Behavioral Education for Human, Animal, Vegetation, and Ecosystem Management (BEHAVE)

Sheep and Goat Preference for and Nutritional Value of Mediterranean Maquis Shrubs

J. Rogosic et al. — Tue, 01 Feb 2011 13:43:38 PST

The objective of this study was to evaluate the nutritive value, intake and preferences of sheep and goats for the dominant six shrubs of the holly oak maquis-type shrublands in Croatia. The experimental sheep (n = 12, mean weight 28.5 kg) were a local Croatian mixed breed. The experimental goats (n = 12, mean weight 13.4 kg) were a mixture of domestic goats crossed with Saanen and Alpine breeds. Sheep and goats differed (P < 0.01) in consumption of almost all of the shrubs. Goats had higher intakes (g/kg B.W., P < 0.01) than sheep of each shrub except Quercus ilex. In Trial 1, shrub intake for goats ranged from 17.7 ± 0.72 g/kg B.W. for Pistacia lentiscus to 33.1 ± 1.40 g/kg B.W. for Erica multiflora. Goats ate more Arbutus unedo (P = 0.004; 19.9 g/kg versus 14.2 g/kg B.W., respectively); E. multiflora (33.1 g/kg versus 21.9 g/kg B.W., respectively) and Pistacia lenticus (17.2 g/kg versus 10.6 g/kg B.W., respectively) than did sheep. Goats ate twice as much Juniperus phoeniceae (P = 0.002) as did sheep (21.0 g/kg versus 10.9 g/kg B.W.), and also ate more Viburnum tinus (P = 0.02) than did sheep (22.6 g/kg versus 13.9 g/kg B.W.). There was a day × treatment interaction (P = 0.001), with goats eating more A. unedo, E. multiflora, J. phoeniceae, P. lenticus and V. tinus than sheep. In Trial 2, the rank order of preference (highest to least) for goats were Q. ilex, E. multiflora, V. tinus, A. unedo, J. phoeniceae and P. lentiscus. The rank order by sheep was similar: Q. ilex, E. multiflora, V. tinus, J. phoeniceae, P. lentiscus and A. unedo. Overall, goats ate 50.5 g/kg B.W. of shrubs per day, while sheep averaged 26.7 g/kg B.W. each day. Goats are better suited to graze Mediterranean maquis in terms of potential shrub use.

The Role of Natural Plant Products in Modulating the Immune System: An Adaptable Approach for Combating Disease in Grazing Animals

Frederick D. Provenza et al. — Tue, 01 Feb 2011 13:43:35 PST

Plants provide herbivores with an array of chemicals with the potential to improve health and well-being. For instance, phytochemicals, known as secondary compounds, which protect plants from consumers and pests can adversely affect cellular and metabolic processes in herbivores, but at low doses and in appropriate mixtures, they can have beneficial effects on animal nutrition and health, though the latter has not been explored in great breadth or depth. In this review, we summarize the potential impact of natural plant products on immunomodulation and other therapeutic effects in herbivores. Development of preventative strategies to help animals resist disease would be a more economical, ecological and socially effective long-term healthcare strategy than treating diseases. In this realm, immunomodulation promoted by forages emerges as an interesting alternative and complement to chemotherapy. The challenge for feeding systems will be to incorporate mixes of plants with bioactive properties in ways that enhance health without compromising animal production and well-being. A solution to this challenge may involve developing management programs that acknowledge the ability of animals to learn about the beneficial effects of diverse foods.

