Prospective Evaluation of Low-Fat Diet Monotherapy in Dogs with Presumptive Protein-Losing Enteropathy.

For dogs with protein-losing enteropathy (PLE) and evidence of lymphangiectasia, the efficacy of low-fat diet as monotherapy or combined with prednisone remains poorly characterized. In this prospective, observational cohort study of 14 dogs with presumptive PLE and ultrasonographic evidence of lymphangiectasia, subjects were placed on various low-fat diets as monotherapy and prednisone was added if response was deemed inadequate. Dogs were assessed and scored at four recheck examinations across a 6 mo study period, including a final recheck ultrasound. Clinical and clinicopathologic variables were collected and dogs were divided into three outcome groups: clinical remission on dietary monotherapy (LOF); clinical remission on dietary therapy plus immunosuppressive prednisone (LOP); and treatment failure (TXF). Eleven of 14 dogs were in clinical remission at the study end date (6 mo after enrollment): 6 LOF dogs and 5 LOP dogs. LOF dogs achieved a significant reduction in Canine Chronic Enteropathy Clinical Activity Index score and a significant increase in serum albumin within 2 wk of beginning dietary monotherapy. Four of 11 dogs in remission also had ultrasonographic evidence of resolution of linear striations. Low-fat diet appears to be an effective monotherapy in some dogs with presumptive PLE and ultrasonographic evidence of lymphangiectasia.

Endogenous fat losses and true and apparent fat digestibility in adult and growing dogs fed diets containing poultry offal fat.

The objective of this study was to evaluate the coefficient of total tract apparent digestibility (CTTAD) of dietary nutrients, endogenous fat loss (EFL), dietary metabolizable energy (ME) content, coefficient of true digestibility (CTD) of fat and faecal parameters of dogs. A total of 16 puppies and 8 adult dogs were distributed according to a double Latin square experimental design. A basal diet was formulated, to which increasing levels (60, 120 and 180 g/kg) of poultry offal fat oil were added. EFL was estimated using hyperbolic and linear regression as a function of LW/day and dry matter (DM) intake, respectively, and the CTD of fat was calculated. The CTTAD of acid-hydrolysis ether extract (AHEE) and ME content increased as dietary poultry offal fat level increased both in adult dogs and in puppies (p < .05). The CTTAD of DM and crude protein were higher in adult dogs than in puppies. EFL was estimated by hyperbolic regression as y = 98.1094 - 13.6202/x and y = 99.1280 - 26.1366/x, where y = CTTAD of AHEE (%) and x = AHEE intake/kg BW, for adult dogs and puppies, respectively, which yielded EFL values of 138 and 262 mg AHEE per kg BW per day for adult dogs and puppies respectively. The EFL estimated by linear regression was 7.89 g and 8.97 g/kg DM intake for adult dogs and puppies respectively. The CTD estimated by both methodologies was higher in puppies than in adults (p < .05). Lower faecal DM and score, and higher ammonia production were obtained in puppies than adult dogs (p < .05). The results indicate good fat utilization and that fat digestibility is underestimated, as the CTTAD of AHEE does not take into account EFL, particularly at low-fat inclusion levels and in growing dogs, which have greater EFL than adult dogs.

Impact of hyperlipidaemia on intermediary metabolism, faecal microbial metabolites and urinary characteristics of lipoprotein lipase deficient vs. normal cats.

Findings in humans and rats indicate that hyperlipidaemia may be associated with enhanced endogenous oxalate (Ox) synthesis, which may be relevant for calcium oxalate (CaOx) urolith formation. Moreover, changes in lipid metabolism are proposed to negatively affect gut microbiota. This study aimed to investigate those potential interactions in hyperlipidaemic cats. Therefore, 10 normal control cats and seven lipoprotein lipase (LPL)-deficient cats were fed a low-fat diet for seven weeks. During the last week of the study, cats were housed in metabolic cages to collect urine and faeces. Blood was taken on the last day of the study. The LPL-deficient cats had significantly higher serum triglyceride concentrations than normal cats, while lactate dehydrogenase (LDH) activity was not different. Urinary relative supersaturation with CaOx, urinary Ox, calcium, and citrate excretions, and urine pH did not differ between groups. Lower faecal acetic, propionic and total short-chain fatty acid concentrations were observed in the LPL-deficient cats. In conclusion, hyperlipidaemia does not appear to be a specific risk factor for CaOx urolith formation in cats. In contrast to results in rats, hyperlipidaemia was not accompanied by elevated serum LDH activity. As LDH can synthesise Ox from glycolate or other precursors, this might be one possible explanation for the similar urinary parameters in the LPL-deficient and normal cats. Non-diet-induced hyperlipidaemia was not associated with marked changes in faecal microbial metabolites, suggesting no differences in the composition of the intestinal microbiota.

