Association between energy status early postpartum and subsequent embryonic mortality in high‐yielding recipient cows

High‐yielding Holstein‐Friesian recipients (n = 43) were used in order to investigate the relation between energy balance status during the early postpartum period and subsequent embryonic mortality after transferring good‐quality frozen embryos. Blood samples were collected during the second, third, fourth, fifth, sixth and seventh weeks postpartum in order to measure energy status indicators. These indicators include β hydroxyl butyric acid (BHBA), non‐esterified fatty acid (NEFA), total cholesterol (T‐chol), glucose and blood urea nitrogen (BUN). Moreover, body condition scores (BCS) were assessed during the same period. Pregnancy diagnosis by ultrasonography at the 28th day postestrus and embryo viability was ascertained until 45 days postestrus in order to detect late embryonic mortality (LEM). The pregnancy rate on day 28 was 44.2% (19/43); however, five cows (11.6%) experienced LEM by day 45. Based on the non‐return rate at day 24, non‐pregnant animals, as diagnosed by ultrasonography, were allocated into animals with longer estrus intervals than 24 days (32.5%; mid‐embryonic mortality (MEM) group) and animals returning to estrus by day 24 postestrus (23.5%; early embryonic mortality (EEM) group). At week 5 postpartum, BCS was significantly (P < 0.05) lower in the LEM group than that of pregnant (PREG), EEM and MEM groups. NEFA was significantly higher in animals that experienced LEM (LEM group) at week 7 postpartum (289.6 ± 47.0 µEq/L; P < 0.01) than that of PREG (196.8 ± 16.0 µEq/L), EEM (157.2 ± 18.6 µEq/L) and MEM groups (191.5 ± 14.4 µEq/L). In conclusion, lower BCS at week 5 postpartum and higher NEFAs at week 7 postpartum may be associated with subsequent LEM in high‐yielding recipient cows.     

Combining ultrasound and lactobacilli treatment for high‐fat‐diet‐induced obesity in mice

Chronic systemic lipopolysaccharide‐induced inflammation can cause obesity. In animal experiments, lactobacilli have been shown to inhibit obesity by modifying the gut microbiota, controlling inflammation and influencing the associated gene expression. A previous study found that high‐fat‐diet‐induced (HFD) obesity was suppressed by lactobacilli ingestion in rats via the inhibition of parasympathetic nerve activity. This study explored the combined use of lactobacilli ingestion and ultrasound (US) to control body weight and body fat deposition in HFD mice over an 8‐week experimental period. Male C57BL/6J mice received an HFD during treatment and were randomly divided into four groups: (i) control group (H), (ii) lactobacilli alone (HB), (iii) US alone (HU) and (iv) lactobacilli combined with US (HUB). The US was targeted at the inguinal portion of the epididymal fat pad on the right side. At the 8th week, body weight had decreased significantly in the HUB group (15.56 ± 1.18%, mean ± SD) group compared with the HU (26.63 ± 0.96%) and H (32.62 ± 5.03%) groups (p < 0.05). High‐resolution microcomputed tomography (micro‐CT) scans revealed that the reduction in total body fat volume was significantly greater in the HUB group (69%) than in the other two experimental groups (HB, 52%; HU, 37%; p < 0.05). The reductions in the thickness of the subcutaneous epididymal fat pads were significantly greater in the HUB group (final thickness: 340 ± 7 μm) than in the H (final thickness: 1150 ± 21 μm), HB (final thickness: 1060 ± 18 μm) and HU (final thickness: 370 ± 5 μm) groups (all p < 0.05). Combination therapy with lactobacilli and US appears to enhance the reduction in body weight, total and local body fat deposition, adipocyte size and plasma lipid levels over an 8‐week period over that achieved with lactobacilli or US alone in HFD mice. These results indicate that US treatment alone can reduce hyperlipidemia in HFD mice.     