Linking Herbivore Experience, Varied Diets, and Plant Biochemical Diversity

Frederick D. Provenza et al. — Tue, 01 Feb 2011 13:43:32 PST

We contend diets and habitats that allow animals to select among alternatives enable individuals to better meet needs for nutrients and to better cope with toxins. All plants contain toxins, and the amount of toxin an animal can ingest depends on the kinds and amounts of nutrients and toxins in the forages on offer. Nutrients and toxins both cause animals to satiate, and excesses of nutrients, nutrient imbalances, and toxins all limit food intake. Thus, individuals can better meet their needs for nutrients and regulate their intake of toxins when offered a variety of foods that differ in nutrients and toxins than when constrained to a single food, even if the food is “nutritionally balanced”. Food intake and preference also depend on differences in how individual animals are built morphologically and how they function physiologically, and marked variation is common even among closely related animals in needs for nutrients and abilities to cope with toxins. Transient food aversions compound the inefficiency of single-food diets—whether in confinement, on pastures, or on rangelands—by depressing intake among individual animals, even if they are suited “on average” to that nutrient or toxin profile. Thus, feeding and grazing practices that allow producers to capitalize on the individuality of animals are likely to improve performance of the herd by enabling the uniqueness of individuals to become manifest. Finally, past experiences play a crucial role in an animal’s propensity to learn to eat different foods. When herbivores are allowed to eat only the most preferred plants, they are not likely to learn to mix foods high in nutrients with foods that contain toxins. Conversely, herbivores encouraged to eat all plants in an area are more likely to learn to eat mixes of plants that mitigate toxicity. Experienced animals who have learned to eat a variety of foods that differ in nutrients and toxins do so even when nutritious alternatives are available, whereas naive animals familiar only with the nutritious alternatives eat only that subset of familiar foods. Different systems of management alter how animals forage. Continuous grazing at low stock densities encourages selectivity and reduces diet and habitat breadth, whereas short-duration grazing at high stock densities increases diet and habitat breadth. Thus, what was traditionally considered proper grazing management—rotational grazing at low stock densities—may have trained generations of livestock to “eat the best and leave the rest” thus inadvertently accelerating a decline in biodiversity and an increase in the abundance of less desirable plant species.

Foraging Ecology of Goats and Sheep on Wooded Rangelands

Thomas G. Papachristou et al. — Tue, 01 Feb 2011 13:43:29 PST

Wooded rangelands are a vast grazing land resource globally, including shrublands, savannas and forested ranges. They generally provide forage year-round for small ruminants and they are vitally important for livestock production, especially goats. While the productivity of wooded rangelands is low to moderate, their importance to small ruminant production is considerable. In this paper, we begin by discussing some anti-quality characteristics (mechanical and chemical defences) of woody vegetation that reduce their forage value, deter foraging, and reduce performance and productivity of small ruminants. We then present examples of grazing studies that illustrate how small ruminants select their diets on wooded rangelands. We conclude by discussing why small ruminants select the diets they do within the evolutionary processes of plant–herbivore interactions. Finally, we discuss how this knowledge can be integrated into approaches for sustainable management of wooded rangelands for small ruminant production. Plant defences are abundant in wooded rangelands but they are not a complete barrier to small ruminants as they often use woody plants as part of their diets. Indeed plants with such defences may represent a significant forage resource enabling small ruminants to survive on wooded rangelands with a prolonged dry period when more preferred defenceless species are absent. Future research in plant–herbivore interactions should include investigating how plant biochemical diversity influences herbivore preference for various plant communities, and integrating this information to develop recommendations for managing wooded rangelands.

Drylot Performance and Ruminal Papillae Development of Lambs Exposed to a High Concentrate Diet while Nursing

L. Ortega-Reyes et al. — Tue, 01 Feb 2011 13:43:26 PST

In 1986 (trial 1), lambs were exposed with their mothers to WB-PMP (whole barley and protein-mineral pellet) for 15 min/d for 0, 2, 4, 8 or 16 d. In 1987 (trial 2), they were exposed for 0, 4 or 8 d; two treatments for 8 d, with one receiving four times more WB-PMP (8H) than the other (8L). Following exposure to WB-PMP in both years, lambs and their dams grazed on summer range for 2 months before the drylot tests. Exposure for 4 d increased (P<0.05) intake of WB-PMP during the first week it was offered in drylot in 1986, but not (P>0.05) in 1987. Lambs exposed for 2, 8 or 16 d in 1986 did not consume more WB-PMP than controls (P>0.05). In 1987, lambs in treatment 8L consumed more (P<0.05) WB-PMP than controls during the first 2 weeks in drylot. Amount of WB-PMP offered affected intake of WB-PMP in drylot. Lambs in treatment 8H consumed more (P<0.05) than controls during the first 3 weeks in drylot. Lambs with high WB-PMP intakes during weeks 1 and 2 in both years consumed less WB-PMP during weeks 3 and 4, especially in 1987. The reduction in intake was greater for lambs previously exposed to WB-PMP than for controls. In 1986, 81% of the lambs exposed for 4 or 8 d and 64% of the lambs for 16 d achieved slaughter condition by week 8 in drylot, while only 50% and 33% of the lambs exposed for 0 or 2 d reached slaughter condition by that time (P<0.05). In 1987, lambs on WB-PMP did not reach slaughter condition sooner than controls, probably due to severe decrease in intake that occurred during weeks 3 and 4 in drylot. Lambs exposed to WB-PMP for 8 d in 1987 entered the drylot with ruminal papillae that had 38% more surface area than did lambs not exposed to WB-PMP; however, the differences disappeared within 3 weeks. Results indicate that exposing lambs to a WB-PMP diet early in life enhanced performance in drylot. Development of rumen papillae as a result of exposure may contribute to this performance.

