Production and carcass quality of thin-tailed sheep fed diets containing protected and unprotected soybean groats

This study was conducted to determine the effect of feeding protected and unprotected soybean groats with different ratios on production and carcass quality of male thin-tailed sheep (TTS). The TTS were fattened for 3 months with an average initial weight of 24.09 ± 1.26 kg. Treatments consist of P1=protected and unprotected soybean groats 10%:5%, P2=protected and unprotected soybean groats 7.5%:7.5% and P3=protected and unprotected soybean groats 5%:10%. Data were analysed using a completely randomized design with three treatments and three replications. The variables observed in this study were the slaughter weight, percentage (carcass, non-carcass, meat, fat), fleshing index, rib eye muscle (longissimus dorsi) area, and meat bone ratio. This study displayed significant improvement from treatment using 10% protected + 5% unprotected soybean groats (P1), having the highest meat and fat percentage, as well as meat bone ratio. Inclusion of protected soybean groats in the diet up to 10% level had limited effect (P>0.05) on slaughter weight, carcass percentage, non-carcass percentage, fleshing index, and rib eye muscle area. This study suggests the combination of soybean groats in the diet in the form of protected:unprotected (10%:5%) provide significant improvement on carcass characteristics, while maintaining quality of carcass in the thin-tailed sheep. Further study on meat quality attributes from these supplementations requires deeper exploration.


Introduction
Sheep are one of the livestock raised extensively by farmers in rural Indonesia as a source of meat.Sheep meat has the potential to be a source of animal protein as more people become aware of the benefits of eating nutrient-dense foods.Between 2009 and 2019 [1], the number of sheep increased by 12% in Central Java and by 74% overall in Indonesia.According to the data given by the central statistics agency (BPS, 2023), Indonesia accounts for a total of 54,650.53-tonsheep meat production, with an annual consumption at 0.4 kg/capita.With its potential, provision of not only quantity, but also quality of sheep carcass needs intensive development.
The effectiveness of thin-tailed sheep to transform offered feed into muscle protein is one of the reasons on extensive raising of these breeds.Sheep productivity will be supported by feed that has the right balance of nutrients and quantities.The availability of feed protein that can support the growth of microorganisms in the rumen and supply feed protein in the intestine has an impact on the quality of the feed for ruminants [2].Soybean groats, a byproduct of the food industry, are one potential source of protein for sheep feed.When entire soybeans are sorted, soybean fractions called "soybean groats" are produced.Broken soybean groats can be utilized as feed ingredients, whilst whole soybean groats are used for human consumption [3].There is numerous essential nutrition that still available within the 1292 (2024) 012013 IOP Publishing doi:10.1088/1755-1315/1292/1/012013 2 goats.It is enriched with the protein content at more than 35% [4], calcium, folate, vitamin B1, B2, and vitamin K, as well as decent amount of potassium and iron.When using protein source feed, factors including rumen protein breakdown, protein quality, intestinal absorption of amino acids, and its effects on animal production performance must all be taken into account [5,6].
Because of the rumen bacteria' ability to degrade high-protein soybean groats, ruminants do not utilize them to their full potential.To prevent microbial breakdown in the rumen, it is therefore vital to protect the protein of feed constituents [7].To ensure that as much feed protein as possible enters the colon for enzymatic digestion, feed protection measures are taken.High-quality feed protein can be broken down by rumen microorganisms into ammonia and energy can be lost during fermentation in the form of gas (CO2 and CH4), which lowers the biological value of high-quality feed protein [8].Feed protections is the effort to provide by-pass energy and protein that is readily adsorb without any significant decrease following entrance into digestive system.It is a modest technological approach to improve animal performance, rumen available nutrients, and provide a more friendly byproducts to environment [8].In addition, pre-treatment using coating materials to delay the degradation rate of essential nutrition were reported by numerous studies [8,9].Formaldehyde was successfully used in-vitro to protect soybean groats, reducing the breakdown rate by 37.6 and 54.4%, respectively.In its pure state, formaldehyde (H2CO) is an odourless vapor or liquid that is extremely soluble in water and all other organic solvents [10].The goal of this study was to find the ideal ratio for feeding male thin-tailed sheep (TTS) protected soybean groats in order to maximize carcass output.In light of these ideas, research on the carcass production of TTS fed a diet containing protected soybean groats is required.

