Pre-slaughter effects on bleed-out times and some behavioural and physiological responses of Nguni and non-descript steers

The effect of loading, transportation, lairage and slaughter conditions on bleed-out times, behavioural and physiological responses of Nguni and non-descript steers reared extensively on natural pastures was investigated. Twenty Nguni (NG) and 20 non-descript (ND) steers were loaded and transported 120 km from the farm to the abattoir in two groups (TG1 and TG2), each comprised of both genotypes. Some environmental conditions and steer behavioural responses were monitored during on- and off-loading, transportation, lairage, and stunning. Trained observers recorded the posture of the steers during transportation, time-budgets during lairage, avoidance-related behaviour, and vocalization scores at stunning were recorded. The steers were slaughtered in four groups (SG1, SG2, SG3 and SG4) and the number of attempts to stun each steer was recorded. Blood samples were collected from each steer during exsanguination for cortisol, glucose and lactate analysis. It took less time to load (370 s) and off-load (602 s) TG1 than TG2 (420 s and 782 s, respectively). All steers were standing throughout transportation and during the lairage observation period. Avoidance-related behaviour and vocalization in the stunning box were not influenced by genotype. The TG1 steers showed more avoidance behaviour (63.2%) and higher cortisol (140.6 ± 14.50 nmol/L) and lactate (12.4 ± 0.83 nmol/L) levels than TG2 (23.9%; 92.8 ± 15.38; 9.0 ± 0.88, respectively). All SG2 steers showed minimal avoidance behaviour with higher cortisol (175.9 ± 17.24 nmol/L) and lactate (13.5 ± 1.12 mmol/L) levels than other groups. Generally, cortisol and lactate levels were positively correlated (r = 0.70). The 5% vocalization recorded was observed from ND steers, TG1 and SG2. In conclusion, steers of different genotypes displayed similar behavioural and physiological responses to identical pre-slaughter conditions that they were exposed to.Keywords: Cortisol, lactate, lairage duration, on- and off-loading, stun-attempts, transportatio

Expression of ovine ubiquitin C-terminal hydroxylase 1, pH and colour of variety meats from head-stunned Dohne Merino sheep

Ubiquitin C-terminal hydroxylase (UCH-L1) has been identified in few transcriptome studies as a biomarker coding for trauma and perception of pain in non-meat species. For the first time, real-time polymerase chain reaction (qPCR) assay was used to quantitate the expression of ovine ubiquitin C-terminal hydroxylase 1 (ovUCH-L1 mRNA) from head-stunned Dohne Merino ewes and lambs presented for slaughter at a high-throughput abattoir. The correlation between ambient environment and quality of variety meats from those ovine species was also determined. The level of ovUCH-L1 mRNA expression found in lambs was high, based on the outcome of qPCR quantification. The effect of head stunning shows that ewes exhibited higher capacity to impede electric insults than lambs. Except for the trachea and heart, ambient conditions had a negative correlation with pH of most variety meats. Similarly, a negative correlation was observed between total colour difference (ΔE*) for fillet and dew point. Saturation index of a few variety meats showed a moderate relationship with ambient temperature. Industrially, the results on ambient conditions are important for post-mortem control of pH, colour, and preservation of other physiochemical properties of variety meats. Findings from qPCR quantification indicated that ovUCH-L1 is a novel candidate marker for pain detection in head-stunned ovine species.Keywords: Biomarker, edible offal, halal slaughter, ovine species, stunnin

Characterization of surface orientation and tenderness of sous vide processed edible offal and psoas muscle from Dohne Merino sheep

The microstructural orientation and tenderness of edible offal and the psoas minor muscle from Dohne Merino sheep were compared in this study. Following evisceration and cleaning, fresh meat samples were collected from slaughtered lambs and ewes of different age groups and thermally processed to varying degrees of doneness using sous vide apparatus. A scanning electron microscope (SEM) was used for the characterization of the surface orientation and elemental composition. The results for tenderness showed that edible offal with anisotropic orientation had higher Warner-Bratzler shear force (WBSF) values, but those with some degrees of uniformity (isotropicity) in their surface orientation were comparatively tender. The rumen and trachea from the lambs, six-tooth and eight-tooth sheep at 10 - 12, 23 - 36 and 28 - 48 months old at slaughter had the highest WBSF values among all the meat samples. Our findings showed that edible offal from the lambs with isotropic orientation was more tender and richer in protein than those from ewes. Also, processing the psoas minor muscle and edible offal with sous vide at 100 ºC in the shortest cooking time of 30 minutes had the greatest effect on tenderness of the meat samples. In descending order, the psoas minor muscle, liver and tongue from the lambs were found to be inherently more proteinaceous than other meat samples. The differences observed in the tenderness and protein contents of the edible offal and the psoas muscle could be attributed to variations in the microstructural organization of the muscle fibres in Dohne Merino and to their response to thermal processing.Keywords: anisotropy, doneness, isotropy, meat processing, Merino, scanning electron microscop

