Slaughter characteristics and market value of traditional beef cattle slaughtered in six abattoirs of Tanzania
Nsiima, M.P.L., Shirima, E.J.M.*, Mwilawa, A.J.**, Temu, J., Shengoto, R., Masakia, B.J., Michael, S. and S. Mlau
Ministry of Livestock and Fisheries Development, Veterinary Complex, 131 Nelson Mandela Road, P.O. Box 9152, 15487 Dar-es-Salaam-Tanzania
*Corresponding author:
**Tanzania Livestock Research Institute, P.O. Box .....
Executive summary
The objective of this study was to examine the slaughter and carcass characteristics and overall market value of slaughtered beef cattle in six abattoirs of Tanzania in three phases between June 2013 and September 2014. The information from 3,133 sampled animals revealed that slaughter characteristics, carcass quality and market value from beef cattle differed due to the number and diversity of breeds and crosses involved, differences in age, sex and the grade of the animals. The overall market weight of traditional herd ranged from 202.0 to 266.0 kg live weight and carcass weight ranged from 100.0 -129.0 kg. The Ankole cattle were heaviest (P<0.05) while the Gogo and Maasai were the lightest (P<0.05) groups with 255.0 kg and 203.9 kg, respectively. The heaviest meat produced was observed from the Ankole group as 129.2 kg while from the Gogo were lowest up to 104.6 kg. The dressing percentage was not significant (P>0.05) in both breed and animal origins, and these ranged from 50.4-51.8. The highest (P<0.05) monetary value per animal was found to be from the Tanzanian special with USD 166.5 and lowest (P<0.05) from Tanzanian No. 3 with USD 117.0. It is concluded that, animals slaughtered in the abattoirs are producing carcass of low weight and monetary value and much is remained to be done to improve their carcass weight and quality and overall monetary value pre-slaughter.
Key words: Carcass characteristics, Live weight, Meat yield, Slaughter value, Traditional systems,
Zebu cattle
INTRODUCTION
Meat and dairy production in Tanzania are mainly comes from the traditional sector that is dominated by Tanganyika Short Horn Zebu (TSZ) distributed in different agro-ecological zones. The agro-pastoral system contributes 80% and pastoral system 14% of the livestock kept (MLFD, 2013). The remaining 6% comes from the commercial ranches and dairy farmers. The average production coefficients for TSZ are generally low, with calving rate ranged from 40 – 50%, calving interval 18 – 24 months, pre weaning mortality 30– 40%, adult mortality 8 – 10%, mature weight 200 – 350kg, offtake rate 8 – 10% per annum and carcass weight 100 – 175 Kg (MLFD, 2013). These values are far below the reported values from other breeds of cattle such as Charolais (Oury et al., 2007), Charolais x Friesian (Keane and Allen, 1998), and Simmental and German Holstein (Nuernberg et al., 2005).
Slaughter characteristics and carcass quality from beef cattle differed due to the number and diversity of breeds and crosses involved, differences in age, sex and the overall feeding systems and post-mortem handling of the carcass (Hansen et al., 2006; Keane and Allen, 2002; Maltin et al., 2003). Similar information have been reported in other livestock including goats (Santos et al., 2007; Werdi-Pratiwi et al., 2007), lambs (Lepitit, 2007; Mahgoub et al., 2000, Martínez-Cerezo et al., 2005). The available Bos indicus beef breeds showed that there are still some differences in carcass production and quality of meat even if the comparison is made at equal weights, sex or age which are mainly associated with their differences in protein retention and rate of maturity (Moran and Wood, 1986; Moreira et al., 2003). There are also some distinct differences in chemical, physical, and organoleptic properties exist between beef cattle from different genetic backgrounds (Monson et al., 2005; Perotto et al., 2000). Muchenje et al (2009) and Vestergaard et al. (2000) reported that under tropical conditions, there is a seasonal loss of live body weight and condition of beef cattle, which is mainly associated with the differences in feeding intensity and feed shortages across the seasons, which ultimately affects the growth rate and carcass characteristics of the animals.
Despite the importance of traditional beef cattle and the overall beef value chain, there is scant comparative data on slaughter and carcass characteristics sufficient to be used for livestock conversion factor. This anomaly, creates difficulties in estimating the exact monetary obtained from traditional beef animals of different sub-breed, age, sex or commercial grading. The few available information in livestock and fisheries basic data has been obtained largely from practical experience and from commercial recording schemes. It does not relate to characteristics of beef cattle sub-breeds, age, sex or the Tanzanian live cattle grading system. The objective of the current study was to give preliminary data on slaughter and carcass characteristics and monetary value from traditional beef cattle. The data entail to supplement the available livestock basic data of 2008 and to become a strategic tool for the Ministry and other stakeholders for effective management of the livestock and fisheries sectors for effective policy decisions, sound and realistic development programmes and plans.