Genetic improvement of feed conversion ratio via indirect selection against lipid deposition in farmed rainbow trout (Oncorhynchus mykiss Walbaum).

In farmed fish, selective breeding for feed conversion ratio (FCR) may be possible via indirectly selecting for easily-measured indicator traits correlated with FCR. We tested the hypothesis that rainbow trout with low lipid% have genetically better FCR, and that lipid% may be genetically related to retention efficiency of macronutrients, making lipid% a useful indicator trait. A quantitative genetic analysis was used to quantify the benefit of replacing feed intake in a selection index with one of three lipid traits: body lipid%, muscle lipid% or viscera% weight of total body weight (reflecting visceral lipid). The index theory calculations showed that simultaneous selection for weight gain and against feed intake (direct selection to improve FCR) increased the expected genetic response in FCR by 1·50-fold compared with the sole selection for growth. Replacing feed intake in the selection index with body lipid%, muscle lipid% or viscera% increased genetic response in FCR by 1·29-, 1·49- and 1·02-fold, respectively, compared with the sole selection for growth. Consequently, indirect selection for weight gain and against muscle lipid% was almost as effective as direct selection for FCR. Fish with genetically low body and muscle lipid% were more efficient in turning ingested protein into protein weight gain. Both physiological and genetic mechanisms promote the hypothesis that low-lipid% fish are more efficient. These results highlight that in breeding programmes of rainbow trout, control of lipid deposition improves not only FCR but also protein-retention efficiency. This improves resource efficiency of aquaculture and reduces nutrient load to the environment.

Short communication: Feeding fat from distillers dried grains with solubles to dairy heifers: III. Effects on posttrial reproductive and lactation performance.

The objective of this research was to determine the subsequent effects on lactation and reproductive performance from feeding fat from distillers dried grains with solubles (DDGS) to growing dairy heifers. During the prepubertal growth phase, 33 Holstein heifers (133±18 d old) were used in a 24-wk randomized complete block design. Treatments included (1) a control diet (CON) containing ground corn and soybean products, 2) a diet with low-fat DDGS (LFDG), and (3) a higher-fat diet with traditional DDGS (HFDG). All diets contained 39.8% grass hay, 24.8% corn silage, and 1.5% vitamins and minerals. Previous results demonstrated that growth performance was maintained across treatments, but plasma cholesterol and fatty acids were greater and puberty may occur earlier in heifers fed HFDG. It was hypothesized that differences among treatments in metabolic profile and puberty may influence reproductive and first-lactation performance. Posttrial data on reproductive performance and milk production for the first 4 mo of lactation were collected for each heifer from dairy herd records. At 3wk prepartum and at calving, body weights, body condition scores, and body measurements were taken. No differences were observed among treatments for age at conception or age at calving. At calving, heifers fed the HFDG were shorter in withers height compared with heifers fed the other diets. Milk yields and components were similar or improved in heifers fed the distillers grains diets compared with heifers fed CON. Heifers fed LFDG had greater milk production and a tendency for greater milk protein yields compared with the heifers fed CON. Energy-corrected milk yields were similar among treatments. Feeding increased dietary fat from DDGS during the prepubertal growth phase did not negatively affect milk production, despite earlier attainment of puberty compared with other treatments. The overall ADG for all 3 treatments was 0.96kg/d during the prepubertal period, which is greater than recommended and may have compromised milk yield across treatments. Based on these findings, producers can feed either DDGS or LFDG with corn in replacement of soybean products and corn to prepubertal heifers and maintain or enhance subsequent reproductive and lactation performance. Dietary fat from DDGS can replace starch from corn as an energy source for prepubertal heifers without detriment to later performance.

Feeding fat from distillers dried grains with solubles to dairy heifers: I. Effects on growth performance and total-tract digestibility of nutrients.

