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Development prospects of the silvopastoral system in the Republic of Serbia
No full textAccording to the United Nations, agroforestry is the most important agricultural innovation in Europe in the 21st century. It is a land-use system that combines trees and shrubs with agricultural plants or pastures and livestock. Agroforestry is an integrated, planned, and targeted cultivation of trees and shrubs on an agricultural land. It has been practiced on over one billion hectares worldwide, and the area is constantly increasing. The silvopastoral system is the most common form of agroforestry and involves a planned use of woody plants, forage plants, and animals in the same place. The Republic of Serbia has a high potential for the development of this system as it has a large pasture area (2023 – 238163 ha) which accounts for 7% of the total agricultural land. The advantages of such a complex, multifunctional system are that it contributes to the preservation of biodiversity, water and soil quality, reduces land degradation and fire risk, adapts to climate change (by increasing drought resistance), preserves the welfare and increases the productivity of domestic animals, diversifies income, improves the ecological aspects and
aesthetics of agricultural and forest landscapes, and contributes to the preservation of traditional cultural heritage. Its disadvantages are the high initial investment, the possibility of damage to trees and shrubs by animals, and the difficulty of applying mechanization. However, over 30 years, pasture productivity increased by 17% and forest by 53%. Trees in pastures can be planted widely spaced, in rows or groups, with planting density depending on the tree species, production objectives, and projected management intensity. The planting density should not exceed 150 trees per hectare, as a further increase reduces the productivity of the pasture. Trees planted on the pasture serve as shelter for animals by providing shade, thereby reducing the impact of heat stress on the animals, increasing animal productivity and improving animal welfare. Tall trees with a smaller crown can be planted for the production of timber, cork and firewood (beech, oak, birch,
poplar, ash, maple, spruce, acacia and others) and fruit species for the production of fruits (apple, pear, olive, walnut, hazelnut, blackberry, raspberry, sweet chestnut and others). In Serbia, it is necessary to educate farmers about the potential of the silvopastoral system, give them guidelines for its establishment and maintenance, and conduct certain research. It is necessary to help livestock farmers transition to switch to such systems by providing funds through investment projects, favorable loans and constant technical support from experts. Also, livestock farmers should be informed with economic and ecological sustainability of such systems, supported by an adequate policy with adequate and financially strong measures of rural development which could solve the problem of abandonment and ageing of villages
Assessment of Affective States in Pre-Weaning Calves Housed in Intensive Production Systems
No full textEmotional states are increasingly recognized as key indicators of animal welfare,
especially in early life stages when young animals are highly sensitive to stress and environmental
challenges. This study explored the emotional responses of pre-weaning calves (up to one month old) on two
intensive farms, involving a total of 1,168 calves (596 on Farm A and 572 on Farm B). The main differences
between farms were related to housing conditions during the first week and group size between days 8 and
30. Emotions were assessed using a 20-trait scoring system (scale 0–120), supplemented by behavioral tests
such as approach and touch tests, and observations of both physiological (e.g., play, social interaction) and
pathological behaviors (e.g., apathy, stereotypies, cross-sucking). Traits were categorized as positive (e.g.,
activity, calmness, curiosity, playfulness, sociability) or negative (e.g., indifference, fear, agitation, boredom,
apathy). During the first week, Farm A calves were calmer but less active and more prone to negative
emotions, while Farm B calves were more curious and socially engaged, though more irritable. By day 15,
Farm A calves showed greater liveliness and satisfaction, while Farm B calves still exhibited more negative
states. On days 22 and 30, Farm A calves demonstrated more activity and play, although some negative
behaviors persisted. Despite fluctuations, overall emotional scores did not differ significantly between farms.
Positive emotions generally dominated. These findings highlight the impact of housing on calf welfare and
support the use of behavioral and physiological indicators to assess emotional well-being. Further research is
needed to develop validated tools and improve husbandry in intensive systems
COMPARISON OF TIME CONSUMPTION BETWEEN TRADITIONAL AND INNOVATIVE METHODS OF PRODUCING QUEEN CELL CUPS
No full textThe production of high-quality honey bee queens is one of the
most important beekeeping operations, considering the key role of the queen in the
colony. On the other hand, queen rearing is a highly challenging process, so the
simplification of certain production segments would represent a significant
advantage. In this paper, we examined and compared the traditional method of
producing wax queen cell cups using a wooden mold with an innovative method
that involves the use of a silicone mold together with a specially designed cell bar.
