Adaptive rumen function in elk (Cervus elaphus nelsoni) and mule deer (Odocoileus hemionus hemionus)

1993 ◽  
Vol 71 (3) ◽  
pp. 601-610 ◽  
Author(s):  
D. E. Spalinger ◽  
C. T. Robbins ◽  
T. A. Hanley

We tested the hypothesis that rumen function is adaptive to diet quality and intake rate using ruminally fistulated elk and mule deer. In experiment 1 we measured rumen particle-size distribution, rumen fill, and particle and liquid passage rates of animals fed three diets varying in quality (chopped pea, alfalfa, and wheat hays). In experiment 2, similar measurements were obtained on elk fed alfalfa hay ad libitum or at restricted intake levels. Rumen characteristics and passage rates of particles and liquids were similar for animals consuming alfalfa and pea hays. Intake, rumen dry-matter concentration and fill, and liquid passage rate were significantly lower when animals consumed wheat hay. Few significant differences in rumen characteristics or passage rates were found between animals fed alfalfa ad libitum or at restricted levels. Rumen liquid volume and dry-matter fill were related linearly to intake (r2 = 0.98 for both) in deer and elk fed alfalfa and pea hays. However, liquid volume and dry-matter fill of elk fed wheat hay and alfalfa at restricted levels were higher than the deer–elk interspecific regression, indicating an adaptive ruminal response. We concluded that rumen function was adaptive to both diet quality and availability, but that the response likely was subject to the limitations imposed by food characteristics and the inherent limitations of rumen structure and function.

2007 ◽  
Vol 85 (7) ◽  
pp. 767-773 ◽  
Author(s):  
G.W. Kuzyk ◽  
R.J. Hudson

Animal-unit equivalences needed for joint-stocking calculations of ungulates are rarely studied because of difficulties deriving accurate estimates of forage intake. We used indigestible internal and external markers (double n-alkane ratio) to determine animal-unit equivalence of bison ( Bison bison (L., 1758)), wapiti ( Cervus elaphus canadensis L., 1758), and mule deer ( Odocoileus hemionus (Rafinesque, 1817)) in the aspen parkland of east-central Alberta. We hypothesized that dry matter intake would differ among species in absolute terms (kg·day–1) but not when expressed as percent body mass (%BM) or when related to metabolic mass (g·kg–1·day–1 BM0.75). We administered slow-release n-alkane capsules to 12 bison, 3 wapiti, and 11 mule deer and released them into separate 3–7 ha paddocks during summer and fall. Intake of dry matter by bison, wapiti, and mule deer differed significantly among species when expressed as total intake (p = 0.009) and %BM (p = 0.014) but not when related to metabolic mass (p = 0.237). Dry matter intake related to metabolic mass did not differ between bison and mule deer in any comparison despite a 6.8-fold difference in body size, suggesting that intake scales to metabolic mass, and is the preferred expression of animal-unit equivalents.


2009 ◽  
Vol 148 (2) ◽  
pp. 233-242 ◽  
Author(s):  
W. CHANCHAI ◽  
S. CHANPONGSANG ◽  
N. CHAIYABUTR