Maternal high‐fat diet promotes onset of diabetes in rat offspring

The onset and progression of type II diabetes is closely related to environmental factors, in particular dietary habit. Moreover, the environmental exposures very early in life can influence the risk for development of type II diabetes later in life. In this study, we investigated pathophysiological changes in the pups of maternal Spontaneously Diabetic Torii (SDT) rats that were fed a high‐fat diet (HFD) throughout gestation and lactation. Maternal SDT rats were continued on HFD for 5 weeks, from day 8 of gestation to day 21 after birth, and biological analyses of the pups were performed from 2 to 22 weeks of age. Results of serum lipid levels in pups from dams fed HFD were higher than pups from dams fed a standard diet, and the onset of diabetes was significantly accelerated in pups from dams fed HFD. In pathological analyses, pups from dams fed HFD showed increases in liver weight and vacuolation of hepatic cells at 2 weeks of age. In conclusion, the metabolic disorder of lipids and glucose in SDT rats is closely related to the nutritional condition of dams during the periods of gestation and lactation.     

The effect of inulin supply to high‐fat diet rich in saturated fatty acids on pork quality and profile of sarcoplasmic protein in meat exudate

The aim of the study was to evaluate the influence of inulin supply to high‐fat diet rich in saturated fatty acids (SFA) on pork quality and profile of sarcoplasmic protein in drip loss. At 50 days of age, twenty cross‐bred pigs (gilts) were randomly allotted to four groups: the control (C) group fed a standard diet, and three experimental (D1, D2 and D3) groups fed a high‐fat diet rich in SFA. Moreover, pigs from the groups D2 and D3 consumed an extra inulin supply (7% of daily feed intake) from 85 to 120 days of age (for 5 weeks) and from 50 to 120 days of age (for 10 weeks) respectively. The addition of inulin to the diet reduced meaty odour and flavour significantly, improved tenderness and overall sensory quality of pork and additionally influenced ultimate pH, L* colour parameter, lactate level and protein content in meat. The diets also affected the profile of sarcoplasmic proteins. Significant effects were observed for the following enzymes—PK/PGI (pyruvate kinase/phosphoglucose isomerase) and ALD (aldolase), which are related to the intensity of post‐mortem glycolysis. Presented data indicate that long‐term inulin supply to high‐fat diet has a positive effect on technological and sensory quality as well as protein profile of pork.     

Effect of l‐glutamic acid supplementation on performance and nitrogen balance of broilers fed low protein diets

The aim of this study was to evaluate the effect of protein reduction and supplementation of l ‐glutamic acid in male broiler diets. A total of 648 chicks of the Cobb 500 strain were distributed in a completely randomized design with six treatments and six replications with eighteen birds per experimental unit. The study comprised pre‐starter (1–7 days), starter (8–21 days), growth (22–35 days) and final (36–45 days) phases. The first treatment consisted of a control diet formulated according to the requirements of essential amino acids for each rearing phase. The second and third treatments had crude protein (CP) reduced by 1.8 and 3.6 percentage points (pp) in relation to the control diet respectively. In the fourth treatment, l ‐glutamic acid was added to provide the same glutamate level as the control diet, and in the last two treatments, the broilers were supplemented with 1 and 2 pp of glutamate above that of the control diet respectively. The reduction in CP decreased the performance of broilers and the supplementation of l ‐glutamic acid did not influence performance when supplied in the diets with excess of glutamate. The lowest excreted nitrogen values were observed in the control diet, and treatments 2 and 3, respectively, in comparison with treatments with the use of l ‐glutamic acid (5 and 6). Retention efficiency of nitrogen was better in the control diet and in the treatment with a reduction of 1.8 pp of CP. It was verified that the serum uric acid level decreased with the CP reduction. A reduction in CP levels of up to 21.3%, 18.8%, 18.32% and 17.57% is recommended in phases from 1 to 7, 8 to 21, 22 to 35 and at 36 to 42 days, respectively, with a level of glutamate at 5.32%, 4.73%, 4.57%, 4.38%, also in these phases.     