A balanced perspective on animal welfare for improved meat and meat products

Increased public concern for animal welfare in the logistics chain has led to a rise in the scrutiny of the treatment of food animals. Factors affecting the status of welfare of slaughter animals begin at the farm and occur during transportation and at the abattoir. The activities that animals pass through before slaughter are thought to have negative effects on both the animal and the product. Before or during this period, animals suffer pain, which compromises their physical, health and biochemical status, and meat quality and quantity; which leads to economic losses. Environmental impact plays a role in the behaviour, growth, development and welfare of animals, even though it is associated with the production of greenhouse gases and biodiversity. Food producers are also mindful of the challenges of feeding the ever-increasing human population. Although the issues of animal production, which range from the environment to human health, have been discussed, animal welfare-related factors that are at play in the production chain of farm animals must still be addressed. An understanding of the animal’s environment, behaviour and the biochemical interactions that are at play in stressful conditions; and the implications of these for animal health and welfare are key to developing effective mitigation strategies. Therefore, the objective of this review is to highlight the literature on animal welfare, and suggest strategies that could be adopted for the improvement of meat animals, meat quality and meat products

A review of current concepts on sex determination in animals

A journal article on the sexual determinants of farm animals.Despite being a complex development process, sex determination is important in reproduction of farm animals. Chromosome sex, which is based on the presence of sex chromosomes, is the most common to scientists. Most common to the layman, is what can be termed phenotypic sex, which is based on what can be seen in an individual. It encompasses the urogenital, external features, such as the external genitalia and secondary sex characteristics. From a molecular genetics point of view, there is also what is termed genetic sex, which is based on the presence of a sex-determining gene. In other words, an XY individual without the sex-determining gene is not a genetic male. The sex-determining gene is located on the Y-chromosome. Since 1959, when the Y-chromosome was shown to be the male-determining factor, there has been controversy as to what really determines sex in animals. However, the identification of what has been termed the sex-determining gene on the Y-chromosome (SRY) in 1990 has narrowed the controversy to the actual mechanism of sex determination. This review focuses on the genetic sex-determination mechanism by which genes determine sex, the fate of the supporting cells and evidence on issues, which are still inconclusive

Should the South African red meat classification system be revised or maintained? A review

The objective of this review was to determine whether the current South African red meat classification system still needs to be revised and changed or maintained. It also gives insight into the most significant challenges related to meat quality evaluation in this system. Red Meat Research and Development South Africa (RMRD SA) was requested to lead an investigation into the relevance of the current South African red meat classification system. A final decision was made to maintain the system as it was in 2016. Nonetheless, it is still unclear whether consumers buy meat according to the standards set by the system, since it is mostly understood and practised efficiently by middlemen, especially abattoir operators. The general perception that this system is not quality based, but descriptive, has resulted in seeming non-transparency among some red meat industry stakeholders. Although the red meat industry is emphasizing that a quality assurance system remains too expensive to be implemented in South Africa and that the current system should be sustained, there is still room for revising it. All predictions in this review indicate that the present system cannot satisfy all the needs of the current consumer. The system seems to be inclined towards meat traders, since it is value based and may not reflect the expectations and needs of consumers in terms of meat quality. This paper therefore concluded that the South African red meat classification system still needs to be revised and more research should be done for it to become more effective.Keywords: Assurance system, consumer needs, meat quality, meat traders, red meat industr

Driving forces for changes in geographic range of cattle ticks (Acari: Ixodidae) in Africa: A review

