Increased Body Condition Research Articles

0830 Increased body condition during lactation increases milk production and pre-weaning growth of Bali cattle

0830 Increased body condition during lactation increases milk production and pre-weaning growth of Bali cattle

Feeding distillers dried grains in replacement of forage in limit-fed dairy heifer rations: Effects on growth performance, rumen fermentation, and total-tract digestibility of nutrients

The objective of this study was to determine the effects of increasing dietary concentration of distillers dried grains (DDGS) in dairy heifer rations. A 16-wk randomized complete block design study was conducted using 48 Holstein heifers [199±2 d of age; body weight (BW) 206±2kg] to evaluate effects of dietary treatment on dry matter (DM) intake, average daily gain, growth performance, rumen fermentation, and nutrient digestibility. Treatments were (1) 30% DDGS with the diet fed at 2.65% of BW, (2) 40% DDGS with the diet fed at 2.50% of BW, and (3) 50% DDGS with the diet fed at 2.35% of BW. The remainder of the diet consisted of grass hay and 1.5% mineral mix. Heifers were individually limit-fed using Calan gates. Heifers were weighed every 2 wk and the ration amount offered was adjusted accordingly. Frame measurements and body condition score were recorded every 2wk. Rumen fluid was collected via esophageal tubing during wk 12 and 16 for pH, ammonia N, and volatile fatty acid analysis. Total-tract digestibility of nutrients was evaluated during wk 16 using fecal grab sampling. No treatment by week interactions were found for any of the growth parameters measured, and growth parameters did not differ among treatments. Heifer DM intake linearly decreased with increasing concentrations of DDGS. Body weight and average daily gain were similar among treatments, whereas gain:feed linearly increased across treatments, with a tendency for a treatment by time interaction. As the dietary concentrations of DDGS increased, rumen ammonia N linearly increased. Acetate proportion and acetate:propionate linearly decreased as DDGS increased, whereas propionate linearly increased. There were treatment by time interactions for propionate proportion and acetate:propionate. Increasing dietary concentrations of DDGS linearly increased total-tract digestibility of DM, organic matter, and crude protein. Limit-feeding diets with greater concentrations of DDGS improved gain:feed and total-tract digestibility of DM and crude protein, and maintained frame growth without increasing body condition score. Results demonstrated that replacing forage with DDGS at up to a 50% inclusion rate in limit-fed rations can maintain heifer growth performance.

Dynamic group size and displacement as avoidance strategies by eiders in response to hunting

Hunting by humans constitutes a major source of mortality that selects for avoidance strategies. Group formation in eiders Somateria mollissima in response to hunting from motorboats was studied in the Danish Wadden Sea as an avoidance strategy to humans. In autumn the birds' food demand and energy consumption are relatively low and the need for optimal feeding opportunities are not as essential as during winter. We tested the hypothesis that eiders aggregate in groups of variable size dependent on predation risk (hunting), season and site. During autumn at the preferred feeding sites eiders occur in small numbers and group size increase together with hunting activity. Opposite during winter, eiders occur in large numbers and group size decrease when hunting activity increase. Hunting activity displaced eiders to adjacent sites with no or low hunting intensity and low food availability where group size of eiders increase during both autumn and winter in relation to the overall hunting activity. The formation into larger groups when hunting activity increase is probably due to increasing effects of vigilance and dilution, whereas formation into smaller groups is assumed to reduce the eiders conspicuousness to hunters. This change in group size made it possible for eiders to forage in areas with high food availability and high hunting intensity, while minimizing the risk of being detected by hunters. When the largest numbers of hunters were present at the preferred feeding site, group sizes during both autumn and winter were 110–125 eiders, indicating an optimal group size in relation to hunting density. Eiders located outside preferred feeding sites were in poorer body condition, suggesting that displacement was a suboptimal decision caused by hunting. We conclude that eiders adopted regrouping and displacement as two different strategies during hunting. Both strategies are tradeoffs between the risks of being detected by hunters and killed, and the benefits of feeding on mussel stocks thereby increasing body condition and hence fitness.