Net energy content of five fiber‐rich ingredients fed to pregnant sows

The present study was conducted to determine the net energy (NE) values and energy efficiency of wheat bran (WB), sugar beet pulp (SBP), corn gluten feed (CGF), soybean hulls (SBH), and defatted rice bran (DFRB) fed to pregnant sows. Thirty‐six multiparous pregnant sows were randomly assigned to six dietary treatments with six replicates per treatment. Each period lasted for 21 days including 14 days for adaptation. On day 15, sows were moved into respiration chambers for heat production (HP) measurement and provided feed at 544 kJ/kg BW^0.75/day. On day 20, sows were fasted to measure the fasting heat production (FHP). Experimental diets included corn‐soybean meal basal diet and five diets containing 29.20% WB, SBP, CGF, SBH, and DFRB, respectively. Results showed that inclusion of WB, SBP, CGF, SBH, and DFRB to basal diet decreased (p < 0.05) the apparent total tract digestibility of energy and nutrients. The average adjusted total HP and FHP were 418 kJ/kg BW^0.75/day and 326 kJ/kg BW^0.75/day, respectively. The average NE:ME ratio of experiment diets was 82.5%. In conclusion, the NE values of WB, SBP, CGF, SBH, and DFRB were 9.05, 8.59, 8.37, 7.64, and 7.93 MJ/kg DM, respectively.     

Capsosiphon fulvescens extracts improve obesity‐associated metabolic disorders and hepatic steatosis in high‐fat diet‐induced obese mice

Herbal dietary supplements have attracted more and more attention owing to their relative effectiveness in obesity ‐related metabolic disorders and diseases. This study investigated the therapeutic effects and underlying mechanisms of Capsosiphon fulvescens (CF) extracts on obesity, their associated metabolic disorders and hepatic steatosis in high‐fat diet (HFD)‐induced obese mice. Male C57BL/6 mice were fed with normal, HFD/Vehicle and HFD/CF (orally 300 mg/kg/day for CF). After 12 weeks, CF blocked HFD‐induced body weight, food intake, liver weight, hepatic triglyceride (TG), fat mass (weight of abdominal subcutaneous fat and epididymal adipose tissue) and biochemical parameters (total cohlesterol, glucose, TG, creatinine, high‐density lipoproteins cholesterol and low‐density lipoprotein cholesterol) of serum. CF also had improved serum levels of adiponectin, leptin and insulin‐like growth factor‐1 in HFD/CF mice. Moreover, CF ameliorated the hepatic steatosis‐reducing size of white adipose tissue. These results indicate that CF have anti‐obesity effects and are effective for reducing metabolic risk and hepatic steatosis.     

The progressive effects of a high‐fat diet on erythrocyte osmotic fragility,growth performance and serum triglyceride and cholesterol levels in Guinea fowl (Numida meleagris) and Muscovy duck (Cairina moschata)

To investigate the progressive effects of a high‐fat diet on erythrocyte osmotic fragility, growth performance and serum lipid concentrations in Guinea fowl and Muscovy ducks, 36 Guinea fowl and 36 Muscovy ducks were divided into two groups, for each species, and fed either a standard (STD = commercial poultry feed) or high‐fat diet (HFD = commercial poultry feed with 20% palm oil and 2% lard) for up to 12 weeks. After 4, 8 and 12 weeks on the diets, six birds from each group were euthanized and blood samples collected. Osmotic fragility was assessed by measuring the haemoglobin released by erythrocytes placed in serially diluted solutions of phosphate‐buffered saline, spectrophotometrically. Serum triglyceride and cholesterol concentrations were also determined. Fragiligrams from erythrocytes from both species of birds on the HFD were not different to those on the STD. However, Muscovy duck erythrocytes were more resistant to haemolysis compared with Guinea fowl erythrocytes. Final body mass and serum triglyceride levels were not significantly different (p > 0.05, anova ) between the birds in the HFD and STD groups, for both species of birds. In contrast, serum cholesterol levels were significantly higher in birds on the HFD compared with those on the STD, after 4, 8 and 12 weeks of feeding, for both species of birds. Feeding Guinea fowl and Muscovy ducks a high‐fat diet for up to 12 weeks resulted in hypercholesterolaemia but had no effect on final body mass, erythrocyte osmotic fragility or serum triglyceride concentrations in either bird species.     