The objective of this study was to determine if increased dietary fat from dried distillers grains with solubles (DDGS) in diets of growing heifers affected dry matter intake, average daily gain (ADG), growth performance, and nutrient digestibility. Thirty-three Holstein heifers (133±18 d old) were used in a 24-wk randomized complete block design. Treatments were (1) control (CON) containing ground corn and soybean products, (2) low-fat (LFDG) containing low-fat, high-protein DDGS and ground corn, and (3) high-fat (HFDG) with traditional DDGS. All diets contained 39.8% grass hay, 24.8% corn silage, and 1.5% vitamins and minerals. The HFDG diet was formulated to contain 4.8% fat compared with 2.8% in the CON and LFDG diets, which were greater in nonfibrous carbohydrate. Diets had a net energy gain of 1.0Mcal/kg of dry matter and were limit-fed at 2.45% of body weight. Heifers were weighed every 2wk and rations were adjusted accordingly. Heart girth, hip and wither heights, body length, and body condition score were recorded every 2wk. Total-tract digestion of nutrients was evaluated during wk16 using fecal grab sampling and an external marker. No treatments by time interactions were found. Dry matter intakes, body weights, ADG, and gain-to-feed ratio were similar among treatments; however, ADG averaged 0.96kg/d among treatments, which is greater than recommended. All body frame measurements and body condition scores were similar among treatments. Total-tract digestibilities of dry matter and organic matter were not different among treatments. However, crude protein and neutral detergent fiber digestibility were increased in the HFDG diet compared with the CON and LFDG diets. These results demonstrate that using DDGS or low-fat DDGS with corn in growing heifer rations can maintain performance. Utilizing the fat in DDGS as a dietary energy source in replacement of starch from corn did not influence growth performance or negatively affect nutrient digestion.

Feeding fat from distillers dried grains with solubles to dairy heifers: II. Effects on metabolic profile.

The objective of this study was to determine if increased dietary fat from dried distillers grains with solubles (DDGS) in diets of growing heifers affected metabolic profile, plasma fatty acid profile, and reproductive maturation. Thirty-three Holstein heifers (133±18 d of age) were used in a 24-wk randomized complete block design with 3 treatment diets. Treatment diets were (1) control (CON) containing ground corn (15.9% of DM) and soybean products (17.9%), (2) low-fat (LFDG) containing low-fat DDGS (21.9%) and ground corn (11.9%), or (3) high-fat (HFDG) with traditional DDGS (33.8%). Diets were isonitrogenous and isocaloric, but the HFDG diet was formulated to contain 4.8% fat compared with 2.8% in the CON and LFDG diets. All 3 diets were limit-fed to 2.45% of body weight on a dry matter basis, and resulted in a mean average daily gain of 0.96kg/d across treatments. Every 4wk, jugular blood was collected for analysis of metabolites and metabolic hormones. During wk20 of the feeding period, blood samples were collected for analysis of plasma fatty acid profiles. When heifers weighed between 200 and 300kg of body weight, coccygeal blood samples were taken twice weekly for analysis of progesterone to determine if puberty had been reached. Plasma concentrations of nonesterified fatty acids were similar among treatments and consistent over the duration of the study. Plasma concentrations of ß-hydroxybutyrate, insulin, insulin-like growth factor-1, and leptin were similar among heifers fed each treatment diet, but increased over the duration of the feeding period. Serum concentrations of glucose tended to be less in heifers fed HFDG compared with heifers fed the CON diet. Glucose concentrations fluctuated throughout the feeding period, but no treatment by time interactions were noted. Plasma urea N concentrations were less in heifers fed LFDG compared with heifers fed HFDG and CON diets. The concentrations of plasma urea N increased over the duration of the feeding period, with no treatment by week interaction. Total plasma cholesterol was greater in heifers fed HFDG compared with the CON and LFDG diets, and a significant week effect and a week by treatment interaction were observed. Fatty acid profiles also differed among treatments based on the supply of fatty acids from the diet. Progesterone analysis indicated that heifers fed HFDG tended to be pubertal at a younger age than heifers on CON. These results demonstrate that dietary fat from DDGS can be used in high-plane of nutrition rations for growing heifers and maintain metabolic energy status compared with starch from corn, but alters the concentrations of different blood lipids.

Digestion of fat and fatty acids along the gastrointestinal tract of broiler chickens.

Two experiments were conducted. The first experiment investigated the digestion of fat and fatty acids (FA) from soybean oil and tallow along the gastrointestinal tract of broiler chickens. The second experiment was conducted to determine endogenous fat and FA losses and the FA profile of chicken bile. In experiment 1, 2-wk-old broilers were fed corn-soy diets supplemented with 50 g/kg of soybean oil or tallow for 7 d and digesta were collected from the duodenum, upper jejunum, upper ileum, and lower ileum. Apparent digestibility coefficients were calculated using the titanium marker ratio in diets, and digesta. Digestibility of fat was determined to be negative in the duodenum, indicating marked net secretion of fat into this segment. Fat was rapidly digested in the jejunum, with digestibility coefficients of 0.60 to 0.64 being determined at the end of the jejunum. The digestion of fat continued in the upper ileum. The apparent digestibility coefficient of fat determined at lower ileum in soybean oil diets was higher (P < 0.05) than that in tallow diets (0.82 vs. 0.74). Linoleic acid was digested throughout the intestinal tract, whereas the digestion of palmitic, stearic, and oleic acids started only in the jejunum. Measurements at the lower ileal level showed that the unsaturated FA (linoleic and oleic acids) were well digested (0.90 to 0.94), irrespective of the source of fat. In contrast, the digestibility of saturated FA (palmitic and stearic acids) was influenced (P < 0.05) by the fat source. Digestibility coefficients of palmitic and stearic acids at lower ileum were markedly higher (P < 0.05) in the diet containing soybean oil (0.77 to 0.85) compared with that containing tallow (0.58 to 0.68). In experiment 2, ileal endogenous fat loss was determined to be 1,714 mg/kg of DM intake. Endogenous fat was composed mainly of palmitic (75 g/kg), stearic (131 g/kg), oleic (73 g/kg), linoleic (133 g/kg), and arachidonic (60 g/kg) acids. Fatty acid profile of endogenous fat was found to be remarkably similar to that of the bile, suggesting that the reabsorption of fat and FA from the bile was incomplete in growing broiler chickens.