Impacts of adding ruminally protected phenylalanine to rations containing high levels of canola meal on performance of high producing Holstein cows

Even though studies supplementing Phe to dairy cattle are rare, it has been identified as limiting in corn silage based rations, after Lys and Met, as well as being important to the mammary gland for overall milk production. Since canola meal (CM) is low in Phe, plasma Phe concentrations decrease as more CM is included in dairy rations. A previous study fed 7.5g/cow/day of intestinally absorbable Phe, but results suggested that it was insufficient to support increased milk production since it was primarily used to support increased body condition score (BCS; Swanepoel et al., 2015a). Our objective was to determine if supplementing 15g/cow/day of intestinally absorbable Phe in a ruminally protected (RP) form (HCMP) to a ration containing 170g/kg CM (HCM) would support increased milk production after fulfilling its apparent 1st priority of restoring previously mobilized peptides to muscle protein synthesis, thereby regaining animal performance possibly lost with higher dietary CM inclusion levels (i.e., 130g/kg (LCM) to 165g/kg (HCM)) based upon Swanepoel et al. (2015a). Ruminally protected Met (2.0g/cow/day intestinally absorbable) was added as part of the treatment ration to HCM treatments to avoid a possible Met limitation. The experimental design was a 3×3 Latin square using 3 pens of ∼315 early lactation cows/pen with three 21day periods. Dry matter (DM) intake was not affected (avg: 27.5±0.5kg/day) by feeding RP Phe and there was no impact of treatment on milk and component yields, except a reduced lactose content (P=0.02) with Phe addition. Even though plasma Phe levels only differed numerically between treatments, its supplementation resulted in energy being diverted towards BCS gain as in Swanepoel et al. (2015a), but not at the expense of milk components, suggesting that higher Phe supplementation supplied enough Phe to replace mobilized muscle protein while maintaining milk production. The lack in change of plasma Phe concentrations could be due to extensive catabolization by the liver or hepatic conversion of Phe to Tyr, which is supported by the change in plasma Tyr concentrations. Interestingly, addition of Phe to the HCM ration increased whole tract neutral- and acid detergent fiber digestibility. Perhaps Phe released into the rumen when Phe was fed stimulated fibrolytic bacteria through a direct impact on microbes of free Phe, which has previously been shown to enhance growth and/or capabilities of cellulolytic bacteria. Total net energy output decreased with HCM feeding, but was restored to the level of the LCM ration for the HCMP treatment suggesting that further investigation to determine if an even higher Phe supplementation level may have additional benefits on milk production may have merit.

Effect of increased adiposity on insulin sensitivity and adipokine concentrations in different equine breeds adapted to cereal-rich or fat-rich meals

The relationships between diet, obesity and insulin dysregulation in equids require further investigation due to their association with laminitis. This study examined the effect of dietary glycaemic load and increased adiposity on insulin sensitivity and adipokine concentrations in different equine breeds. Equal numbers of Standardbred horses, mixed-breed ponies and Andalusian horses were provided with ad libitum hay plus either cereal-rich (CHO; n = 12), fat-rich (FAT; n = 12) or control (CON; n = 9) meals over 20 weeks. The isocaloric CHO and FAT diets were fed to induce obesity by gradually increasing the supplementary feeds to provide 200% of daily digestible energy requirements by Week 20. The CON group were fed a basal ration only and maintained moderate body condition.At Week 20, the CHO and FAT groups demonstrated significantly increased body condition score, bodyweight, total body fat mass and plasma leptin concentrations compared with the CON group (P < 0.001). The CHO group had lower insulin sensitivity (SI; P < 0.001) and higher acute insulin response to glucose (P = 0.002) than the CON group. In contrast, the FAT group was no different to the control group. Ponies and Andalusians had lower SI values compared with Standardbreds, regardless of diet group (P = 0.001). Adiponectin concentrations were similar between the FAT and CON groups, but were significantly lower in the CHO group (P = 0.010). The provision of cereal-rich meals appeared to be a more important determinant of insulin sensitivity than the induction of obesity per se. Whether hypoadiponectinaemia is a cause or consequence of insulin dysregulation warrants further investigation.