Expression of genes related to liver fatty acid metabolism in fat‐tailed and thin‐tailed lambs during negative and positive energy balances

Fat‐tailed sheep breeds can tolerate periods of negative energy balance without suffering from elevated concentration of plasma non‐esterified fatty acid (NEFA). This ability was attributed to unique metabolism of fat‐tailed adipose depot, whereas role of liver as an influential organ in fatty acid metabolism was not evaluated yet. Hence, current study was conducted to evaluate the effects of negative and positive energy balances on liver expression of genes related to fatty acid metabolism in fat‐tailed and thin‐tailed lambs. Lambs experienced negative (21 days) and positive (21 days) energy balances and were slaughtered at the beginning and end of negative energy balance and at the end of positive energy balance. Real‐time quantitative polymerase chain reaction (RT‐Q‐PCR) was conducted to evaluate changes in gene expression. Expression of diglyceride acyltransferase 1 (DGAT1), 3‐hydroxy‐3‐methylglutaryl‐CoA synthase 2 (HMGCS2) and apolipoprotein B (APOB) was not affected by genotype, energy balance and their interaction. Expression of carnitine palmitoyltransferase 1 (CPT1) was significantly higher in liver of fat‐tailed comparing to thin‐tailed lambs regardless of energy balance (p < 0.02). Catalase mRNA abundance was increased in response to negative energy balance (p < 0.02), and severity of this enhancement was higher in fat‐tailed lambs (p < 0.06). Expression of CPT1 was positively correlated with expression of HMGCS2 in both fat‐tailed (p < 0.05) and thin‐tailed lambs (p < 0.002); however, the correlation was weaker in fat‐tailed lambs (0.72 vs. 0.57, respectively, for thin‐tailed and fat‐tailed lambs). There was a positive correlation between DGAT1 and APOB genes expression in fat‐tailed lambs (0.94; p < 0.001), whereas this correlation was not observed in thin‐tailed lambs. Results demonstrate that liver of fat‐tailed lambs has higher capacity for metabolism of mobilized NEFA exposed to liver during negative energy balance.     

Metabolic parameters and their relationship to energy balance in multiparous Simmental,Brown Swiss and Holstein cows in the periparturient period as influenced by energy supply pre‐ and post‐calving

A study was conducted to evaluate the effects of three energy supply (E) levels [low (L), medium (M), high (H)], both pre‐partum (PRE) and post‐partum (POST), and their interactions on metabolic parameters and energy balance (EB) in dairy cows of three breeds. In both phases, E levels applied to a total of 81 multiparous cows of breeds Simmental (SI), Brown Swiss (BS) and Holstein–Friesian (HF; n = 27 for each breed) were 75%, 100% and 125% of recommendations of the German Society of Nutrition Physiology, using a 3 × 3 factorial arrangement of treatments. During the pre‐calving period, serum concentrations of non‐esterified fatty acids (NEFA) were higher for L_PRE cows, and glucose concentrations were elevated for H_PRE cows. During the lactation period, NEFA concentrations were greatest for treatment L_POST. Mean concentrations of β‐hydroxybutyrate (BHB) were highest for cows of the L_POST treatment, intermediate for M_POST and lowest for H_POST. Glucose concentrations were lower for L_POST cows. SI cows had lower BHB concentrations both pre‐ and post‐calving and higher glucose concentrations during early lactation than the other breeds. BHB concentration POST was highest for BS cows. Restricted feeding PRE resulted in a better energy status of cows fed above energy requirements POST (E_PRE × E_POST interaction). HF cows had a higher EB pre‐calving, whereas SI cows had a less negative EB during early lactation, compared with the other breeds respectively. Correlations of serum NEFA, BHB and glucose concentrations with EB were strongest during the transition period. Results suggest that controlling energy intake during the dry period might be advantageous for the energy status of dairy cows after calving, whereas energy restriction in early lactation leads to metabolic stress. Evidence is provided of a clear relationship between EB and the blood metabolites NEFA and BHB, especially in the transition period.     

