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The relevance of feed diversity and choice in nutrition of ruminant livestock



In this position paper, we argue that the realisation of forage diversity and feed choice for ruminant livestock should be considered as an essential aspect of animal welfare because selection from an array of different plants is an important experience for such animals. We provide examples that diet balancing with regard to nutrients and plant secondary metabolites is particularly for ruminants so much essential that this ability must be a deeply rooted cognitive and behavioural predisposition. In this context, we assume feed choice to be a behavioural need of ruminants. Therefore, we argue in favour of nutritional concepts, which account for botanical and biochemical diversity and are based on behavioural research approaches. We provide a brief outlook of potential research topics, which we consider important if the societal target of animal welfare is to be reached in European ruminant production systems.
Leiber et al. (2020) · LANDBAUFORSCH · J Sustainable Organic Ag ric Syst · 70(1):35–38
DOI:10.32 20/LBF1592393539000
The relevance of feed diversity and choice
in nutrition of ruminant livestock
Florian Leiber1, Michael Walkenhorst
1, Mirjam Holinger1
1 Research Institute of Organic Agriculture (FiBL), Switzerland
CONTACT: orian.leiber@
In this position paper, we argue that the realisation of forage
diversity and feed choice for ruminant livestock should be
considered as an essential aspect of animal welfare because
selection from an array of dierent plants is an important
experience for such animals.
We provide examples that
diet balancing with regard to nutrients and plant secondary
metabolites is particularly for ruminants so much essen-
tial that this ability must be a deeply rooted cognitive and
behaviour al predisposition. In this context, we assume feed
choice to be a behavioural need of ruminants. Therefore, we
argue in favour of nutritional concepts, which account for
botanical and bioche mical diversity and are based on behav-
ioural research approaches.
We provide a brief outlook of
potential research topics, which we consider important
if the societal target of animal welfare is to be reached in
European ruminant production systems.
1 Feeding as part of animal welfare
Animal welfare cannot be dened only by the absence of dis-
tress like fear, pain, hunger, and disease; it also must include
the presence of certain stimuli, including eustress (Vil lalba
and Manteca, 2019), and the opportunity to express key
species-specic behaviour (Fraser et al., 2013). The latter is
realised in many livestock systems to a very limited degree
or not at all. Degrees of freedom in social and reproductive
behaviour are extremely low, as is the range of movement
and the opportunity to explore the environment compared
to situations in wildlife for the same species. A further aspect
of behaviour, which appears to be underestimated in its
meaning to animals in agriculture, is feed selection, includ-
ing the experience of taste, smell, exploration, and choice.
Using ruminants as an example,
the presented position pap er
argues that feed choice could be a
undamental physiological
and behavioural need of herbivores.
Therefore, neglecting
it in contemporary feeding schemes would imply a serious
violation of welfare.
2 Biological background
In their natural feeding behaviour, animals do not primarily
optimise the ratio of spent over gained energy. T
hey often
rather prefer to explore and to search for less easily ac ces-
sible feed (Inglis et al., 1997), select not only nutrients but
also bioactive plant compounds (Villalba et al., 2010), and
thereby maintain diurnal rhythms (Rutter, 2010) and
ance metabolic processes (Villalba et al., 2010). There appear
to be several evolutionary reasons for the development of
such behaviour. For herbivores, the balancing of their diets
by combining feed plants with dierent nutrient proles is
essential for digestive eciency and metabolic health.
these nutrient proles change with phenologi cal stage, the
animals have to be able to adapt their be haviour continu-
ously (Westoby, 1978). However, the
challenge is not only
Received: September 23, 2019
Revised: D ecember 15, 2019
Accepted: Januar y 23, 2020
KEYWORDS animal welfare, grazing, ruminant physiology,
pasture biodiversity, forage selection
Florian Leiber Michael Walkenhorst Mirjam Holinger
© Cornelia Kögler
© Andi Basler
© Andi Basler
36 Leiber et al. (2020) · LANDBAUFORSCH · J Sustainable O rganic Agric Syst · 70(1):35–38
to balance nutrients like proteins and carbohydrates. Her-
bivores also have to avoid or select potential toxins in cer-
tain situations, e.g. when they are needed in low dosages in
order to control diseases or metabolic processes (Villalba et
al., 2010; Poli et al., 2018). For ruminant livestock, this has also
a veterinary aspect (Walkenhorst et al., 2020).