Supplemental Energy and Protein Increase Use of Sagebrush by Sheep

Luthando E. Dziba et al. — Tue, 01 Feb 2011 13:43:23 PST

The ability of sheep to consume big sagebrush (Artemisia tridentata Nutt.), a shrub that contains terpenes, may be improved with supplemental energy and protein needed for detoxification processes. We compared feeding behavior of supplemented and unsupplemented ewes grazing separately in three 0.5 ha plots of 40 m × 120 m during October 2001. Supplemented ewes were offered a choice of a high-energy (50% corn and 50% beet pulp—3.62 Mcal/kg DE and 9.5% CP) and a high-protein (85% alfalfa and 15% soybean meal—2.89 Mcal/kg DE and 15% CP) supplement for 15 min/day. Supplemented ewes consumed 492 g (S.E. = 24.3) of the high-energy supplement and 140 g (S.E. = 9.8) of the high-protein supplement. The incidence of feeding on sagebrush was recorded using scan sampling at 10-min intervals from 09:00 to 17:00 h every other day for 10 days. Incidence of feeding on sagebrush increased gradually for both treatments from 0.4% on day 1 to 28% on day 10 (P < 0.01), but supplemented ewes increased feeding frequency on sagebrush to nearly twice that of unsupplemented ewes by the end of the trial. Averaged throughout the trial, incidence of eating sagebrush was twice as high for supplemented compared to unsupplemented ewes (22% versus 11% of the total time feeding, P < 0.01). The results of this study show that supplemental macronutrients increase use of sagebrush by ewes. Thus, strategic supplementation during fall and winter may be a way to increase intake of sagebrush by sheep and enhance and maintain biodiversity in areas of the sagebrush steppe where sagebrush is deemed too abundant.

Neem-Tree (Azadirachta indica Juss.) Extract as a Feed Additive Against the American Dog Tick (Dermacentor variabilis) in Sheep (Ovis aries)

S. Y. Landau et al. — Tue, 01 Feb 2011 13:43:20 PST

Acaricides can be conveyed to ticks via the blood of their hosts. As fruit and kernel extracts from the Meliaceae family, and, in particular the tetranortriterpenoid azadirachtin (AZA) inhibits tick egg production and embryogenesis in the Ixodidae ticks, we investigated the effects of Neem Azal®, an extract containing 43% AZA, given as a feed additive to lambs artificially infested with engorging adult Dermacentor vairiabilis ticks. After tick attachment, the lambs were allotted to three dietary treatments: AZA0 (control, n=10), AZA0.3 (n=5), and AZA0.6 (n=5), with feed containing 0%, 0.3%, and 0.6% AZA on DM basis, respectively. In half of the AZA0 lambs, ticks were sprayed on day 4 after attachment with an ethanol:water:soap emulsion containing 0.6% AZA (AZA0S). In spite of its very pungent odor, the neem extract was well accepted by all but one lamb. No differences were found between treatment groups in liver enzymes in blood, and there was no indication of toxicity. The plasma AZA concentrations after 7 and 14 days of feeding AZA were (4.81 and 4.35 µg/mL) for the AZA0.6 and (3.32 and 1.88 µg/mL) for the AZA0.3 treatments, respectively (P<0.0001). Treatments were not lethal to ticks, but tick weights at detachment were 0.64, 0.56, 0.48, and 0.37 g for ticks from the AZA0, AZA0.3, AZA0S, and AZA0.6 treatments (P<0.04), respectively, suggesting that blood AZA impaired blood-feeding. The highest mortality rate after detachment was for AZA0.6 (P<0.09). As AZA affects embryo development and ticks at the molting stages, we expect that following treatments of hosts for longer periods, one-host ticks will be more affected than the three-host tick D. variabilis.

