikationer på att nötkreatur bidrog till näringstransport inom beteshagen genom att de betade på vissa ytor och gödslade och urinerade på andra Studier från fyra olika betessäsonger finns sammanfattade i rapporten. År 1 och 2 gjordes studier och mätningar tre gånger per säsong (juni, juli och augusti) på två betesmarker. Inga stora skillnader i betesbeteende mellan månader kunde observeras och år tre utvidgades studien till att omfatta nio olika hagar men mätningar gjordes detta år endast en gång per säsong och hage. Sista året gjordes en kompletterande studie i september i tre hagar för att studera betesbeteendet även under sensommaren/hösten. Djurens beteende registrerades under 24 timmarsperioder under studiens år 2-4. Registreringar gjordes på vilken vegetationstyp som djuren föredrog att beta, vila, urinera och gödsla. Samtidigt togs betesprover såväl från de olika vegetationstyperna som från den vegetation som djuren betade för att bestämma näringsinnehåll. Mätningar av tillgänglig mängd bete vid beteendeobservationerna och av den totala säsongsavkastningen i olika vegetationstyper gjordes även. Den relativa preferensen (RP) för att beta, vila, gödsla och urinera på varje vegetationstyp beräknades genom att beräkna hur ofta beteendet ägde rum på varje typ av vegetation och samtidigt ta hänsyn till andelen av hagens totala yta som utgjordes av denna vegetationstyp (se avsnittet om beräkning av relativ preferens under rubriken statistisk bearbetning i Material och Metoder). Resultaten visade att djuren föredrog att vistas på den näringsrika vegetationstypen (N) när de betade och avgav urin och gödsel samtliga försöksår (Tabell 4). I de flesta fall var den relativa preferensen för vila även högt på de näringsrika områdena men år två och tre erhölls också en hög relativ preferens för att vila på den torra vegetationstypen. Under september tycks det vara mindre skillnaderna mellan den relativa preferensen för olika vegetationstyper men RP för vegetationstyp N och F var ändå signifikant högre än för T. Den vegetation som växte på de gödselpåverkade ytorna (N) och i viss mån de friska (F) ytorna hade i de flesta fall högre innehåll av omsättbar energi jämfört med det som växte på B, T och S (Tabell 6) och det är troligen den viktigaste orsaken till att djuren föredrog den typen av vegetation. Vegetationstyp N hade även en förhållandevis hög säsongsavkastning (Tabell 8) vilket också kan bidragit till att djuren hade en hög relativ preferens för denna vegetationstyp. Beteendet gödsla och urinera följde väl betesbeteendet och i de flesta fall tycks djuren ha gödslat och urinerat i samma utsträckning som de betade på de olika vegetationstyperna. De gödslade och urinerade alltså oftare på näringsrik och frisk vegetationstyp än på torr. Resultatet i studien tyder på att det ej tycks finnas något omfattande problem med näringstransport från näringsrika vegetationstyper (N) till mer näringsfattiga områden med hög biologisk mångfald (T) i denna typ av marker
|
|
| 2. |
- Andrée O´ Hara, Elisabeth, et al.
(författare)
-
An observational study of the dry period length and its relation to milk yield, health, and fertility in two dairy cow breeds
- 2020
-
Ingår i: Preventive Veterinary Medicine. - : Elsevier BV. - 0167-5877 .- 1873-1716. ; 175
-
Tidskriftsartikel (refereegranskat)abstract
- This study evaluated associations between dry period length (DPL) in dairy cows and energy-corrected milk (ECM) production, health, and fertility, using a dataset involving 78 577 lactations in cows of two breeds, Swedish Red (SR) and Swedish Holstein (SH). Herds with at least 20 cows and at least 20 % purebred SR and at least 20 % SH during the year 2015/2016 were included in the dataset. Cows were divided into parity groups 2 and 3 or older and DPL was classified into six 10-day groups (30-39 to 80-89 d). Associations between DPL and the outcome variables were assessed with linear and generalized linear mixed models. Production of ECM at the first three test milkings and the 305-d lactation was highest in the 50-59 d and 60-69 d DPL groups, and lowest in the 30-39 d and 80-89 d groups (p<0.001). Mastitis and somatic cell count (SCC) did not differ between DPL groups, except at the third test milking, where cows in the 40-49, 50-59, and 60-69 DPL groups had lower SCC (p<0.001) than cows in the 70-79 and 80-89 d groups. The odds ratio (OR) for retained placenta was 1.9 for cows with 30-39 d DPL relative to cows with 60-69 d DPL. Cows in DPL groups 40-49 d and 50-59 ha d the lowest odds of culling (OR=0.89 and 0.92). The OR for culling in cows with DPL 70-79 d and 80-89 was 1.2 and 1.4, respectively, relative to cows with 60-69 d DPL. The conception rate at first insemination did not among between DPL groups. The SR cows produced less ECM than the SH cows, but had lower SCC and lower OR for mastitis, retained placenta, puerperal paresis, and culling within 90 DIM. Although DPL <40 days or >80 days reduced milk production in early lactation and the 305-d lactation, the estimated additional milk production in the preceding lactation in cows with short DPL compensated for this reduction. A DPL of 40 days did not affect health and fertility in comparison with a conventional 60 d DPL, while a DPL of >70 d was unfavorable due to low milk production, increased risk of culling, and decreased fertility. The response to DPL was not affected by breed or parity.
|
|
| 3. |
- Andrée O´ Hara, Elisabeth, et al.
