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Shade effects on feeding behavior, feed intake, and daily gain of weight in female goat kids
Journal of Veterinary Behavior 8 (2013) 466e470
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Journal of Veterinary Behavior journal homepage: www.journalvetbehavior.com
Research
Shade effects on feeding behavior, feed intake, and daily gain of weight in female goat kids L. Alvarez*, N. Guevara, M. Reyes, A. Sánchez, F. Galindo Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, México DF, Mexico
a r t i c l e i n f o
a b s t r a c t
Article history: Received 29 October 2012 Received in revised form 4 April 2013 Accepted 7 August 2013 Available online 16 September 2013
Solar radiation and high ambient temperatures negatively affect feeding time, performance, and animal welfare in several species. The provision of shade is a simple method that helps to minimize the negative effects. To determine whether shade influences feeding behavior, feed intake, and daily weight gain (DWG) in female goat kids, 40 dairy goat kids were used in 2 similar pens whose feeders were shaded (n ¼ 20) or unshaded (n ¼ 20) during 60 days. From May to July, behavioral data were collected through 10-minute scan samples during a 24-hour period for a total of 300 hours. Both pens were shaded on the opposite side to the feeder with 15 m2 each in a resting area. All goat kids were observed for their position inside the pen, and the number of times they were seen eating was recorded. When the concentrate was provided (between 13:00 and 13:30 hours, as usually in the farm), the time was recorded until >50% of the animals stopped feeding and went back to the resting area (concentrate test). Food wastes were collected and weighed daily to calculate the food consumption. Ambient and black globe temperatures were daily recorded. Body weight was recorded every week to calculate DWG. A higher percentage of animals feeding was recorded in the shaded feeders than that in the unshaded feeders (P < 0.05). Food refusal was higher in the unshaded feeders (30 1.8%) than that in the shaded feeders (25 1.9%; P ¼ 0.05). The concentrate test duration was 26.6 minutes (1.3) in the shaded feeders and 16.1 minutes (1) in the unshaded feeders (P < 0.05). The concentrate test duration was negatively correlated to the ambient temperature in the unshaded animals (r ¼ 0.50 and r2 ¼ 0.25; P ¼ 0.02), and it was not significant in the shaded ones (r ¼ 0.23, r2 ¼ 0.05; P > 0.05). DWG was not different between groups (0.08 0.03 kg per group; P > 0.05). Results suggest that shade on feeders helps to ameliorate some negative effects of solar radiation increasing feeding time and feed intake in female goat kids. This could be of great interest to prevent performance and welfare negative affectations. Ó 2013 Elsevier Inc. All rights reserved.
Keywords: heat stress goats shade welfare feeding behavior feed intake
Introduction High ambient temperature and lack of protection against solar radiation affects severely physiological responses (Darcan and Güney, 2008; Broucek et al., 2009), performance (Darcan and Cankaya, 2008; Marcillac-Embertson et al., 2009), and the welfare (Silanikove, 2000; Johnson et al., 2008) of farm animals. Body temperature regulation in hot weather is an important condition for cattle production and welfare. Solar radiation and high ambient temperature are also associated with lower cattle performance (Muller et al., 1994b; Brown-Brandl et al., 2004; da Conceição et al., * Address for reprint requests and correspondence: Dr. L. Alvarez, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, 04510 México DF, Mexico. Tel: (52) 55 5622 5886; Fax: (52) 55 5616 7169. E-mail address: [email protected] (L. Alvarez). 1558-7878/$ e see front matter Ó 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jveb.2013.08.002
2008). The provision of shade is a simple method that helps to minimize the negative effects of solar radiation in grazing (Blackshaw and Blackshaw, 1994; da Conceição et al., 2008) and housing conditions (Bucklin et al., 1991; Mitlohner et al., 2001a; Marcillac-Embertson et al., 2009). It has been argued, however, that the use of shade would induce nonproductive behaviors (Widowski, 2001) as the grazing time would be reduced and resting time would increase (Bennett et al., 1984). Those arguments have been rejected in some studies with cows (Widowski, 2001; Tucker et al., 2008) and red deer (Mejía, 2011). Although goats are considered to be resilient to high ambient temperatures, there is evidence of their negative response to those environmental conditions (Appleman and Delouche, 1958; Lu, 1989), especially if no prevention measures are taken (Darcan et al., 2008). In 8-month-old kids, solar radiation exposure
L. Alvarez et al. / Journal of Veterinary Behavior 8 (2013) 466e470
increases body temperature, heart rate, and respiratory frequency (Al-Tamimi, 2007). Practices as the use of spraying and ventilation have been used to improve goat productive and physiological parameters (Darcan and Güney, 2002; Darcan and Cankaya, 2008; Darcan et al., 2008; Ocak et al., 2009). Evidence clearly indicates that without protection against solar radiation, animals visit the feeder less frequently, and their consumption decreases. Yet some housing designs for goats consider building feeders at nonshaded areas, which may have important negative consequences for the animal and for the farm. Structures that shade feeders increase milk production and improve reproductive results in dairy cows compared with those that lack the shade (Roman-Ponce et al., 1977; Urdaz et al., 2006). No information is available about the effects of shading feeding spaces of goats on behavior and feed intake, which can affect production. The aim of the present study was to determine the effects of additional shade at feeding bunks on feeding behavior, feed intake, and daily weight gain (DWG) of female goat kids.
Materials and methods The study was approved by the Internal Committee for Ethical Use of Animals in Experimentation.
