Jeremy Marchant-Forde's Main Page
Current Research Program
1. The use of tear-staining as a non-invasive welfare indicator in pigs
During part of her MS research, Shelly DeBoer noticed that pigs housed with a lack of environmental control appeared to develop more red-brown facial staining around the eyes than pigs with more control. There is a small body of scientific literature on tear staining in rodents (chromodacryorrhoea – or 'bloody tears') and that this is as a result of Harderian glands secreting the iron-containing compound porphyrin, especially under conditions of stress. As a result of the observation, we have carried out a number of studies scoring tear staining in pigs, using both a 0-5 scoring scale and also taking photographs and measuring the area and circumference of the stain, and investigating whether they relate to other measures of stress.
So far, our pilot studies have shown that tear staining increases in response to social isolation, increases with increasing sympathetic nervous activation and is greater in piglets with low social status.
Figure 1: Relationship between social rank and the perimeter of left eye tear stain in piglets.
This project is ongoing with some funding support from the Global Animal Partnership. Our methodology is also being tested by colleagues at the University of Helsinki, Finland, the University of Newcastle, UK and Charles Sturt University, Australia.
Some of these initial results are available here:
DeBoer, S.P. and Marchant-Forde, J.N. (2013) Tear staining as a potential welfare indicator in pigs. In. (Eds. M.J. Hotzel & L.C. Pinheiro Machado) Proceedings of 47th Congress of the International Society for Applied Ethology. P125.
2. Factors influencing piglet mortality in indoor farrowing systems
Piglet mortality is a significant swine welfare problem and economic loss to the swine industry. Losses due to stillbirths can range from 2 to 9% of the litter and liveborn neonatal mortality prior to weaning adds 9.5% to 15.5% mostly due to a combination of starvation and crushing. These issues are increasing as average litter sizes continue to increase across the swine industry. However, the causes of both liveborn and stillborn piglet mortality are multifactorial and interrelated, and include elements of the farrowing environment, the biology of the sow and the biology of her litter.
Temperature requirements for the lactating sow ranges from 15 to 24°C but newborn piglets actually prefer a temperature of 42°C, a temperature above their thermoneutral zone of 35°C. When the temperature falls below 34°C, the newborn piglet is subjected to cold stress. Without supplemental heat, the piglet is at risk of dying from any one or a combination of hypothermia, starvation or crushing. The sow is also susceptible to heat stress if the ambient temperature in the farrowing house rises above 24-26°C.
Superimposed upon the thermal environment is the physiology and behavior of the sow and her litter. The nutritional state of the dam is influential. Piglets who have low energy reserves/availability (difficult birth, hypoxic, or little energy to start), and struggle to maintain body temperature (low energy, small body size) are most at risk. Smaller pigs have also been documented to be more likely to become crushed by the sow during posture changes, especially during the first 24 h post-partum. Reducing sow activity, which could be achieved partially by dietary inclusion of increased tryptophan together with maintaining an ideal ambient temperature for both the sow and the litter, thus attracting small piglets away from the sow, could reduce live-born mortality.
Figure 2: Relationship between piglet birth weight and percentage survival to seven days postpartum.
The objective of our current research is to reduce piglet mortality by manipulating the environment and biology of the sow and her piglets. We aim to help the sow maintain homeostasis by providing external cooling through the floor and we also aim to reduce peri-parturient activity by increasing dietary tryptophan in the sow's diet. We aim to help the piglet to maintain homeostasis by providing external heat through the floor, and by increasing the piglet's ability to maintain body temperature by increasing energy stores. We also aim to improve our understanding of the role that micro-environment plays in piglet mortality within the same macro-environment.
These studies are ongoing with internal funding support. External collaborators include MP3 Farms, Williamsport, IN. We are also still collaborating with the Universities of Warwick and Bristol on a data set investigating piglet mortality in outdoor production systems in the UK.
Some of previous work on piglet mortality is available here:
Marchant, J.N., Rudd, A.R., Mendl, M.T., Meredith, M.J., Broom, D.M., Corning, S. and Simmins, P.H. (2000) Timing and causes of piglet mortality in conventional and experimental farrowing systems. The Veterinary Record, 147: 209-214.
Marchant, J.N., Broom, D.M. and Corning, S. (2001) The influence of sow behaviour on piglet mortality due to crushing in an open farrowing system. Animal Science, 72: 19-28.
O'Reilly, K.M., Harris, M.J., Mendl, M.T., Held, S., Moinard, C., Statham, P., Marchant-Forde, J.N. and Green, L.E. (2006) Generating hypotheses for factors associated with pre-weaning mortality on commercial pig farms in England and Wales. Veterinary Record, 159: 193-196.
And some initial results of current studies are available here:
Morello, G., Marchant-Forde, J.N., Richert, B.T., Lay, D.C. and Rodrigues, L.H.A. (2013) The effects of non-uniform environmental conditions on piglet mortality and behavior of sows. In. (Eds. M.J. Hotzel & L.C. Pinheiro Machado) Proceedings of 47th Congress of the International Society for Applied Ethology. P69.
3. Understanding and reducing aggression when sows are mixed in a grouped gestation system
The largest single challenge of keeping sows in groups is that of inter-sow aggression. We know that sows will fight when mixed and when having to compete for access to resources. However, there is little information on the sequence of detailed behaviors that are performed by adult sows when mixed, that either result in a fight or a decision not to fight. We also do not know to what extent the sequence of aggressive behaviors can be changed, and hence fighting reduced, by pre-exposing groups of sows to each other prior to mixing.