Effects of N,N-dimethylglycine sodium salt on apparent digestibility, vitamin E absorption, and serum proteins in broiler chickens fed a high- or low-fat diet.

The objective of this study was to assess the effect of supplementation with sodium salt of N,N-dimethylglycine (DMG-Na) on apparent digestibility (AD) in broiler chickens fed low- and high-fat diets. Twenty-eight 1-d-old broiler chickens were fed one of the dietary treatments: a low-fat diet (LF) or a high-fat diet (HF) supplemented with or without 1,000 mg/kg of DMG-Na. Body weight and feed consumption were recorded at 14 and 35 d of age. Average daily growth, daily feed intake, and feed conversion ratio were calculated. The AD of DM, organic matter (OM), CP, total fat (TF), and α-tocopheryl-acetate were assessed by 2 digestibility trials (at 18-21 and 32-35 d, respectively). Serum protein and plasma α-tocopherol concentrations were assessed at 35 d of age. Final BW, feed intake, carcass, breast, and spleen weight were higher in groups fed LF than HF diets (P = 0.048, P = 0.002, P = 0.039, P < 0.001, P = 0.007, respectively). Liver weight was increased in DMG-Na-unsupplemented groups (P = 0.011) for both fat levels. During the first digestibility trial (18-21 d), the AD of DM (P = 0.023), OM (P = 0.033), CP (P = 0.030), and α-tocopheryl-acetate (P = 0.036) was higher in the DMG-Na-supplemented group than control. Digestibility of total fat was increased by DMG-Na supplementation in the LF groups (P = 0.038). A trend for improvement of digestibility was observed during the second digestibility trial (32-35 d) for DM (P = 0.089), OM (P = 0.051), and CP (P = 0.063) in DMG-Na groups. Total serum proteins (and relative fractions) were positively influenced by DMG-Na supplementation both in LF and HF diets (P = 0.029). Plasma α-tocopherol concentration was higher in groups fed LF than HF diets (P < 0.001).

Link between lipid metabolism and voluntary food intake in rainbow trout fed coconut oil rich in medium-chain TAG.

We examined the long-term effect of feeding coconut oil (CO; rich in lauric acid, C12) on voluntary food intake and nutrient utilisation in rainbow trout (Oncorhynchus mykiss), with particular attention to the metabolic use (storage or oxidation) of ingested medium-chain TAG. Trout were fed for 15 weeks one of the four isoproteic diets containing fish oil (FO) or CO as fat source (FS), incorporated at 5% (low fat, LF) or 15% (high fat, HF). Fat level or FS did not modify food intake (g/kg(0·8) per d), despite higher intestinal cholecystokinin-T mRNA in trout fed the HF-FO diet. The HF diets relative to the LF ones induced higher growth and adiposity, whereas the replacements of FO by CO resulted in similar growth and adiposity. This, together with the substantial retention of C12 (57% of intake), suggests the relatively low oxidation of ingested C12. The down-regulation of carnitine palmitoyl-transferase-1 (CPT-1) confirms the minor dependency of medium-chain fatty acids (MCFA) on CPT-1 to enter the mitochondria. However, MCFA did not up-regulate mitochondrial oxidation evaluated using hepatic hydroxyacyl-CoA dehydrogenase as a marker, in line with their high retention in body lipids. At a low lipid level, MCFA increased mRNA levels of fatty acid synthase, elongase and stearoyl-CoA desaturase in liver, showing the hepatic activation of fatty acid synthesis pathways by MCFA, reflected by increased 16 : 0, 18 : 0, 16 : 1, 18 : 1 body levels. The high capacity of trout to incorporate and transform C12, rather than to readily oxidise C12, contrasts with data in mammals and may explain the absence of a satiating effect of CO in rainbow trout.

