Effects of early experience with low‐quality roughage on feed intake,digestibility and metabolism in lambs

The objective of this study was to compare the feed intake, digestibility and metabolism in lambs fed low‐quality roughage with those of lambs fed normal roughage from an early stage of their life. The study consisted of two treatments [low‐quality roughage group (LR) and control group (C)] over three time periods (P1, P2 and P3; 2 months each). Four lambs (4 months old) were allocated to each treatment. In P1 and P2, LR was fed sudangrass hay (CP: 5.1% DM; NDF: 70.4% DM), whereas C was fed timothy hay (CP: 8.4% DM; NDF: 60.3% DM). In P3, all lambs were fed sudangrass hay. Although the feed intake was significantly greater (p < 0.05) in C in P1, there were no differences between the groups in P2. The digestibility, serum glucose (GLU), urea nitrogen (SUN) and insulin‐like growth factor 1 (IGF‐1) did not differ between the groups in P1 and P2. The average nitrogen retention, triiodothyronine (T3) and thyroxine (T4) were significantly higher in C (p < 0.05) during P1 and P2. No interaction was observed between the treatment and periods. In P3, the feed intake was greater in C (p < 0.05), whereas digestibility and nitrogen retention tended to be greater in LR. The body weight did not differ between the treatments. T4 and T3 were numerically lower in LR, while the SUN was greater in LR (p < 0.05). These results suggest that the early experience with low‐quality roughage may have improved feed digestibility and nitrogen metabolism in lambs after 4 months of rearing. Furthermore, the experienced lambs became more efficient at utilizing the low‐quality roughage. The lower thyroid hormone concentrations observed in LR suggest an adaptive change occurred in experienced lambs that to a lower basal metabolic rate.     

Effects of a Brown‐midrib corn hybrid on nutrient digestibility in wethers and on dry matter intake,performance, rumen and blood variables in dairy cows

The aim of the present trials was to determine the effect of an experimental Brown‐midrib (Bm) corn hybrid in relation to a commercial corn hybrid (Con) on digestibility in wethers and on dry matter intake (DMI), milk yield and milk composition in dairy cows. Digestibility of crude fibre (CF), neutral detergent fibre (NDFom) and acid detergent fibre (ADFom) were higher for Bm (CF Con: 57.8%; Bm: 67.2%; NDFom Con: 56.8%; Bm: 64.8%; ADFom Con: 52.0%; Bm: 63.9%), but concentration of net energy for lactation did not differ (Con: 6.4 MJ/kg DM; Bm: 6.3 MJ/kg DM). A total of 64 lactating German Holstein cows were assigned to one of the two dietary treatments Con or Bm according to milk yield, lactation number, days in milk and live weight. In Trial 1, cows were fed a total mixed ration consisting of 50% corn silage (Con or Bm) and 50% concentrate on dry matter (DM) basis. In Trial 2, the same animals were fed the respective silage for ad libitum intake and 5.3 kg of concentrate DM per animal per day. In Trial 1, DMI and milk‐fat content were decreased significantly for the Bm‐treatment (DMI Con: 22.5 kg/day; Bm: 21.5 kg/day; milk fat Con: 3.8%; Bm: 3.3%). In Trial 2, milk yield and fat‐corrected milk (FCM) were increased significantly, whereas milk‐fat% was decreased significantly (milk yield Con: 25.8 kg/day; Bm: 29.4 kg/day; FCM Con: 27.2 kg/day; Bm: 29.6 kg/day; fat Con: 4.4%; Bm: 4.0%). Diets did not influence ruminal pH or temperature. Diets, furthermore, did not influence rumination in either trial. Additional research on digestibility and rumen fermentation should, however, be carried out using dairy cows at respective intake levels as trials with wethers cannot be transferred to high‐yielding ad libitum fed cows.     

Effects of food processing and fibre content on the digestibility,energy intake and biochemical parameters of Blue‐and‐gold macaws (Ara ararauna L. – Aves,Psittacidae)

Considering the increased incidence of obesity and metabolic diseases in caged psittacines, the effect of fibre and food processing was evaluated in the Blue‐and‐gold macaw. Four food formulations (0%, 7%, 14% and 21% of sugarcane fibre) processed by pelleting or extrusion were studied, resulting in eight diets. To study digestibility, 48 macaws housed in pairs in cages was used in a block design. Subsequently, diets containing 0% or 21% sugarcane fibre, pelleted or extrude was fed for 4 months to evaluate energy intake and blood metabolites. A 2 × 2 × 2 (two fibre levels, two food processing methods and two genders) factorial arrangement with subplots (beginning and end) was used. When differences were detected in anova 's F test, data were submitted to polynomial contrasts in the first experiment and to orthogonal contrasts in the second experiment (p < 0.05). Fibre addition reduced protein, fat and energy (p < 0.001) digestibility in both food processing. Pelleted foods presented higher dry matter digestibility and food metabolisable energy (ME) than the extruded ones (p < 0.05). Fibre addition or the type of processing did not change ME ingestion (p > 0.05). The macaws gained body weight (p < 0.05) regardless of the diet (p > 0.05), but females fed with the high‐fibre diets did not gain weight (p > 0.05), suggesting a low food ME (12.5 kJ/g).The substitution of the original diet (sunflower seeds, fruits and cooked maize) by the experimental foods decreased the basal (12‐h fast) concentrations of glucose, cholesterol and triglycerides (p < 0.001). The consumption of pelleted diets reduced serum glucose and cholesterol (p < 0.05). Results suggest that the pelleted diets were more beneficial and can be used to reduce blood metabolites related to metabolic disorders that are commonly observed in macaws.     