Diet balancing (Westoby, 1978) and targeted selection
for or against specic secondary plant metabolites have a
further dimension in ruminants: control of the foregut fer-
mentation process. The rumen microbiome is sensible to diet
char acter istics regarding degradability of carbohydrates as
well as energy to protein balances (Snelling et al., 2019), but
also concerning bioacti ve compounds such as sap onins (Goel
et al., 2008) and polyphenols (Vasta et al., 2019). Balance of
nutrients (including their ruminal degradability) is impo rtant
in order to avoid inecient utilisation of protein or energy
but also to prevent collapse of the rumen, for instance, by
rumen acidosis or bloat. However, there are also other dier-
en tiated balances, which the ruminant has to maintain in
the foregut, for instance in order to protect essential plant
metabolites from ruminal degradation.
One illustrious ex am-
ple is linolenic acid, which is the only relevant source of ome-
ga- 3 fatty acid conguration for herbivores.
More than 95 % of
ingested linolenic acid, which is essential for many functions
in the mammal organism (Sinclair et al., 2002), may be lost by
derivatisation in the rumen (Chilliard et al., 2007). Given this
example, it is our hypothesis that a foregut-fermenting spe-
cies must by all means ensure that the microbiome in their
stomach is balanced so that not too much of essential plant
nutrients are degraded or modied and lost. One eective
instrument for the animal to control the rumen microora
are bioactive secondary plant compounds (e.g. essential oils,
phenols, alkaloids) with antimicrobial properties ( Vasta et al.,
2019). Experimental evidence shows that dietary secondary
plant compounds can protect linolenic acid in the rumen
(Vasta et al., 2019), which results in increased linolenic acid
concentrations in milk (Kälber et al., 2011), muscle and adi-
pose tissue (Willems et al., 2014). The case of linolenic acid is
an example that shows the importance of rumen control by
nely dosed ingestion of secondary plant metabolites. We
hypothesize that this requires a highly dierentiated feed
selection ability of the ruminant. The concept of nutrient
bal ancing (Westoby, 1978) must therefore take into account
these substances, also considering the trade-o with fermen-
tation eciency in the rumen, which makes the task for the
(wild) ruminant even more challenging.
3 Does feed choice have an emotional
Nutrients, as well as secondar y plant metabolites, possess
odour and taste properties, such as sweet, bitter, astringent,
or sharp but also specic ally aromatic (Wichtl, 2009). A neuro-
nal relation between metabolic needs for (or excess of) cer-
tain substances and the odour and taste experience is there-
fore strongly developed in ruminants (Ginane et al., 2011). A
sensory feedback, based on genetic determination (Clauss
et al., 2010), epigenetic eects (Wiedmeier et al., 2012), and
individual experience (Villalba and Manteca, 2019) inuences
dosed selection or refusal of nutrients and bioactive plant
compounds ingested from the natural forage environment
in which ruminants have evolved. We should consider that
the ability to translate metabolic needs into avour-guided
dierentiation of herbal biomass must be deeply rooted
in the ruminants’ behaviour because it is a precondition of
their survival and evolution. This ability is expressed in vari-
ous examples of self-medication in ruminants (Villalba et al.,
2010; Poli et al., 2018). A further aspect of selective eating
behaviour is diurnal alteration in preferences as described
by Rutter (2010), who found that ruminants decrease their
preference for protein-rich forage during the course of the
day. Another study demonstrated high sensibility of the di ur-
nal eating and rumination rhythm of dairy cows to even small
changes in monotonous mixed rations (Leiber et al., 2015). It
seems likely that ruminants are able and show a behavioural
need to inuence their “gut feeling” in accordance with their
sensory fee dback by actively choosing not only the composi-
tion but also time, duration, and amount of intake.
Diet selection by ruminants has thus at least three inter-
related levels of implication: (i) the physiological need for
selection, (ii) the translational processes, which connect
physiological needs with sensorial experience and action,
and (iii) the emotional importance for the animal to display a
dierentiated explorative behaviour in challenging environ-
ments (reviewed by Villalba and Manteca, 2019). We consider
the emotional level of behavioural experience to be pos sibly
so much important that the deprivation from feed selec-
tion may have a highly negative impact, even if all nutrients
and phytochemicals are provided in a perfect diet.