Location and treatments The study was carried out at an experimental farm located 150 km north of Mexico City. A total of 40 dairy goat kids (2.53 months age, 10-15 days after weaning) were allocated in a 180 m2 pen, equipped with a feeder of 13.5 m in length. The pen was divided into 2 identical sections whose feeders were shaded (shaded group, n ¼ 20, 13.1 0.2 kg of body weight; 23 m2 of a shade cloth >80% of solar protection) or unshaded (unshaded group, n ¼ 20, 13.08 0.2 kg of body weight). The experiment lasted 60 days, from May to June. All animals had access to a permanent shade in resting areas, at the opposite side of the feeder, with a total of 15 m2 per section.
Behavioral records and temperature measurements Scan sampling was used every 10 minutes during daytime (09:00-18:00 hours) and for a total of 200 hours to record behavioral states as described by Mitlohner et al. (2001b). Feeding was considered when the animal had its head inside the feeder, drinking when the head of the animal was inside the water trough, walking when the animal was in locomotion or moving from one place to another, standing when the animal was inactive with its 4 legs on the ground, and lying when the body was in contact with the ground. On each scan, the number of animals showing the respective behavior was recorded. The same behavioral records were carried out during the night (19:00-08:00 hours) for a total of 100 hours (Mitlohner et al., 2001b). Ambient and black globe temperatures were also recorded during the behavioral sampling and every hour using devices located within the feeder area in both groups (Alzina et al., 2001). The black globe temperature device was adapted using a thermometere hygrometer and a copper bulb (wired thermometer/hygrometer, model 63-1032, Radioshack, Mexico; Yokohama, 2009, personal communication). At the same time, soil temperature was recorded in shaded and nonshaded areas using an infrared thermometer (infrared and contact thermometer, model 561; Fluke Corporation, Everett, WA).
467
Body weight, feed consumption, and concentrate test All animals were weighed every week to calculate the total DWG at the end of the study. Food (alfalfa hay and concentrate) was given according to the National Research Council instructions (NRC, 1981). Feed wastes were daily collected and weighed to calculate the average percentage of consumption per group. To determine the motivation to stay in the feeder area when the favorite food is provided (Abijaoudé et al., 2000), a concentrate test was applied. This consisted on measuring the time from the moment the food was provided until the moment when >50% of the goats stopped feeding and withdrew from the feeder area. The test was done every 3 days during the study and always at the same time of the day (13:00-13:30 hours). Data analysis Behavioral data were expressed in percentage, and an arcsine transformation of data was carried out to use parametric tests (analysis of variance and general linear model procedure for repeated measures). Previous to the use of such test, the normal distribution of data was confirmed by the ShapiroeWilk test. A Duncan test was used for multivariate comparisons, feed consumption, and the DWG (SAS, 1999). The same tests were used to compare ambient temperatures (SAS, 1999). The diurnal and nocturnal records were analyzed separately. A Pearson correlation was used to determine the relationship between the concentrate test duration and the temperatures recorded at that time of the day (SAS, 1999). Results Temperature records Figure 1 shows the mean ambient and black globe temperatures during the 24-hour period. The temperatures during daytime periods (09:00-18:00 hours) were higher in the unshaded group than those in the shaded group (P < 0.05). In the night hours, no significant differences between groups were seen (P > 0.05; Figure 1). The highest ambient temperature recorded in the unshaded group was 35.4 C (0.81), whereas in the shaded group, this was of 31.8 C (0.66). The highest black globe temperature recorded was 45.9 C (1.24) in the unshaded group and 33.9 C (1.24) in the shaded group. Soil temperature was higher in the unshaded area and reached maximum averages of 51.3 C (1.2, P < 0.05; Figure 2). Feeding behavior and feed intake The percentage of animals that were seen feeding in the shaded group was higher than that in the unshaded group (P < 0.05;
Figure 1. Mean ambient and black globe temperatures during the day in shaded and unshaded feeding areas. *Significant difference between groups (unshaded vs. shaded; P < 0.05).
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Figure 2. Average soil temperature ( C standard error of the mean) in different areas of the pen.
Figure 3). In the shaded group, a higher percentage of animals was recorded eating from 9:50 to 12:00 noon and at different times from 13:30 to 16:00 hours. During the night, there were no differences between groups (P > 0.05; Figure 3). The duration of the concentrate test was higher in the animals of the shaded group (26.6 1.3; minutes standard error of the mean; P < 0.05) than that in the animals of unshaded group (16.1 1; minutes standard error of the mean). There was a negative correlation between the duration of the concentrate test and the ambient temperature in the unshaded group (r ¼ 0.50, r2 ¼ 0.25, P ¼ 0.02; Figure 4). In the shaded group, this correlation was not significant (r ¼ 0.23, r2 ¼ 0.05, P ¼ 0.3). The percentage of animals lying during the day in the feeder area was higher in the shaded group (P < 0.05; Figure 5). Goats clearly avoided standing in areas of sun during the hottest hours of the day (Figure 6); shaded areas were preferred to stand during the day, and no differences between groups were found (P > 0.05; Figure 7). No differences were found in locomotion and drinking activity between groups (P > 0.05). The average percentage of waste of food throughout the study was lower in the shaded group (25.8 1.9) than that in the unshaded group (30.4 1.8; P ¼ 0.05). The average percentage of net feed consumption per day was 74.1 1.8 and 69.6 1.8 for shaded and unshaded groups, respectively (P ¼ 0.05). Daily weight gain The final body weight was not different between groups (unshaded, 17.8 0.63 and shaded, 17.9 0.66 kg; P > 0.05). The average DWG for the goat kids in both groups was not different (0.08 0.03, kg standard error of the mean; P > 0.05).
Figure 3. Percentage of goats feeding at different times of the day in each group. *Significant difference between groups (P < 0.05).
Figure 4. Relationship between the ambient temperature and the duration of the concentrate test in the unshaded group. The negative correlation was significant (P < 0.05).