The effect of dietary lipid content and stress on egg quality in farmed Atlantic cod Gadus morhua.

The present study assessed differences in fecundity and egg quality from Atlantic cod Gadus morhua fed isoproteic diets containing 13% fat (low fat, LF) or 20% fat (high fat, HF) and either stressed or left unstressed as a control over the spawning season. Each diet was fed to triplicate groups of G. morhua from June 2009, through to first maturation and spawning. In January 2010 sub-groups of G. morhua were moved to land-based spawning tanks where the experimental trial was carried out. At the start of the experiment, G. morhua fed the high-fat diet were significantly larger than G. morhua fed low-fat diet. These differences were maintained through the spawning season, although with a loss of mass in both dietary groups. Relative fecundity through the season was significantly lower in stressed G. morhua fed LF compared to unstressed G. morhua fed the same diet. Stressed G. morhua had a higher variability in weekly amount of eggs spawned, spawning occurred more irregularly, and the spawning period lasted longer than in unstressed G. morhua. Several egg quality variables were also affected: eggs from G. morhua fed LF and exposed to stress had lower fertilization and hatching rates compared to the unstressed G. morhua fed the same diet as well as all G. morhua fed HF. Gadus morhua fed a low-fat diet appeared less tolerant to stress than fish fed a high-fat diet.

Associations among serum insulin, calprotectin, and C-reactive protein concentrations in Miniature Schnauzers with idiopathic hyperlipidemia before and after feeding an ultra-low-fat diet.

BACKGROUND: Miniature Schnauzers (MS) commonly have idiopathic hypertriglyceridemia (HTGL), which is associated with insulin resistance (IR) and a subclinical inflammatory phenotype. OBJECTIVES: Determine the association between indicators of IR and inflammatory biomarkers in MS with and without HTGL and identify how indicators of IR are affected by dietary intervention in MS with HTGL. ANIMALS: Seventy MS with HTGL and 79 MS without HTGL. In addition, 15 MS with HTGL were placed on a low-fat diet. METHODS: Serum concentrations of triglycerides, cholesterol, calprotectin, insulin, and glucose were compared between groups. RESULTS: Serum glucose and calprotectin concentrations (shown to be higher in MS with HTGL than in MS without HTGL) were inversely correlated (ρ = -.28; P < .001). After dietary intervention, median serum insulin concentrations were 8.1 mU/L compared to 20.8 mU/L before dietary intervention (P = .06). Dogs with complete resolution of HTGL after dietary intervention (5 dogs) had significantly lower serum insulin concentrations compared to baseline (P = .03). CONCLUSION AND CLINICAL IMPORTANCE: The subclinical inflammatory phenotype in MS with HTGL appears to be associated with IR. Resolution of HTGL by dietary intervention is associated with a decrease in serum insulin concentrations. The implication of the increase in serum calprotectin concentrations after resolution of HTGL warrants further study.

Effect of inclusion levels of low-fat dried distillers grains in finishing diets on protein and energy intake and retention and estimation of protein and energy requirements of young Nellore bulls fed with high concentrate diets.

The objective was to evaluate the effect of including low-fat dried distillers grains (DDG) in finishing diets on protein and energy intake and retention and to estimate the protein and energy requirement of young Nellore bulls. Thirty-five animals were used: baseline (n = 4), maintenance (n = 4), and ad libitum intake (n = 27). Ad libitum animals were divided into four groups: diets with the inclusion of DDG at the levels of 0, 150, 300, and 450 g/kg (dry matter basis). At the end of the experiment, all animals were slaughtered. There was a linear reduction with increasing DDG levels in the total digestible nutrients intake (p = 0.008), metabolizable energy (ME) intake (p < 0.010), in total retained energy (p = 0.065), and in heat production (p < 0.001). Metabolizable protein (MP) intake increased linearly (p < 0.010) but retained protein did not differ (p = 0.499). Daily net energy and ME requirement for maintenance were 75.9 and 122 kcal/kg0.75 EBW, respectively. Daily MP for maintenance was 3.6 g/kg0.75 shrunk body weight. DDG inclusion in finishing diets reduces energy intake and deposition, and we recommend the equations of this study to estimate the requirements of young Nellore bulls.

Impact of different levels of low-fat dried distillers grains on performance of young Nellore bulls during the finishing phase.