If animal
nutrition does only account for the molecular composition
of diets in order to elevate nutrient eciency
to the max,
we must assume that the better the nutritionists work, the
worse it will be for the animal as a b eing which needs to have
varying sensorial experience. Scientists, which have worked
on selection behaviour of ruminants, have clearly stated the
possibility of frus tration and poor welfare if feed choice is not
possible (Rutter, 2010; Villalba et al., 2010). This implies that
the standardisation of feed rations for ruminants, commonly
used in most European dairy production systems, including
organic, impairs welfare and neglects
the principle of en a-
species-specic behaviour in livestock husbandry in a
rather severe way.
A paradigm-shift for ruminant
“Even after thousands of years of domestication, livestock
appear to retain at least some of the survival traits that
evolved in their ancestors. Rather than ignore these evolu-
tionary traits, we should endeavour to consider them when
designing livestock management systems” (Rutter, 2010).
In the light of the above-mentioned considerations, a
paradigm shift in agricultural ruminant nutrition is needed
with the primary intention to include the animals’ feeding
behaviour as an integrative aspect into the concepts for live-
stock nutrition. The discussion on whether it must become
Leiber et al. (2020) · LANDBAUFORSCH · J Sustainable Organic Ag ric Syst · 70(1):35–38
strategies with cattle. Returning to more
natural feeding systems would consequently also include
changes in breeding goals towards genotypes better adapt-
ed to regionally available resources (Bieber et al., 2019).
5 Conclusion
There is evidence that feed selection behaviour has such
high importance for the cognitive well-being of ruminants
that access to feed diversity should be a compulsory cri-
teri on of welfare
. Under this paradigm, always feeding total
mixed rations would be no longer acceptable, and new
concepts that take into account diversity of fe eds are
required. It appears that a more natural feeding concept for
ruminants can result in several positive eects. Besides the
animal welfare and health aspect of more diverse feed and
natural feeding, the suggested approach could also result in
higher biodiversity of pastures and feed crops, as a positive
Last but not least, product quality also in creases
ruminants receive diverse types of forage with high
proportions of herbs. We must therefore pay more attention
to these aspects, in practice, in research, and in standards, in
particular in the context of organic agriculture.
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and give them oppor tunities for choice is of particular impor-
tance in organic agriculture striving for high animal welfare.
How this can be realised largely depends on factors such as
farmland resources, animal productivity levels, and trade-o
considerations with sustainability issues.
From a researcher’s point of view, we need a new feed-
ing recommendation system, which regards the feeding
behaviour of animals as a welfare issue. Also, feeding be hav-
iour should be systematically used as an evaluation tool for
metabolic needs of the animals, in particular in terms of
phyto chemicals. This requires a large range of new research,
including systematic evaluation of behavioural and meta-
bolic responses of animals to forage plants rich in secondary
metabolites and oered separately or integrated into new
sward mixtures. Basic research is needed in order to reach a
new understanding of ruminant requirements in a dynamic
interaction between animal phenotypes and botanical envi-
ronments (which include barn feeding), respecting temporal
patterns of intake and feed choice.
In applied research, practical solutions for the realisation
of feed diversity need to be developed and introduced into
teaching materials and production standards. Access to pas-
ture swards with high botanical diversity is surely the most
direct way to achieve such goals.
However, also for winter
feeding and for permanent indoor systems, it would be nec-
to develop options of forage diversica tion (more
plant species, introduction of browse, sequential oers of
dierent feed qualities, oers on choice). In concentrated
phenol- rich components like buckwheat, spices, or
spe cic oilseeds,
but also all kinds of by-products, could be
considered. The main target of developments for the prac-
tice should be to enable animals to choose their feed or at
least to oer feed in sequential variation. On the forage pro-
level, we also need to develop practical solutions
for achieving
higher diversity (botanical, phenological, bio-
chemical) because the existing knowledge is not yet broadly
applicable to agricultural systems.
Depending on dierent production systems (low-input,
high-input, organic, etc.) dierent approaches are needed
to realise feed diversity. If we consider the aforementioned
importance of feed diversity for animal welfare, we must
also reassess production systems where high milk yields are
achieved only on the basis of highly designed diets,
apparently do not provide deliberate feed choices or at least
varying feed oers.
The question of where diversity and
choice can be integrated into diets of high-yielding cows
should be an open topic of research. Nonetheless, what we
demand is to shift the idea of a perfect diet away from an
engineer’s work targeted at maximal performance of the
ruminal fermentation chamber towards a cooperation proj ect
between the researcher, the farmer and the cow with the aim
of an optimal balance of the processes in the foregut (Leiber,
2014). Clearly, our approach is much more directed to natural
low-input rather than high-input diets.