Increased body condition score through increased lean muscle, but not fat deposition, is associated with reduced reproductive response to oestrus induction in beef cows

Energy reserve, estimated as body condition score (BCS), is the major determinant of the re-initiation of ovarian activity in postpartum cows. Leptin, IGF-I and insulin are positively related to BCS and are putative mediators between BCS and reproductive function. However, when BCS and body composition dissociates, concentrations of these metabolic hormones are altered. We hypothesized that increasing lean muscle tissue, but not fat tissue, would diminish the reproductive response to oestrus induction treatments. Thirty lactating beef cows with BCS of 3.10±1.21 and 75.94±12 days postpartum were divided in two groups. Control cows (n=15) were supplemented with 10.20 kg of concentrate daily for 60 days. Treated cows (n=15) were supplemented equally, and received a β-adrenergic receptor agonist (β-AA; 0.15 mg/kg BW) to achieve accretion of lean tissue mass and not fat tissue mass. Twelve days after ending concentrate supplementation/β-AA treatment, cows received a progestin implant to induce oestrus. Cows displaying oestrus were inseminated during the following 60 days, and maintained with a fertile bull for a further 21 days. Cows in both groups gained weight during the supplementation period (Daily weight gain: Control=0.75 kg v. β-AA=0.89 kg). Cows treated with β-AA had a larger increase in BCS (i.e. change in BCS: control=1 point (score 4.13) v. β-AA=2 points (score 5.06; P<0.05), as a result of muscle accretion (i.e. change in muscle depth: control 0.21 cm v. β-AA 0.97 cm; P<0.05) but not adipose tissue (i.e. change in back fat depth; control 0.13 cm v. β-AA −0.06 cm; P<0.05). The changes in body composition in β-AA cows were associated with a reduction in serum concentrations of IGF-I (25.4%) and leptin (27.9%), without observed changes in insulin. Ovulation and pregnancy to 1st service (P>0.05) did not differ between groups. However, the number of cows displaying oestrus (control 13/15 v. β-AA 8/15; P<0.05) and the percentage cycling (control 6/8 v. β-AA 3/10; P=0.07) after progestin treatment and the pregnancy percentage at the end of the breeding period (control 13/15 v. β-AA 8/15; P<0.05) were lower in β-AA than control cows. In summary, the increase BCS through muscle tissue accretion, but not through fat tissue accretion, resulted in a lower response to oestrus induction, lower percentage of cycling animals and lower pregnancy percentage after progestin treatment; which was associated with a decrease in serum concentrations of leptin and IGF-I.

Cardiomyopathy prevalence in 780 apparently healthy cats in rehoming centres (the CatScan study)

ObjectivesHypertrophic cardiomyopathy (HCM) appears to be common in cats and, based on pilot data, a prevalence of 15% has been hypothesized. The objectives were to screen a large population of apparently healthy adult cats for cardiac disease, and identify factors associated with a diagnosis of HCM. AnimalsA total of 1007 apparently healthy cats ≥6 months of age. MethodsIn this prospective, cross-sectional study, the inclusion criteria were: apparently healthy cats, aged ≥6 months, available for rehoming over a 17-month period from two rehoming centres. Hypertensive or hyperthyroid cats were excluded. Body weight, body condition score, auscultation, systolic blood pressure and two-dimensional (2-D) echocardiography were evaluated. Cats with left ventricular end-diastolic wall thickness ≥6 mm on 2-D echocardiography were considered to have HCM. ResultsComplete data were obtained in 780 cats. Heart murmur prevalence was 40.8% (95% confidence interval (CI) 37.3–44.3%), 70.4% of which were considered functional. The prevalence of HCM was 14.7% (95% CI 12.3–17.4%), congenital disease 0.5% (95% CI 0.1–1.3%), and other cardiomyopathies 0.1% (95% CI 0.0–0.7%). The HCM prevalence increased with age. The positive predictive value of a heart murmur for indicating HCM was 17.9–42.6% (higher in old cats), and the negative predictive value was 90.2–100% (higher in young cats). The factors associated with a diagnosis of HCM in binary logistic regression models were male sex, increased age, increased body condition score and a heart murmur (particularly grade III/VI or louder). ConclusionsHypertrophic cardiomyopathy is common in apparently healthy cats, in contrast with other cardiomyopathies. Heart murmurs are also common, and are often functional.

