| 1. |
- Edvardsson Rasmussen, Anna, et al.
(författare)
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A randomized study on the effect of an extended voluntary waiting period in primiparous dairy cows on fertility, health, and culling during first and second lactation
- 2023
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Ingår i: Journal of Dairy Science. - 0022-0302 .- 1525-3198. ; 106, s. 8897-8909
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Tidskriftsartikel (refereegranskat)abstract
- When the voluntary waiting period (VWP), defined as the days between calving and when the cow is eligible to receive the first insemination, is extended, high-yielding dairy cows may have better opportunities to regain energy balance before first insemination. This study investigated the effect of an extended (145–215 days in milk [DIM], n = 280) or conventional (25–95 DIM, n = 251) VWP treatment on fertility, disease incidence, and culling rate in cows during their first lactation. The cows were also followed through a second lactation without intervention regarding VWP, during which the farmers could decide when they wished to start the inseminations. This was done in a randomized-controlled study on 16 high-yielding commercial herds in southern Sweden, containing a total of 531 primiparous cows of the Holstein and Red Dairy Cattle breeds. Data from the Swedish national dairy herd recording scheme collected between August 2018 and September 2021 were used in the analysis, including records on breed, calvings, estrus intensity, inseminations, disease, somatic cell count, culling date, and culling reason. During first lactation, more cows receiving the extended VWP treatment showed strong estrus intensity (score 4–5, 55% vs. 48%) and fewer showed moderate estrus intensity (score 3, 35% vs. 43%) at first insemination, compared with cows receiving the conventional VWP treatment. First service conception rate (FSCR) was higher (67% vs. 51%) and number of inseminations per conception (NINS) was lower (1.6 vs. 2.0) during the first lactation for cows receiving the extended compared with the conventional VWP treatment. For disease incidence rate or culling rate expressed as number of events per cow-time in the study, we found no differences between the cows receiving the 2 VWP treatments in any lactation. Calving to first service interval during second lactation was longer (86 vs. 74 d) for cows with extended compared with conventional VWP. In conclusion, primiparous cows with extended VWP showed improved reproductive functions, in the form of higher estrus intensity, greater FSCR, and lower NINS, during the first lactation. However, we observed no apparent effect on these fertility measures during the following lactation (without VWP intervention) and no differences in disease prevalence or culling between cows receiving the 2 different VWP treatments in either lactation. Compliance with the planned VWP treatment was lower for cows with planned extended compared with planned conventional VWP treatment. We studied the “intention-to-treat” effect (i.e., the results for all cows randomized to each treatment regardless of whether the planned VWP was achieved or not) to identify any bias arising due to degree of compliance. However, we found no difference in culling rate between cows randomized to an extended VWP compared with those randomized to a conventional VWP. These findings can be used to support management decisions on VWP length in high-yielding dairy herds.
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| 2. |
- Edvardsson Rasmussen, Anna, et al.
(författare)
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A randomized study on the effect of extended voluntary waiting period in primiparous dairy cows on milk yield during first and second lactation
- 2023
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 106, s. 2510-2518
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Tidskriftsartikel (refereegranskat)abstract
- Extending the voluntary waiting period (VWP) for primiparous cows can have a positive impact on fertil-ity without a negative impact on milk production per day in the calving interval (CInt). We investigated the effect of extended VWP during first lactation on milk yield (MY) during 2 consecutive lactations in primipa-rous cows. The study involved 16 commercial herds in southern Sweden. A total of 533 Holstein and Red dairy cattle (Swedish Red, Danish Red, Ayrshire) dairy cows were randomly assigned to a conventional 25 to 95 d VWP (n = 252) or extended 145 to 215 d VWP (n = 281). Data on calvings, inseminations, and test-day yields were retrieved from the Swedish Milk Record -ing System. Cows with VWP according to plan and completing 1 or 2 CInt with a second or third calving were included in the data analysis. Whole lactation and 305-d energy-corrected milk (ECM) yield were higher for the extended VWP group than the conventional VWP group in both the first lactation (12,307 vs. 9,587 and 9,653 vs. 9,127 kg ECM) and second lactation (12,817 vs. 11,986 and 11,957 vs. 11,304 kg ECM). We found no difference between the VWP groups in MY per day during the first CInt or during the first and second CInt combined, although MY per day during the second CInt was around 1.5 kg higher for cows with extended VWP than for cows with conventional VWP. Thus extended VWP for primiparous cows can be used as a management tool without compromising MY.
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| 5. |
- Kronqvist, Cecilia, et al.