Since the continua-
tion of arable crop inputs into dairy and beef production
is challenged for reasons of sustainability (Schader et al.,
2015), our suggestion includes a general critique towards
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... Nevertheless, entirely pasture-based milk production is of minor importance among the major milk producers in temperate climate, apart from Ireland and New Zealand (Joubran et al.2021) [2]. Recently, however, concerns regarding total mixed ratio (TMR) feeding are arising as this prevents ruminants from displaying their species-specific selective behavior and might, thus, reduce animal welfare (Villalba 2010;Leiber et al. 2020) [6,7]. Grassland-based production comes along with a number of essential services affecting various areas of ruminant livestock production (Peyraud, 2017) [8]. ...
... Nevertheless, entirely pasture-based milk production is of minor importance among the major milk producers in temperate climate, apart from Ireland and New Zealand (Joubran et al.2021) [2]. Recently, however, concerns regarding total mixed ratio (TMR) feeding are arising as this prevents ruminants from displaying their species-specific selective behavior and might, thus, reduce animal welfare (Villalba 2010;Leiber et al. 2020) [6,7]. Grassland-based production comes along with a number of essential services affecting various areas of ruminant livestock production (Peyraud, 2017) [8]. ...
... Several scientists called for a new paradigm in animal nutrition by implementing feed diversity as a measure to improve animal wellbeing in otherwise homogeneously fed livestock production systems (Leiber et al. 2020) [7]. Irrespectively of feed provision on Journal of Veterinary Science & Animal Husbandry Volume 10 | Issue 1 pasture or in housing, a mixed diet consisting of a range of individual items in varying physico-chemical constitution offering the animal to deliberately chose is regarded as diverse feed (Gregorini et al. 2017) [23]. ...
Full-text available
Several scientists called for a new paradigm in animal nutrition by implementing feed diversity in otherwise homogeneously fed livestock production systems as former was shown to have a notable impact on animal productivity and health and the ecological footprint thereby decrease concerns regarding global food security from a societal perspective. However , there are no specific definitions and no threshold values available, so far, for desired grazed grassland feed diversity levels on pastures that enable envisaged sustainable ruminant livestock production and possibly the production of animal products with particular human health-values. Therefore, we conceptualize grazed grassland feed diversity in multiple layers for the very first time in this review to define its relevance from an animal perspective and implications for human health. The data reviewed reveals a close relationship between grazed grassland feed diversity with regard to plant secondary metabolites and animal characteristics that include animal health, welfare, and behavior as well as product quality with possible human health value. Nevertheless, it remains an open question whether plant species diversity per se or increasing occurrence of plant metabolites are responsible for feed diversity effects at grazing. Further, we demonstrate that solely the information about the level of feed diversity present on a field is not sufficient for deducing possible effects on animal related parameters and product quality as other interacting effects such as production level, pedo-climatic effects, and animal breed, have a relevant impact on the actual feed diversity consumed by the animal. Therefore, further research is required to shed light in the dark to understand the interaction between botanical compositions, pasture feed diversity and animal related factors for obtaining benefits for animal health, product quality and its human health value.
... The meaning of phytochemical diversity: precision livestock farming on pasture An important aspect of providing feed to ruminants by grazing can be botanical diversity of the feed and consequently, opportunity for selection (Leiber, Walkenhorst, & Holinger, 2020). Botanical diversity implies biochemical diversity (Villalba, Beauchemin, & Karen, 2019), especially when considerable proportions of herbs are part of the swards. ...
... As outlined above, this may have considerable effects on the digestive and metabolic health of animals, product quality and methanogenesis. Furthermore, it must be regarded as relevant part of animal welfare (Beck & Gregorini 2020;Leiber et al., 2020). ...
... Such perspectives show large potential for future development of nutrition research and they might represent a particular form of precision livestock farming. If steering of fermentation processes in the rumen by the animal through selection or avoidance of forages with different biochemical compositions would be understood with more clarity, this could indeed be a way of feeding ruminants much more precisely regarding their metabolic needs, and at the same time, respecting their nature (Beck & Gregorini 2020;Leiber et al., 2020;Villalba et al., 2010). One target of such research activities should be the development of botanical communities for pastureland and fodder production which support, as exactly as possible, the specific needs of ruminants for nutrients, PSC and the opportunity for selection. ...