Correlations between circulating leptin concentrations and growth performance,carcass traits,and meat quality indexes in finishing Simmental × Luxi bulls fed high‐concentrate diets

Circulating leptin concentrations could potentially be used as a predictor of production traits in cattle. This study aimed to clarify the correlations between circulating leptin concentrations and growth performance, carcass traits, and meat quality indexes in finishing bulls fed high‐concentrate diets (concentrate‐to‐forage ratio 70:30). Fifty‐seven Simmental × Luxi F1 crossbred bulls were used for 112‐day finishing experiment. Circulating leptin concentrations and relevant indexes of growth performance, and carcass traits and meat quality were measured during or after finishing trail. The results indicated that the leptin concentrations tended to be negatively correlated with dry matter intake (DMI) (r = ?.233, p = .081), and were positively correlated with 12th‐rib fat thickness (r = .330, p = .012), marbling score (r = .336, p = .011), and intramuscular fat content (r = .368, p = .021). Moreover, the leptin concentrations were negatively correlated with cholesterol content (r = ?.339, p = .037) and were not correlated with sensory indexes including tenderness, juiciness, and like flavor (p > .05). In conclusion, circulating leptin concentrations may potentially be used as a predictor of carcass traits related to content of fat and beef quality traits related to content of cholesterol in finishing bulls fed high‐concentrate diets.     

A 90‐day adaptation to a high glycaemic diet alters postprandial lipid metabolism in non‐obese horses without affecting peripheral insulin sensitivity

High glycaemic feeds are associated with the development of insulin resistance in horses. However, studies that evaluated the effect of high glycaemic feeds used horses that either ranged in body condition from lean to obese or were fed to increase body condition over a period of months; thus, the ability of high glycaemic feeds to induce insulin resistance in lean horses has not been determined. This study evaluated the insulin sensitivity of 18 lean horses fed a 10% (LO; n = 6), 20% (MED; n = 6) or 60% (HI; n = 6) non‐structural carbohydrate complementary feed for 90 days. Although both the MED and HI diets increased insulinaemic responses to concentrate feeding in relation to the LO diet (p > 0.05), neither induced insulin resistance, as assessed by glucose tolerance test, following the 90‐day feeding trial. Interestingly, the post‐feeding suppression of plasma non‐esterified fatty acids was less pronounced in HI‐fed horses (p = 0.054) on days 30 and 90 of the study, potentially indicating that insulin‐induced suppression of adipose tissue lipolysis was reduced. As insulin‐resistant animals often have elevated plasma lipid concentrations, it is possible that altered lipid metabolism is an early event in the development of insulin resistance. The effects of high glycaemic feeds that are fed for a longer duration of time, on glucose and lipid metabolism, should be investigated further.     

Total nutrient digestibility and small intestine starch digestion in Nellore and Angus young bulls fed a whole shelled corn diet

Eighteen Nellore and 18 Angus young bulls with BW of 381 ± 12 kg were randomly assigned into two feeding groups (whole shelled corn [WSC] or ground corn with silage [GC]) to evaluate the interaction of breed and diet on total nutrient digestibility, pancreatic α‐amylase, and maltase activity and SLC5A1expression in the small intestine. Experimental diets (DM basis) included (a) a diet containing 30% corn silage and 70% GC and soya bean meal‐based concentrate and (b) a diet containing 85% WSC and 15% of a soya bean meal‐ and mineral‐based pelleted supplement. The treatments were Nellore fed GC diet; Nellore fed WSC diet; Angus fed GC diet; and Angus fed WSC diet. Total faecal collection for the digestibility trial occurred from day 48 until day 50 of the experimental period. Feeding the WSC diet reduced DM and NDF intake (p < 0.01). Angus had greater DM and nutrient intake in kg/day (p < 0.01). However, there was no breed effect on DM and nutrient intakes based on percentage of BW (p > 0.19). Angus had greater starch digestibility (p = 0.03) than Nellore. Cattle fed the WSC diet had greater DM, NDF and starch digestibility (p < 0.01) compared with those fed the GC diet. The activity of pancreatic α‐amylase (U/g of protein) was greater in Nellore (p < 0.01) and was not affected by diet (p = 0.52). In duodenum, maltase activity (U/g of protein) was greater in bulls fed GC diet (p = 0.02). Expression of the gene SLC5A1was not affected by breed or diet (p > 0.05). In conclusion, Nellore had less capacity to digest starch. However, they did not have less pancreatic α‐amylase and duodenal maltase activity compared to Angus. The use of the WSC diet increases DM and total nutrient digestibility.     