Influence of a high-protein diet on energy balance in obese cats allowed ad libitum access to food

The influence of a high-protein [HP, 47% of metabolizable energy (ME)] diet on energy balance was evaluated in obese cats allowed ad libitum access to food. Energy intake, body weight, body composition, energy expenditure, and concentrations of hormones and metabolites associated with carbohydrate and lipid metabolism (glucose, insulin, free fatty acids, triglycerides and leptin) were measured in cats after consuming either a moderate protein (MP, 27% of ME) or HP diet for 4 months. Indirect respiration calorimetry showed that resting and total energy expenditure (kJ/day) adjusted for either body weight or lean body mass was increased in cats consuming the HP in relation to MP diets. However, voluntary energy intake also was increased in the HP treatment and, thus, there was no difference in body weight between animals consuming the two diets. Body composition measurements using deuterium oxide dilution showed that dietary protein content did not alter amounts of either lean body mass or fat mass. No significant differences (p > 0.05) were observed between the two treatment groups for blood glucose, free fatty acid or leptin concentrations, although there was a trend (p = 0.054) towards an increase of serum insulin concentrations in the cats eating the HP diet. This study showed that short-term ad libitum feeding of an HP diet did not reduce food intake or promote weight loss in obese cats. However, energy expenditure was increased in the HP diet group and it is possible that this effect of HP might help promote weight loss when energy intake is restricted.     

Effects of segregation and impact of specific feeding behaviour and additional fruit on voluntary nutrient and energy intake in yellow‐shouldered amazons (Amazona barbadensis) when fed a multi‐component seed diet ad libitum

Parrots are commonly fed multi‐component seed diets; however, both segregation and feeding behaviour might alter ingredient and nutrient composition of the offered diet. First, the nutritional impact of segregation was assessed as it occurs when multi‐component diets are temporarily stored in food containers that are replenished before completely emptied and birds being fed from the upper layer. The most detrimental effect hereof was a vast decrease in mineral supplements, leading to a decrease in Ca:P ratio in the offered food in relation to the formulated diet. Next, caloric distribution shifted towards more EE energy at the expense of NFE energy, as proportion of oilseeds increased and NFE‐rich seeds decreased. Next, a feeding trial was performed on six yellow‐shouldered amazons (Amazona Barbadensis) in which nutritional impact of parrot‐specific feeding behaviour was assessed as well as the influence of additional provision of fruit next to the seed mixture. Profound selective feeding behaviour and dehusking of seeds resulted in a vast increase in energetic density by up to 64% in the ingested fraction in relation to the offered mixture in toto. Furthermore, the already suboptimal Ca:P ratio further deteriorated and caloric distribution shifted by over twofold towards EE energy accompanied with a vast decline in NFE energy, CP energy remaining similar. Finally, provision of fruit next to the seed diet significantly lowered voluntary energy intake from 936 ± 71 to 809 ± 109 kJ ME/kg^0.75/day, without compromising adequate protein intake. In conclusion, notwithstanding efforts of nutritionists to formulate diets to approximate estimated, species‐specific requirements, nutritional composition of the actually consumed fraction of multi‐component seed diets can be vastly deteriorated by both animal and management factors. Furthermore, offering of fruit next to a seed‐based diet effectively reduces voluntary energy intake and can hence be applied to abate obesity.     