Worldwide, grasslands provide an agricultural resource with large potentials for global food security and ecosystem services. However, productivity potentials are currently poorly realized. In many regions, grasslands are degraded through abandonment or overstocking, as well as by climate change effects. Nonetheless, there are great opportunities to improve productivity and ecological sustainability simultaneously, and various management constraints need to be solved. In principle, grassland-based food production with ruminants offers a viable form of agriculture, which can merge natural production with high ecological values, animal health and welfare, and special nutritional product quality. In this chapter, the so far wasted potential of grassland-based production systems is analyzed along three main lines: the challenges of herding and land management in pasture areas; the importance of botanical and biochemical diversity for natural ruminant nutrition and healthy food products; and the necessity to develop site-adaptive cattle breeds and create grassland-based production systems on different genetic foundations than the currently dominant milk yield-oriented approach. Along opportunities and challenges for grassland-based livestock systems, the chapter stresses the urgent requirement for research progress in ruminant nutrition and breeding adapted to grassland production.
... However, feeding relatively short feed particles in a homogeneous mixture (i.e., TMR) restricts the animals' need for feed selection (Leiber et al., 2020) and may therefore impair welfare. Satisfying this need may at least partly be achieved by (additionally) providing long, un-chopped forage such as silage or hay or access to pasture. ...
It has been suggested that reducing forage particle size as well as feeding hay compared to silage may improve forage intake. Little is known; however, how such ration characteristics affect other aspects of cattle behaviour. Therefore, this study investigated the lying behaviour of cows in response to particle size reduction (LONG versus SHORT; Trial 1) and preservation method (SILAGE versus HAY; Trial 2) of forages which constituted ≥ 80% of the rations’ dry matter. Two feeding groups with 10 (Trial 1) and 9 Holstein cows each (Trial 2) received the experimental rations for approximately 5 weeks. Cows were housed in a free-stall barn with straw-bedded cubicles and rubberized floor in the alleys. Lying behaviour was recorded using HOBO Pendant® acceleration data loggers during the last 3 weeks of the experimental period as well as for 3 consecutive days during the week preceding the experiment, the latter serving as a baseline covariate to consider individual cow lying behaviour. SHORT-fed cows (Trial 1) had a longer daily lying time (+ 1.1 h/d; P = 0.003) and tended to have more lying bouts (+ 3.1; P = 0.090) than cows fed the LONG ration. In both groups, a preference towards the left lying side (57%) was observed. A similar pattern was observed for both groups with regard to rumination time while lying. Cows fed SILAGE or HAY (Trial 2) did not differ with regard to lying times (12.8 h/d). However, cows on HAY tended to reduce the lying time on the left side (- 1.1 h/d; P = 0.098) and number of lying bouts per day (-2.5 bouts/d; P = 0.039). Consequently, these cows showed nearly an equal preference for the left and right lying side with 49.1% and 51.6%, respectively; whereas cows on SILAGE tended to prefer the left lying side (55.6%), also when ruminating. In contrast, cows on HAY tended to reduce rumination time on the left lying side (-0.61 h/d; P = 0.079). Effects observed may be attributed to changes in eating behaviour as well as the amount of feed ingested in a given time period. Under the conditions investigated, time budgets for lying may be limited and changes of the forage characteristics (e.g. particle size reduction) could mitigate these constraints.
The animal welfare debate includes unresolved key issues, like defining animal welfare principles and requirements in legislation and private standards, practically implementing and measuring them and ways to most efficiently support them through public and/or private means. In this chapter, different definitions for animal welfare are explored. Improved legislation and rules are discussed, with a focus on organic farming. The chapter then proposes more outcome-oriented approaches to assess animal welfare, including also avenues to involve consumers and market actors in the development of commercial products with a high level of animal welfare. The role of policymakers, legislators and private standard-setters is emphasized for the development of clear and easy to implement animal welfare rules, including both farmers self-assessments and third party certification. At last, financial rewards and innovation for animal-welfare friendly husbandry and assessment systems will play a role in advancing animal welfare.