The comparison of efficiency between the tested methods was carried out through
the measurement of time consumption for both methods. Our results indicate that
the production of queen cell cups using the innovative method is 2.66 times faster
compared to the traditional method. In addition, we examined the differences in
queen cell cup height obtained by the traditional method, which showed high
variability, ranging from 8.1 mm to 15.9 mm, unlike the innovative method in
which queen cell cups were uniform and measured 11 mm. On professional
apiaries, where there is a high demand for the production of honey bee queens,
queen cells, and royal jelly, our innovative method can significantly facilitate
production by accelerating the process of producing queen cell cups, while at the
same time ensuring the uniformity of the produced cell cups. Also, using a
specially designed cell bar allows all queen cells to be added or removed at once
from the grafting frame and provides the possibility of simple individual separation
of the queen cells
A Field Trial to Demonstrate the Potential of a Vitamin B Diet Supplement in Reducing Oxidative Stress and Improving Hygienic and Grooming Behaviors in Honey Bees
No full textThe honey bee is an important insect pollinator that provides critical pollination
services for natural and agricultural systems worldwide. However, inadequate food weakens honey bee colonies, making them vulnerable to various biotic and abiotic factors. In this study, we examined the impact of supplementary feeding on bees’ genes for antioxidative enzymes and vitellogenin, oxidative stress parameters, and the hygienic and grooming behavior. The colonies were divided into two experimental groups (with ten hives each): a treatment group that received the plant-based supplement and a control group. The experiment was conducted in two seasons, spring and summer. After the treatment, in both seasons, all the monitored parameters in the treatment group differed from those in the control group. The expression levels of genes for antioxidative enzymes were significantly lower, but the vitellogenin gene transcript level was significantly higher. Values of oxidative stress parameters were significantly lower. The levels of hygienic and grooming behavior were significantly higher. Therefore, our field study indicates that the tested supplement exerted beneficial effects on bees, reflected in reduced oxidative stress and enhanced hygienic and grooming behavior
Comprehensive review of heat stress effects on dairy cattle the implications for production, reproduction, and adaptation in the context of climate change
No full textHeat stress poses a significant threat to dairy cattle, impacting their physiological, reproductive, and production performance. This review aims to provide an in-depth examination of the effects of heat stress on dairy cattle, focusing on how elevated ambient temperatures influence milk production, reproductive efficiency, and overall animal health. The physiological responses to heat stress, including increased respiration rate, elevated body temperature, and changes in feeding and drinking behaviors were analysed and discussed. Heat stress leads to a decrease in feed intake, an increase in water consumption, reduced growth rates, and diminished milk yield and quality. Reproductive performance is also adversely affected, with reduced fertility and increased risk of embryonic loss. Dairy breeds, particularly those with higher production levels, are more susceptible to heat stress due to their higher metabolic heat production. The review highlights the impact of heat stress on the immune and endocrine systems, increasing vulnerability to diseases and inflammatory conditions. Given the limited capacity of animals to adapt to the rapid pace of climate change, the review underscores the need for effective management strategies, including environmental modifications and genetic selection, to mitigate the adverse effects of heat stress. Finally, sustainable dairy farming remains a significant challenge in the context of global climate change and rising temperatures
Livestock Sector in Serbia: Challenges, Structural Gaps, and Strategic Pathways Towards Sustainability
No full textThe livestock sector in Serbia has been experiencing a prolonged period of structural and
economic challenges, characterized by decreasing animal numbers, low productivity, and
reduced competitiveness in both domestic and EU markets. This study analyses the key
structural, technological, economic, and policy factors shaping these trends to provide
strategic recommendations for sustainable sector revitalization. The methodology integrates
macroeconomic analysis, agricultural economic accounts, and international trade
data, applying regression modelling to examine relationships between domestic food prices,
exchange rates, and agri-food import volumes. The results indicate that livestock’s share of
agricultural gross value added remains below 35%, significantly lower than EU averages,
while export quotas remain underutilized and the trade balance for animal products is
persistently negative. Contributing factors include fragmented farm structures, outdated
production technologies, limited adoption of innovations, demographic decline in rural
areas, and insufficient alignment with EU CAP Strategic Plans and Green Deal objectives.