Survival of female mallards along the Vermont–Quebec border region

ABSTRACTUnderstanding effects of location and timing of harvest seasons on mortality of ducks and geese from hunting is important in forming regulations that sustain viable waterfowl populations throughout their range. During 1990 and 1991 we alternately marked 80 hatching year (HY), female mallards along the Vermont–Quebec border; half with radio‐transmitters and bands and half with only aluminum leg bands. We monitored radio‐marked ducks daily and recorded survival status weekly for 15 weeks from August until December each year. Mallard mortalities began 25 September when the hunting season opened in the Province of Quebec, Canada. Overall survival of mallards at week 10 did not differ between years (0.51 in 1990 vs. 0.43 in 1991) or differ from that of HY American black ducks (0.44 females, 0.42 males) based on proportional hazard analysis in a Bayesian framework. The mortality rates for mallards from hunting (0.47) and causes unrelated to hunting (0.06) were similar between years and to those rates for HY black ducks at that same site. Hunter harvest accounted for most of the mortality recorded during this study and illegal feeding (i.e., baiting) at sites just before and during the hunting season was observed. Females with lower body condition index had greater mortality rates; a 1‐standard‐deviation increase in condition index would reduce mortality hazard by about 29%. Management options that may increase mallard survival in the area include lowering daily bag limit in Quebec and suspending split hunting seasons in Vermont that increase harvest, delaying opening date of hunting in Quebec to allow for increased body condition before hunting season opens, and improving enforcement of baiting restrictions. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Brain size-related breeding strategies in a seabird.

The optimal compromise between decision speed and accuracy may depend on cognitive ability, associated with the degree of encephalization: larger brain size may select for accurate but slow decision-making, beneficial under challenging conditions but costly under benign ones. How this brain size-dependent selection pressure shapes avian breeding phenology and reproductive performance remains largely unexplored. We predicted that (1) large-brained individuals have a delayed breeding schedule due to thorough nest-site selection and/or prolonged resource acquisition, (2) good condition facilitates early breeding independent of relative brain size, and (3) large brain size accrues benefits mainly to individuals challenged by environmental or intrinsic constraints. To test these predictions, we examined how the relative head volume of female eiders (Somateria mollissima) of variable body condition correlated with their breeding schedule, hatching success and offspring quality. The results were consistent with our predictions. First, large head size was associated with a progressively later onset of breeding with increasing breeding dispersal distance. Second, increasing body condition advanced the timing of breeding, but this effect was significantly weaker in large-brained females. Third, larger head volume was associated with increased hatching success mainly among late breeders and those in poor body condition, and duckling body condition was positively related to maternal head volume, but only in poor-condition mothers. Our study is, to our knowledge, the first to demonstrate the presence of brain size-related differences in reproductive strategies within a single natural population.

Increasing body condition score is positively associated interleukin-6 and monocyte chemoattractant protein-1 in Labrador retrievers

The accumulation of excess body fat is a growing problem in dogs as well as people. Contrary to prior understanding of adipose tissue, fat is now considered to be an active endocrine organ that promotes a chronic low-grade inflammatory state often characterized by an increase in pro-inflammatory cytokines and chemokines. These have been implicated in several obesity-related disorders such as insulin resistance, cardiovascular disease, and neoplasia. The purpose of this study was to characterize fasting plasma cytokine concentrations in ninety-two healthy client-owned Labrador retriever dogs of various ages and body condition scores. The dogs were grouped according to body condition score (BCS) into three categories, lean, overweight and obese. The following cytokines and chemokines were evaluated; tumor necrosis factor-alpha, interleukin-2, interleukin-6, interleukin-8, and monocyte chemotactic protein-1 (TNF-α, IL-2, IL-6, IL-8, MCP-1). Our results indicated that fasting plasma IL-6 and MCP-1 concentrations are associated with increasing BCS. This data suggest that certain markers of inflammation increase with increasing body condition score, and that dogs, similar to humans, may be fostering a chronic inflammatory state due to obesity.