This study evaluated the effect of including low-fat dried distillers grains (DDG) on young Nellore bulls performance, nutritional parameters, and nitrogen metabolism. Thirty-five Nellore cattle were randomly divided into four diets: without dried distillers grains (D0) or with the inclusion of DDG at 150 g/kg (D150), 300 g/kg (D300), or 450 g/kg (D450). The evaluation period lasted 126 days, and three periods of collection of feces and urine were carried out. Final body weight (P = 0.099) and average daily gain (P = 0.097) tended to decrease linearly; the digestibility of dry matter (P < 0.001), organic matter (P < 0.001), ether extract (P < 0.001) and nonfiber carbohydrates (P < 0.001), and intakes of total digestible nutrients (TDN, P < 0.001) decreased linearly. The increase in crude protein intake (P < 0.001) did not result in an increase in the amount of nitrogen retained (P = 0.540). We concluded that the inclusion of low-fat DDG in finishing diets up to the level of 450 g/kg tends to reduce animal performance and the intake of TDN.

Fenofibrate treatment for severe hypertriglyceridemia in dogs.

Lipid disorders are relatively common in dogs. Hyperlipidemia can be primary or secondary to other diseases. In humans, fenofibrate is used to control hypertriglyceridemia. In dogs, there are no studies evaluating fenofibrate in hypertriglyceridemia. The aim of the study was to evaluate the safety and efficacy of fenofibrate to control severe hypertriglyceridemia in dogs. A total of 124 dogs (n = 124) with severe hypertriglyceridemia (>300 mg/dL, 3.39 mmol/L) were randomly distributed in the fenofibrate group (n = 64) and the diet group (n = 60). Dogs of the fenofibrate group were treated with fenofibrate (10 mg/Kg) once daily. Dogs of the diet group were treated with low-fat diet (10%). Serum triglycerides (TGs), total cholesterol (TC), liver enzymes, and creatine kinase concentrations were evaluated, before and after 1 mo of medical or dietary treatment. Triglyceride concentrations were reduced with fenofibrate (P < 0.001), and 85.93% of the dogs normalized their levels. Triglyceride concentrations also decreased with low-fat diet (P < 0.001), but only 26.6% of the dogs normalized their levels. Triglyceride concentrations were reduced with fenofibrate (P < 0.01) and with low-fat diet (P < 0.01). Of the cases with hypercholesterolemia, 53.7% and 50% of the dogs normalized their TC concentrations, with fenofibrate and diet, respectively. No significant adverse effects were observed (3% showed diarrhea). Fenofibrate was safe and effective in reducing and normalizing TG concentrations in dogs with severe hypertriglyceridemia, regardless of the cause of hyperlipidemia. The low-fat diet was effective in reducing, but not normalizing, TG concentrations. Fenofibrate and low-fat diet were effective in reducing TC concentrations. This is the first study evaluating fibrates in dogs with severe hypertriglyceridemia and comparing results with a low-fat diet.

Performance and amino acid utilization of early lactation dairy cows fed regular or reduced-fat dried distillers grains with solubles.

The objective of this study was to evaluate lactation response and AA utilization of early lactation cows fed 2 types of dried distillers grains with solubles (DG): regular (DDGS) or reduced-fat (RFDGS). Thirty-six Holstein cows 19.7+/-2.6 d in milk at the start of the experiment were used in a randomized complete block design for 14 wk including a 2-wk covariate period. Treatments consisted of the following diets: 1) control (CON) diet containing 0% DG; 2) diet containing 22% DDGS; and 3) diet containing 20% RFDGS. Distillers grains replaced soybean meal, expeller soybean meal, and soyhulls from the CON diet. Diets were formulated to be similar in crude protein, ether extract, neutral detergent fiber, and net energy for lactation concentrations. Dry matter intake (24.7 kg/d) and milk yield (39.3 kg/d) were similar for all diets. Milk fat and lactose percentages were unaffected by diets; however, protein percentage was greater for cows fed the DG diets compared with the CON diet. Consequently, milk protein yield was also greater for the DG diets compared with CON. Milk urea nitrogen decreased for cows fed DG diets and averaged 11.8, 10.9, and 10.1 mg/dL, respectively, for CON, DDGS, and RFDGS. Feed efficiency tended to be greater and N efficiency was greater for cows fed DG compared with CON. Body weight (711 kg), body weight change (+0.49 kg/d), and body condition score (3.36) were similar for all diets, but cows fed CON tended to gain more body condition (+0.14) than cows fed DG diets. Amino acid utilization was evaluated at the peak of milk production corresponding to wk 9 of lactation. Arterial Lys concentration was lower with DG diets (70.4, 58.6, and 55.8 microM/L). Cows fed DG had greater arterial Met concentration (21.3 microM) compared with CON (14.9 microM). Arterio-venous difference of Lys was similar across diets, whereas that of Met was greater for the DG diets compared with the CON diet (10.3 vs. 13.0 microM/L). Extraction efficiency of Lys by the mammary gland was greater for DG diets than for CON (76.1 vs. 65.4%). Mammary uptake of Lys (2.56 g/kg of milk) was similar for all diets, and the uptake of Met tended to increase in cows fed DG diets. Plasma glucose, triglyceride, and total cholesterol were unaffected by treatment; however, cows fed DG diets had lower beta-hydroxybutyrate and tended to have lower nonesterified fatty acid concentrations than cows fed the CON diet. Despite the apparent deficiency of Lys, milk protein percentage was increased in cows fed DG diets.