SUMMARYThe aim of the current study was to determine how cooling and supplemental recombinant bovine somatotropin (rbST) affect body function with respect to digestion kinetics, digestibility and other variables relevant to milk production in cross-bred Holstein cattle. Ten primiparous cross-bred dairy cattle (0·875 Holstein Friesian×0·125 Red Shindi) were used and divided into two groups of five animals each that were housed in a normal shaded barn (NS barn; non-cooled cows) and in a shaded barn with mist-fan cooling (MF; cooled cows). The cows in each group were supplemented with rbST in early, mid and late stages of lactation with three consecutive subcutaneous injections of 500 mg rbST every 14 days. All cows were fed the same total mixed ration twice daily at approximately 1·1 of assumed ad libitum intake and water was offered ad libitum. During the experimental periods, values of ambient temperatures and temperature humidity index (THI) in the NS barn were significantly higher than in the MF barn, whereas the relative humidity in the MF barn was significantly higher than in the NS barn (P<0·01). The respiration rate and rectal temperature were significantly higher for non-cooled cows than for cooled cows during the daytime whether there was or was not rbST supplementation. Supplementation of rbST for either cooled or non-cooled cows significantly increased dry matter intake (DMI), the efficiency of feed utilization and milk yields (P<0·05). Digesta kinetics using chromic oxide as an external marker showed a high digesta passage rate constant and low mean retention time of digesta in cows either by cooling or supplementation of rbST, whereas no changes were seen for the digestibility of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre (NDF) and acid detergent fibre (ADF). The half-time of Cr2O3 in the whole digestive tract of cooled cows was lower than those of non-cooled cows and significantly decreased (P<0·05) during rbST supplementation in both groups in all stages of lactation. The magnitude of responses for the digesta passage rate and efficiency of feed utilization were larger in animals supplemented with rbST than in animals under MF cooling only.The main effect of cooling and supplemental rbST was to improve digestion by an increase in the rate of passage of digesta and in turn an increase in feed intake. Digestibility was not influenced by changes in passage rate of digesta either by cooling or rbST supplementation. Milk production in response to rbST supplementation is probably enhanced with cooling. The increased milk production induced by rbST supplementation was mediated by increased efficiency of feed utilization without changes in diet digestibility.


1989 ◽  
Vol 69 (4) ◽  
pp. 973-987 ◽  
Author(s):  
MARINA A. G. VON KEYSERLINGK ◽  
G. W. MATHISON

The in situ bag technique was evaluated as a method of predicting the voluntary intake and digestibility of forages. Nine feedstuffs including three cereal straws, three alfalfa (Medicago sativa L.) and grass hay mixtures, two alfalfa-grass silages, and a prairie (Festuca hallii L.) grass hay were each fed to five steers (350 ± 49.5 kg) at ad libitum and approximately maintenance feeding levels. Hays and silages were also fed at near the twice maintenance feeding level. Voluntary forage dry matter (DM) intakes ranged from 1.00 to 2.85% of body weight. Apparent forage DM digestibilities ranged from 37 to 64%. At the lower feeding level fractional rates of particulate passage through the digestive tract were higher (P < 0.05) for 37% DM silage (0.037 h−1) than for two of the straw-based diets (0.020–0.023 h−1). Particulate passage rates were not (P > 0.05) affected by feeding level. Predictions from in situ results were most accurate when 24 and 36 h degradation values were used to estimate DM digestibility (R2 = 0.92) and intake (R2 = 0.86), respectively. The neutral detergent fiber content of forage was equally well correlated with DM digestibility (R2 = 0.86) and voluntary DM intake (R2 = 0.85). Inclusion of information on rates of passage in prediction equations did not (P > 0.05) improve accuracies of predictions over those obtained using in situ results or chemical feed components. Key words: Steers, in situ, voluntary intake, digestibility, passage rates, prediction


1989 ◽  
Vol 40 (5) ◽  
pp. 1037 ◽  
Author(s):  
A Djajanegara ◽  
PT Doyle

Prior to the experiment two groups of 10 sheep were fed to either gain (group F) or lose (group T) weight. At the beginning of the experiment group F sheep weighed on average 57.7 kg fleece-free liveweight (W) and had a total body fat (TBF) content of 154 kg, while group T sheep weighed 42.6 kg and had a TBF content of 9.7 kg. During the experiment all sheep were given a urea-treated rice straw-based diet ad libitum for 56 days with an intra-ruminal infusion of urea and sodium sulfate. Measurements were made of feed intake and digestibility and of the amounts and composition of digesta in the reticula-rumen (ReRu) and flowing through the abomasum.Group T sheep consumed more feed (dry matter intake 1 170 v. 1040 g day-1, 24.9 v. 19.1 g kg W-1) and spent more time chewing (16.5 v. 14.1 h day-1) than group F sheep. There were no differences in the digestibility of dietary constituents.Associated with the greater feed intakes by group T sheep were increased amounts of total digesta (8.59 v 7.67 kg) and of dry matter (DM) (1040 v. 960 g), organic matter (OM) (820 v. 750 g) and neutral detergent fibre (NDF) (690 v. 620 g) in the ReRu. Flows of total digesta (22.45 v. 18.64 kg day-1), DM (910 v. 800 g day-1), OM (600 v. 510 g day-1) and NDF (330 v. 270 g day-1) through the abomasum were also greater in group T sheep. However, there were no differences between treatments in the proportion of digestion which occurred in the ReRu, in the fractional digestion rate of NDF in the ReRu or in the fractional passage rate of NDF from the ReRu.Group T sheep generally maintained weight (-4 g day-1) throughout the experiment and their TBF only declined from 9.7 to 9.1 kg. In contrast, group F sheep lost weight at 74 g day-1 and TBF declined from 15.8 to 14.1 kg.It is concluded that removal of limitations of essential nutrients enabled sheep in poor condition to consume more of this straw-based diet than those in good condition.