Effect of dietary threonine on laying performance and intestinal immunity of laying hens fed low‐crude‐protein diets during the peak production period

Threonine (Thr) may be a limiting amino acid for laying hens fed diets with lowered protein level. An experiment was conducted to examine laying performance, and the intestinal immune function of laying hens provided diets varying in digestible Thr levels. Lohmann Brown laying hens (n = 480), 28 weeks of age, were allocated to six dietary treatments, each of which included five replicates of 16 hens. Dietary crude protein (CP) 16.18% diet was offered as the positive control diet. L‐Thr was added to the negative diet (14.16% CP) by 0, 1.0, 2.0, 3.0 and 4.0 g/kg, corresponding 0.44%, 0.43%, 0.49%, 0.57%, 0.66% and 0.74% digestible Thr. At 40 weeks, a reduction in CP level decreased laying performance (p < 0.05). In the low CP, increasing dietary Thr increased (p < 0.05) egg production and egg mass and rose to a plateau between 0.57% and 0.66%. The hens fed 0.66% Thr showed the lowest value (p < 0.05) of feed conversion ratio (FCR). Serum level of uric acid showed the lowest values (p < 0.05) at 0.57–0.66%. In addition, serum‐free Thr maximized (p < 0.05) between 0.66% and 0.74%. Digestive trypsin activity decreased (p < 0.05) when hens fed the low‐CP diet compared with hens fed CP (16.18%) and hens fed 0.57–0.66%. Expressions of ileal MUC2 mRNA maximized (p < 0.05) at 0.66% Thr. Occludin mRNA increased with increasing Thr level (p < 0.05). sIgA mRNA reached to the maximum level (p < 0.05) at 0.66% and 0.74% Thr. INF‐γ mRNA reached to the lowest level (p < 0.05) at 0.65%. Expressions of ileal IL‐2, IL‐6, IL‐1β mRNA decreased with increasing Thr level (p < 0.05). In conclusion, Thr supplementation resulting in optimal laying performance and stimulated the mucosal immune system, suggesting that it is a limiting amino acid in the low‐crude‐protein diet of laying hens during the peak production period.     

The effects of transportation stress on Japanese quail (Coturnix Coturnix japonica) fed corn‐based diet in comparison with wheat‐based diet supplemented with xylanase and phytase

Harvesting, handling and transporting quails to the slaughterhouses, other farms and laboratories might covertly reduce their welfare. The aim of this study was to evaluate the effects of two major sources of energy in poultry nutrition on reducing transportation stress in Japanese quail (Coturnix Coturnix japonica). Male quails (n = 60) were divided into two groups. The first group was fed corn‐based diet, and the second was fed wheat‐based diet supplemented with xylanase and phytase. At the end of the experiment (day 35), quails were subjected to 80 km of transportation. Immediately on arrival and after 24 h, heterophil counts, lymphocyte counts and H:L ratios were measured. On arrival, H counts were lower, L counts were higher, and H:L ratios were lower for corn‐fed group. After 24 h, wheat‐fed group showed lower increment of H counts, greater increment of L counts and also decrement of H:L ratios rather than corn‐fed group which showed increment of H:L ratios. However, these ratios were still lower in corn‐fed group. Results indicate that corn‐based diets can help Japanese quail to better resist transportation stress, although it seems that feeding wheat‐based diets supplemented with xylanase and phytase could have positive effects for coping better with stress after journeys.     