Change in the Beaufort Sea ecosystem: Diverging trends in body condition and/or production in five marine vertebrate species

Studies of the body condition of five marine vertebrate predators in the Beaufort Sea, conducted independently during the past 2–4 decades, suggest each has been affected by biophysical changes in the marine ecosystem. We summarize a temporal trend of increasing body condition in two species (bowhead whale subadults, Arctic char), in both cases influenced by the extent and persistence of annual sea ice. Three other species (ringed seal, beluga, black guillemot chicks), consumers with a dietary preference for Arctic cod, experienced declines in condition, growth and/or production during the same time period. The proximate causes of these observed changes remain unknown, but may reflect an upward trend in secondary productivity, and a concurrent downward trend in the availability of forage fishes, such as the preferred Arctic cod. To further our understanding of these apparent ecosystem shifts, we urge the use of multiple marine vertebrate species in the design of biophysical sampling studies to identify causes of these changes. Continued long-term, standardized monitoring of vertebrate body condition should be paired with concurrent direct (stomach contents) or indirect (isotopes, fatty acids) monitoring of diet, detailed study of movements and seasonal ranges to establish and refine baselines, and identification of critical habitats of the marine vertebrates being monitored. This would be coordinated with biophysical and oceanographic sampling, at spatial and temporal scales, and geographic locations, that are relevant to the home range, critical habitats and prey of the vertebrate indicator species showing changes in condition and related parameters.

Urban habitats and feeders both contribute to flight initiation distance reduction in birds

Animals respond to approaching predators by taking flight at a distance that optimizes the costs and benefits of such flight. Previous studies have shown that urban populations of birds have shorter flight initiation distances than rural populations of the same species, that this difference is partly explained by differences in the community of predators, and that a longer history of urbanization implies a greater reduction in flight initiation distance in urban populations. The use of birdfeeders may be an additional factor reducing flight initiation distance not only in cities but also elsewhere by among other effects increasing body condition, increasing availability and reliability of food, and hence reducing the relative cost of flight. Here, we tested the prediction that urban habitats and presence of feeders independently accounted for reductions in flight initiation distance using extensive samples from different cities in Poland. We found independent significant effects of urban habitat and presence of feeders on flight initiation distance. These findings suggest that different factors have contributed to the “tameness” of urban birds.

Effect of increasing body condition on key regulators of fat metabolism in subcutaneous adipose tissue depot and circulation of nonlactating dairy cows

In response to negative energy balance, overconditioned cows mobilize more body fat than thin cows and subsequently are prone to develop metabolic disorders. Changes in adipose tissue (AT) metabolism are barely investigated in overconditioned cows. Therefore, the objective was to investigate the effect of increasing body condition on key regulator proteins of fat metabolism in subcutaneous AT and circulation of dairy cows. Nonlactating, nonpregnant dairy cows (n=8) investigated in the current study served as a model to elucidate the changes in the course of overcondition independent from physiological changes related to gestation, parturition, and lactation. Cows were fed diets with increasing portions of concentrate during the first 6wk of the experiment until 60% were reached, which was maintained for 9wk. Biopsy samples from AT of the subcutaneous tailhead region were collected every 8wk, whereas blood was sampled monthly. Within the experimental period cows had an average BW gain of 243±33.3 kg. Leptin and insulin concentrations were increased until wk 12. Based on serum concentrations of glucose, insulin, and nonesterified fatty acids, the surrogate indices for insulin sensitivity were calculated. High-concentrate feeding led to decreased quantitative insulin sensitivity check index and homeostasis model assessment due to high insulin and glucose concentrations indicating decreased insulin sensitivity. Adiponectin, an adipokine-promoting insulin sensitivity, decreased in subcutaneous AT, but remained unchanged in the circulation. The high-concentrate diet affected key enzymes reflecting AT metabolism such as AMP-activated protein kinase and hormone-sensitive lipase, both represented as the proportion of the phosphorylated protein to total protein, as well as fatty acid synthase. The extent of phosphorylation of AMP-activated protein kinase and the protein expression of fatty acid synthase were inversely regulated throughout the experimental period, whereas the extent of phosphorylation of hormone-sensitive lipase was consistently decreasing by the high-concentrate diet. Overcondition in nonpregnant, nonlactating dairy cows changed the expression of key regulator proteins of AT metabolism and circulation accompanied by impaired insulin sensitivity, which might increase the risk for metabolic disorders.