1993 ◽  
Vol 30 (1) ◽  
pp. 36-45 ◽  
Author(s):  
E. S. Williams ◽  
S. Young

The pathology of the central nervous system of nine mule deer ( Odocoileus hemionus) and six elk ( Cervus elaphus nelsoni) with chronic wasting disease, a spongiform encephalopathy of mule deer and elk, was studied by light microscopy. Lesions were similar in both species and were characterized by spongiform transformation of gray matter, intracytoplasmic vacuolation of neurons, neuronal degeneration and loss, astrocytic hypertrophy and hyperplasia, occurrence of amyloid plaques, and absence of significant inflammatory response. Distribution and severity of lesions were evaluated at 57 locations; there were only minor differences between deer and elk. Consistent, severe lesions occurred in olfactory tubercle and cortex, hypothalamus, and the parasympathetic vagal nucleus of deer, and sections examined from these regions would be sufficient to establish a diagnosis of chronic wasting disease. Lesions were milder in these locations in elk but were sufficiently apparent to be of diagnostic value. Other differences included increased severity of lesions in some thalamic nuclei in elk in contrast to deer, the occurrence of amyloid plaques demonstrable by hematoxylin and eosin and histochemical stains in deer in contrast to elk, and the presence of mild white matter lesions in elk but not in deer. Lesions of chronic wasting disease were qualitatively comparable to those of scrapie, bovine spongiform encephalopathy, transmissible mink encephalopathy, and the human spongiform encephalopathies. Topographic distribution and lesion severity of chronic wasting disease were most similar to those of scrapie and bovine spongiform encephalopathy. Duration of clinical disease did not significantly influence lesion distribution or severity in either species.


1992 ◽  
Vol 72 (3) ◽  
pp. 619-631 ◽  
Author(s):  
S. Wairimu ◽  
R. J. Hudson ◽  
M. A. Price

Ten yearling wapiti stags were used to investigate effects of winter nutrition on subsequent growth on summer pasture. One group of five (LOW) was wintered on medium-quality hay, and the other group of five (HIGH) was wintered on hay and alfalfa–barley pellets (16% crude protein). By the time they grazed spring pasture in mid-April, HIGH wapiti had larger frame dimensions and were 20 kg heavier than those wintered on hay alone, despite their lower pre-winter weights. However, subsequent catch-up growth rapidly narrowed these differences, and both groups attained similar weights and frame measurements by late July. Liveweight gains on summer pasture were 0.30 and 0.15 kg d−1 for LOW and HIGH wapiti, respectively. Although LOW wapiti tended to have higher gut fill (3.3 vs. 2.5 kg dry matter), the difference (corrected for assumed dry-matter content) was insufficient to explain compensatory weight gain. Digestibilities and mean retention times did not differ consistently between the treatment groups but were reciprocally related to one another. Forage intakes rose as pastures flushed but declined sharply in July with overgrazing and resumption of supplemental feeding. LOW wapiti consumed more pasture dry matter than HIGH wapiti in May and June. Efficiencies of forage utilization were unrelated to nutritional history. Using data pooled for the two treatment groups from April to June gave estimates of 878 kJ W−0.75 for maintenance and 33.4 kJ g−1 for liveweight gain. The main factor contributing to compensatory gain on summer pasture was higher forage intakes, particularly in relation to metabolic weight. Key words: Game farming, elk, compensatory growth, forage intake, passage rate, energy requirements