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Abstract Background Dietary intake is known to be a driver of microbial community dynamics in ruminants. Beef cattle go through a finishing phase that typically includes very high concentrate ratios in their feed, with consequent effects on rumen metabolism including methane production. This longitudinal study was designed to measure dynamics of the rumen microbial community in response to the introduction of high concentrate diets fed to beef cattle during the finishing period. A cohort of 50 beef steers were fed either of two basal diet formulations consisting of approximately 10:90 or 50:50 forage:concentrate ratios respectively. Nitrate and oil rich supplements were also added either individually or in combination. Digesta samples were taken at time points over ~ 200 days during the finishing period of the cattle to measure the adaptation to the basal diet and long-term stability of the rumen microbiota. Results 16S rRNA gene amplicon libraries were prepared from 313 rumen digesta samples and analysed at a depth of 20,000 sequences per library. Bray Curtis dissimilarity with analysis of molecular variance (AMOVA) revealed highly significant (p
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Herbivores grazing in extensive systems are exposed to a series of challenges, rooted in the inherent spatial and temporal variability of their environment that potentially constrain their health, nutrition, and welfare. Nevertheless, in this review, we argue that challenges induced by some biotic (e.g., vegetation) and abiotic (e.g., terrain) factors may also be viewed as “positive” sources of stress or eustress, since they present complex problems, that when solved successfully elicit a greater degree of behavioral plasticity and adaptability in grazing animals. Chemically and structurally diverse landscapes require animals to display complex behaviors and exhibit adaptive capabilities, like building a balanced and safe diet or finding shelter, which ultimately lead to positive emotional states. Thus, maintaining or enhancing the diversity occurring in natural systems represent a management approach that can be used to improve welfare and prepare the animal for an efficient adaptation to future, and potentially unknown, environmental challenges.
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Increasing efficiency in livestock production and reducing the share of animal products in human consumption are two strategies to curb the adverse environmental impacts of the livestock sector. Here, we explore the room for sustainable livestock production by modelling the impacts and constraints of a third strategy in which livestock feed components that compete with direct human food crop production are reduced. Thus, in the outmost scenario, animals are fed only from grassland and by-products from food production. We show that this strategy could provide sufficient food (equal amounts of human-digestible energy and a similar protein/calorie ratio as in the reference scenario for 2050) and reduce environmental impacts compared with the reference scenario (in the most extreme case of zero human-edible concentrate feed: greenhouse gas emissions -18%; arable land occupation -26%, N-surplus -46%; P-surplus -40%; non-renewable energy use -36%, pesticide use intensity -22%, freshwater use -21%, soil erosion potential -12%). These results occur despite the fact that environmental efficiency of livestock production is reduced compared with the reference scenario, which is the consequence of the grassland-based feed for ruminants and the less optimal feeding rations based on by-products for non-ruminants. This apparent contradiction results from considerable reductions of animal products in human diets (protein intake per capita from livestock products reduced by 71%). We show that such a strategy focusing on feed components which do not compete with direct human food consumption offers a viable complement to strategies focusing on increased efficiency in production or reduced shares of animal products in consumption.
In contrast to natural and historical diets of wild and domesticated ruminants, the diversity of plant species is limited in diets of modern dairy cows. Are “production diseases” linked to this? We conducted a trial to test the effects of a multicomponent herbal feed additive (HFA) on health, performance and fertility traits. A dose‐finding study (DF) with 62 cows on 11 commercial farms compared a low (50 g) and a high (100 g) dose of HFA (HFA‐50, HFA‐100) with a placebo (PL). In a subsequent field trial (FT) with 280 cows on 30 commercial farms, HFA‐100 was compared to PL. Cows were randomly assigned to HFA and PL groups and received HFA or PL individually daily from 14 days pre‐ to 300 days post‐calving. Data were analysed with mixed effects models. No differences between HFA and PL were found regarding performance, body condition score and overall culling rates. A tendency towards lower milk urea for HFA‐100 compared to PL (p = .06) was found in DF. HFA significantly reduced elevated milk acetone observations (≥10 mg/L) in the first 10 lactation weeks (HFA‐100: 4%; HFA‐50: 4%; PL: 12%) in DF. HFA‐50 significantly reduced lameness incidence (HFA‐100: 11%; HFA‐50: 2%; PL: 14%) in DF. Calving intervals were 15 days shorter in HFA compared to PL in both trials, which could be confirmed by tendency (p = .07) in FT. In both trials, the proportion of test days with elevated somatic cell score (≥3.0) was significantly lower in HFA compared to PL (DF: HFA‐100: 40%, HFA‐50: 45% and PL: 55%; FT: HFA‐100: 38% and PL: 55%) which is also reflected by tendency (p = .08) in lower culling rates due to udder diseases in FT. HFA showed no negative impact on any of the measured parameters. The effects of HFA indicate a potential of phytochemically rich and diverse feed additives for dairy cows' nutrition and physiology.