Climate change impacts, such as droughts and heat stress, alongside animal disease outbreaks
and macroeconomic pressures, further exacerbate these vulnerabilities. The study
recommends modernizing production systems through investment in technological upgrades,
strengthening farmer organizations and cooperatives, enhancing biosecurity and
animal welfare standards, and improving policy frameworks to align with EU sustainability
objectives. Emphasis is placed on developing integrated approaches that simultaneously
address productivity, economic resilience, and environmental sustainability. Implementing
these strategic measures is essential for enhancing food security, supporting rural development,
and ensuring Serbia’s successful integration into the EU market as part of a more
sustainable and resilient agri-food system
Genetic Evaluation of Milk Production Traits in the Serbian Saanen Goat Population
No full textWithin the framework of this study, a genetic evaluation of milk traits was conducted in
the Saanen goat breed. The focus of the research was placed on the application of more
advanced models for estimating heritability and breeding values of economically important
milk traits. The study included 670 Saanen goats and a total of 2155 lactations between
2010 and 2021 on a single farm located in the Autonomous Province of Vojvodina. The milk
production traits included total milk yield per lactation (TMY), milk fat yield (FY), protein
yield (PY), and the content of milk fat (MF) and protein (PC). The fixed effects included
in the Sire and Animal models were as follows: kidding season, type of kidding, year of
kidding, and lactation number. The permanent environmental effect of the doe and the
animal’s additive genetic effect were considered as random effects. In the Animal model,
the estimated heritability values for the traits were: 0.2216 (TMY), 0.2564 (FY), 0.2556 (PY),
0.3977 (MF), 0.2864 (PC). The heritability estimates obtained using the sire model were
slightly higher: 0.2742 for TMY, 0.3256 for FY, 0.3855 for PY, 0.3925 for MF, and 0.3502 for PC. The estimation of breeding values for bucks was performed using both the Sire model
and the Animal model. Breeding values for the bucks derived from the two models showed
a close relationship, with correlations ranging from 0.85 for TMY to 0.90 for PC. The results
of this study confirm that the application of the BLUP-Animal model provides a more
accurate estimation of breeding values and represents a reliable basis for the selection of
the Saanen goat breed. The findings from this study provide a practical basis for enhancing
breeding programs and developing an effective strategy for genetic improvement of milk
production in the population
ENDANGERED BUT RESILIENT: POPULATION AND HEALTH INSIGHTS OF LIPA PRAMENKA SHEEP IN SERBIA
No full textLipa Pramenka sheep, an endangered but resilient breed in Serbia, has seen a 4.8-fold increase in population in recent years, although numbers are not yet sufficient for long-term stability. This study examines population trends and biochemical parameters and shows that total protein (69.34–77.56 g/L), albumin (30.45–34.02 g/L) and glucose (2.69–3.50 mmol/L) are within physiological ranges, while AST (112.94–153.37 IU/L) and calcium (2.32–2.72 mmol/L) vary significantly between farms, reflecting differences in diet and management. The results underline the need for targeted maintenance, optimized feeding and sustainable breeding strategie
EFFECT OF SUPPLEMENTING TANNINS ON NUTRITIONAL VALUE OF RATION AND PRODUCTIVE RESULTS OF FINISHING LAMBS
Get PDFTanini su, kao velika grupa heterogenih jedinjenja različitog biološkog porekla, široko rasprostranjeni u biljnom svetu. Zbog svoje heterogenosti, tanini ispoljavaju različite efekte u ishrani preživara. Cilj ove doktorske disertacije je bio ispitivanje upotrebe preparata kestenovih tanina u obroku tovne jagnjadi, kako bi se ispitao njihov uticaj na fiziološke i proizvodne pokazatelje.
Ispitivanja su obavljena kroz dva, metodološki različita ogleda. U oba ogleda je uključeno po 30 jagnjadi MIS rase, neposredno nakon završenog perioda odbijanja od majki. Prosečna telesna masa jagnjadi u ogledu 1 je iznosila 20,55 kg, dok je u ogledu 2 iznosila 20,50 kg. U ogledu 1 je korišćen standardni farmski obrok za ishranu odlučene jagnjadi, dok su u ogledu 2 formulisani obroci tako da zadovolje potrebe u metaboličkom proteinu (MP) za prirast od 250 g/dan, dok je neto energije za porast (NEmeat) bilo više za oko 14%, što odgovara prirastu od oko 275 g/dan. Na taj način, su u ogledu 2 korišćena tri obroka uz pretpostavku da će uticaj tanina dovesti do zadovoljenja potreba za prirast veći od 250 g/dan.