Effect of pre‐ and post‐partum supplementation with lipid‐encapsulated conjugated linoleic acid on milk yield and metabolic status in multiparous high‐producing dairy cows

We evaluated the lactation performance, liver lipid content and plasma metabolites indicating the energy balance of dairy cows supplemented with conjugated linoleic acid (CLA) pre‐ and post‐partum (PP) vs. only PP. A total of 60 cows were divided into three groups (n = 20). Daily diet of cows was supplemented with 14 g of CLA (7 g cis‐9, trans‐11 and 7 g trans‐10, cis‐12 isomers) from week 3 before the expected date of calving (group CLA1), or from the day of calving (group CLA2) until 77–91 days PP. Control cows were fed an isocaloric, isonitrogenous and isolipidic diet without CLA. Between week 3 and week 6 PP, the milk yield of cows in both CLA‐treated groups was approximately 4.5 kg higher (p < 0.05) than in control. Milk fat concentrations decreased from week 3 and were lower in both CLA groups than in control (p < 0.01). Body condition score loss was lower (p < 0.05) in the CLA1 than in the control group on week 5 PP. By week 11 PP, the body condition of both CLA1 and CLA2 groups exceeded that of control. Plasma non‐esterified fatty acid was lower in CLA1 compared to CLA2 and control during the early PP period (p < 0.05), while this difference faded away by the late PP period. Beta‐hydroxybutyrate (BHBA) increased rapidly in all groups following calving. In CLA1 group, it began to decrease sooner than in CLA2 and control. The prevalence of subclinical ketosis (BHBA > 1.2 mm ) was lower in CLA1 group than in CLA2 and control (p < 0.05). Liver biopsy analyses showed that CLA1 treatment decreased (p < 0.05) the total lipid content of liver compared to control at week 5 after calving. Our results show that CLA supplementation is more efficient in alleviating body mass mobilization and decreasing the incidence of subclinical ketosis when applied as early as 3 weeks before calving than started feeding after calving.     

Effects of grass forage species and long‐term period of low quality forage diet feeding on growth performance,nutrient utilization and microbial nitrogen yield in growing wether lambs

Six growing lambs were used to evaluate the feeding value of two forage‐based diets in a long‐term feeding period by measuring body weight (BW) gain, digestibility, nitrogen (N) retention and microbial N (MBN) yield. The animals were fed imported low‐quality timothy hay (TH) with concentrate diet (THD) or imported low‐quality Italian ryegrass straw (IR) with concentrate diet (IRD) for 9 months. The forages were offered at 2% BW, and concentrate was fed at 40% of forage intake. The BW gain averaged 82.6 and 66.2 g/day for THD and IRD, respectively, without showing significant difference. Average forage intake (% BW) was significantly greater for IR than for TH, although it was not affected by feeding periods. The digestibility did not differ between diets or periods. The numerically greater (P = 0.06) ratio of retained N to absorbed N for IRD than that for THD was prominent. Neither diet nor period had significant effect on MBN supply and efficiency of MBN synthesis. The results suggest that the IR‐based diet can be also used for long‐term periods of feeding to growing ruminant animals as a grass hay‐based diet without any detrimental effects on nutrient utilization and growth performance.     

Effects of limit‐feeding diets with different forage‐to‐concentrate ratios on nutrient intake,rumination, ruminal fermentation,digestibility, blood parameters and growth in Holstein heifers

The objective of this study was using a wide range of dietary concentrate levels to investigate the major effects of limit‐feeding on heifers. Twenty‐four Holstein heifers were blocked into six groups and fed with one of four diets containing different levels of concentrate (20%, 40%, 60% and 80% on a dry matter (DM) basis) but with same intakes of metabolizable energy for 28 days. Increasing levels of dietary concentrate caused decreased (P ≤ 0.02) intakes of dry matter (DMI) and neutral detergent fiber and total rumination time, but increased (P < 0.01) nonfiberous carbohydrates intake, ruminal concentrations of NH₃‐N, propionate and butyrate, and digestibility of DM and crude protein. Dietary concentrate levels had no significant effect on most plasma concentrations and body measurements. The corrected average daily gain (CADG) and feed efficency (ADG/DMI, CFE) were linearly increased (P < 0.01) with increasing dietary concentrate levels when gut fill impact was removed. In conclusion, heifers limit‐fed high concentrate diets increased most ruminal fermentation parameters, CADG and CFE with similar body growth and blood metabolites as heifers fed low concentrate diets, and had the potential to be used as an effective feeding strategy in dairy heifers.     