Discussion In the present study, the provision of shaded areas is associated with a higher percentage of animals eating at different times of the day. At times with the highest temperatures, more goats were observed feeding in feeders with shade. At no time of day, the goats in the unshaded group were seen eating at a higher rate than goats in the shaded group. This coincides with other studies with sheep (Sevi et al., 2001) and cows (Muller et al., 1994a; Mitlohner et al., 2002). Others have found that voluntary feed intake is reduced when animals are exposed to high temperatures (Abdalla et al., 1993; Sevi et al., 2001; Al-Tamimi, 2007), especially if food is of poor quality (Costa et al., 1992) because of the effort to reduce heat production and the low digestive transit time (Bernabucci et al., 1999; Sevi et al., 2001). In an attempt to maintain thermal balance with the environment, the animal reduces its feed intake and physical activity to reduce body heat, whereas water consumption and the frequency of urination increases (Abdalla et al., 1993; Hahn, 1999). In the present study, the animals had the possibility to move to shaded areas of the yard, and the decrease in food intake in the unshaded group is explained by the fact that fewer of them were seen in feeding areas. A clear finding that indicates the preference of goats for shaded areas when temperature is high is that goats of both groups clearly avoided areas of sun during the hottest hours of the day. The time the animals spent in the feeder areas after administration of the concentrate increased by 40% when the area had shade. This strongly suggests a negative effect of high temperature conditions, confirmed with the respective environmental measurements, in the preferences of the animal (Lu, 1989). In our study, the negative correlation found between ambient temperature and feeding time clearly reinforces this fact. In the medium and long
Figure 5. Percentage of goats lying in shaded and unshaded feeder areas during the day. *Significant differences between groups (P < 0.05).
L. Alvarez et al. / Journal of Veterinary Behavior 8 (2013) 466e470
Figure 6. Percentage (mean standard error of the mean) of goats standing in areas of sun during the day.
term, a higher waste of food in unshaded areas could exacerbate economic losses for the farm (St-Pierre et al., 2003). Furthermore, the higher percentage of goats eating during the hottest times of the day in shaded group clearly suggests that the resource should be considered to maintain the animal motivation in the feeding area. Although feeding activity was clearly synchronized because the food was provided at the same time, the shade resource allowed to have a higher percentage of animals feeding at different periods of the day. Animals seek and use the shade when body temperature exceeds 39.1 C (Seath and Miller, 1946; Blackshaw and Blackshaw, 1994). Although this study did not record body temperature of goats, results of experiments in progress indicate that body temperatures can reach up to 41.5 C when the animal is fully exposed to sunlight for short periods (Alvarez et al., not published). In the present study, ambient and black globe temperatures peaked a maximum of 43.9 C and 54.7 C, respectively, which goes beyond what is considered as thermal comfort zone for the species (Lu, 1989). It should be noted that these temperatures correspond to those recorded with the devices exposed to solar radiation during the study, thermal monitoring technique that is accepted and used in the literature of the subject (Roman-Ponce et al., 1977; Buffington et al., 1981; Widowski, 2001; Al-Tamimi, 2007) and are considered valid records as perceived by the animal permanently exposed to certain environmental conditions. Similarly, the literature agrees that shade can improve animal welfare indicators, and for this reason, it should be considered as an important tool in animal management (Blackshaw and Blackshaw, 1994; Caroprese, 2008; Schütz et al, 2009). Our findings on DBW were similar to those reported by Marsico et al. (1993) and Nagpal et al. (1995) in kids of similar age and intensive systems but lower than others using males of an older age (Darcan and Güney, 2002). In the present study, DWG did not differ between groups during the observation period. Given the low conversion rates of the species and its high metabolic capacity to
Figure 7. Percentage (mean standard error of the mean) of goats standing in shaded areas during the day. No differences were found between groups (P > 0.05).
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accommodate dietary restrictions (Arriaga, 2007; Paz, 2010), it may require a longer period of exposure or a total absence of shade over the feeders and no shade available in other areas to observe differences in the development of the animal or detect an eventual negative effect on productivity. It is important to remember that in the present study, all animals had access to shade at any time of the day. In other cases, in older male kids permanently exposed to heat stress for periods of 40 days (Darcan and Güney, 2002), DWG decreases significantly compared with those that were sprayed with water twice a day. We conclude that the use of shade at the feeders increases the visits of goats to this area and the time and net consumption of food and reduces food waste. These changes are directly related to high ambient temperature in different areas of the pen. The use of shade over the feeders for a period of 60 days did not alter the DWG of young goats. These results generate suggestions to study the effect of shade during longer periods of time. Acknowledgments The authors thank project PAPIIT IN205810, DGAPA, UNAM, for funding the investigation. References Abdalla, E.B., Kotby, E.A., Johnson, H.D., 1993. Physiological responses to heatinduced hyperthermia of pregnant and lactating ewes. Small Rumin. Res. 11, 125e134. Abijaoudé, J., Morand-Fehr, P., Tessier, J., Schmidely, P., Sauvant, D., 2000. Influence of forage:concentrate ratio and type of starch in the diet on feeding behaviour, dietary preferences, digestion, metabolism and performance of dairy goats in mid lactation. Anim. Sci. 71, 359e368. Al-Tamimi, H.J., 2007. Thermoregulatory response of goat kids subjected to heat stress. Small Rumin. Res. 71, 280e285. Alzina, L., Farfán, J., Valencia, E., Yokohama, J., 2001. Condición ambiental y su efecto en la temperatura rectal y frecuencia respiratoria en bovinos cruzados (Bos taurus x Bos indicus) del estado de Yucatán, México. Rev. Biomed. 