Ticks are the most important external parasites of cattle and are known to transmit more pathogens than any other group of arthropods worldwide. About 80% of the world cattle population is at risk of ticks and tick-borne diseases, causing a global annual loss of $US22–30 billion. In Africa, the impact of ticks is ranked high, and they transmit diseases such as cowdriosis, anaplasmosis, bovine babesiosis and theileriosis. A range expansion of ixodid ticks has been observed in Africa, in particular for the genera Amblyomma and Rhipicephalus, which contribute greatly to cattle loss owing to morbidity and mortality. Distributional changes in ticks can lead to the emergence or re-emergence of infectious and parasitic diseases. Climate change is frequently invoked as the primary cause of tick distribution, but it is not the only factor. Human lifestyle changes, including transportation of livestock within countries, have promoted the introduction of new tick species and the diseases they transmit. One such example is the spread of the Asian cattle tick Rhipicephalus (Boophilus) microplus to West Africa. Rhipicephalus (Boophilus) microplus was recorded for the first time in Namibia and was probably introduced into Namibia from South Africa. Likewise, Amblyomma variegatum, the vector of heartwater disease, has the largest distribution in Africa. Its spread is outside its native range and it is considered the second most invasive tick species after R. (B.) microplus on the continent. Rhipicephalus (Boophilus) microplus is a one-host tick that is reported to be resistant to conventional acaricides and this contributes largely to its spread into non-endemic areas.Keywords: Acaricide resistance, climate change, epidemiology, range expansion, tick ecolog

Adjusting lactation milk yield of Zimbabwean Holstein dairy cows for the joint effects of age at calving and month of calving

A research paper on adjusting lactation milk yield of Zimbabwean Holstein dairy cows.Milk yield is influenced by both genetic and non-genetic factors. For accurate genetic evaluations there is need to account for these factors and quantify their effects on milk yield. The main objective of this study was to quantify the joint effects of age at calving and month of calving on lactation milk yield and to compute appropriate adjustment factors for milk yield. A total of 29 315 edited lactation records of Zimbabwean Holstein dairy cows collected from 1979 to 1994 by the Zimbabwe Dairy Herd Improvement Association (ZDHIA) were used. The data were divided into two sub-sets. The first set of 16 073 records was used to develop multiplicative age-month adjustment factors and for determination of genetic parameters. The second data set with 13 242 records was used for verification of the adjustment factors. This was done to test the effectiveness of multiplicative age-month adjustment factors which were developed in this study. An Animal Model was run in the Average Information — Restricted Maximum Likelihood (AIREML) software package. The multiplicative adjustment factors for lactation milk yield varied with age at calving and month of calving. The factors were highest in young cows (1.21), decreasing with increasing age at calving and were lowest (0.89) at mature age (72 to 84 months). After 72 to 84 months the adjustment factors started increasing. The adjustment factors were also highest (1.21) in summer (December, January and February) and lowest (0.89) in winter (May, June and July). Heritability estimates were highest for first lactation cows and were low for later lactation cows. The heritability estimates were similar for both adjusted and unadjusted records. The heritability estimates for the unadjusted records were 0.38, 0.26, 0.24 and 0.21 for first, second, second and over, and all combined lactations, respectively. The corresponding estimates for the adjusted records were 0.45, 0.25, 0.25 and 0.24. This study showed that age-month adjustments were effective. The local Holstein dairy industry is recommended to use these age-month adjustment factors developed using local data to eliminate biases in genetic evaluations. Heritabilities are high enough to practise an effective progeny test and selection scheme for milk yield

Animal welfare in multipurpose cattle production Systems and its implications on beef quality

Animal welfare and its influence on beef production are major  considerations in many developed countries. In the developing world, where food insecurity and poverty are prevalent, the welfare of animals receives low priority due to factors such as traditional customs and beliefs, lack of knowledge in animal handling and sub standard handling facilities. This is worsened by the fact that cattle are used for several purposes, such as meat production, milk production, draught power and traditional ceremonies. Research on animal welfare and how it relates to animal production have been done in the developed world. The objective of this study is to discuss indicators of animal welfare assessment, their impact on meat quality and applications to improve beef production in developing countries.Key words: Behavioural assessments, flight zones, meat quality, ritual slaughter

The effect of Acacia karroo supplementation and thermal preparation on meat sensory characteristics of the indigenous Xhosa lop-eared goat genotype

The objective of the current study was to determine the effect of Acacia karroo supplementation and thermal preparation on consumer sensory scores of meat from indigenous Xhosa lop-eared goat breed. 18 castrated four-month-old Xhosa lop-eared kids were kept at the University of Fort Hare Farm until slaughter. Sample cuttings for meat tasting were made from the Longistimus dorsi muscle. A. karroo supplementation improved meat tenderness and juiciness. There were no (P > 0.05) significant effects of A. karroo supplementation on meat flavour of the supplemented goats. Thermal preparation and consumer background had a significant (P < 0.05) effect on meat sensory characteristics. Results from this study show that A. Karroo supplementation and thermal preparation have an effect on meat quality attributes such as tenderness and juiciness.Key words: Boiling, roasting, consumer sensory scores, thermal preparation, consumer background