Selection for high and low oxygen consumption‐induced differences in maintenance energy requirements of mice

Maintenance energy requirements (MER) of mice selected for high (H) or low (L) oxygen consumption (OC) were compared. Forty‐four mice from H and L OC lines were weaned at 3 weeks and divided into four experimental groups: group A were sacrificed at 4 weeks; group B were fed ad libitum, and groups C and D were fed 2.8 and 2.4 g/day, respectively, from 4 to 8 weeks of age. Groups B–D were sacrificed at 8 weeks. Chemical components were estimated for all groups. MER was estimated using a model that partitioned metabolizable energy intake into that used for maintenance, and protein and fat deposition. The feed conversion ratio for the B group was significantly higher in the H than in the L line. Feed intake for metabolic energy content per metabolic body size was significantly also higher in the H line, whereas accumulated energy content per metabolic body size was significantly higher in the L line. MER of the H line was greater than that of the L line (P < 0.10). These results suggest that selection for H or L OC produced differences in chemical components, feed efficiency, and MER between the H and L lines.     

Body weight,meat quality and blood metabolite responses to carbohydrate administration in the drinking water during pre‐slaughter feed withdrawal in broilers

This study was conducted to determine weights of body (BW), carcass (CW), gastrointestinal tract (GTW), meat quality and some blood metabolite responses to corn starch, saccharose or glucose administration in the drinking water during pre‐slaughter feed withdrawal (FW) in broilers. On day 42 of age, 200 broilers (Ross 308) were allocated randomly to five treatments with four replicates. During a 10‐h FW, control broilers (C) were provided with non‐treated water and the standard finisher diet ad libitum, whereas fasted broilers provided with non‐treated (NFW) or treated water, 3 g glucose (G), saccharose (S) or corn starch (CS)/L. Eight birds (four males and four females) per treatment were slaughtered. Birds receiving non‐treated or treated water had lower BW and higher carcass yield than the full‐fed broilers. The full‐fed broilers had higher absolute and relative GTW than the fasted birds. Broilers consumed more readily treated water compared with non‐treated water. While the a* value of breast meat from CS birds was higher than that from NFW, the b* value of that was higher than S and C birds. The c* values of breast meat from S birds were lower compared with that from the CS treatment. The thigh meat from NFW broilers had higher h* value than that from C and G broilers. The thigh meats of C and CS broilers had higher c* value than that of G birds. The full‐fed broilers had higher plasma triglyceride concentration than NFW, S and G birds. The full‐fed broilers had higher plasma uric acid and uric acid nitrogen concentrations than S birds. These results show that carbohydrate administration in the drinking water cannot be a good alternative for the FW period before slaughter due to the fact that the carbohydrates do not reduce BW losses and do not lead to increases in meat quality.     

Effect of the proportion of roughage fed as rolled and baled hay on repressing wool‐biting behavior in housed sheep

Wool‐biting behavior in housed sheep is a serious animal welfare problem and is difficult to control. Since we have found that sheep fed on rolled hay performed less post‐feeding wool‐biting than those fed on baled hay, here we mixed these two kinds of hay in four different proportions (0%, 33%, 67% and 100% of rolled hay) to test the effect of rolled hay on repressing wool‐biting behavior. We also measured the pulling force needed to remove a piece of rolled hay, baled hay, wool and fresh grass. Wool‐biting occurred most frequently in the treatment containing 0% rolled hay; however, there was no significant difference between the other three treatments. The pulling force needed to remove a piece of baled hay was significantly weaker than that for the other three objects; no other significant differences in pulling force were found. Our results suggest that the wool‐biting behavior of sheep was due to feeding frustration, which arises when they lack the appropriate oral stimulation from performing their normal foraging movement; this then redirects to the wool on their pen‐mates. Feeding sheep rolled hay, even in low quantities, can provide them with appropriate oral stimulation and was effective in repressing wool‐biting behavior.