12, 112e121. Appleman, R.D., Delouche, J.C., 1958. Behavioral, physiological and biochemical responses of goats to temperature, 0 C to 40 C. J. Anim. Sci. 17, 326e335. Arriaga, A., 2007. Evaluación del estado corporal y sus efectos sobre el comportamiento productivo en cabras lecheras. Tesis de Maestría, FMVZ, UNAM, México DF, p. 65. Bennett, I., Finch, V., Holmes, C., 1984. Time spent in shade and its relationship with physiological factors of thermoregulation in three breeds of cattle. Appl. Anim. Behav. Sci. 13, 227e236. Bernabucci, U., Bani, P., Ronchi, B., Lacetera, N., Nardone, A., 1999. Influence of shortand long-term exposure to a hot environment on rumen passage rate and diet digestibility by Friesian heifers. J. Dairy Sci. 82, 967e973. Blackshaw, K., Blackshaw, A., 1994. Heat stress in cattle and the effect of shade on production and behaviour: a review. Australian J. Experim. Agricult. 34, 285e295. Broucek, J., Kisac, P., Uhrincat, M., 2009. Effect of hot temperatures on the hematological parameters, health and performance of calves. Int. J. Biometeorol. 53, 201e208. Brown-Brandl, T., Eigenberg, R., Nienaber, J., Hahn, G., 2004. Indicators of heat stress in shaded and non-shaded feedlot cattle. In: Meeting, A.A. (Ed.). Amer. Soc. Agricultural Biological Engineers. Paper number 044037. Bucklin, R., Turner, L., Beede, D., Bray, R., Hemken, R., 1991. Methods to relieve heat stress for dairy cows in hot, humid climates. Appl. Eng. Agricult. 7, 241e247. Buffington, D., Collazo-Arocho, A., Canton, G., Pitt, D., Thatcher, W., Collier, R., 1981. Black-globe humidity index (BGHI) as comfort equation for dairy cows. Trans. Am. Soc. Agricultural Engineers. 24, 711. Caroprese, M., 2008. Sheep housing and welfare. Small Rumin. Res. 76, 21e25. Costa, P., da Silva, R., de Souza, R., 1992. Effect of air temperature and humidity on ingestive behaviour of sheep. Int. J. Biometeorol. 36, 218e222. da Conceição, M., da Silva, I., Dos Santos-Dias, C., 2008. Artificial shade effects in the performance and physiology of dairy heifers in pasture. In: Asabe (Ed.), Livestock Environment VIII. American Society of Agricultural and Biological Engineers, Iguassu Falls, Brazil. Electronic 701P0408. Darcan, N., Cankaya, S., 2008. The effects of ventilation and showering on fattening performances and carcass traits of crossbred kids. Small Rumin. Res. 75, 192e198. Darcan, N., Cedden, F., Cankaya, S., 2008. Spraying effects on some physiological and behavioural traits of goats in a subtropical climate. Ital J. Anim. Sci. 7, 77e85. Darcan, N., Güney, O., 2002. Effect of spraying on growth and feed efficiency of kids under subtropical climate. Small Rumin. Res. 43, 189e190.
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Darcan, N., Güney, O., 2008. Alleviation of climatic stress of dairy goats in Mediterranean climate. Small Rumin. Res. 74, 212e215. Hahn, G.L., 1999. Dynamic responses of cattle to thermal heat loads. J. Anim. Sci. 77, 10e20. Johnson, A.K., Mitloehner, F.M., Morrow, J.L., McGlone, J.J., 2008. Effects of shaded versus unshaded wallows on behavior, performance, and physiology of the outdoor lactating sow. J. Anim. Sci. 86, 3628e3634. Lu, C.D., 1989. Effects of heat stress on goat production. Small Rumin. Res. 2, 151e162. Marcillac-Embertson, N.M., Robinson, P.H., Fadel, J.G., Mitloehner, F.M., 2009. Effects of shade and sprinklers on performance, behavior, physiology, and the environment of heifers. J. Dairy Sci. 92, 506e517. Marsico, G., Vicenti, A., Contoducati, P., Braghieri, A., 1993. Influence of weaning age on productive performance of kids slaughtered at 107 days of age. Small Rumin. Res. 12, 321e328. Mejía, H., 2011. Patrones conductuales y peso corporal al final de la gestación de hembras de ciervo rojo (Cervus elaphus) en pastoreo con y sin sombra artificial. Producción Animal. Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, México DF, p. 41. Mitlohner, F., Morrow, J.L., Dailey, J.W., Wilson, S., Galyean, M., Miller, M., McGlone, J., 2001a. Shade and water misting effects on behavior, physiology, performance, and carcass traits of heat-stressed feedlot cattle. J. Anim. Sci. 79, 2327e2335. Mitlohner, F.M., Galyean, M.L., McGlone, J.J., 2002. Shade effects on performance, carcass traits, physiology, and behavior of heat-stressed feedlot heifers. J. Anim. Sci. 80, 2043e2050. Mitlohner, F.M., Morrow-Tesch, J.L., Wilson, S.C., Dailey, J.W., McGlone, J.J., 2001b. Behavioral sampling techniques for feedlot cattle. J. Anim. Sci. 79, 1189e1193. Muller, C., Botha, J., Coetzer, W., Smith, W., 1994b. Effect of shade on various parameters of Friesian cows in a Mediterranean climate in South Africa. 2. Physiological responses. South African J. Anim. Sci. 24, 56. Muller, C., Botha, J., Smith, W., 1994a. Effect of shade on various parameters of Friesian cows in a Mediterranean climate in South Africa. 1. Feed and water intake, milk production and milk composition. South African J. Anim. Sci. 24, 49e55. Nagpal, A.K., Singh, D., Prasad, V.S.S., Jain, P.C., 1995. Effect of weaning age and feeding system on growth performance and carcass traits of male kids in three breeds in India. Small Rumin. Res. 17, 45e50.