Kao izvor tanina korišćen je preparat kestenovih tanina, komercijalnog naziva Farmatan®. U ogledu 1 formirane su tri grupe, sa po 10 jagnjadi, na osnovu sadržaja Farmatan®-a u suvoj materiji (SM) obroka: K (kontrola, bez dodatih tanina); T1 (9,46 g preparata/kg SM obroka) i T2 (18,87 g preparata/kg SM obroka). U ogledu 2, na osnovu sadržaja preparata u obroku, formirane su sledeće grupe: KON (kontrola, bez dodatih tanina); 10T (20,17 g preparata/kg SM obroka) i 20T (40,33 g preparata/ kg SM obroka). Oba ogleda su postavljena kao jednofaktorski ogledi sa po tri tretmana, gde su analizom varijanse testirane razlike između njih, a značajnost razlika između srednjih vrednosti određene na osnovu testa najmanjih razlika (LSD test). Oba ogleda su trajala 60 dana (ne računajući adaptacioni period), tokom kojih je dnevno praćeno konzumiranje SM. Na svakih 15 (u ogledu 1), odnosno 10 dana (u ogledu 2) praćene su promene u telesnoj masi jagnjadi, kako bi se odredili dnevni i ukupni prirasti, kao i parametri iskoristivosti hrane (konverzija, Klajberov odnos - KR, kao i efikasnost proteina - EP i efikasnost energije - EEN). Kako bi se utvrdilo da li tanini mogu uticati na promene vrednosti biohemijskih parametara krvi, u ogledu 1 jagnjadima je uzorkovana krv prvog i poslednjeg dana ogleda, nakon čega su odrađene analize. Određivanje prividne svarljivosti u oba ogleda je utvrđena indirektnom metodom korišćenjem pepela nerastvorljivog u hlorovodoničnoj kiselini kao indikatora, kroz tri kolekciona perioda u oba ogleda. U ogledu 1 kolekcioni periodi su trajali 5 dana, i to od 15. do 19. dana (I period); od 30. do 34. dana (II period) i od 45. do 49. dana ogleda (III period). U ogledu 2, kolekcioni periodi su trajali 6 dana, a obavljani su u periodu od 14. do 19. dana (I period), od 29. do 34. dana (II period) i od 44. do 49. dana (III period). Prividna svarljivost je određena za sledeće parametre: SM, organska materija (OM), SP, sirove masti (SMa), sirova celuloza (SC), deterdžentska vlakna (nerastvorljiva u neutralnom - NDF, odnosno kiselom deterdžentu - ADF), bezazotne ekstraktivne materije (BEM) i nestrukturni ugljeni hidrati (NFC). Po završetku hranidbenog dela ogleda, sva jagnjad su žrtvovana kako bi se ispitale klanične osobine, hemijski i masnokiselinski sastav mesa. Kao dodatni efekat, izvršena je i analiza ekonomske održivosti korišćenja preparata kestenovih tanina u obroku u oba ogleda. Ova analiza je obuhvatila troškove ishrane na osnovu dana (THd), troškove ishrane na osnovu prirasta (THp), neto profit (NP) i ekonomsku isplativost (EKI) korišćenja ovog izvora tanina.
Konzumiranje SM u ogledu 1 je bilo identično kod K i T2 (1,20 kg SM/dan) i veće od T1 (1,13 kg SM/dan), što se pre svega objašnjava slabijim konzumiranjem kabaste komponente obroka (sena) kod ove grupe. Postavka i sprovođenje ogleda 2 je omogućilo konzumiranje slične količine SM kod sve tri grupe, te je prosečno iznosilo 0,97 kg SM, 0,99 kg SM i 1,00 kg SM dnevno za KON, 10T i 20T, redom. Iako se usled adstringentnog ukusa tanina moglo očekivati da će doći do smanjenog konzumiranja, u ispitivanim količinama, kestenovi tanini nisu uticali na ovu pojavu. Razlike u konzumiranju se objašnjavaju kumulativnim efektom promenljivih parametara mikroklime, povremenom izlaganju blagom uznemiravanju, a u ogledu 2 i promenama obroka i hijerarhijskim odnosima u grupi. Iako je poređenje ova dva ogleda moguće sprovesti samo do određene mere, primećuje se da je u ogledu 1 konzumiranje bilo veće u toku celog perioda trajanja ogleda. Takođe, u ogledu 1 je konzumiranje bilo veće nego što korišćeni holandski normativi (CVB, 2018) preporučuju, i gotovo bez ograničenja, dok je u ogledu 2 količina date hrane određivana svakodnevno, na osnovu grupe koja je najslabije konzumirala prethodnog dana.
Na bolju iskoristivost hrane ukazuju veći prirasti pri istom nivou konzumiranja, čime se sugeriše povoljan uticaj kestenovih tanina. Posledično, najbolje konverzije SM, zatim najveće vrednosti KR, EP i EEN u ogledu 1 su ostvarila grla iz grupe T2 (4,46 kg SM/kg prirasta, 0,0181, 1,03 i 27,95), dok su najnepovoljniji parametri bili kod K (5,28, 0,0159, 0,83 i 23,26, redom). U ogledu 2, parametri su podeljeni po polovima, te su konverzije kod muških grla povoljnije kod taninskih (4,50 i 4,33 kg SM/kg prirasta redom za 10T i 20T) nego kod kontrolne (5,05 kg SM/kg prirasta). Uz ovo, kod muških životinja, taninske grupe (10T i 20T, redom) imaju veću vrednost KR (0,0155 i 0,0157), EP (1,47 i 1,60) i EEN (33,15 i 34,79) nego kod kontrolne grupe, kod koje su KR, EP i EEN redom iznosile 0,0137; 1,19 i 26,58). Sličan trend je primećen i kod ženskih grla, te je najbolja konverzija utvrđena kod 10T grupe (4,53), a najlošija kod KON (5,55).