METHODOLOGY
Location of the study
Data was gathered from slaughter facilities (abattoirs) located in six agricultural zones of Tanzania famously known for beef consumption including Northern (Arusha Meat Company-Arusha), Central (Dodoma Modern Abattoir- Dodoma), Eastern (Morogoro Municipal Abattoir-Morogoro), Western (Kariakoo Abattoir-Tabora), Southern highlands (Mbeya Slaughter House - Mbeya) and Lake (Nyakato Abattoir-Mwanza). The selection of these abattoirs was based on the relative number of indigenous animals received for slaughter from secondary markets within the respective zone. The Arusha Meat Company slaughtered cattle, sheep and goats bought from the auction markets mainly from Arusha, Manyara and Kilimanjaro regions. On the other hand, Dodoma Modern abattoir slaughters the animals sold from Dodoma, Singida and from the neighbouring regions. Morogoro slaughter house slaughters animals from Morogoro and neighbouring regions, Kariakoo slaughter house in Tabora municipal slaughters animals from Tabora, Kigoma and Katavi regions. Mbeya slaughter house slaughters animals from Mbeya and Rukwa, while the Nyakato Abattoir in Mwanza serves for Mwanza, Geita, Tabora, Shinyanga, Simiyu, Mara and Kagera regions.
Duration of the study, sampling units, size and procedures
A total of 56 days in three phases (14 days for phase I conducted in June 2013; 21 days each for phases II January 2014 and 21 III in September 2014) were used for data collection. Slaughter facility was used as sampling unit and each individual animal passed and selected for slaughter was used as an observation unit. From the animals selected for slaughter, relative proportion of females and males were established. The method of probability proportional to size was used to arrive at 20% sample size for the study. In addition males selected were either castrates or entire (bulls) whereas females were either empty or pregnant. Owners of sampled animals were the respondent in the interview for respective animal. The sample size for the study was at least 20% of the ante-mortem inspected animals that were passed for slaughter. The animals passed for slaughter were kept in lairage for 16 hours before slaughter and starved for water and feed. The selected animals for study were given unique slaughter identification number and graded using the Field Guide developed by Msanga (2000) and Tanzanian Live Cattle Grading System (MLD, 1982) and Carcass grades set by the Meat Industry (Livestock and Carcass grading) Regulations 2010. Grading was done based on mature slaughter cattle as Tanzanian Special (SP), Tanzanian No.1, Tanzanian No. 2, Tanzanian No. 3 and Tanzanian No. 4. The age of the animals was also determined by incisor teeth and the history of the animal from the sellers who were mainly the owners at the primary markets.
Data collection
Data were collected through interviews and physical measurement of individual animal. Interviews were conducted by administering structured questionnaires to the slaughter facility managers and animal owners. Data gathered included general information about slaughter facilities, animal history, source and age of the animal, means of transport and breed. Physical measurements involved live weight estimation of individual animal, carcass and non-carcass component weights.
a) Live weight (LW) estimation
Live weights of sampled animals were estimated immediately after selection. The LW was determined from the heart girth using a special Measuring Tape for Cattle. In determining the LW of cattle, the chest circumference of the animal was measured behind the humps of the elbow-joints. After measuring the circumference in centimetres, the corresponding LW in kilograms was directly read as per manufacturer guidance.
b) Carcass and non- carcass measurements
Prior to slaughter, animals were stunned using electrical stunner which is the normal practice at the slaughter facilities and immediately suspended in the Achilles tendon. The animals were slaughtered on a neck using very sharp knives. As a matter of rule the animals were slaughtered by authorized Muslim personnel for the meat to be Halal. Thereafter, the suspended animal was skinned and dressed. Following the removal of internal organs, a dressed carcass was separated into left and right carcass by cutting using a meat saw/or sharp axes available at the slaughter house. Both left and right hot carcass weight (HCW) was taken using digital Mini Crane Scale. The total HCW was taken as the sum of the left and right hot carcass weight.