Time and place of the study
This research was conducted from July 2019 to January 2020 in the sheep barn of Jatikuwung Experimental Farm, Department of Animal Husbandry, Faculty of Agriculture, Sebelas Maret University, Surakarta in Jatikuwung Village, Gondangrejo District, Karanganyar Regency, with recorded average temperature at 29.63 o C

Materials
This study used 15 male TTS with an average initial weight of 24.09 ± 1.26 (CV = 5.24%) aged 1.5-2 years.The ration used in this study consisted of elephant grass and concentrate supplemented with soybean groats.The ration given was based on the dry matter requirement of 4.5% of the body weight of the sheep.The research was conducted through two stages, namely the maintenance stage and the data collection stage.The maintenance stage was carried out for 90 days after the feed adaptation process for 14 days.The data collection stage was conducted after sheep slaughter.

Research parameters
The research was conducted to assess the protection of soybean groats using formaldehyde at several levels, namely 10% protected, 7.5% protected, and 5% protected.The observed variables included slaughter weight, percentage (carcass, non-carcass, meat, fat), fleshing index, rib eye muscle area, and meat bone ratio.The treatments were -P1 (10% protected soybean groats + 5% unprotected soybean groats) -P2 (7.5% protected soybean groats + 7.5% unprotected soybean groats) -P3 (5% protected soybean groats + 10% unprotected soybean groats).The soybean groats protection method was carried out by mixing 37% formaldehyde and water in a ratio of 1:5.The formaldehyde solution was sprayed on soybean groats that had been mashed until homogeneous and then matured for 8 hours and then dried for 24 hours [11].Sheep that will be slaughtered are fed for 12 hours but still given drinking water ad libitum [12].Sheep are skinned then eviscerated and then obtained whole carcasses which are then weighed and measured carcass length using a measuring tape to determine the fleshing index [13].Length measurement is the result of measuring the length of the cattle carcass after cutting measured from the front end of the shoulder to the end of the hip bone (os pubis) [14].The carcass is cut into 2 parts front and back by cutting on the part between the 12th and 13th ribs then measuring the rib eye muscle area by attaching a plastic grid to the surface of the rib eye muscle in the 12th rib loin eye area then drawing the shape of the rib eye muscle using a permanent marker, after which calculating the area using a millimeter block [15].Carcass parts were weighed and then deboned and fleshed separating bones, meat, and fat to calculate the percentage.

Data analysis
Data were analyzed using a completely randomized design (CRD) unidirectional pattern with 3 treatments and 3 replicates.The data obtained were analyzed for variance and if there were differences in the results, further tests were carried out using the Duncan Multiple Range Test (DMRT) [16].

Results and discussion
The test results obtained the average value of slaughter weight, carcass percentage, non-carcass percentage, meat percentage and fat percentage are listed in Table 1.

Slaughter weight
The cutting weight of all treatments was the same (P>0.05).The cutting weights used in this study's treatments were essentially the same.These outcomes can be ascribed to the ingestion of protein and the availability of energy for muscle retention.According to [17], the amount of protein consumed and the available energy play a significant role in determining how much tissue is preserved.Both P1, P2, and P3 had ration protein contents that were comparatively similar when compared to the treatment rations.
According to [18], DET carcass tissue would have a relatively same composition if the total amount of dry matter nutrients, crude protein, crude fiber, and total digestible nutrients were consumed in all regimens at roughly the same rates.The study's usage of a particular breed of sheep also affected the findings regarding slaughter weight.The slaughter weight of Malpua sheep in [19] study resulted in a greater slaughter weight compared to this study (38.5 vs 34.51 and 37.24), despite both given formaldehyde-protected soybean groats.