Relationship between body conformation and milk yield and composition in Zaraibi and Damascus goats.

ABSTRACTThis experimental work was carried out to investigate the relationship among age, body weight, body length, body circumference, body height or body condition score and reproductive performance, (represented in mating period, gestation period, litter size, weaning weight and growth rate till weaning), milk yield and composition for Damascus and Zaraibi goats.Damascus does showed that mating period decreased significantly (P<0.05), while birth weight increased significantly (P<0.05) with aging. Litter size was significantly (P<0.05) lower, while weaning weight was significantly (P<0.05) higher for does aged 3-6 years. However, growth rate till weaning decreased significantly (P<0.05) with increasing does age above 6 years. Average daily milk yield and protein content increased significantly (P<0.05) with increasing age. Mating period was significantly (P<0.05) higher with body weight of 41-50 kg. Litter size decreased significantly (P<0.05), while both birth and weaning weight increased significantly (P<0.05) with increasing body weight more than 40 kg. Average daily milk yield did not significantly affected by body weight and body circumference. The contents of lactose and solids not fat in milk decreased significantly (P<0.05) with increasing body weight over 40 kg. Milk yield increased significantly (P<0.05) with increasing body length. The content of fat, protein, solids not fat and total solids were significantly (P<0.05) higher with body circumference over 100 cm. Mating period decreased significantly (P<0.05), however, birth and weaning weight and growth rate till weaning increased significantly (P<0.05) with increasing body height more than 65 cm. Mating period decreased significantly (P<0.05) with increasing body condition score. Litter size, birth and weaning weight and growth rate till weaning increased significantly (P<0.05) with increasing body condition score up to 4. Milk yield and fat content increased significantly (P<0.05) with increasing body condition score up to 4 and the contents of protein, solids not fat and total solids increased significantly (P<0.05) with increasing body condition score up to 3. While, lactose content was significantly (P<0.05) lower with body condition score 1. With regard to Zaraibi does, mating period, birth and weaning weight and growth rate till weaning were higher significantly (P<0.05) with age 3-6 years. Average daily milk yield and protein content increased significantly (P<0.05) with increasing age, however, lactose content decreased significantly (P<0.05) after 6 years of age. Mating period decreased significantly (P<0.05), while litter size, birth and weaning weight and growth rate till weaning increased significantly (P<0.05) with increasing body weight more than 30 kg. Average daily milk yield and the contents of fat, protein, solids not fat and total solids in milk were significantly (P<0.05) higher in does with body weighed 41-50 kg. Milk yield increased significantly (P<0.05) with increasing body length. Mating period was significantly (P<0.05) lower, while litter size, birth and weaning weight and growth rate till weaning were significantly (P<0.05) higher with body circumference more than 80 cm. While, milk yield and composition were not significantly affected by body circumference. Mating period decreased significantly (P<0.05), however, birth and weaning weight and growth rate till weaning increased significantly (P<0.05) with increasing body height more than 55 cm. Milk yield increased significantly (P<0.05) with increasing body height more than 60 cm. However, the contents of fat, lactose, solids not fat and total solids in milk decreased significantly (P<0.05) with increasing body height more than 55 cm. Mating period decreased significantly (P<0.05) with increasing body condition score. Litter size, birth and weaning weight and growth rate till weaning, milk yield and the contents of protein, lactose, solids not fat and total solids in milk increased significantly (P<0.05) with increasing body condition score up to 4. While, fat content increased significantly (P<0.05) with increasing body condition score up to 3.