NRC, 1981. Nutrient Requirements of Domestic Animals. Nutrient Requirements of Goats: Angora, Dairy and Meat Goats in Temperate and Tropical Countries. National Academy Press, Washington, DC. Ocak, S., Darcan, N., Çáankaya, S., Inal, T.C., 2009. Physiological and biochemical responses in German Fawn kids subjected to cooling treatments under Mediterranean climate conditions. Turk. J. Vet. Anim. Sci. 33, 455e461. Paz, H., 2010. Evaluación del efecto regulatorio de leptina sobre el metabolismo energético y comportamiento productivo en cabras de genotipo cárnico. Tesis de Maestría, FMVZ, UNAM, México DF, p. 77. Roman-Ponce, H., Thatcher, W.W., Buffington, D.E., Wilcox, C.J., Van Horn, H.H., 1977. Physiological and production responses of dairy cattle to a shade structure in a subtropical environment. J. Dairy Sci. 60, 424e430. SAS, 1999. SAS Statistics Users’ Guide. Cary, N.C., USA. Schütz, K.E., Rogers, A.R., Cox, N.R., Tucker, C.B., 2009. Dairy cows prefer shade that offers greater protection against solar radiation in summer: shade use, behaviour, and body temperature. Appl. Anim. Behav. Sci. 116, 28e34. Seath, D.M., Miller, G.D., 1946. Effect of warm weather on grazing performance of milking cows. J. Dairy Sci. 29, 199e206. Sevi, A., Annicchiarico, G., Albenzio, M., Taibi, L., Muscio, A., Dell’Aquila, S., 2001. Effects of solar radiation and feeding time on behavior, immune response and production of lactating ewes under high ambient temperature. J. Dairy Sci. 84, 629e640. Silanikove, N., 2000. Effects of heat stress on the welfare of extensively managed domestic ruminants. Livest. Prod. Sci. 67, 1e18. St-Pierre, N.R., Cobanov, B., Schnitkey, G., 2003. Economic losses from heat stress by US livestock industries. J. Dairy Sci. 86, E52eE77. Tucker, C.B., Rogers, A.R., Schütz, K.E., 2008. Effect of solar radiation on dairy cattle behaviour, use of shade and body temperature in a pasture-based system. Appl. Anim. Behav. Sci. 109, 141e154. Urdaz, J.H., Overton, M.W., Moore, D.A., Santos, J.E.P., 2006. Technical note: effects of adding shade and fans to a feedbunk sprinkler system for preparturient cows on health and performance. J. Dairy Sci. 89, 2000e2006. Widowski, T., 2001. Shade-seeking behavior of rotationally-grazed cows and calves in a moderate climate. In: Richard, R., Stowell, R.B., Bottcher, R.W. (Eds.), Livestock Environment VI: Proceedings of the 6th International Symposium. American Society of Agricultural and Biological Engineers, Louisville, Kentucky, USA, pp. 632e639.
Contents lists available at ScienceDirect
Journal of Veterinary Behavior journal homepage: www.journalvetbehavior.com
Research
Shade effects on feeding behavior, feed intake, and daily gain of weight in female goat kids L. Alvarez*, N. Guevara, M. Reyes, A. Sánchez, F. Galindo Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, México DF, Mexico
a r t i c l e i n f o
a b s t r a c t
Article history: Received 29 October 2012 Received in revised form 4 April 2013 Accepted 7 August 2013 Available online 16 September 2013
Solar radiation and high ambient temperatures negatively affect feeding time, performance, and animal welfare in several species. The provision of shade is a simple method that helps to minimize the negative effects. To determine whether shade influences feeding behavior, feed intake, and daily weight gain (DWG) in female goat kids, 40 dairy goat kids were used in 2 similar pens whose feeders were shaded (n ¼ 20) or unshaded (n ¼ 20) during 60 days. From May to July, behavioral data were collected through 10-minute scan samples during a 24-hour period for a total of 300 hours. Both pens were shaded on the opposite side to the feeder with 15 m2 each in a resting area. All goat kids were observed for their position inside the pen, and the number of times they were seen eating was recorded. When the concentrate was provided (between 13:00 and 13:30 hours, as usually in the farm), the time was recorded until >50% of the animals stopped feeding and went back to the resting area (concentrate test). Food wastes were collected and weighed daily to calculate the food consumption. Ambient and black globe temperatures were daily recorded. Body weight was recorded every week to calculate DWG. A higher percentage of animals feeding was recorded in the shaded feeders than that in the unshaded feeders (P < 0.05). Food refusal was higher in the unshaded feeders (30 1.8%) than that in the shaded feeders (25 1.9%; P ¼ 0.05). The concentrate test duration was 26.6 minutes (1.3) in the shaded feeders and 16.1 minutes (1) in the unshaded feeders (P < 0.05). The concentrate test duration was negatively correlated to the ambient temperature in the unshaded animals (r ¼ 0.50 and r2 ¼ 0.25; P ¼ 0.02), and it was not significant in the shaded ones (r ¼ 0.23, r2 ¼ 0.05; P > 0.05). DWG was not different between groups (0.08 0.03 kg per group; P > 0.05). Results suggest that shade on feeders helps to ameliorate some negative effects of solar radiation increasing feeding time and feed intake in female goat kids. This could be of great interest to prevent performance and welfare negative affectations. Ó 2013 Elsevier Inc. All rights reserved.