Dalje, u ogledu 1, najveće prosečne dnevne i ukupne priraste su ostvarila grla iz T2 grupe (270,37 g/dan i 16,22 kg), najmanje grla iz K (222,92 g/dan i 13,37 kg) uz primetnu značajnost razlika (p 0,05). Slično, u ogledu 2, najveće prosečne dnevne i životne priraste su ostvarila grla iz 20T grupe (230,00 g/dan i 13,80 kg za muška, odnosno 220,00 g/dan i 13,20 kg za ženska grla), koji su značajno veći (p < 0,05) od prirasta postignutih kod KON (191,67 g/dan i 11,50 kg za muška, odnosno 174,17 g/dan i 10,45 kg za ženska grla), dok se ostvareni rezultati kod 10T nisu značajno razlikovali od prethodno dve navedene grupe. Na osnovu rezultata o prirastima za ceo period ogleda, u oba sprovedena ogleda, može se tvrditi da kestenovi tanini u obroku utiču na povećane priraste kod jagnjadi u tovu. Ukoliko se posmatra ceo period ogleda 2 (od 1. do 60. dana), eksperimentalne grupe su ostvarile veće priraste od jagnjadi iz grupa koje nisu dobijale tanine, što može ukazivati na to da kestenovi tanini utiču na poboljšano korišćenje proteina.
Prividna svarljivost SM i OM u ogledu 2 je u prvom kolekcionom periodu (od 14. do 19. dana ogleda) bila, iako slična, nešto veća kod KON (84,02% i 85,23%) nego kod 10T (83,87% i 85,41%) i 20T (80,69% i 82,09%). Svarljivost SP je pratila sličan trend (78,44%, 78,42% i 69,04% za KON, 10T i 20T, redom), dok je svarljivost SMa rasla sa porastom tanina u obroku (83,53%, 89,15% i 90,44%). Trendovi vezani za svarljivost SMa se nastavljaju i u naredne dve kolekcije, što može značiti da su kestenovi tanini uticali na bolje iskorišćavanje masti usled promena u procesima buražne fermentacije. Zaključke vezane za svarljivost SP nije jednostavno doneti zbog eventualnog uticaja tanina na povećanje dotoka SP u tanko crevo. Drugim rečima, usled povećanog dotoka SP dolazi i do povećanja njegovog sadržaja u fecesu, što nužno ne znači njegovu lošiju iskoristivost. U prilog ovome govori i činjenica da su jagnjadi iz taninskih grupa ostvarila veće priraste od onih iz kontrolne.
Ispitivanjem osnovnih parametara krvi u ogledu 1, nisu utvrđeni negativni uticaji kestenovih tanina na jagnjad u tovu.
Iako se u literaturnim navodima uviđa da tanini mogu imati različit uticaj na hemijski sastav i masnokiselinski profil mesa, ovi efekti nisu utvrđeni u okviru disertacije, budući da u oba ogleda nisu utvrđene statističke značajnosti razlika ovih parametara među grupama.
Analiza ekonomske održivosti je pokazala da je vrednost EKI u oba ogleda opadala sa dodavanjem kestenovih tanina u obroke, te je prosečna vrednost ovog parametra iznosila 1,47, 1,29 i 0,98 u ogledu 1 za K, T1 i T2, redom.
U zavisnosti od obroka i pola, vrednost EKI se kretala kod KON 1,30-2,50, kod 10T 0,74-1,56, i kod 20T 0,54-1,06. Ovo ukazuje da kestenovi tanini utiču na smanjenje ekonomske efikasnosti u proizvodnji jagnjadi za tov. Ipak, pored cene preparata, na ovaj parametar utiče i paritet cena, koji je trenutno nepovoljan uz skupa hraniva i nisku cenu žive mere. Kestenovi tanini su uticali na poboljšanje konverzije i veće priraste jagnjadi, što ukazuje na bolju iskoristivost hrane, što je svakako prednost, naročito u velikim farmskim sistemima. Uz činjenicu da troškovi ishrane u stočarstvu čine najveći deo ukupnih troškova proizvodnje, u velikim sistemima, svaki dan skraćenja tova, kao i ušteda svakog kilograma obroka predstavlja veliku stavku u postizanju ekonomski efikasne proizvodnje, te kestenovi tanini predstavljaju potencijalno korisni dodatak u proizvodnji jagnjećeg mesa. Drugim rečima, upotrebu kestenovih tanina u tovu jagnjadi je moguće opravdati u takvim uslovima tržišta koji podrazumevaju jeftiniju proizvodnju hrane i povećanje tržišne cene žive mere jagnjadi.