Our aim was to map the performance of local (native) dairy cattle breeds in Austria, Switzerland, Poland, and Sweden with regard to production, fertility, longevity, and health-associated traits and to compare them with commercial (modern) breeds. For this purpose, we analyzed test-day records (July 1, 2011, to June 30, 2014) and treatment records (Austria, Sweden) of cows managed on organic farms. We performed country-wise comparisons of 123,415 lactations from Original Braunvieh (OB) and Grey Cattle (AL) with Braunvieh (BV; Brown Swiss blood >60%) in Switzerland; AL with BV (Brown Swiss blood >50%) in Austria; Polish Black and White (ZB), Polish Red and White (ZR), and Polish Red (RP) with Polish Holstein Friesian (PHF) in Poland; and Swedish Red (SRB) with Swedish Holstein (SH) in Sweden. Average milk yields were substantially lower for local compared with commercial breeds in all countries; differences ranged from 750 kg (Sweden) to 1,822 kg (Austria), albeit on very different average levels. Local breeds showed a longer productive lifetime by 0.64, 0.83, 1.42, and 0.20 lactations in Switzerland, Austria, Poland, and Sweden, respectively, again on very different levels in each country. Regarding fertility traits, calving interval was shorter in local than in commercial breeds by 13 (Sweden), 14 (Switzerland), and 20 d (Austria, Poland). Insemination index was lower in certain local breeds by 0.15 (Switzerland), 0.14 (Austria), 0.21 (Poland), and 0.13 (Sweden). Several local breeds showed a lower proportion of cows with >100,000 somatic cells/mL. This was the case in Switzerland (OB 24.2%; BV 35.8%), Austria (AL 25.3%; BV 36.9%), and Sweden (SRB 42.4%; SH 43.4%). In contrast, the respective proportion in Poland exceeded 82% in all breeds except the commercial PHF (76.1%). In Sweden, lactations with veterinary treatments were considerably less prevalent in SRB (15.6%) than in SH (21.7%). In Austria, breeds differed only in treatments for udder disorders, which favored AL. In conclusion, the markedly lower milk yields of local breeds are partly counterbalanced by (somewhat inconsistent) advantages in longevity, fertility, and health traits across 4 European countries. This indicates that the robustness of local breeds can contribute to improved sustainability of organic dairy systems.
The interest of the scientific community in the effects of plant polyphenols on animal nutrition is greatly increasing. These compounds, in fact, are ubiquitous in the plant kingdom, especially in some spontaneous plants exploited as feeding resources alternative to cultivated crops and in several agro-industry by-products. Polyphenols interact with rumen microbiota, affecting carbohydrate fermentation, protein degradation, and lipid metabolism. Some of these aspects have been largely reviewed, especially for tannins; however, less information is available about the direct effect of polyphenols on the composition of rumen microbiota. In the present paper, a review of the most recent literature about the effect of plant polyphenols on rumen microbiota responsible for unsaturated fatty acid biohydrogenation, fiber digestion, and methane production is presented, taking into consideration the advances in microbiota analysis achieved in the last 10 yr. Key aspects, such as sample collection, sample storage, DNA extraction, and the main phylogenetic markers used in the reconstruction of microbial community structure, are examined. Furthermore, a summary of the new high-throughput methods based on next generation sequencing is reviewed. Several effects can be associated with dietary polyphenols. Polyphenols are able to depress or modulate the biohydrogenation of unsaturated fatty acids by a perturbation of ruminal microbiota composition. In particular, condensed tannins have an inhibitory effect on biohydrogenation, whereas hydrolyzable tannins seem to have a modulatory effect on biohydrogenation. With regard to fiber digestion, data from literature are quite consistent about a general depressive effect of polyphenols on gram-positive fibrolytic bacteria and ciliate protozoa, resulting in a reduction of volatile fatty acid production (mostly acetate molar production). Methane production is also usually reduced when tannins are included in the diet of ruminants, probably as a consequence of the inhibition of fiber digestion. However, some evidence suggests that hydrolyzable tannins may reduce methane emission by directly interacting with rumen microbiota without affecting fiber digestion.
