Time：2020-10-20 Hits：0 Compile：福乐沃
In this "pigsty illumination technical specification" standard discussion meeting, we invited experts and teachers from Tsinghua University, Hunan Agricultural University, Jiangxi Agricultural University, South China Agricultural University, and domestic and foreign well-known breeding equipment enterprises Big Herdsman, China's leading pig enterprises representative Zhengbang, The representative of domestic and foreign famous pig lighting manufacture szAMB made a speech, for the standard to offer Suggestions.
The essence of light is energy transmission, which is based on the quantum of light as the unit of energy. The pigsty lighting needs to reflect the response of photon energy of different wavelengths to pig eye vision, so as to improve the economic benefits of breeding. Piggery lighting contributes to the scientific environment of piggery and affects the quality of pork supplied in the market. The application of piggery lighting belongs to the field of bio-optics.
The Technical Specification for Pigsty Lighting is the first in the world to study the response of photon energy to pig-eye vision to guide how to control the lighting conditions required in the pigsty growing environment.
Shenzhen facility agriculture industry association President li columbium expressed, technical specification of piggery light is a meaningful thing, biological light of domestic and international technology, and plays an important role in the development of meat and poultry breeding industry, it is helpful for technological innovation, through the guide industry development on enterprise merit by carrier, also can improve the output quality of pigs, for consumers and the meat and poultry market have very positive meaning.
According to Dr. Zhou Zhizhou of Hunan Agricultural University, modern agriculture needs to rely on technology to get rid of the disadvantages of traditional agriculture. By comparing the cultivation of plants with that of animals, Dr. Zhou proposed that the development of animals in different periods should have corresponding light demand, which is necessary to complete the metabolism of animals, improve their comfort level and obtain heat. Dr Zhou said understanding the synergy between light and the animals' gut, blood and brain could be the key to improving the quality of meat and poultry.
Lu pointed out that the adoption of this standard will better serve the swine producer customers and play an important role in the whole lighting industry and the farming industry.
Xu Dong, honorary President of the Shenzhen Facility Agriculture Industry Association, said the group's standards were based on the latest biooptics. Xu pointed out that the growth of living things is necessarily accompanied by light, and the standard is to start from how to make living things grow more comfortable, to study the effects and effects of various spectra on living things. Since then, President Xu to this standard in the content of a detailed interpretation.
LAN Xianglian, the technical director of Shenzhen AMB technology, said that as agricultural lighting manufacturer who export their technology ,experience and products more than 14years , they would present their views at the meeting to help the whole industry. Later, He Shared some of their experience with pig lighting technology and added some parameters of lighting.
Evidence shows that pigs have poorer colour perception than humans and in particular a reduced sensitivity to the red end of the spectrum. There is little research into the effect of coloured lights on pig production. In cases where red light has been used, pigs respond as though in darkness. (Taylor ,2010)
Light is a key environmental factor that influences and directs physiological processes in all animals. In domestic boars, research has shown that there is seasonality in sperm production related to the light in the animals environment. Light exposure mediates the level of melatonin secretion, which ultimately affects the quality and quantity of the boar’s reproductive products. Specifically, it has been found that lighting affects seasonality in the production of domestic boar semen (Andersson et al., 1998; Claus et al., 1985; Tast et al. 2001).
Light in the boar stud's environment affects the hypothalamus-pituitary-gonadal axis regulation of sperm production and epididymis maturation in the testes (FIGURE 1). It is believed this occurs via melatonin secretions from the pineal gland in the animal’s brain (Andersson, 2000).
In swine farming overall, temperature and light are viewed as major environmental factors affecting animal physiology (Andersson et al., 1998; Rivera et al., 2005)
Pigs need the right light levels so that they can identify each other, communicate and see pen features，such as feeders. This knowledge is vital when deciding how to light your indoor or outdoor pig units.Commercial lighting is unlikely to reach a level which pigs find aversive, however, high intensity lighting e.g. spotlights shouldbe avoided. (Taylor ,2010)
THE SIGNIFICANCE OF LIGHT SPECTRUM (COLOR) IN BOAR LIGHTING PROGRAMS，
As with acuity, spectral sensitivity can be estimated from the anatomy of the eye or by behaviour; indirect methods such as electrophysiology show the abilities of the cone types, but not the perception by the animal. Electrophysiological studies of the cone cells of pigs show two classes of receptor, Pigs have dichromatic vision; in the pig’s eye there are two sets of cones that give the animal peak wavelength sensitivity at 439 nm (blue color) and 556 nm (green color). The photoreceptors in a pig’s eye cannot detect the color red (>650 nm) (Neitz & Jacobs, 1989; Taylor, 2006).
Past research indicates that in order to get a physiological response from domestic pigs, the light exposure for “daylight should be within the light spectrum of 380 to 580 nm (Tast, 2002 ; Taylor, 2006).
An additional characteristic of artificial lighting, which may influence its appropriateness for use with animals, is the 100 or 120 Hz flicker inherent in magnetic ballast fluorescent sources (Kaufmann,1966).
Less study has been done on this aspect of lighting, especially with regard to mammals,although it has been studied in poultry (Jarvis et al., 2002) and starlings (Greenwood et al.,2004). Under visible frequencies of flicker, humans report a variety of unpleasant effects that increase with the visibility of the flicker, e.g. visual fatigue (Brundrett, 1974) epileptic fits (Trenite, 1998),headaches and migraine (Wilkins et al., 1991).