Prikazani rezultati ukazuju da korišćenjem kestenovih tanina kao aditiva u obrocima jagnjadi u tovu može doći do poboljšanja produktivnih parametara životinja, bez štetnih uticaja. U ispitivanim količinama, kestenovi tanini nisu uticali na pojavu smanjenog konzumiranja hrane, koja se eventualno mogla očekivati usled njihovog adstringentnog ukusa. Takođe, njihovom ingestijom tanini nisu ispoljili štetne uticaje na organizam životinja. Korišćenjem kestenovih tanina došlo je do poboljšanja iskoristivosti hrane, što je rezultiralo većim prirastima i nižim konverzijama u poređenju sa grupama koje nisu konzumirale dodate tanine, što je pre svega posledica boljeg korišćenja proteina. Analizom ekonomske održivosti je utvrđeno da, uz trenutni paritet cena, dodavanje kestenovih tanina u obroku može dovesti do finansijskog opterećenja proizvodnje, te ovo inicijalno deluje kao skupa opcija. Ali, ukoliko bi se postigla jeftinija proizvodnja hrane, uz povećanje tržišne cene jagnjadi, njihova upotreba se može opravdati. Smanjenje troškova proizvodnje se pre svega može ostvariti na velikim farmama, te se potencijal upotrebe kestenovih tanina pre svega u takvim sistemima može iskoristitiTannins, as a large group of heterogeneous compounds of different biological origins, are widely distributed in the plant world. Due to their heterogeneity, tannins exhibit various effects in the ruminant nutrition. The aim of this doctoral dissertation was to investigate the use of chestnut tannin product in the diet of fattening lambs to examine its impact on physiological and production indicators.
The research was conducted through two methodologically different experiments. Both experiments included 30 lambs of the MIS breed, immediately after weaning from their mothers. The average body weight of lambs in experiment 1 was 20.55 kg, while in experiment 2, it was 20.50 kg. In experiment 1, a standard farm diet was used for the feeding of the selected lambs, while in experiment 2, diets were formulated to meet the metabolic protein (MP) requirements for a gain of 250 g/day, with net energy for gain (NEmeat) being about 14% higher, equivalent to a gain of about 275 g/day. Thus, in experiment 2, three diets were used assuming that the influence of tannins would lead to meeting gain requirements greater than 250 g/day.
Chestnut tannin product, commercially known as Farmatan®, was used as the source of tannins. In experiment 1, three groups were formed, each consisting of 10 lambs, based on the Farmatan® content in the dry matter (SM) of the diet: K (control, no added tannins); T1 (9.46 g of product/kg of SM diet) and T2 (18.87 g of product/kg of DM diet). In experiment 2, groups were formed based on the following content of the product in the diet: KON (control, no added tannins); 10T (20.17 g of product/kg of SM diet) and 20T (40.33 g of product/kg of SM diet). Both experiments were set up as single-factor designs with three treatments, and differences between them were tested by analysis of variance, with the significance of differences between means determined by the least significant difference (LSD) test. Both experiments lasted for 60 days (excluding the adaptation period), during which daily SM intake was monitored. Changes in lamb body weight were recorded every 15 days (experiment 1) or 10 days (experiment 2) to determine daily and total gains, as well as feed utilization parameters (conversion, Kleiber ratio - KR, protein efficiency - EP, and energy efficiency - EEN).
To investigate whether tannins could influence changes in blood biochemical parameters, blood samples were collected from the lambs in experiment 1 on the first and last days of the experiment, followed by analysis. Apparent digestibility in both experiments was determined using an indirect method with ash insoluble in hydrochloric acid as an indicator during three collection periods in both experiments. In experiment 1, collection periods lasted for 5 days: from day 15 to 19 (Period I), day 30 to 34 (Period II), and day 45 to 49 (Period III). In experiment 2, collection periods lasted for 6 days, and they were conducted from day 14 to 19 (Period I), day 29 to 34 (Period II), and day 44 to 49 (Period III). Apparent digestibility was determined for the following parameters: SM, organic matter (OM), CP, crude fat (SMa), crude fiber (SC), detergent fiber (neutral detergent fiber - NDF and acid detergent fiber - ADF), non-nitrogenous extractives (BEM) and non-fiber carbohydrates (NFC). At the end of the experiments, all lambs were slaughtered to examine the slaughter traits, chemical composition, and fatty acid profile of the meat.
As an additional effect, an analysis of the economic sustainability of using chestnut tannins in the diet in both experiments was conducted. This analysis included feed costs per day (THd), feed costs per gain (THp), net profit (NP), and economic efficiency (EKI) based on the use of this tannin source.