Firstly, we have investigated, in detail, the aggressive behavior of 64 pregnant sows when mixed to form pairs in situations where space is limited (i.e. - indoor, slatted pen system - one sow mixed with one sow - 16 pairs) - and where space is "limitless" (i.e. - outdoor, paddock-based system at Newman Farm - one sow mixed with one sow - 16 pairs).
Secondly, we have also investigated, in detail, the aggressive behavior of 96 pregnant sows when mixed to form groups of 6 in situations where space is limited (i.e. - indoor, slatted pen system - 3 sows mixed with 3 sows - 8 groups) and where space is "limitless" (i.e. - outdoor, paddock-based system - 3 sows mixed with 3 sows - 8 groups). For both these studies, the data is being entered into a custom-written database for further processing and analysis. The database will then read through each sequence, performing the thousands of iterations and calculations required to perform a Markov analysis. The database will then read through each sequence, performing the thousands of iterations and calculations required to perform a Markov analysis. This will statistically distinguish meaningful patterns of behavior from randomly occurring behavioral transitions. The pattern of association between subsequences and following acts can then be compared between individuals or between treatments using repeated measures GLM. The results will help us to understand which types of behavior might function best to allow the sows to acquire information to prevent interaction escalation.
For our third NPB-funded experiment, we looked at the effects of pre-exposure on aggression at mixing and this was carried out in collaboration with Whiteshire Hamroc LLC. As producers move towards group housing in the U.S., many will continue to house sows in crates around breeding, before forming the group after pregnancy checking. Often, sows are randomly allocated into service crates at weaning with selection for subsequent groups made post-mating based on size and body condition. Thus, sows forming the group can be drawn from any crate in the row. Our study investigated the effects of pre-selection on subsequent aggression when the group was formed. We put sows that became the group into neighboring crates, thereby allowing them to establish some degree of social relationship prior to mixing.
All three of these studies are being carried out in collaboration with Dr. Joe Garner (Stanford) and Dr. Anna Johnson (Iowa State).
And some initial results of current studies are available here:
Marchant-Forde, J.N., Garner, J.P., Lay Jr., D.C., and Johnson, A.K. (2011) Action-reaction: using Markov analysis to elucidate social behavior when unacquainted sows are mixed. In. (Eds. E.A. Pajor & J.N. Marchant-Forde) Proceedings of 45th Congress of the International Society for Applied Ethology. P71.
We will also begin investigating the neighbor effect in more detail and follow up some previous work looking at the effects of increasing tryptophan and looking at other dietary manipulations to influence aggression at mixing.
Poletto, R., Meisel, R.L., Richert, B.T., Cheng, H.W. and Marchant-Forde, J.N. (2010) Aggression in replacement grower and finisher gilts fed a short-term high-tryptophan diet and the effect of long-term human-animal interaction. Applied Animal Behaviour Science, 122: 98-110.
4. Hazard characterization and exposure assessment of tail biting
Tail biting in pigs is a problem with a complicated multifactorial background, including a wide range of risk factors and consequences. A major collaborative project, of which we are a part, will investigate three of the most important welfare hazards related to tail biting: (i) tail docking, which is a widely used preventive measure against tail biting, but is a welfare hazard in itself; (ii) inadequate enrichment, one of the main risk factors for tail biting; and (iii) poor health, which is known to be both a risk factor for, and a consequence of, tail biting. This will be accomplished within three interrelated work-packages. The project firstly focuses on both the magnitude and duration of pain related to tail docking and tail biting. Secondly, enrichment is investigated as a risk-reducing agent, and studies are included on the welfare effects of enrichment use, focusing on characterization of the amount of enrichment needed, on implementation in practice and on its relationship with tail docking. Thirdly, animal based welfare indicators are improved to implement practical evaluation of the appropriateness of the enrichment used. Thus, lesion scores will be validated as a measure of abnormal behavior indicative of enrichment insufficiency, and an innovative measure of stress in pigs, i.e. tear staining, will be tested. Fourthly, the aim is to provide basic information on porcine sickness behavior, and on the behavioral etiology of tail biting, enabling a detailed evaluation of approaches for early warning of tail biting and related poor health.
This project is about to start with major funding support from the ANIHWA-ERA-net in collaboration with colleagues at the University of Helsinki, Finland, the University of Newcastle, UK, University of Aarhus, Denmark, Norwegian School of Veterinary Science, INRA, France, Wageningen UR, Netherlands, SRUC, UK and the Swedish University of Agricultural Sciences.
5. Effects of group size and age at grouping on welfare of calves
As the U.S. veal and dairy industries examine individual calf housing practices, we are looking at the effects of group size and the effects of age at grouping on calf welfare, in a project led by Dr. Susan Eicher. Our first study has compared the effects of group sizes of 2, 4 or 8 on the welfare of veal calves.
Initial results show that the number of veal calves in a group, given the same space, did not affect production, physiological, and hematological indicators of welfare but did have a transient effect on health during the finishing period.
Some initial results of current studies are available here:
Abdelfattah, E.M., Schutz, M.M., Lay Jr., D.C. Marchant-Forde, J.N. and Eicher, S.D. (2013) Group size of veal calves does not affect production,physiological, or hematological indicators of welfare and has transient effects on health. Journal of Animal Science, 91 (E-Suppl. 2): 529
Abdelfattah, E.M. Schutz, M.M., Lay Jr., D.C. Marchant-Forde, J.N. and Eicher, S.D. (2013) Group size alters postures, and maintenance, oral, locomotor, and social behaviors of veal calves. Journal of Animal Science, 91 (E-Suppl. 2): 430