Non carcass component (NCC) measurements included weighing of the internal organs (Gastro-Intestinal Track - GIT, pluck (trachea, heart, liver and kidney), head, legs and hides were taken, using digital Mini Crane Scale (Model OCS-03-L) with maximum capacity 300kg (Chinese GB/T 11883-2002 Class III Equivalent to OIML R76). Also, the weights of full gut content and empty gut content were weighed using the same equipments. The value of the animals were computed from the existing market prices in Tanzania per kilogramme in USD values (1USD=2000 TAS) i.e Live weight price as 1.3 USD/kg, Carcass as 3.0 USD/kg and NCC as 1.5 USD/kg. Abattoir Costs were included as handling fees, storage/chilling costs, trekking/transportation of cattle from the secondary market to the abattoir, and these amounted to USD 20/animal. The following parameters were also derived from the live weight, carcass and non-carcass components:-
Dressing percentage (DP) = (Dressed hot carcass weight (kg) /estimated live weight (kg)) x 100
Weight of empty gut – GITempty (kg)= Weight of full Gut (kg) - Weight of gut content (kg)
Live Weight Value (USD) = Live weight (kg) x 1.3 USD/kg
Hot Carcass Value (USD) = Weight of hot carcass (kg) x 3 USD/kg
NCC Value (USD) = Weight of NCC (kg) x 1.5 USD/kg
Animal Value (USD) = Hot Carcass Value (USD) + NCC Value (USD)
Net Value of an animal (USD) = Animal Value (USD) - Live Weight Value (USD)-Abattoir Costs
c) Data analysis
The data collected from the interviews and physical measurements were recorded in a structured questionnaire and checked for completeness. Data from the questionnaire were entered into Excel spread sheets. All the data were analyzed using the General Linear Model procedure of SAS (2001). For all analyses, when least square means were significantly different (P<0.05),they were separatedby Least Significant Difference test (SAS, 2001).This was done to demonstrate the relevance of classifying cattle into zones, strains, grading and sex.
RESULTS AND DISCUSSION
Slaughter characteristics and market values of slaughtered animals
Table 1 showed the number of 3,133 sampled animals for the three phases, in six agro-ecological zones of Tanzania. Table 2 showed the overall market weight of traditional herd ranging from 202 to 266kg live weight and carcass weight ranging from 100-129kg. From these data, there are substantial heterogeneities between regions in terms of cattle weight as well as carcass and non-carcass components production. For instance, cattle are heaviest in Arusha both ante- and post-mortem, with carcasses there weighing around 28% more than in Mbeya. Also, the animals slaughtered in Arusha abattoir were heaviest (P<0.05) followed by those slaughtered in Morogoro abattoir. The market weights of animals in these two zones were heaviest as compared to the rest of the surveyed markets probably due to market influence existing in those two sites. The Arusha market could be influenced by the existence of largest tourist hotels while that of Morogoro due to the neighboring market from the largest city of Dar-es-Salaam. It is also speculated that, the heterogeneities in ante- and post-mortem performance are partially attributable to exogenous agro-climatic conditions and the spatial distribution of breeds, and at the same time the type of farming practices and educational differences among the livestock keepers in the six zones surveyed. In Arusha and Morogoro regions, for example, the large number of stock is kept by Maasai. The Maasai tribe employs a farming technique which involves moving animals to suitable grazing areas throughout the year, thereby ensuring that cattle are consistently sufficiently fed. This information is supported by Vestergaard et al (2000) who reported a positive influence of feeding intensity, grazing and finishing regimes on slaughter and meat eating quality of Friesian bulls.
The observed live and carcass values are within the reported values by MLFD (2013) who showed mature weight of indigenous cattle to be 200-350kg LW with carcass weight 100-175kg. These values from Zebu are far below to those reported in exotic breeds of cattle due to their differences in genetic traits (Perotto et al., 2000) and at the same time low slaughter values due to pre-slaughter treatments of the animals such as low finishing regimes (Dabrowska, 2000; Kerth, 2007; Vecerek and Vecerkova, 2000; Vestergaard et al., 2007) and poor transportation (Gregory, 1996; Ekiz et al., 2012). Similar to this, poor feeding and delayed farming practices in Charolais heifers have been reported to cause delayed slaughter age for equivalent carcass weight (Oury et al., 2007; Laborde et al., 2002) and overall poor meat quality (Zaman et al., 2002). The observed poor carcass quality among the animals might be associated by post mortem muscle biochemistry which is closely related to calpain proteolytic system which plays a central role in post mortem proteolysis and ultimately tenderization of the meat (Koohmaraie et al., 2006; Geesink, 2006). Okeudo and Moss (2007) reported poor slaughter weight and meat quality in sheep due to lack of intramuscular lipid and fatty acid profile when those animals were subjected to poor plane of nutrition few days pre-slaughter.
Table 3 showed that the net values from the slaughtered cattle differ (P<0.05) across the regions. For instance, the animals slaughtered in Arusha and Dodoma had the lowest (P<0.05) net monetary value despite the fact that the animals brought to the market were heaviest compared to other sites. The lowest values were probably associated with the observed lowest dressing percentage, which indicated that there was lowest carcass sold to the market. The highest net values were observed in Tabora, Morogoro and Mbeya probably due to the observed significantly heavier NCC (skin, heads and GIT-empty) than those from Arusha, Dodoma and Mwanza, and is most likely due to differences in breeds. The low dressing percentage have reported to lower monetary value due to its effects on the saleable carcass of lambs (Mahgoub et al., 2000, Lepit, 2007).