In experiment 1, intake of SM was identical in K and T2 (1.20 kg SM/day) and higher than in T1 (1.13 kg SM/day), primarily explained by lower intake of roughage in this group (hay). The setup and execution of experiment 2 allowed for similar SM intake in all three groups, averaging 0.97 kg DM, 0.99 kg DM, and 1.00 kg DM per day for KON, 10T, and 20T, respectively. Although it could have been expected that the astringent taste of tannins would lead to reduced intake, in the tested amounts, chestnut tannins did not affect this phenomenon. Differences in consumption are explained by the cumulative effect of variable microclimate parameters, occasional exposure to mild stress, and in experiment 2, changes in the diet and hierarchical relationships within the group. While the comparison of these two experiments can only be made to a limited extent, it is noticeable that consumption was higher throughout the duration of experiment 1. In addition, in experiment 1, consumption was higher than the Dutch standards (CVB, 2018) recommended, and almost without limitations, while in experiment 2, the amount of feed given was determined daily based on the group that consumed the least the previous day.
Better feed efficiency is indicated by higher gains at the same level of consumption, suggesting a favorable effect of chestnut tannins. Consequently, the best SM conversion, followed by the highest KR, EP, and EEN values in experiment 1 were achieved by the T2 group (4.46 kg SM/kg gain, 0.0181, 1.03, and 27.95, respectively), while the least favorable parameters were observed in the K group (5.28, 0.0159, 0.83, and 23.26, respectively). In experiment 2, parameters were divided by gender, and feed efficiency was more favorable in male lambs in the tannin groups (10T and 20T, respectively) compared to the control (KON), with SM conversions of 4.50 and 4.33 kg DM/kg gain for 10T and 20T, respectively, while control had 5.05 kg SM/kg gain. Furthermore, in male animals, the tannin groups (10T and 20T) had higher KR values (0.0155 and 0.0157), EP values (1.47 and 1.60), and EEN values (33.15 and 34.79) than the control group, which had KR, EP, and EEN values of 0.0137, 1.19, and 26.58, respectively. A similar trend was observed in female lambs, with the best conversion in the 10T group (4.53) and the worst in the KON group (5.55).
In experiment 1, the highest average daily and total gains were achieved by the T2 group (270.37 g/day and 16.23 kg), and the lowest by the K group (222.92 g/day and 13.37 kg), with significant differences (p 0.05). Similarly, in experiment 2, the highest average daily and lifetime gains were achieved by the 20T group (230.00 g/day and 13.80 kg for males, 220.00 g/day and 13.20 kg for females), which were significantly higher (p < 0.05) than the gains achieved by KON (191.67 g/day and 11.50 kg for males, 174.17 g/day and 10.45 kg for females), while the results for 10T were not significantly different from the other two groups. Based on the gain results for the entire experimental period, in both experiments, it can be stated that chestnut tannins in the diet have a positive effect on lamb growth during fattening. If the entire experimental period of experiment 2 (from day 1 to day 60) is considered, the experimental groups achieved higher gains compared to the groups that did not receive tannins, indicating that chestnut tannins improve protein utilization.
In experiment 2, apparent digestibility of SM and OM in the first collection period (from day 14 to 19) was slightly higher in KON (84.02% and 85.23%) compared to 10T (83.87% and 85.41%) and 20T (80.69% and 82.09%). CP digestibility followed a similar trend (78.44%, 78.42%, and 69.04% for KON, 10T, and 20T, respectively), while CF digestibility increased with the addition of tannins in the diet (83.53%, 89.15%, and 90.44%). Trends related to CF digestibility continued in the next two collection periods, indicating that chestnut tannins influenced better fat utilization due to changes in ruminal fermentation processes. Conclusions regarding CP digestibility are not straightforward due to the potential effect of tannins on increased flow of CP into the small intestine. In other words, increased CP flow also leads to an increase in its content in feces, which does not necessarily imply poorer utilization. This is supported by the fact that lambs in the tannin groups achieved higher gains than those in the control group.
In experiment 1, an examination of basic blood parameters did not reveal any negative effects of chestnut tannins on fattening lambs.
Although literature indicates that tannins can have different effects on the chemical composition and fatty acid profile of meat, these effects were not observed in this dissertation, as there were no statistically significant differences in these parameters among the groups in both experiments.
The economic analysis showed that the economic efficiency index (EKI) in both experiments decreased with the addition of chestnut tannins to the diets, with average values of this parameter being 1.47, 1.29, and 0.98 in experiment 1 for K, T1, and T2, respectively. Depending on the diet and gender, EKI values ranged from 1.30 to 2.50 for KON, 0.74 to 1.56 for 10T, and 0.54 to 1.06 for 20T. This indicates that chestnut tannins reduce economic efficiency in lamb production. However, besides the cost of the used tannin product, this parameter depends on the parity of prices, which is currently unfavorable due to expensive feed and low live lamb prices. Chestnut tannins improved feed conversion and increased lamb gains, indicating better feed utilization, which is an advantage, especially in large farm systems. Considering that feed costs in livestock production constitute the largest part of total production costs, in large systems, each day of shortened fattening and every kilogram of saved feed represent significant cost savings, making chestnut tannins a potentially valuable addition to lamb production. In other words, the use of chestnut tannins in lamb fattening can be justified under such market conditions which includes cheaper feed production and higher market prices for live lambs. Cost reduction can primarily be achieved in large farms, so the potential use of chestnut tannins is particularly relevant in such systems.