Post-Exposure Performance of Lambs Exposed to Whole Barley Early in Life

P. G. Hatfield et al. — Tue, 01 Feb 2011 13:43:17 PST

Thirty-four cross-bred lambs were used to investigate the effects of early exposure to whole barley on subsequent diet preference and animal performance. Seventeen lambs (mean age 7 weeks) were individually exposed to 50 g x lamb^-1 x d^-1 whole barley for 8 days at 15 minutes per day in 0.74 m² pens. Lambs were exposed to the barley with their mothers; however, ewes and lambs were separated by a wire panel to allow recording of individual lamb intake. Control lambs (n=17) were treated in the same manner as the exposed lambs except they were offered alfalfa pellets during the 15 minutes per day exposure period. Alfalfa pellets were the basal diet for all animals. After weaning in September when mean lamb age was 146 days, lambs were fitted with fecal collection bags, confined in individual pens, and allowed ad libitum consumption of a whole barley finishing ration. The initial ration was 40% whole barley and 60% alfalfa pellets. Quantity of barley in the ration was increased every third day by 10% until the quantity of barley in the ration was 80%. Early exposure to whole barley did not affect live weight gains (P>0.24). Early exposure had no effect (P>0.42) on intake or dry matter digestibility during the confinement feeding study. Refused feed of lambs exposed to whole barley early in life had a higher (P=0.03) CP values than control lambs, indicating the presence of more alfalfa than barley in the refusal sample. The amount of barley consumed by exposed treatment lambs during exposure did not affect (P>0.16) variables measured in the feeding trial. Based on the methods used to expose lambs to whole barley, only minimal advantage for lambs exposed early was detected in this study.

Conditioned Food Aversion: From Theory to Practice

Michael H. Ralphs et al. — Tue, 01 Feb 2011 13:43:14 PST

In most plant communities there are plants that can poison animals. A few plants contain high levels of toxins, or contain highly toxic compounds, and pose a real threat to grazing livestock. Some of these plants may be readily grazed by livestock, which makes it difficult to manage around them. Conditioned food aversion offers a way to train livestock to avoid eating specific poisonous plants.

Twenty-Five Years of Paradox in Plant-Herbivore Interactions and "Sustainable" Grazing Management

Frederick D. Provenza — Tue, 01 Feb 2011 13:43:11 PST

Science, Myth, and the Mangement of Natural Resources

Frederick D. Provenza — Tue, 01 Feb 2011 13:43:08 PST

In what follows, I draw a distinction between reductionist science that accents parts and systems science that accents wholes. I conclude that both views are deeply interrelated, and that neither position alone will solve the problems we face today. Science provides understanding of processes, but it can only provide likelihoods of behaviors of systems, given sets of conditions, none of which are known absolutely. Moreover, science only elucidates what is, not what ought to be.

Learning and Memory in Grazing Livestock Application to Diet Selection

Karen L. Launchbaugh et al. — Tue, 01 Feb 2011 13:43:05 PST

When you think of intelligent animals, a cow or sheep is probably not the first creature that comes to mind. With respect to grazing, however, livestock are smart. Researchers consistently report that livestock select diets more nutritious than if they foraged at random (Arnold and Dudzinski 1978). However, scientists disagree on how livestock know which foods are nutritious or toxic. Some traditional theories suggest that animals are born knowing what to eat and do not need specific learning experience. These theories suggest that diet selection is inflexible and stereotypic.

Range scientists have been reluctant to replace these traditional theories with concepts that depend upon animal learning and experience. However, many successful management practices which ranchers have been using for decades are based on the assumptions that livestock learn and remember the plants they eat. For example, many ranchers select replacement heifers from their own herd because they "know" the range better than heifers purchased from outside herds. Most managers realize that livestock deaths from poisonous plants generally increase when animals are not familiar with a particular plant, such as when livestock graze new pastures. A few savvy ranchers even wean animals on the same feed used for creep feeding because the calves seem to "recognize" the feed, eat more of it, and gain weight more quickly.

How Do Animals Learn if Rangeland Plants are Toxic or Nutritious?

Larry D. Howery et al. — Tue, 01 Feb 2011 13:43:02 PST

Over the past 15 years, Dr. Frederick Provenza and his associates at Utah State University have studied how animals use certain physiological and behavioral processes to learn whether rangeland forages are toxic or nutritious. This article summarizes key concepts presented in recent articles (e.g., Provenza et al. 1992; Provenza 1995, 1996, 1997) about how learning plays a major role in the development of dietary choices made by rangeland animals.