(författare)
-
Effects of dry period length on metabolic status, fertility, udder health, and colostrum production in 2 cow breeds
- 2019
-
Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 102, s. 595-606
-
Tidskriftsartikel (refereegranskat)abstract
- Shortening the dry period improves postpartum energy balance, which has potential positive effects on metabolic health. This concept has been mainly studied in Holstein cows. The aim of this study was to assess the effect of a short dry period of 4 wk, compared with a standard dry period of 8 wk, on the metabolic status, progesterone profiles, health, and colostrum quality of dairy cows of 2 breeds, Swedish Red (SR) and Swedish Holstein (SH), not treated with antibiotics at dry off. The IgG uptake in calves was also studied to reflect the colostrum quality when shortening the dry period. Cows of both SH and SR were blocked by breed and parity and then randomly allocated to a short dry period of 4 wk (4W, n = 43) or a conventional dry period of 8 wk (8W, n = 34). Blood samples were collected wk 8, 4, 2, 1 and 1, 2, 3, 4, 6, 9, and 12 relative to calving. Prepartum, cows with a 4-wk dry period had higher concentrations of nonesterified fatty acids and lower concentrations of insulin-like growth factor-1. and insulin than 8W cows. Postpartum, plasma concentration of nonesterified fatty acids was lower, whereas plasma insulin and insulin-like growth factor-1 tended to be higher for 4W cows than for 8W cows. Plasma concentration of beta-hydroxybutyrate did not differ between dry period lengths. Swedish Holstein cows with a 4W dry period responded with a lower concentration of insulin prepartum than SR and SH on an 8W dry period. The dry period length had no effect on the proportion of disturbed progesterone profiles; disturbed progesterone profiles occurred in 30% of the 4W cows and 47% of the 8W cows. In this trial, only 48.8% of the SR cows had a normal progesterone profile, which differed from the SH where 76.5% had a normal profile. Fertility-related diseases (endometritis, pyometra, anestrus, ovarian cyst) did not differ between the 2 dry period groups: 21% in the 8W group versus 12% in the 4W group, whereas mastitis tended to be more common: 26% of the 4W cows versus 9% of the 8W cows. A short dry period resulted in less colostrum but with a higher content of protein and somatic cell count. Calves were fed colostrum from their dam, and the IgG and total protein in plasma did not differ between calves to mothers with different a dry period length. Shortening the dry period could improve metabolic status in cows of both SH and SR breed postpartum, without compromising the colostrum quality. Health and progesterone profiles were not affected by the dry period length for SH or SR in this study.
|
|
| 4. |
- Andrée O´ Hara, Elisabeth, et al.
(författare)
-
Effects of dry period length on milk production and energy balance in two cow breeds
- 2018
-
Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 12, s. 508-514
-
Tidskriftsartikel (refereegranskat)abstract
- Shortening the dry period (DP) has been proposed as a strategy to improve energy balance (EB) in cows in early lactation. This study evaluated the effects of shortening the DP on milk yield (MY), EB and residual feed intake (RFI) in two breeds; Swedish Red (SR) and Swedish Holstein (SH). Cows were blocked by breed and parity and then randomly assigned to one of two treatments; short DP of 4 weeks (4W, n = 43) or conventional DP of 8 weeks (8W, n = 34). Cows were kept and fed under the same conditions, except for the 4 weeks when the 4W group were still lactating prepartum and thus kept with the lactating cows. Milk yield and BW were recorded and body condition score (BCS) was rated from 10 weeks prepartum to 12 weeks postpartum. Dry matter intake (DMI) was recorded for lactating cows postpartum. Milk yield was reduced by 6.75 kg/day during the first 12 weeks postpartum ( P< 0.001) for the 4W cows compared with 8W cows, but there was no significant difference in total MY (3724 kg compared with 3684 kg, P = 0.7) when the milk produced prepartum was included. Protein content was higher in 4W cows (3.42%) than in 8W cows (3.27%) ( P<0.001) postpartum. In the 8W group, cows lost more BCS after calving ( P<0.05). Cows of SR breed had higher BCS than cows of SH breed (SR = 3.7, SH = 3.2, P< 0.001), but no differences in BW were found between breed and treatment. Energy balance was improved for cows in the 4W group ( P< 0.001), while feed efficiency, expressed as RFI, was reduced for 4W cows than for 8W cows (5.91 compared with −5.39, P<0.01). Shortening the DP resulted in improved EB postpartum with no difference between the breeds and no milk losses when including the milk produced prepartum.