Based on the Rovamo model (Rovamo, 1999) and its application (Jarvis et al., 2003), the current best estimate for critical fusion frequency (CFF), in the pig is 70-80 Hz, based on a similar α wave response time to the cat (Rosolen et al., 2005; Rosolen et al., 2008); Dodt and Enroth found a CFF in the cat of 70-80 Hz, strongly suggesting that the pig will not see flicker from correctly functioning fluorescent lighting, however differences in processing speed of mechanisms subsequent to the retina in the two species could affect this assumption. Pigs may be able to detect the 50 or 60 Hz flicker of fluorescent light sources as they begin to fail, so light sources which flicker visibly to humans should be removed from pig housing. This effect may also be relevant when light enters the pigs’ environment through a rotating fan.LED light normally is flicker free
THE SIGNIFICANCE OF LIGHT INTENSITY IN BOAR LIGHTING PROGRAMS
European (EU) rules for light intensity in swine buildings define a minimum day standard of at least 40 lux (Costa et al., 2009; Pannekoek, 2010; Taylor 2010). This level of intensity is also the minimum required by the Canadian and New Zealand governments with respect to animal welfare considerations.
In the United States, the 2002 edition of the Swine Care Handbook recommended the following lighting levels for practicing good husbandry, inspecting the pigs adequately, maintaining their wellbeing and working safely in pig holding areas:
• 20 foot-candles (200 lux) for special inspection areas;
• 15 foot-candles (150 lux) for breeding, gestation and farrowing areas;
• 10 foot-candles (100 lux) for nurseries;
• 5 foot-candles (50 lux) for growing and finishing areas (MWPS, 1983).
Research by Tast et al. (2002) found in pigs there was a melatonin response to light at intensity as low as 40 lux. When changing abruptly from short to long days however, Tast suggested higher intensities (> 240 lux) be used to suppress the established melatonin rhythms. It is important to note that Tast’s scotophase
THE SIGNIFICANCE OF PHOTOPERIOD IN BOAR LIGHTING PROGRAMS
In the past, manipulation of the natural photoperiod through artificial lighting was not a common practice in AI units because it was believed that supplemental lighting did not change semen quality of postpubertal boars. As stated by Rivera et al. (2005), [...]variations of photoperiod do not induce substantial changes in overall semen-quality parameters*" However, new research strongly contradicts this position. There is now reason to believe that photoperiod manipulation can be a useful tool for enhancing semen production (Knecht et al., 2013 ; Sancho, 2005).
1) Photoperiod length (hours of illumination)
An 8-hour photoperiod for animal welfare purposes is prescribed by a number of different government regulations (United States, European Union, Canada, New Zealand) as the minimum length of time lighting should be available in piggeries. These 8 hours do not have to be consecutive. Specifically for boars, the 2013 edition of the Pig Improvement Company (PIC) Boar Stud Manual recommended illumination in the boar holding units be less than 16 hours and limited to a minimum of 8 hours of darkness.
2) Why change in direction of the photoperiod is important A review of past research indicates a photoperiod, where the light exposure time is incrementally decreasing in time, has a significant effect on boar performance. Researchers found that semen volume and semen concentration show a seasonality with the highest levels associated with decreasing photoperiods. Kennedy and Wilkins (1984) claimed, after examining 12,000 ejaculates from AI boars, that “in these data, semen volume increased almost linearly from June to December, coincident with decreasing day length*"Anderson (2000), Kunavongkrit et al., (2005), Sancho (2006) and Taylor (2010) commented on the rate of change in the photoperiod being a significant factor in physiological response.
In 1985, Claus et al. used a “reversed photoperiod strategy”, subjecting boars to an artificial light environment that was opposite to ambient seasonal lighting. He found a significant difference in the performance of boars held under an artificial lighting program simulating a decreasing autumn photoperiod. Most notably “with the light reverse program there was a maximum of sperm production under decreasing light condition in summer, the same season when in the daylight (control) boars a lower production was observed"
Rutten et al. (2000) examined boar production in AI units in the United States. They reported boars were most productive in fall and winter and least productive in spring and summer. Wolf and Smittal (2009) examined 150,000 ejaculates from 2000 AI boars during a 7-year period, with the animals maintained under a variety of holding conditions. They reported “semen volume had the greatest values from October to December and was least in March and April. Sperm concentration was greatest in winter and early spring (December to April) and least in late summer and early autumn"
Knetcht et al. (2013) studied the effects of photoperiod on selected parameters of boar semen and found a statistically proven effect of photoperiod on semen volume and semen concentration. This research noted that “boar reaction to photoperiod was breed-dependent” but regardless of breed, “during increasing photoperiod there was a decrease in the number of insemination doses*" Thus, light programs with a decreasing photoperiod (autumn/winter) have shown the greatest impact on enhancing boar reproductive performance. Other important effects of seasonality:
• Increasing day length (15–18 hours) increases piglet suckling
• Increasing day length increases food intake in growers/finishers
• 24 hour light can increase stress levels and disruptive behaviour can reduce productivity (especially in young pigs).