Keywords: heat stress goats shade welfare feeding behavior feed intake
Introduction High ambient temperature and lack of protection against solar radiation affects severely physiological responses (Darcan and Güney, 2008; Broucek et al., 2009), performance (Darcan and Cankaya, 2008; Marcillac-Embertson et al., 2009), and the welfare (Silanikove, 2000; Johnson et al., 2008) of farm animals. Body temperature regulation in hot weather is an important condition for cattle production and welfare. Solar radiation and high ambient temperature are also associated with lower cattle performance (Muller et al., 1994b; Brown-Brandl et al., 2004; da Conceição et al., * Address for reprint requests and correspondence: Dr. L. Alvarez, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, 04510 México DF, Mexico. Tel: (52) 55 5622 5886; Fax: (52) 55 5616 7169. E-mail address: [email protected] (L. Alvarez). 1558-7878/$ e see front matter Ó 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jveb.2013.08.002
2008). The provision of shade is a simple method that helps to minimize the negative effects of solar radiation in grazing (Blackshaw and Blackshaw, 1994; da Conceição et al., 2008) and housing conditions (Bucklin et al., 1991; Mitlohner et al., 2001a; Marcillac-Embertson et al., 2009). It has been argued, however, that the use of shade would induce nonproductive behaviors (Widowski, 2001) as the grazing time would be reduced and resting time would increase (Bennett et al., 1984). Those arguments have been rejected in some studies with cows (Widowski, 2001; Tucker et al., 2008) and red deer (Mejía, 2011). Although goats are considered to be resilient to high ambient temperatures, there is evidence of their negative response to those environmental conditions (Appleman and Delouche, 1958; Lu, 1989), especially if no prevention measures are taken (Darcan et al., 2008). In 8-month-old kids, solar radiation exposure
L. Alvarez et al. / Journal of Veterinary Behavior 8 (2013) 466e470
increases body temperature, heart rate, and respiratory frequency (Al-Tamimi, 2007). Practices as the use of spraying and ventilation have been used to improve goat productive and physiological parameters (Darcan and Güney, 2002; Darcan and Cankaya, 2008; Darcan et al., 2008; Ocak et al., 2009). Evidence clearly indicates that without protection against solar radiation, animals visit the feeder less frequently, and their consumption decreases. Yet some housing designs for goats consider building feeders at nonshaded areas, which may have important negative consequences for the animal and for the farm. Structures that shade feeders increase milk production and improve reproductive results in dairy cows compared with those that lack the shade (Roman-Ponce et al., 1977; Urdaz et al., 2006). No information is available about the effects of shading feeding spaces of goats on behavior and feed intake, which can affect production. The aim of the present study was to determine the effects of additional shade at feeding bunks on feeding behavior, feed intake, and daily weight gain (DWG) of female goat kids.
Materials and methods The study was approved by the Internal Committee for Ethical Use of Animals in Experimentation.
Location and treatments The study was carried out at an experimental farm located 150 km north of Mexico City. A total of 40 dairy goat kids (2.53 months age, 10-15 days after weaning) were allocated in a 180 m2 pen, equipped with a feeder of 13.5 m in length. The pen was divided into 2 identical sections whose feeders were shaded (shaded group, n ¼ 20, 13.1 0.2 kg of body weight; 23 m2 of a shade cloth >80% of solar protection) or unshaded (unshaded group, n ¼ 20, 13.08 0.2 kg of body weight). The experiment lasted 60 days, from May to June. All animals had access to a permanent shade in resting areas, at the opposite side of the feeder, with a total of 15 m2 per section.
Behavioral records and temperature measurements Scan sampling was used every 10 minutes during daytime (09:00-18:00 hours) and for a total of 200 hours to record behavioral states as described by Mitlohner et al. (2001b). Feeding was considered when the animal had its head inside the feeder, drinking when the head of the animal was inside the water trough, walking when the animal was in locomotion or moving from one place to another, standing when the animal was inactive with its 4 legs on the ground, and lying when the body was in contact with the ground. On each scan, the number of animals showing the respective behavior was recorded. The same behavioral records were carried out during the night (19:00-08:00 hours) for a total of 100 hours (Mitlohner et al., 2001b). Ambient and black globe temperatures were also recorded during the behavioral sampling and every hour using devices located within the feeder area in both groups (Alzina et al., 2001). The black globe temperature device was adapted using a thermometere hygrometer and a copper bulb (wired thermometer/hygrometer, model 63-1032, Radioshack, Mexico; Yokohama, 2009, personal communication). At the same time, soil temperature was recorded in shaded and nonshaded areas using an infrared thermometer (infrared and contact thermometer, model 561; Fluke Corporation, Everett, WA).
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Body weight, feed consumption, and concentrate test All animals were weighed every week to calculate the total DWG at the end of the study. Food (alfalfa hay and concentrate) was given according to the National Research Council instructions (NRC, 1981). Feed wastes were daily collected and weighed to calculate the average percentage of consumption per group. To determine the motivation to stay in the feeder area when the favorite food is provided (Abijaoudé et al., 2000), a concentrate test was applied. This consisted on measuring the time from the moment the food was provided until the moment when >50% of the goats stopped feeding and withdrew from the feeder area. The test was done every 3 days during the study and always at the same time of the day (13:00-13:30 hours). Data analysis Behavioral data were expressed in percentage, and an arcsine transformation of data was carried out to use parametric tests (analysis of variance and general linear model procedure for repeated measures). Previous to the use of such test, the normal distribution of data was confirmed by the ShapiroeWilk test. A Duncan test was used for multivariate comparisons, feed consumption, and the DWG (SAS, 1999). The same tests were used to compare ambient temperatures (SAS, 1999). The diurnal and nocturnal records were analyzed separately. A Pearson correlation was used to determine the relationship between the concentrate test duration and the temperatures recorded at that time of the day (SAS, 1999). Results Temperature records Figure 1 shows the mean ambient and black globe temperatures during the 24-hour period. The temperatures during daytime periods (09:00-18:00 hours) were higher in the unshaded group than those in the shaded group (P < 0.05). In the night hours, no significant differences between groups were seen (P > 0.05; Figure 1). The highest ambient temperature recorded in the unshaded group was 35.4 C (0.81), whereas in the shaded group, this was of 31.8 C (0.66). The highest black globe temperature recorded was 45.9 C (1.24) in the unshaded group and 33.9 C (1.24) in the shaded group. Soil temperature was higher in the unshaded area and reached maximum averages of 51.3 C (1.2, P < 0.05; Figure 2). Feeding behavior and feed intake The percentage of animals that were seen feeding in the shaded group was higher than that in the unshaded group (P < 0.05;
Figure 1. Mean ambient and black globe temperatures during the day in shaded and unshaded feeding areas. *Significant difference between groups (unshaded vs. shaded; P < 0.05).