(författare)
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Effects of replacing grass with foliage on growth rate and feed intake in goats—a systematic review and meta-analysis
- 2021
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Ingår i: Animals. - : MDPI AG. - 2076-2615. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Small ruminants such as goats have a higher preference for browse species than cattle and sheep. In a meta-analysis of 42 papers describing 117 experimental treatments found by a search performed in June 2021 in PubMed and Web of Knowledge, we examined the general effect of including foliage in the diet of goats, replacing grasses, on dry matter intake and average daily weight gain. The inclusion requirement for a paper was that it described a controlled trial with a control diet of grass and with grass replaced by foliage in the experimental diet. Publication bias was estimated by calculating the Fail-safe n. Random effects analyses were conducted, using effect size calculated as Hedges’ d. The results showed that inclusion of foliage increased feed intake (Hedges’ d = 1.350, SE = 0.388) and average daily weight gain (Hedges’ d = 1.417, SE = 0.444) compared with a grass-based control. The positive effect of foliage inclusion on dry matter intake was associated with lower neutral detergent fiber (NDF) and higher crude protein (CP) in the foliage than in the grass it replaced. The positive effect on average daily weight gain was associated with higher CP concentration in the foliage than in grass. Foliage inclusion level showed a quadratic relationship with dry matter intake, with maximum dry matter intake achieved at a level of 50–60%. There was wide variation between the studies reviewed, and this variation was not reduced by subgroup analysis based on different kinds of foliage. In conclusion, the addition of foliage to goat diets can increase feed intake and daily weight gain, as an effect of the dietary preferences of goats and of generally higher nutritional value in foliage species compared with natural/semi-natural grass species.
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| 6. |
- Kronqvist, Cecilia, et al.
(författare)
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Evaluation of production parameters, feed sorting behaviour and social interactions in dairy cows: Comparison of two total mixed rations with different particle size and water content
- 2021
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 251
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Tidskriftsartikel (refereegranskat)abstract
- Dairy cow performance is affected by both the nutritional composition and the physical structure of the diet. The structure of total mixed rations (TMR) largely depends on the ingredient composition and structure of forage, dry matter (DM) content, mixing time and type of mixer used. This study investigated feed intake, eating time, milk production, DM digestibility, ruminal pH, time budget, and sorting and antagonistic behaviours in lactating dairy cows fed grass/clover silage and concentrate, either in a TMR or in a compact total mixed ration (CTMR) with decreased particle size and DM content due to addition of water. Two cross-over experiments (3-week periods), each involving 40 lactating dairy cows of the Swedish Red and Holstein breeds, were run simultaneously. Experiment 1 was designed to measure production parameters, feed digestibility and ruminal pH, while Experiment 2 was designed to measure time budget, feed sorting behaviours and antagonistic behaviours at the feed bunk. Diets were fed ad libitum, with the same ingredient composition and a forage:concentrate ratio of 60:40 (DM basis). Decreased particle size in the CTMR diet was achieved by mixing the grass-clover silage in a feed mixer with a vertical auger with knives, before mixing with concentrate in a feed mixer without knives. Decreased DM content in CTMR was achieved by adding water to the mix. Mean DM content of the diet was 51% DM for TMR and 37% DM for CTMR. The results showed lower daily DM intake (26.7 kg DM) and shorter eating time (242 min) in cows fed CTMR than in cows fed TMR (28.5 kg DM and 278 min). Feed digestibility, ruminal pH, daily milk yield (35.1 kg and 35.8 kg for CTMR and TMR, respectively) and milk composition did not differ between the diets. Cows fed CTMR showed less sorting and fewer antagonistic behaviours at feeding than cows fed TMR. The daily time budget of the cows also differed, with cows fed CTMR spending more time resting (+45 min) than cows fed TMR.
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| 7. |
- Mohamad Salleh, Suraya Binti, et al.
(författare)
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Using machine learning methods to predict dry matter intake from milk mid-infrared spectroscopy data on Swedish dairy cattle
- 2023
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Ingår i: Journal of Dairy Research. - 0022-0299 .- 1469-7629. ; 90, s. 5-8
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Tidskriftsartikel (refereegranskat)abstract
- In this research communication we compare three different approaches for developing dry matter intake (DMI) prediction models based on milk mid-infrared spectra (MIRS), using data collected from a research herd over five years. In dairy production, knowledge of individual DMI could be important and useful, but DMI can be difficult and expensive to measure on most commercial farms as cows are commonly group-fed. Instead, this parameter is often estimated based on the age, body weight, stage of lactation and body condition score of the cow. Recently, milk MIRS have also been used as a tool to estimate DMI. There are different methods available to create prediction models from large datasets. The main data used were total DMI calculated as a 3-d average, coupled with milk MIRS data available fortnightly. Data on milk yield and lactation stage parameters were also available for each animal. We compared the performance of three prediction approaches: partial least-squares regression, support vector machine regression and random forest regression. The full milk MIRS alone gave low to moderate prediction accuracy (R-2 = 0.07-0.40), regardless of prediction modelling approach. Adding more variables to the model improved R-2 and decreased the prediction error. Overall, partial least-squares regression proved to be the best method for predicting DMI from milk MIRS data, while MIRS data together with milk yield and concentrate DMI at 3-30 d in milk provided good prediction accuracy (R-2 = 0.52-0.65) regardless of the prediction tool used.