Behavioral Factors in Rotational Grazing Systems

Mark W. Brunson et al. — Tue, 01 Feb 2011 13:42:59 PST

Many in the range profession are perplexed by the apparent discrepancy between experimental studies suggesting that rotational grazing carries no advantage over continuous grazing and the observations of ranchers and range managers who have personally seen benefits for livestock production and plant communities by shifting to a rotational system. We believe one reason for this seeming contradiction is that research on plant and animal production is typically designed to control for the effects of behavior of grazing animals and their owners. As researchers who have spent many years studying the behavior of range livestock and people, we argue that understanding human and animal behavior as it relates to grazing management can help to bridge the gap between science and practice. In this paper we discuss how livestock behavior factors (such as prior experience and stress) and managers’ learning processes can influence the outcomes of grazing management practices, why a standard experimental approach may not detect those influences, and how an improved knowledge of behavior can help both ranchers and researchers achieve their goals with respect to rotational grazing systems.

Conditioned Food Aversions: Principles and Practices, with Special Reference to Social Facilitation

Michael H. Ralphs et al. — Tue, 01 Feb 2011 13:42:56 PST

Conditioned food aversion is a powerful experimental tool to modify animal diets. We have also investigated it as a potential management tool to prevent livestock from grazing poisonous plants such as tall larkspur (Delphinium barbeyi), white locoweed (Oxytropis sericea) and ponderosa pine (Pinus ponderosa) on western US rangelands. The following principles pertain to increasing the strength and longevity of aversions: mature animals retain aversions better than young animals; novelty of the plant is important, although aversions can be created to familiar plants; LiCl is the most effective emetic, and the optimum dose for cattle is 200 mg/kg body weight; averted animals should be grazed separately from non-averted animals to avoid the influence of social facilitation which can rapidly extinguish aversions. Social facilitation is the most important factor preventing widespread application of aversive conditioning. When averted animals see other animals eat the target food they will sample it, and if there is no adverse reaction they will continue eating and extinguish the aversion. However, if averted animals can be grazed separately, aversions will persist. Aversive conditioning may provide an effective management tool to prevent animals from eating palatable poisonous plants that cause major economic loss.

Food Color, Flavor, and Conditioned Avoidance among Red-Winged Blackbirds

Scott J. Werner et al. — Tue, 01 Feb 2011 13:42:53 PST

The relationship between food flavors and postingestive feedback enables mammalian herbivores to procure nutrients and avoid toxins within ever-changing environments. We conducted four experiments with red-winged blackbirds (Agelaius phoeniceus) in captivity to determine the relative roles of color and flavor cues paired with negative postingestive feedback. We first conducted baseline tests to assess preferences for colors and flavors. All blackbirds preferred red- to blue-colored food, and they preferred umami- (L-alanine) flavored to bitter/astringent food (tannic acid). We observed no difference in consumption of salty (NaCl) vs sour (citric acid) foods during baseline tests (i.e., neutral flavors). We then conditioned experimentally naïve blackbirds with intraperitoneal injections of lithium chloride (LiCl) to avoid food treated with red and L-alanine, or red and NaCl (n=30 birds per conditioning group). Subsequent to conditioning with LiCl, three test groups were established from each conditioned group to evaluate color and flavor preferences, and preferences for novel color-flavor pairings (e.g., red/tannic acid vs blue/L-alanine). Blackbirds avoided red and salty food throughout the 4-day test. Avoidance conditioned with LiCl extinguished for preferred flavors, but not for colors, of food. Conditioning affected indifference for the otherwise preferred flavor and avoidance for the otherwise neutral flavor. Relative to the neutral-flavor conditioning group, the group conditioned with a preferred flavor exhibited stronger conditioned avoidance of colored food. Unlike conditioned flavor avoidance, birds were conditioned to avoid red food only when blue food was made familiar prior to conditioning. Collectively, these results illustrate that blackbirds used affective processes (flavor-feedback relationships) to shift preference for both novel and familiar flavors, and cognitive associations (colors) to avoid food, subsequent to toxin exposure. We discuss the opportunities afforded by affective and cognitive processing for reducing agricultural damage caused by blackbirds.

Proximal Cues of Pocket Gopher Burrow Plugging Behavior: Influence of Light, Burrow Openings, and Temperature

Scott J. Werner et al. — Tue, 01 Feb 2011 13:42:51 PST

Burrow plugging is readily observed among mammals adapted for digging (i.e., fossorial mammals) as they create and maintain their burrows. We investigated the influence of light, burrow openings, and thermal environment as cues of pocket gopher (Thomomys mazama, Thomomys talpoides) behavior. When given free access to light and no light during artificial-burrow preference trials, both Thomomys spp. consistently plugged (i.e., avoided) light treatments. Burrow openings did not notably affect plugging behavior of T. mazama. Gophers (T. talpoides) plugged the artificial burrows within the light and cold (7° C) treatments, but not within the no-light, and 18 or 31° C treatments when light and temperature were varied independently. Whereas the presence of light and low ambient temperatures induce burrow maintenance by pocket gophers, these cues help meliorate adverse conditions within subsurface environs.