Effect of a low-fat diet on serum triglyceride and cholesterol concentrations and lipoprotein profiles in Miniature Schnauzers with hypertriglyceridemia.

BACKGROUND: Hypertriglyceridemia is common in Miniature Schnauzer (MS). Dietary management of hypertriglyceridemia is important, but no studies are available. HYPOTHESIS/OBJECTIVES: To evaluate the effect of a commercially available low-fat diet on serum triglyceride and cholesterol concentrations and lipoprotein profiles in MS with hypertriglyceridemia. ANIMALS: Sixteen MS with hypertriglyceridemia and 28 MS without hypertriglyceridemia. METHODS: Prospective clinical trial. Four blood samples (1-2 months before and 1 day before diet change and 2 and 3 months after the dogs were fed the low-fat diet) were collected from the MS with hypertriglyceridemia. RESULTS: Serum triglyceride concentrations for the 2 samples after the diet change (median of sample 3 = 177 mg/dL; range, 48-498; median of sample 4 = 168 mg/dL; range, 77-745) were significantly lower than the 2 samples before the diet change (median of sample 1 = 480 mg/dL; range, 181-1320; median of sample 2 = 493 mg/dL; range, 114-1395; P < .001). Serum cholesterol concentrations for the 2 samples after the diet change (mean for sample 3 = 257 mg/dL, SD = 82.2; mean for sample 4 = 178 mg/dL, SD = 87.4) were also significantly lower than the 2 samples before the diet change (mean for sample 1 = 381 mg/dL, SD = 146.1; mean for sample 2 = 380 mg/dL, SD = 134.7; P < .001). Before the diet change, 15/16 (94%) of hyperlipidemic MS were classified as hyperlipidemic based on their lipoprotein profiles alone. After the diet change, significantly fewer MS (7/16; 44%; odds ratio = 19.3; 95% CI = 2.0-184.0; P = .006) were classified as hyperlipidemic based on lipoprotein profile analysis. CONCLUSIONS AND CLINICAL IMPORTANCE: The study diet was effective in reducing serum triglyceride and cholesterol concentrations and correcting lipoprotein profiles in MS with hypertriglyceridemia.

Comparison of regression and fat-free diet methods for estimating ileal and total tract endogenous losses and digestibility of fat and fatty acids in growing pigs.

An experiment was conducted to 1) compare the regression and fat-free diet methods for estimating total or basal endogenous losses of fat (ELF) and fatty acids (ELFA) and true digestibility (TD) or standardized digestibility (SD) of fat and fatty acids in growing pigs and 2) compare these estimated values at the end of the ileum and over the entire intestinal tract. Ten barrows (initial body weight: 45.1 ± 2.8 kg) were surgically fitted with a T-cannula in the distal ileum and allotted to one of five experimental diets in a three-period Youden Square design. A fat-free diet was formulated using cornstarch, soy protein isolate, and sucrose. Four oil-added diets were formulated by adding four levels of soybean oil (2%, 4%, 6%, and 8%) to the fat-free basal diet at the expense of cornstarch. All diets contained 26% sugar beet pulp and 0.40% chromic oxide. Results indicated that there were no differences between true ileal digestibility (TID) of fat and true total tract digestibility (TTTD) of fat when pigs were fed soybean oil. The TID of C18:0 and total saturated fatty acids (TSFA) was greater than TTTD (P < 0.05). The total ELF at the end of the ileum were not different from that over the entire intestinal tract. In addition, total endogenous losses of C18:0 and TSFA were greater for the entire intestinal tract than at the end of the ileum, whereas total endogenous losses of C18:2 and total unsaturated fatty acids were just the opposite. Similar results were observed for basal ELF and ELFA. As the inclusion level of soybean oil increased, apparent digestibility (AD) of fat and fatty acids increased linearly (P < 0.05) except for apparent ileal digestibility of C18:0. However, SD of fat and fatty acids was not influenced by the inclusion level of soybean oil. Estimation of ELF and ELFA observed by the regression and fat-free diet methods did not differ when measured at the end of the ileal or total tract. There were no differences between the estimations of TD and SD of fat and fatty acids for soybean oil. Collectively, the estimation of TD or SD of fat can be measured over the entire intestinal tract, whereas the ileal analysis method should be used to determine the ELF, ELFA, and TD or SD of fatty acids. Correcting AD for basal ELF and ELFA can accurately estimate SD values of fat and fatty acids.