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Figure 2. Average soil temperature ( C standard error of the mean) in different areas of the pen.
Figure 3). In the shaded group, a higher percentage of animals was recorded eating from 9:50 to 12:00 noon and at different times from 13:30 to 16:00 hours. During the night, there were no differences between groups (P > 0.05; Figure 3). The duration of the concentrate test was higher in the animals of the shaded group (26.6 1.3; minutes standard error of the mean; P < 0.05) than that in the animals of unshaded group (16.1 1; minutes standard error of the mean). There was a negative correlation between the duration of the concentrate test and the ambient temperature in the unshaded group (r ¼ 0.50, r2 ¼ 0.25, P ¼ 0.02; Figure 4). In the shaded group, this correlation was not significant (r ¼ 0.23, r2 ¼ 0.05, P ¼ 0.3). The percentage of animals lying during the day in the feeder area was higher in the shaded group (P < 0.05; Figure 5). Goats clearly avoided standing in areas of sun during the hottest hours of the day (Figure 6); shaded areas were preferred to stand during the day, and no differences between groups were found (P > 0.05; Figure 7). No differences were found in locomotion and drinking activity between groups (P > 0.05). The average percentage of waste of food throughout the study was lower in the shaded group (25.8 1.9) than that in the unshaded group (30.4 1.8; P ¼ 0.05). The average percentage of net feed consumption per day was 74.1 1.8 and 69.6 1.8 for shaded and unshaded groups, respectively (P ¼ 0.05). Daily weight gain The final body weight was not different between groups (unshaded, 17.8 0.63 and shaded, 17.9 0.66 kg; P > 0.05). The average DWG for the goat kids in both groups was not different (0.08 0.03, kg standard error of the mean; P > 0.05).
Figure 3. Percentage of goats feeding at different times of the day in each group. *Significant difference between groups (P < 0.05).
Figure 4. Relationship between the ambient temperature and the duration of the concentrate test in the unshaded group. The negative correlation was significant (P < 0.05).
Discussion In the present study, the provision of shaded areas is associated with a higher percentage of animals eating at different times of the day. At times with the highest temperatures, more goats were observed feeding in feeders with shade. At no time of day, the goats in the unshaded group were seen eating at a higher rate than goats in the shaded group. This coincides with other studies with sheep (Sevi et al., 2001) and cows (Muller et al., 1994a; Mitlohner et al., 2002). Others have found that voluntary feed intake is reduced when animals are exposed to high temperatures (Abdalla et al., 1993; Sevi et al., 2001; Al-Tamimi, 2007), especially if food is of poor quality (Costa et al., 1992) because of the effort to reduce heat production and the low digestive transit time (Bernabucci et al., 1999; Sevi et al., 2001). In an attempt to maintain thermal balance with the environment, the animal reduces its feed intake and physical activity to reduce body heat, whereas water consumption and the frequency of urination increases (Abdalla et al., 1993; Hahn, 1999). In the present study, the animals had the possibility to move to shaded areas of the yard, and the decrease in food intake in the unshaded group is explained by the fact that fewer of them were seen in feeding areas. A clear finding that indicates the preference of goats for shaded areas when temperature is high is that goats of both groups clearly avoided areas of sun during the hottest hours of the day. The time the animals spent in the feeder areas after administration of the concentrate increased by 40% when the area had shade. This strongly suggests a negative effect of high temperature conditions, confirmed with the respective environmental measurements, in the preferences of the animal (Lu, 1989). In our study, the negative correlation found between ambient temperature and feeding time clearly reinforces this fact. In the medium and long
Figure 5. Percentage of goats lying in shaded and unshaded feeder areas during the day. *Significant differences between groups (P < 0.05).
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Figure 6. Percentage (mean standard error of the mean) of goats standing in areas of sun during the day.
term, a higher waste of food in unshaded areas could exacerbate economic losses for the farm (St-Pierre et al., 2003). Furthermore, the higher percentage of goats eating during the hottest times of the day in shaded group clearly suggests that the resource should be considered to maintain the animal motivation in the feeding area. Although feeding activity was clearly synchronized because the food was provided at the same time, the shade resource allowed to have a higher percentage of animals feeding at different periods of the day. Animals seek and use the shade when body temperature exceeds 39.1 C (Seath and Miller, 1946; Blackshaw and Blackshaw, 1994). Although this study did not record body temperature of goats, results of experiments in progress indicate that body temperatures can reach up to 41.5 C when the animal is fully exposed to sunlight for short periods (Alvarez et al., not published). In the present study, ambient and black globe temperatures peaked a maximum of 43.9 C and 54.7 C, respectively, which goes beyond what is considered as thermal comfort zone for the species (Lu, 1989). It should be noted that these temperatures correspond to those recorded with the devices exposed to solar radiation during the study, thermal monitoring technique that is accepted and used in the literature of the subject (Roman-Ponce et al., 1977; Buffington et al., 1981; Widowski, 2001; Al-Tamimi, 2007) and are considered valid records as perceived by the animal permanently exposed to certain environmental conditions. Similarly, the literature agrees that shade can improve animal welfare indicators, and for this reason, it should be considered as an important tool in animal management (Blackshaw and Blackshaw, 1994; Caroprese, 2008; Schütz et al, 2009). Our findings on DBW were similar to those reported by Marsico et al. (1993) and Nagpal et al. (1995) in kids of similar age and intensive systems but lower than others using males of an older age (Darcan and Güney, 2002). In the present study, DWG did not differ between groups during the observation period. Given the low conversion rates of the species and its high metabolic capacity to
Figure 7. Percentage (mean standard error of the mean) of goats standing in shaded areas during the day. No differences were found between groups (P > 0.05).