2017 ◽  
Vol 44 (7) ◽  
pp. 523 ◽  
Author(s):  
L. Mark Elbroch ◽  
Jennifer Feltner ◽  
Howard Quigley

Context Many institutions of wildlife management and their hunting constituents tend to value ungulates over large carnivores, in part due to financial incentives associated with ungulate hunting over carnivore hunting. This system benefits from mythology that presents large carnivores as competitors for antlered male ungulates most prized by the hunting community. Aims We explored puma (Puma concolor) foraging and prey selection in two study areas in the Rocky Mountains, USA, to test whether pumas were competing with human hunters for antlered elk (Cervus elaphus) and mule deer (Odocoileus hemionus). Methods We employed GPS technology to track pumas and document their prey. We measured population- and individual-level selection by comparing prey killed by pumas to two estimates of prey availability: (1) landscape-level as determined by annual agency game counts; and (2) total prey killed by marked pumas. Key results Pumas in both study systems killed small numbers of antlered elk and mule deer. Pumas exhibited avoidance of mature elk, instead strongly selecting for elk calves over any other age or sex class. Pumas in both systems also selected for mule deer fawns; however, they also exhibited small positive selection (Jacob’s index of 0.08 in CO and 0.11 in WY on a scale of 0.0–1.0) for antlered mule deer. Conclusions In terms of numbers killed, pumas were not a competitor with human hunters for either antlered species. In terms of prey selection, pumas showed that they may be greater competition for rare antlered mule deer but not for antlered elk. In both study sites, antlered elk and deer remained at levels at which they could perform their ecological functions. Implications Our results highlight the fact that the overhunting of large carnivores over competition for antlered ungulates is mostly unfounded; we should instead focus management, media attention and conservation science on disentangling the complex ecology driving localised declines of mule deer, elk and other important ungulate resources, many of which are anthropogenic in nature and can be addressed.


2006 ◽  
Vol 80 (18) ◽  
pp. 9104-9114 ◽  
Author(s):  
Gültekin Tamgüney ◽  
Kurt Giles ◽  
Essia Bouzamondo-Bernstein ◽  
Patrick J. Bosque ◽  
Michael W. Miller ◽  
...  

ABSTRACT Chronic wasting disease (CWD) is a fatal prion disease in deer and elk. Unique among the prion diseases, it is transmitted among captive and free-ranging animals. To facilitate studies of the biology of CWD prions, we generated five lines of transgenic (Tg) mice expressing prion protein (PrP) from Rocky Mountain elk (Cervus elaphus nelsoni), denoted Tg(ElkPrP), and two lines of Tg mice expressing PrP common to white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus), denoted Tg(DePrP). None of the Tg(ElkPrP) or Tg(DePrP) mice exhibited spontaneous neurologic dysfunction at more than 600 days of age. Brain samples from CWD-positive elk, white-tailed deer, and mule deer produced disease in Tg(ElkPrP) mice between 180 and 200 days after inoculation and in Tg(DePrP) mice between 300 and 400 days. One of eight cervid brain inocula transmitted disease to Tg(MoPrP)4053 mice overexpressing wild-type mouse PrP-A in ∼540 days. Neuropathologic analysis revealed abundant PrP amyloid plaques in the brains of ill mice. Brain homogenates from symptomatic Tg(ElkPrP) mice produced disease in 120 to 190 days in Tg(ElkPrP) mice. In contrast to the Tg(ElkPrP) and Tg(DePrP) mice, Tg mice overexpressing human, bovine, or ovine PrP did not develop prion disease after inoculation with CWD prions from among nine different isolates after >500 days. These findings suggest that CWD prions from elk, mule deer, and white-tailed deer can be readily transmitted among these three cervid species.


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