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| 8. |
- Ruvuga, Peter, et al.
(författare)
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Dry matter intake, dry matter digestibility and growth performance in goats fed grass-based diet (Brachiaria or Cenchrus) compared with a concentrate-based diet
- 2022
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Ingår i: African Journal of Agricultural Research. - 1991-637X. ; 18, s. 52-57
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Tidskriftsartikel (refereegranskat)abstract
- Dry matter digestibility (DMD), dry matter intake (DMI) and growth performance of concentrate- and forage-based diets were investigated using 24 growing Blended goats (12 males, 12 females) weighing 16.5±1.2 kg (mean±sd). Goats were blocked by sex and assigned randomly to three dietary treatments that were fed for 10 weeks, after two weeks of adaptation. Dietary treatments were MRG (40% maize bran, 40% rice bran, 20% Gliricidia leaf meal), BG (80% Brachiaria brizantha cv. Piatã, 20% Gliricidia leaf meal) and CG (80% Cenchrus ciliaris, 20% Gliricidia leaf meal). All diets contained sufficient nutrients to meet the requirements of growing goats. The MRG diet had lower DMI than CG, likely because MRG had small particle size and goats adapted slowly to that diet. Average daily weight gain was 10.7, 9.9 and 22.8 g/day for MRG, BG, and CG respectively, and did not differ among the diets. Goats fed MRG had lower overall live weight change than goats fed CG, while goats fed BG were intermediate. These findings indicate that B. brizantha cv. Piatã and C. ciliaris are equally useful as supplementary feedstuffs for growing goats during the dry season.
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| 9. |
- Ruvuga, Peter, et al.
(författare)
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Evaluation of rangeland condition in miombo woodlands in eastern Tanzania in relation to season and distance from settlements
- 2021
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Ingår i: Journal of Environmental Management. - : Elsevier BV. - 0301-4797 .- 1095-8630. ; 290
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Tidskriftsartikel (refereegranskat)abstract
- Miombo woodlands sustainability in east and south-central Africa is threatened by human activities, including overgrazing. This study investigated seasonal variations in rangeland condition in three grazed areas in miombo woodlands in eastern Tanzania. Transect lines were established across the grazing areas, sampling points were identified and marked at every 10% of the length of transect line. Sampling points were categorised in different distances with respect to settlement. The line intercept method was used to collect data on vegetation cover and forage distribution, while herbaceous forage biomass was estimated using a disc pasture meter. A total of 118 different plant species were observed and grasses comprised 40.6% of all herbaceous species. Bothriochloa pertusa, Cynodon plectostachyus, Hyparrhenia rufa and Urochloa mosambicensis grass species dominated miombo grazed areas in various seasons and distances. These perennial grass species are desirable and indicated moderate grazing activities in miombo. Season affected grass cover, herbaceous forage biomass and nutritional composition. Grass cover and forage biomass were at the lowest during late dry season while forage nutritional quality was best during early dry season. Distance from settlement had no effect on grass cover and herbaceous forage biomass. Rangeland condition was generally fair, livestock stocking rate in continuously grazed drylands should be set at the lowest monthly forage biomass in order to ensure grazing land sustainability.
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| 10. |
- Ruvuga, Peter, et al.
(författare)
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Indigenous Rangeland and Livestock Management Among Pastoralists and Agro-pastoralists in Miombo Woodlands, Eastern Tanzania
- 2020
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Ingår i: Rangeland Ecology and Management. - : Elsevier BV. - 1550-7424 .- 1551-5028. ; 73, s. 313-320
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Tidskriftsartikel (refereegranskat)abstract
- Indigenous rangeland management practices, forage quality and availability, and livestock production by pastoralists and agro-pastoralists in miombo woodlands were investigated in a study conducted in Kilosa district, Tanzania. The study methods comprised household interviews, key informant and focus group discussions, and forage laboratory analyses. Preferred forage species and indigenous rangeland and livestock management practices among pastoral and agro-pastoral communities in miombo woodlands were identified, and the nutrient content of the forages was determined. In general, rangeland management in the study area faces challenges such as unclear or disputed land tenure regime and lack of technical knowledge. Moreover, the nutritional value of some native forage species identified in miombo was found to be too low to meet the nutrient requirements of livestock. Livestock in miombo contribute greatly to household livelihoods and food security, but forage scarcity was identified as a limiting factor. Overall, it was concluded that rangeland improvement practices are poor or nonexistent in allocated grazing areas in Kilosa's miombo woodlands. (C) 2019 The Society for Range Management. Published by Elsevier Inc. All rights reserved.
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