Plant bioactives can potentially benefit herbivores through their effects on health and nutrition. The objective of this study was to determine the importance of polyphenols and terpenes on the ability of lambs to self-select these compounds when challenged by a parasitic infection and the subsequent impact on their health and productivity. Thirty-five lambs were housed in individual pens and assigned to five treatment groups (7 animals/group), where they received: 1) A basal diet of beet pulp:soybean meal (90:10) (CONTROL); 2) The same diet, but containing 0.3% of bioactive natural plant compounds extracted from grape, olive and pomegranate (BNP); 3) A simultaneous offer of the diets offered to the Control and BNP groups (Choice-Parasitized; CHP-1); 4) The Control diet, and when lambs developed a parasitic infection, the choice described for CHP-1 (CHP-2); and 5) The same choice as CHP-1, but animals did not experience a parasitic burden (Choice-Non-Parasitized; CHNP). Lambs, except CHNP, were dosed with 10,000 L3 stage larvae of Haemonchus contortus. Infected lambs under choice treatments (CHP-1 and CHP-2) modified their feeding behavior in relation to the CHNP group as they increased their preference for the feed containing polyphenols and terpenes, interpreted as a behavior aimed at increasing the likelihood of encountering medicinal compounds and nutrients in the environment that restore health. This change in behavior corresponded with an improvement in feed conversion efficiency. However, an increased preference for the diet with added plant bioactives did not have an effect on parasitic burdens, hematological parameters, blood oxidation, or serum concentration of IgE.
Experiences early in life influence preferences for the forages which animals eat as adults, but little is known about how such experiences affect forage intake and digestibility. We hypothesized that experience with high fiber (HF) diets in utero enables cattle to better utilize HF diets by enhancing intake and digestibility of HF diets. We exposed cows to either HF or low fiber (LF) diets from October 20 until parturition on March 15. The HF diet was primarily ammoniated wheat straw (AWS), while the LF diet was mainly grass hay (700 g/kg orchardgrass and 300 g/kg meadow bromegrass). The two diets were iso-net energy (NEm), isonitrogenous, and similar in mineral and vitamin contents, but they varied 10-fold in neutral detergent soluble carbohydrates. Following weaning, the 8 mo old calves from mothers fed HF or LF diets during pregnancy were fed AWS and a high fiber supplement, and dry matter (DM) intake and digestibility were measured during the last half of a 40 d experiment (i.e., 26 d adaptation, 14 d measured DM intake, 5 d measured DM digestibility). Intake (5.6 versus 5.3 kg/d; P=0.04) and digestibility (545 versus 523 g/kg; P=0.03) of AWS were higher for calves fed HF than for those fed LF diets. As a result, digestible DM intake of AWS was higher for HF than LF (3.1 versus 2.8 kg/d; P<0.01). Calves fed HF diets ate more straw as a proportion of their diet than did calves fed LF (733 versus 723 g/kg; P=0.05). Total digestible DM intake (i.e., AWS + supplement) was higher for calves fed HF than LF diets (4.7 versus 4.4 kg/d; P<0.01), as was total diet DM digestibility (613 versus 600 g/kg; P=0.07). Calves were weighed at the conclusion of the DM intake and digestibility measurement periods, and then fed an AWS/processed wheat middlings diet for an addition 28 d to determine daily gain. Collectively, increases in intake and digestibility affected body weight gains such that HF diet fed calves numerically gained more than LF fed calves even during this short period (0.45 versus 0.41 kg/d; P=0.13). Higher DDM intake is likely important for pregnant cows and their offspring which winter for many months under extensive range conditions on dormant forages where their NEm requirements are marginally satisfied. These effects on offspring, further magnified by experiences with their mothers early in life, make cows and their progeny better adapted to using dormant forages during winter.
Based on the assumption that the reduction of the use of imported protein concentrates, such as soybean from overseas, is a goal of ecologically sustainable livestock production, this paper is discussing significant aspects of dairy cows’ demand for dietary protein. These aspects are put in a general context of rumen fermentation efficiency. The main question is, whether new perspectives on optimal rumen functioning could be found, which allow to develop low-input feed evaluation systems for dairy cattle, especially in organic livestock systems. It is argued that besides the reduction in concentrated feedstuff, such systems should base on aspects of feeding behaviour and feed diversity. Such approaches are expected to avoid nutrition-based metabolic disorders of the cattle and to generate advantageous side effects regarding food quality and ecology coming along with low-concentrate feeding. An approximate outline of topics for research and development in order to achieve such systems is presented with this paper.