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accommodate dietary restrictions (Arriaga, 2007; Paz, 2010), it may require a longer period of exposure or a total absence of shade over the feeders and no shade available in other areas to observe differences in the development of the animal or detect an eventual negative effect on productivity. It is important to remember that in the present study, all animals had access to shade at any time of the day. In other cases, in older male kids permanently exposed to heat stress for periods of 40 days (Darcan and Güney, 2002), DWG decreases significantly compared with those that were sprayed with water twice a day. We conclude that the use of shade at the feeders increases the visits of goats to this area and the time and net consumption of food and reduces food waste. These changes are directly related to high ambient temperature in different areas of the pen. The use of shade over the feeders for a period of 60 days did not alter the DWG of young goats. These results generate suggestions to study the effect of shade during longer periods of time. Acknowledgments The authors thank project PAPIIT IN205810, DGAPA, UNAM, for funding the investigation. References Abdalla, E.B., Kotby, E.A., Johnson, H.D., 1993. Physiological responses to heatinduced hyperthermia of pregnant and lactating ewes. Small Rumin. Res. 11, 125e134. Abijaoudé, J., Morand-Fehr, P., Tessier, J., Schmidely, P., Sauvant, D., 2000. Influence of forage:concentrate ratio and type of starch in the diet on feeding behaviour, dietary preferences, digestion, metabolism and performance of dairy goats in mid lactation. Anim. Sci. 71, 359e368. Al-Tamimi, H.J., 2007. Thermoregulatory response of goat kids subjected to heat stress. Small Rumin. Res. 71, 280e285. Alzina, L., Farfán, J., Valencia, E., Yokohama, J., 2001. Condición ambiental y su efecto en la temperatura rectal y frecuencia respiratoria en bovinos cruzados (Bos taurus x Bos indicus) del estado de Yucatán, México. Rev. Biomed. 12, 112e121. Appleman, R.D., Delouche, J.C., 1958. Behavioral, physiological and biochemical responses of goats to temperature, 0 C to 40 C. J. Anim. Sci. 17, 326e335. Arriaga, A., 2007. Evaluación del estado corporal y sus efectos sobre el comportamiento productivo en cabras lecheras. Tesis de Maestría, FMVZ, UNAM, México DF, p. 65. Bennett, I., Finch, V., Holmes, C., 1984. Time spent in shade and its relationship with physiological factors of thermoregulation in three breeds of cattle. Appl. Anim. Behav. Sci. 13, 227e236. Bernabucci, U., Bani, P., Ronchi, B., Lacetera, N., Nardone, A., 1999. Influence of shortand long-term exposure to a hot environment on rumen passage rate and diet digestibility by Friesian heifers. J. Dairy Sci. 82, 967e973. Blackshaw, K., Blackshaw, A., 1994. Heat stress in cattle and the effect of shade on production and behaviour: a review. Australian J. Experim. Agricult. 34, 285e295. Broucek, J., Kisac, P., Uhrincat, M., 2009. Effect of hot temperatures on the hematological parameters, health and performance of calves. Int. J. Biometeorol. 53, 201e208. Brown-Brandl, T., Eigenberg, R., Nienaber, J., Hahn, G., 2004. Indicators of heat stress in shaded and non-shaded feedlot cattle. In: Meeting, A.A. (Ed.). Amer. Soc. Agricultural Biological Engineers. Paper number 044037. Bucklin, R., Turner, L., Beede, D., Bray, R., Hemken, R., 1991. Methods to relieve heat stress for dairy cows in hot, humid climates. Appl. Eng. Agricult. 7, 241e247. Buffington, D., Collazo-Arocho, A., Canton, G., Pitt, D., Thatcher, W., Collier, R., 1981. Black-globe humidity index (BGHI) as comfort equation for dairy cows. Trans. Am. Soc. Agricultural Engineers. 24, 711. Caroprese, M., 2008. Sheep housing and welfare. Small Rumin. Res. 76, 21e25. Costa, P., da Silva, R., de Souza, R., 1992. Effect of air temperature and humidity on ingestive behaviour of sheep. Int. J. Biometeorol. 36, 218e222. da Conceição, M., da Silva, I., Dos Santos-Dias, C., 2008. Artificial shade effects in the performance and physiology of dairy heifers in pasture. In: Asabe (Ed.), Livestock Environment VIII. American Society of Agricultural and Biological Engineers, Iguassu Falls, Brazil. Electronic 701P0408. Darcan, N., Cankaya, S., 2008. The effects of ventilation and showering on fattening performances and carcass traits of crossbred kids. Small Rumin. Res. 75, 192e198. Darcan, N., Cedden, F., Cankaya, S., 2008. Spraying effects on some physiological and behavioural traits of goats in a subtropical climate. Ital J. Anim. Sci. 7, 77e85. Darcan, N., Güney, O., 2002. Effect of spraying on growth and feed efficiency of kids under subtropical climate. Small Rumin. Res. 43, 189e190.
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