Palmitic acid increased yields of milk and milk fat and nutrient digestibility across production level of lactating cows

The effects of palmitic acid supplementation on feed intake, digestibility, and metabolic and production responses were evaluated in dairy cows with a wide range of milk production (34.5 to 66.2kg/d) in a crossover design experiment with a covariate period. Thirty-two multiparous Holstein cows (151±66 d in milk) were randomly assigned to treatment sequence within level of milk production. Treatments were diets supplemented (2% of diet DM) with palmitic acid (PA; 99% C16:0) or control (SH; soyhulls). Treatment periods were 21 d, with the final 4 d used for data and sample collection. Immediately before the first treatment period, cows were fed the control diet for 21 d and baseline values were obtained for all variables (covariate period). Milk production measured during the covariate period (preliminary milk yield) was used as covariate. In general, no interactions were detected between treatment and preliminary milk yield for the response variables measured. The PA treatment increased milk fat percentage (3.40vs.3.29%) and yields of milk (46.0vs. 44.9kg/d), milk fat (1.53vs.1.45kg/d), and 3.5% fat-corrected milk (44.6vs. 42.9kg/d), compared with SH. Concentrations and yields of protein and lactose were not affected by treatment. The PA treatment did not affect dry matter (DM) intake or body weight, tended to decrease body condition score (2.93vs. 2.99), and increased feed efficiency (3.5% fat-corrected milk/DM intake; 1.60vs.1.54), compared with SH. The PA treatment increased total-tract digestibility of neutral detergent fiber (39.0vs.35.7%) and organic matter (67.9vs.66.2%), but decreased fatty acid (FA) digestibility (61.2vs.71.3%). As total FA intake increased, total FA digestibility decreased (R2=0.51) and total FA absorbed increased (quadratic R2=0.82). Fatty acid yield response, calculated as the additional FA yield secreted in milk per unit of additional FA intake, was 11.7% for total FA and 16.5% for C16:0 plus cis-9 C16:1 FA. The PA treatment increased plasma concentration of nonesterified FA (101vs.90.0μEq/L) and cholecystokinin (19.7vs. 17.6pmol/L), and tended to increase plasma concentration of insulin (10.7vs. 9.57μIU/mL). Results show that palmitic acid fed at 2% of diet DM has the potential to increase yields of milk and milk fat, independent of production level without increasing body condition score or body weight. However, a small percentage of the supplemented FA was partitioned to milk.

Use of multi‐state models to explore relationships between changes in body condition, habitat and survival of grizzly bears Ursus arctos horribilis

One of the principal goals of wildlife research and management is to understand and predict relationships between habitat quality, health of individuals and their ability to survive. Infrequent sampling, non‐random loss of individuals due to mortality and variation in capture susceptibility create potential biases with conventional analysis methods. To account for such sampling biases, we used a multi‐state analytical approach to assess relationships between habitat, health and survival of grizzly bears Ursus arctos horribilis over a 10‐year period along the east slopes of the Canadian Rockies in Alberta, Canada. We defined bear health states by body condition estimated from the relationship between weight and body length. We used a sequential model building process to first account for potential sampling biases, and then explored changes in body condition relative to habitat use and survival. Bears that used regenerating forest habitats (mostly due to forest harvesting) containing a diversity of age classes were more likely to see gains in their body condition, whereas bears that used older forests were more likely to see reductions in body condition. Survival rate was reduced most by road densities which in turn were positively correlated with regenerating forest habitat. Human activities which promote young regenerating forests, such as forest harvesting, therefore promotes improved health (increased body condition) in bears, but are offset by reductions in survival rates. Multi‐state analyses represents a robust analytical tool when dealing with complex relationships and sampling biases that arise from dynamic environments.

Evaluation of a fast, objective tool for assessing body condition of budgerigars (Melopsittacus undulatus)

There is currently no suitable system available for the assessment of budgerigar body condition. A tool has been developed that uses an algorithmic decision tree of yes-no answers based on physical examination to objectively guide the assessor to a body condition score. The aim of this work was to evaluate the guide. Repeatability and reproducibility were measured by four assessors on three sequential days, using 38 budgerigars of mixed sex, age and weight. Data were analysed using a 3-factor anova, with Person and Bird as variable factors and occasion as a fixed factor. The association between body condition score and body fat was measured using three assessors and 63 dead budgerigars, which were chemically analysed for fat content after assessment. Data were statistically analysed to determine correlation using Spearman's Rank Coefficient. Occasion and person had no significant effect on body condition score (p = 0.988 and 0.347 respectively). Body condition score and percentage body fat were highly significantly correlated (R(2) = 0.768): percentage fat increased with increasing body condition score. The guide would appear to be a repeatable measure of body condition in budgerigars, suitable for use during physical examinations.