Carcass percentage
The analysis of variance findings in Table 1 indicates that the use of formaldehyde in the diet to protect soybean groats has no discernible impact (P>0.05) on carcass percentage.The study's various feed treatments responded to carcass percentage in a manner that was generally similar.This is consistent with [17]'s findings on thin tailed Up to 20% of protected soybean groats fed to sheep had no appreciable impact on the carcass percentage, which ranged from 48.07 to 48.46%.This is because protein retention to supply muscle mass is likewise very similar, which results in a pretty equal protein content ratio.The amount of tissue that is stored depends on energy availability and protein intake [18].
Comparing the carcass weight with slaughter weight, then multiplying by 100%, yields the carcass percentage [19].The average carcass percentage in Table 1 reveals that P1 had the highest carcass percentage with 10% formaldehyde-protected soybean groats before declining in P2 with 7.5% and again in P3 with 5% protected soybean groats.P1, P2, and P3 had the greatest carcass percentages, at 48.46%, followed by 48.09% and 48.07%, respectively.The proportion of carcasses produced in this study was higher than the findings of [20], which had a TTS carcass percentage of 45.35% with a supplement of 10% protected soybean groats in the ration and with a sheep carcass percentage of 46.33% [21].Body conformation and degree of fatness are the two key variables that influence carcass percentage.Because not all digested protein can be utilized by cattle, a rise in the provision of protected soybean groats is not accompanied by an increase in the proportion of carcass.Protein that has been digested will be absorbed as amino acids.Protein will be broken down into amino acids and NH3 during protein degradation in the rumen.Although the ratio of soybean groats protected by formaldehyde differs in this investigation, it is believed that the amino acids produced from feed protein degradation are largely the same.The opinion of [22] supports this claim, stating that the procedure of protein breakdown into amino acids followed by the amount of NH3 present in the rumen has a significant impact on both the deamination process that produces NH3 and microbial production.

Meat percentage
Treatment has a considerable impact on the percentage of various meats.[20] It has been possible to modify the Merino Branco sheep carcass % by applying tannin from Cistus ladanifer L. The percentages of carcass, meat, bone, and fat were essentially the same between treatments.The percentage of flesh in cattle will be directly proportional to the slaughter weight, but the percentage of bones will be inversely proportionate.Other hypotheses suggest that animals can still develop the ideal amount of muscle even when fed greater protein feed.[18] revealed that despite the animals consuming high-quality feed, the limits of muscular development could not be overcome.[10] That providing soy groats in insufficient amounts can result in protein being absorbed into the small intestine.

Fat percentage
The findings of the analysis of variance revealed a significant difference (P 0.05) between the proportion of fat and the use of protected soy groats.The ability to transform feed into a carcass composition that is too diverse despite having the same genetics is assumed to be the cause of this.Genetic factors, sex, physiology, age, body weight, and diet can all have an impact on the makeup of lamb carcasses.This study's proportion of results-which ranged from 15.81 to 23.08% of carcass weight-was higher than that of [21].This is assumed to be because animals aren't getting enough nutrients to meet their fundamental needs.After the basic needs of life are met, if there is a surplus of nutrients, the excess is utilized to promote the development of body fat.Unlike other tissues, fat grows extremely slowly initially but quickly accelerates during the fattening phase.The test results obtained by the average value of fleshing index, rib eye muscle area and meat bone ratio are listed in Table 2.

Fleshing index
The provision of formaldehyde-protected soybean groats had no discernible impact (P>0.05) on the fleshing index of TTS, according to the results of the analysis of variance in Table 2.According to studies by [17], giving TTS a ration of protected soybean groats up to 20% of the time had no discernible impact on their fleshing index, which averaged 25.98 kg/m.This is due to the slaughter weight being essentially the same.One component of objective carcass assessment, which can take the place of subjective visual carcass conformation assessment, is the fleshing index [13].According to [23], the fleshing index is the ratio of carcass weight to carcass length.As a result, a high carcass percentage does not automatically translate into a high fleshing index because the fleshing index is also influenced by other characteristics, such as carcass length.According to [24], the fleshing index can be used to estimate how much meat is consumed by livestock.The study's P1 sample produced the highest fleshing index value at 26.82 kg/m with the addition of 10% protected soybean groats.P2 and P3 followed with lower values of 24.59 kg/m and 7.5% protected soybean groats, respectively, and then increased once more to 25.66 kg/m with the addition of 5% protected soybean groats.The findings of this study were better than those of [25], who provided 10% protected soybean groats and had an average fleshing index of 19.37 kg/m.The fleshing index of TTS fed kapok seeds was 13.06 kg/m [26].The measurement results in the study demonstrated that a short carcass length and a high carcass weight produced a high fleshing index.This is supported by [27]'s assertion that corpses that if the carcasses are the same length but weigh differently, the heavier carcasses will have a higher trade index, and the opposite is true.