Transient reductions in milk fat synthesis and their association with the ruminal and metabolic profile in dairy cows fed high-starch, low-fat diets.

Sub-acute ruminal acidosis (SARA) is sometimes observed along with reduced milk fat synthesis. Inconsistent responses may be explained by dietary fat levels. Twelve ruminally cannulated cows were used in a Latin square design investigating the timing of metabolic and milk fat changes during Induction and Recovery from SARA by altering starch levels in low-fat diets. Treatments were (1) SARA Induction, (2) Recovery and (3) Control. Sub-acute ruminal acidosis was induced by feeding a diet containing 29.4% starch, 24.0% NDF and 2.8% fatty acids (FAs), whereas the Recovery and Control diets contained 19.9% starch, 31.0% NDF and 2.6% FA. Relative to Control, DM intake (DMI) and milk yield were higher in SARA from days 14 to 21 and from days 10 to 21, respectively (P < 0.05). Milk fat content was reduced from days 3 to 14 in SARA (P < 0.05) compared with Control, while greater protein and lactose contents were observed from days 14 to 21 and 3 to 21, respectively (P < 0.05). Milk fat yield was reduced by SARA on day 3 (P < 0.05), whereas both protein and lactose yields were higher on days 14 and 21 (P < 0.05). The ruminal acetate-to-propionate ratio was lower, and the concentrations of propionate and lactate were higher in the SARA treatment compared with Control on day 21 (P < 0.05). Plasma insulin increased during SARA, whereas plasma non-esterified fatty acids and milk ß-hydroxybutyrate decreased (P < 0.05). Similarly to fat yield, the yield of milk preformed FA (>16C) was lower on day 3 (P < 0.05) and tended to be lower on day 7 in SARA cows (P < 0.10), whereas yield of de novo FA (<16C) was higher on day 21 (P < 0.01) in the SARA group relative to Control. The t10- to t11-18:1 ratio increased during the SARA Induction period (P < 0.05), but the concentration of t10-18:1 remained below 0.5% of milk fat, and t10,c12 conjugated linoleic acid remained below detection levels. Odd-chain FA increased, whereas branched-chain FA was reduced during SARA Induction from days 3 to 21 (P < 0.05). Sub-acute ruminal acidosis reduced milk fat synthesis transiently. Such reduction was not associated with ruminal biohydrogenation intermediates but rather with a transient reduction in supply of preformed FA. Subsequent rescue of milk fat synthesis may be associated with higher availability of substrates due to increased DMI during SARA.

Association of serum calprotectin (S100A8/A9) concentrations and idiopathic hyperlipidemia in Miniature Schnauzers.

BACKGROUND: Idiopathic hyperlipidemia (IH) is a common condition in Miniature Schnauzers (MS). Studies in people have linked IH to low-grade inflammation, which plays an important role in the pathogenesis of IH complications. The role of inflammation in MS with IH is unknown. OBJECTIVE: Evaluation of the inflammatory markers serum calprotectin and S100A12 in MS with IH and in response to dietary intervention for IH management. ANIMALS: One-hundred fifty clinically healthy MS. METHODS: Serum triglyceride, cholesterol, calprotectin, and S100A12 concentrations were measured before and after placing the dogs on an ultra-low fat diet. RESULTS: Hypertriglyceridemia (HTGL, P < .001) and hypercholesterolemia (HCHOL, P = .01) were independently associated with increased serum calprotectin but not S100A12 concentrations. Compared to normolipidemic MS, serum calprotectin concentrations were significantly higher in MS with HTGL (P < .001) or combined hyperlipidemia (P = .02), but not those with isolated HCHOL (P = 1.0000). Presence (P = .005) and severity (P = .003) of HTGL and serum cholesterol concentrations (P = .04) decreased in MS with IH within 14-26 weeks after being placed on the ultra-low fat diet, but neither serum calprotectin nor S100A12 concentrations changed significantly with this dietary intervention. CONCLUSIONS AND CLINICAL IMPORTANCE: Subclinical (low-grade) inflammation appears to be present in some MS with IH, and an ultra-low fat diet does not decrease serum concentrations of inflammatory proteins in those dogs. Whether this presumed inflammatory phenotype in MS with IH is associated with the development of IH complications (eg, insulin resistance) requires further research.