Life-history strategies of North American elk: trade-offs associated with reproduction and survival

The principle of energy allocation states that individuals should attempt to maximize fitness by allocating resources optimally among growth, maintenance, and reproduction. Such allocation may result in trade-offs between survival and reproduction, or between current and future reproduction. We used a marked population of North American elk (Cervus elaphus) to determine how energetic costs of reproduction in the current year affect survival and reproduction in the subsequent year. Using a multistate mark–recapture model we examined the influence of individual and environmental variation on trade-offs between these 2 life-history traits. We observed no difference in survival probabilities between pregnant and nonpregnant individuals or as a function of recruiting an offspring. Nonetheless, there was a negative effect of recruiting an offspring in the current year on becoming pregnant the following year. Increased body condition, and higher precipitation, contributed to greater probabilities of becoming pregnant in a particular year regardless of reproductive state and previous recruitment. Costs associated with reproduction led to a reduced probability of future reproduction rather than a reduction in survival. These findings are consistent with risk-sensitive reproductive allocation, where adult survival is maintained through variation in reproductive effort resulting in high and stable adult survival and more-variable reproduction.

Diet supplementation with clinoptilolite improves energy status, reproductive efficiency and increases milk yield in dairy heifers

The objective of this study was to investigate the effect of long-term dietary inclusion of clinoptilolite on the energy status, reproductive parameters and milk yield of dairy heifers. Eighty Holstein pregnant heifers were equally divided to two groups: treatment group heifers were fed the ration supplemented with 200 g clinoptilolite per day; control group heifers were fed the basal ration and served as controls. The experiment started on Day 210 of gestation and lasted until the end of the first lactation period. Blood samples were collected from each animal at the start of the experiment, 30 days later on the day of calving and then on a monthly basis and were analysed for serum glucose and ketone bodies. On the same days, all animals were monitored for body condition score. Cows were observed for heat every day and were inseminated at first heat after the 60th day postpartum. Calving to first heat interval, calving to first service interval, number of services per conception and calving interval were calculated for both groups. Milk yield for each cow was recorded monthly and 305-day milk yield was calculated. Clinoptilolite supplementation significantly increased body condition score and blood serum concentration of glucose and significantly decreased blood serum concentration of ketone bodies. Clinoptilolite also improved significantly the reproductive parameters evaluated and significantly increased milk production. These results indicate that daily dietary administration of 200 g of clinoptilolite can be used for the improvement of animal performance in dairy herds.

Evaluation of the relationship between body condition of high-yield Black-and-White Polish Holstein-Friesian cows and their productivity / Ocena zależności pomiędzy kondycją wysokowydajnych krów rasy phf cb a ich produkcyjnością

The aim of the study was to evaluate the relationship between the body condition of cows and their daily milk yield and composition of the milk. Body condition was assessed once a month (according to the 5-point BCS system) in a herd of 52 Black-and-White Polish HolsteinFriesian cows with annual milk yield of over 10,000 kg. The analysis covered 607 body condition assessments and test-day milking results. The data were analysed using the SAS package. Daily milk yield decreased significantly as BCS scores increased. Cows with the lowest BCS ( 2.25) produced 35.3 kg of milk, when for the highest scores (BCS > 3.75 pts) the amount of milk obtained amounted to 25.1 kg. Increasing body condition scores were accompanied by a significant increase in the content of protein, lactose and dry matter in the milk. Somatic cell count was not affected by body condition scores. At the beginning of lactation, multiparous cows used their energy reserves more intensively than primiparous cows, and from the sixth month replenished them to a greater degree. Lactations in primiparous cows were more persistent.