Rib eye muscle area
The results of analysis of variance showed that TTS fed with formaldehyde-protected soybean groats had no significant effect (P>0.05) on rib eye muscle area of TTS.This is because the percentage of carcasses produced is relatively the same.The results showed the value of rib eye muscle area ranged from 20.21 -20.40 cm 2 .The results of this study are slightly higher than the research conducted by [28] with a rib eye muscle area value of 19.65 cm 2 .The formation of rib eye muscle area is determined by the amount of cutting weight produced and its genetics [29].
Rib eye muscle area is closely related to carcass.The appearance of rib eye muscle area can give an idea of the carcass produced.This is in accordance with [30] explain that the rib eye muscle area describes the proportion of meat in the carcass, namely the wider the rib eye muscle area the greater the proportion of meat in the carcass.Giving formaldehyde-protected soybean groats up to 10% level has not been able to improve the rib eye muscle area.The rib eye muscle area value obtained is still in the normal range.This is supported by the results of research by [31] where the rib eye muscle area of TTS supplemented with formaldehyde-protected soybean groats was 18.28 -22.9 cm 2 .
The area of rib eye muscle area is related to the proportion of carcass meat veins, the wider the rib eye muscle area, the greater the proportion of meat veins in the carcass.[32] showed that rib eye muscle area is positively correlated with slaughter weight.Slaughter weight can reflect the carcass percentage of an animal.The increase is thought to be due to the increase in body weight of livestock which illustrates the growth of muscle tissue.Body protein is mostly found in the muscle tissues of the livestock body [33].

Meat bone ratio
The results of analysis of variance and DMRT further test showed that the provision of formaldehydeprotected soybean groats up to 10% level in the ration had a very significant effect (P <0.01) on the meat bone ratio of TTS.This is probably because the protein supply from soybean groats can be absorbed optimally in the intestine.[34] stated that high body protein deposition will be used by the body for meat growth so that it will increase carcass weight and ultimately increase meat weight.This is thought to be because livestock efficiently use the deposition of protein to form tissues so that the weight of the meat obtained becomes greater.
The meat bone ratio value is obtained by dividing the amount of meat by the number of bones from the resulting carcass [35].The research data in Table 1 shows that the meat bone ratio value of P1 is 4.58%, higher than P2 which has a value of 3.39% and P3 which has a meat bone ratio of 3.44%.This can be caused by the highest PK content of the P1 ration among the three treatments so that it can spur the addition of more muscle mass.The meat bone ratio of P2 decreased because it had a lower PK than P1 and increased again in P3 because although it had low PK, it had the highest TDN.High energy and protein balance in ruminant feed is done to increase the efficiency of ration utilization [36].The rate of degradation of carbohydrates and feed protein in the rumen can have a major influence on the final product of fermentation and animal performance [37], besides that it can have an influence on livestock productivity.The average meat bone ratio of all treatments was 3.8%.This result is higher than [12] in their research reported that TTS given rice bran concentrate had a meat bone ratio of 2.91%.Giving formaldehyde-protected soybean groats produces a value This is thought to be due to differences in feed protein provision so that livestock efficiently use the protein that is deposited to form tissues so that the weight of the meat obtained becomes greater.In line with the opinion [37] which states that carcass weight, carcass percentage, carcass components and meat bone ratio, are strongly influenced by the quality, consumption and nutritional composition of the feed constituents used in the study.Feed type, chemical composition and feed consumption have a major effect on growth.Higher protein and energy consumption will result in faster growth rates.[38] reported that different nutritional treatments cause major differences in the relationship between body components.
Carcass components consist of meat, bone and fat.A good quality carcass has a low proportion of bone, a high proportion of meat and an optimal proportion of fat [12].According to [38] bone is very important in the growth that will determine the body size of livestock.Bone grows first, because it is the skeleton that determines body conformation, then meat and finally fat.This shows that bone growth is relatively fixed and not affected by the overall body growth rate.Sheep slaughtered above 1.5 years old, with a slow bone growth rate, cause the bone growth response to feed is also low so that it can produce optimal meat.An increase in meat weight is followed by an increase in intramuscular fat.

Conclusion
TTS fed rations using protected soybean groats up to 10% level produced higher meat percentage and lower fat percentage than 7.5% and 5% levels.Meat bone ratio fed with protected soybean groats at P1 level of 10% was 35% higher than P2 level of 7.5% and 33% higher than P3 level of 5%.Giving protected soybean groats up to 10% level can increase the meat bone ratio of TTS.Slaughter weight, carcass percentage, fleshing index, and rib eye muscle area had similar results.

Table 2 .
Carcass quality of male TTS