Relationship between Reluctance to Eat Novel Foods and Open-Field Behavior in Sheep

Juan J. Villalba et al. — Tue, 01 Feb 2011 13:42:47 PST

Fear, a key aspect of temperament with important implications for both animal welfare and production, may be manifest in responses to novelty. Herbivores typically prefer the familiar to the novel, and they generally regard anything novel with caution (i.e., they are reluctant to eat novel foods). We hypothesized animals differ in their fearfulness towards food and non-food items due to individuality which is influenced by genetics and contrasting environmental experiences. We further hypothesized fear of unknown foods and environments are correlated. Our objective was to determine if sheep differ in their fear responses and whether or not there is a link between general fearfulness and response to separation – as measured by the open field test (OFT) and stress induced hyperthermia (SIH) – and the readiness to eat new foods. We assessed reluctance to eat novel foods, open field behavior, and SIH in two groups of sheep (Group 1: Rambouillet–Columbia–Finn–Targhee crossbreds; Group 2: composite Suffolk) raised under contrasting environmental conditions. Lambs in Group 1 showed lower number of bleats and higher SIH than lambs in Group 2. When offered novel foods, lambs in Group 1 were more reluctant to eat them than lambs in Group 2. There was a negative relationship between number of bleats in OFT and reluctance to eat novel foods. Thus, reluctance to eat novel foods and response to separation in the OFT behavior differed among animals and a correlation was found between these behaviors. Our results suggest that reluctance to ingest new foods is influenced by sociality. Individuals less responsive to social isolation (lower number of bleats) may be less cautious at accepting novel foods than individuals more responsive to social isolation. Such variability implies some individuals may be more adept at consuming diverse diets in diverse locations whereas others may be more adept at consuming single foods at fixed locations.

Food Aversion Conditioned in Anesthetized Sheep

Frederick D. Provenza et al. — Tue, 01 Feb 2011 13:42:44 PST

We discovered that a food aversion could be conditioned in anesthetized sheep. Sheep were allowed to eat a familiar food (alfalfa-grain pellets) for 30 min, and 90 min later they were given either an intraruminal (IR) injection of water (C), an IR injection of LiCl (L), anesthesia followed by an IR injection of water (A), or anesthesia followed by an IR injection of LiCl (A+L). Induction of anesthesia was by an intraveneous injection of pentobarbitone sodium, and maintenance of deep anesthesia was by halothane. Sheep were maintained in deep anesthesia for 2 h to ensure that the effects of LiCl on the acquisition of a food aversion, which occur within about 1 h, were completed before they awakened. When tested 5 days later, sheep that received LiCl (treatments L and A+L) consumed less alfalfa-grain pellets than sheep that did not receive LiCl (treatments C and A) (241 g vs. 306 g; p = 0.057). Intake of sheep that were anesthetized (treatments A and A+L) did not differ from that of sheep that were not anesthetized (treatments C and L) (295 g vs. 252 g; p = 0.183). Nor was there an interaction between LiCl and anesthesia (p = 0.423). Thus, we conclude that changes in preferences for foods caused by postingestive feedback occur automatically every time food is ingested (i.e., they are noncognitive), and the kind and amount of feedback is a function of the match between the food's chemical characteristics and its ability to meet the animal's current demands for nutrients.

Garlic in the Ovine Fetal Environment

Dale L. Nolte et al. — Tue, 01 Feb 2011 13:42:41 PST

We investigated whether the odor of garlic can cross the placental barrier from the mother to the fetal environment. Samples of amniotic fluid, allantoic fluid, fetal blood, and maternal blood were collected 0, 50, 100, and 150 min after a pregnant ewe (approximately day 110 of gestation) was gavaged with 6 ml of Egyptian garlic oil. A panel of judges detected (p < 0.05) garlic odor in samples of allantoic fluid, fetal blood, and maternal blood collected 50, 100, and 150 min after the ewe was given garlic and in samples of amniotic fluid collected 100 min after treatment.