|
|
| 5. |
|
|
| 6. |
- Andrée O´ Hara, Elisabeth
(författare)
-
The effect of dry period length on milk production, health and fertility in two cow breeds
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The transition from not producing milk during the dry period to the huge nutrient demands as milk production rapidly increases after parturition imposes significant metabolic strain on high-yielding dairy cows. The drying-off procedure is also demanding and high milk yield at dry-off increases the risk of mastitis and metabolic problems. A dry period of approximately 8 weeks is generally recommended, but a shorter dry period might reduce the metabolic strain on high-yielding cows at dry-off and in early lactation. This thesis investigated the effects of different dry period lengths on the health and performance of two cow breeds. An experimental trial was conducted in which multiparous Swedish Red (n=43) and Swedish Holstein (n=34) cows were blocked by breed and parity, and then randomly allocated to two different treatments; a conventional DP of 8 weeks (8W) or a short DP of 4 weeks DP (4W). An observational study was performed using data on 78 577 lactations from cows enrolled in the Swedish Official Milk Recording Scheme. The experimental and observational studies both showed that shortening the dry period resulted in a reduction in milk yield during the following lactation. However, when the milk produced during the extended lactation was added, the difference diminished. Feed intake was virtually identical between cows subjected to a short and conventional dry period. The reduced milk production while feed intake was maintained in 4W cows improved their energy balance markedly. Cyclicity and commencement of luteal activity was not affected by dry period length in the experimental study and no effects of dry period on health and fertility traits were observed in the observational study. However, culling rate was lower in cows with a shorter dry period. Cows of the different breeds and of different parities responded similarly to changes in dry period. The volume of colostrum was reduced, but the protein content was higher, in cows with a short dry period. The Immunoglobulin G status of calves was not affected by the dry period of their dam. Tests on dry period >70 days showed it was not favourable, due to low milk production, increased risk of culling and decreased fertility. In conclusion, this thesis shows that energy balance and metabolic status improve, but not health and fertility, in cows subjected to a short dry period. The reduction in milk yield after calving is compensated for by additional yield prior to calving.
|
|
| 7. |
- Andrée O´ Hara, Elisabeth, et al.
(författare)
-
The impact of body condition after calving on metabolism and milk progesterone profiles in two breeds of dairy cows
- 2016
-
Ingår i: Acta Veterinaria Scandinavica. - : Springer Science and Business Media LLC. - 0044-605X .- 1751-0147. ; 58
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Optimal body condition in early lactation is generally accepted as a prerequisite for good reproductive performance. Examination of milk progesterone profiles offers an objective method for characterization of postpartum ovarian activity in dairy cows. The present study investigated the relationship between body condition after calving, some metabolic parameters in blood plasma, and fertility, as reflected by milk progesterone profiles in the two dairy breeds Swedish Red (SR) and Swedish Holstein (SH).Results: Multiparous dairy cows (n = 73) of SR and SH breeds were selected and divided into three groups based on their body condition score (BCS) after parturition. Selected plasma metabolites were determined, milk progesterone profiles were identified and body condition was scored. Over-conditioned cows and atypical progesterone profiles were more common among SR cows. Insulin sensitivity was lower and IGF 1 higher among SR cows. Insulin was positively related to body condition, but not related to breed.Conclusions: Atypical progesterone profiles were more common and insulin sensitivity lower in SR than in SH cows, but the SR breed had a higher proportion of over-conditioned SR cows. It is reasonable to assume that breed differences in body condition contributed to these results.
|
|
| 8. |
- Forsbäck, Linda, et al.
(författare)
-
Day-to-day variation in milk yield and milk composition at udder quarter level
- 2010
-
Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 93, s. 3569-3577
-
Tidskriftsartikel (refereegranskat)abstract
- Automatic in-line measurement of milk composition and milk yield could be a useful tool in management of the dairy herd. Data on milk components and milk yield provide information on milk quality alterations and cow health status but are also useful in planning feeding and breeding. In automatic milking systems, udder quarters are milked individually, enabling analysis and recording at the udder-quarter level. Frequent records of components require knowledge about day-today variations. A component with greater day-to-day variation needs more frequent sampling when used as a diagnostic tool and for management decisions. Earlier studies have described the day-to-day variations in milk components for cow composite milk, but with the quarter milking technique and the possible sampling at the udder-quarter level, knowledge about day-to-day variations at the udder-quarter level is needed. In this study, udder-quarter and cow composite milk samples were collected from 42 consecutive milkings of 10 cows during 21 d. Milk yield was recorded and the milk was analyzed for total protein, whey protein, casein, fat, lactose, and somatic cell count. The results showed that the day-to-day variations and mean values for 4 healthy udder quarters within a cow were similar. In addition, different milk components had different levels of day-to-day variation, the least variation being found in lactose (0.9%) and the greatest in fat (7.7%). This suggests that repeated milk sampling and analysis at the udder-quarter level can be used to detect alterations in composition and cow health and would, thus, be helpful in the management of the dairy herd.
|
|