The presented results indicate that the use of chestnut tannins as additives in lamb diets can lead to improved production parameters without harmful effects. In the tested quantities, chestnut tannins did not affect reduced food consumption, which could have been expected due to their astringent taste. Additionally, their ingestion did not show harmful effects on the animals. The use of chestnut tannins improved feed utilization, resulting in higher gains and lower conversions compared to groups that did not consume tannins, primarily due to better protein utilization. The economic analysis found that, with the current price parity, adding chestn
Stanje u proizvodnji krmnog bilja i stočarstvu u Republici Srbiji
No full textПољопривреда је најплеменитија људска делатност јер производи храну за људе. Сточарство је најважнија пољопривредна грана јер представља индикатор развијености пољопривреде, параметар је животног стандарда и значајан чинилац еколошких и орнаменталних својстава простора. Удео сточарства у укупној вредности пољопривредне производње у земљама са развијеном пољопривредом је преко 60% (у Данској чак 83%), што говори о спровођењу адекватних пољопривредних политика и ефикасном коришћењу природних ресурса, посебно пољопривредног земљишта и климатских услова (Draganescu, 2014). Чињеница да је удео сточарства у укупној вредности пољопривреде у Србији 2012. године био 41,2% (Поповић, 2013) а да је данас тек 34% говори да се природни ресурси недовољно и неадекватно користе. Крмне биљке су јефтин и квалитетан извор хране за животиње. Стварају велику вегетативну масу и богате су протеинима, угљеним хидратима и другим хранљивим материјама. Користе се као кабаста или концентрована сточна храна, односно за испашу, зелену храну, спремање сена, сенаже, силаже, пелетираних смеша, прераду у брашно, и друго. Економски важне крмне биљке припадају различитим фамилијама (Poaceae, Fabaceae, Brassicaceae i Amaranthaceae), поседују различита мофролошка и биолошка својства и могу веома успешно користити агроеколошке услове, како у чистом усеву, тако и у смешама. Уз правилно планирање производње крмних биљака (одабир врсте и сорте, правилна агротехника) могу се постићи високи и квалитетни приноси, а самим тим и обезбедити интензивирање сточарске производње, пре свега говедарске и овчарске, и добити јефтинији сточарски производи. Могућност гајења различитих крмних биљака отвара простор за смањење негативног утицаја климатских промена на производњу биомасе за сточну храну. Упркос континуираном смањењу површина укупног пољопривредног земљишта, обрадивог земљишта, ливада и пашњака, Србија са око 0,50 хектара обрадивог земљишта по становнику спада у групу добро обезбеђених земаља овим, најважнијим ресурсом. Међутим, структура усева на обрадивом земљишту је веома неповољна, пре свега са аспекта производње сточне хране. На око 67% обрадивог земљишта се гаје жита, док се крмне биљке гаје на свега 9% површина а легуминозне крмне биљке на само 160 хиљада хектара. Тренд пада површина под ораничним крмним биљем, ливадама и пашњацима поклапа се са трендом пада броја свих врста домаћих животиња, посебно говеда, оваца и свиња. Само у периоду 2018-2022. године у Србији је смањен број свих условних грла за 20%, говеда за 17,7%, оваца за 5%, коза за 31,5%, свиња за 30,7% и живине за 5% (РЗС, 2023). Примена специфичних функција за прогнозирање, на основу података за дужи временски интервал (1977-2024) указује на могућност драстичног и забрињавајућег пада броја говеда и оваца и површина под крмним биљем у наредних 20 година. Један од главних узрока пада сточарске производње јесте ниска конкурентност и акумулативност ове производње и непостојање сигурности у пласману и цени сточарских производа што је уско повезано са смањењем површина под крмним биљем. Тржишна нестабилност, смањен обим извоза сточарских производа, неповољан однос цена стоке и њихових производа и концентроване сточне хране, али и деаграризација и депопулација руралних подручја, такође утичу на смањење сточног фонда. Иако, савремена наука и техника и повољни климатски услови пружају веома велике могућности за максимално искоришћавање генетичког потенцијала крмног биља и домаћих животиња, у Републици Србији ови ресурси се не користе на адекватан начин. Такође, тренутне предузете мере аграрне политике не дају позитивне резултате у ревитализацији пољопривредне производње. Оне морају бити базиране на детаљној рејонизацији, свеобухватније и укључити и друге мере попут подстицања опстанка и развоја руралних подручја, поготову у брдско-планинским и пограничним рејонима