Effects of feeding mother liquor,by‐product of monosodium glutamate,on digestibility,energy and nitrogen balances,and rumen condition in Thai native bulls

Four Thai native bulls were used to evaluate the availability of mother liquor (ML), by‐product of monosodium glutamate, as a replacement of soybean meal (SBM) consisting of 10% in concentrate. The SBM was replaced by the ML at 0% (C), 20% (T1), 40% (T2), and 60% (T3), and the experiment was a randomized block design experiment. The animals were fed concentrate and roughage (60:40, on a dry matter [DM] basis). There were no significant differences in the digestibility of DM, crude protein, ether extract, acid detergent fiber expressed exclusive of residual ash and non‐fibrous carbohydrate, and energy and nitrogen balances among the treatments. However, the digestibility of the neutral detergent fiber in T2 was lower than the other treatments (p < .05). The valeric acid of T2 was lower than those of C and T1 and the iso‐valeric acid of T3 was the lowest (p < .05), followed by those of T2, T1, and C at 4 hr post‐feeding. No significant differences were observed in the ruminal total VFA concentrations, pH, and NH₃‐N among the treatments. These results suggested that SBM could be replaced by the ML up to 60% without adverse effects on nitrogen and energy balance, rumen conditions, and blood metabolites in Thai native bulls.     

Effects of dietary fibre level and body weight of pigs on nutrient digestibility and available energy in high‐fibre diet based on wheat bran or sunflower meal

The objectives of this study were (a) to investigate the effect of body weight (BW) on available energy in fibre‐rich diets containing two NDF levels; and (b) to evaluate the effect of fibre type and NDF level on AA digestibility. In Exp. 1, barrows (24 at 33.4 ± 1.1 kg; 24 at 86.8 ± 3.3 kg) were randomly allotted to 4 diets containing a high protein basal (HPB), a low protein basal (LPB), 70% HPB + 30% wheat bran (WB) (HPB‐WB) and 70% LPB + 30% sunflower meal (SFM) (LPB‐SFM). In Exp. 2, barrows (24 at 33.5 ± 1.8 kg; 24 at 87.0 ± 3.8 kg) were randomly allotted to 4 diets containing no SFM with 12% NDF (SFM0LF), no SFM with 16% NDF (SFM0HF), 24% SFM with 12% NDF (SFM24LF) and 24% SFM with 16% NDF (SFM24HF). In Exp. 3, twelve barrows (35.5 ± 3.4 kg) fitted with T‐cannulas were allotted to two 6 × 4 Youden square design with 6 diets (4 same diets as in Exp. 2 and 2 nitrogen‐free diets). The concentration of DE, ME and ATTD of GE, CP, NDF and ADF in diets was greater (p < .01) when fed to 90 kg pigs compared with 30 kg pigs. The ME in ingredients was not affected by BW. The ATTD of NDF was negatively correlated with the CF (r = ?.98; p < .01), ADF (r = ?.99; p < .01) and ADL content (r = ?.96; p < .01). The ME of diets was negatively correlated with the ATTD of CF (r = ?.98; p < .01). The addition of SFM increased the standardized ileal digestibility (SID) of Met (p < .05). In conclusion, diets rich in fibre had different nutritional values at different pig weight stages. The AA digestibility depends mainly on chemical composition of diets.     

Feed processing effects on digestibility,palatability, excreta fermentation products and blood parameters in blue‐fronted amazon parrots (Amazona aestiva)†

Captive parrots show a high incidence of obesity and other metabolic disorders due to the consumption of unbalanced diets. Therefore, this study evaluated the digestibility and metabolic effects of transitioning blue‐fronted amazons from a high fat diet (sunflower seeds) to processed diets with three degrees of starch gelatinization (SG). The same feed formulation was processed to obtain pelletized feed (PEL) at 27.1% SG; low‐cooked extruded feed (EXT_L) at 81.6% SG; and high‐cooked extruded feed (EXT_H) at 98.5% SG. Thirty adult parrots were fed sunflower seeds for 90 days, then were distributed in a completely randomized design with 10 repetitions per treatment, and fed one of the three prepared diets for 160 days. Feed palatability, apparent digestibility, excreta concentrations of volatile fatty acids, lactate and ammonia, initial and final radiographic examinations, blood cell counts and glucose, triglycerides, cholesterol, total protein, albumin, aspartate aminotransferase (AST) and uric acid levels were evaluated. The data were analysed by an analysis of variance and compared by Tukey's test (p < 0.05). Sunflower seed was more digestible than processed feeds (p < 0.05). Diet processing interfered with fat and starch digestibility (p < 0.001), being higher in the PEL than in the EXT_H and EXT_L respectively. Transitioning from sunflower seeds to balanced diets reduced serum glucose, triglycerides, cholesterol and AST (p < 0.05) and increased red blood cell, haemoglobin, lymphocyte, monocyte and leucocyte counts (p < 0.01). Radiographs indicated a decreased hourglass (p = 0.015) and a reduced heart‐liver ratio after ingesting the processed feeds (p < 0.05). Feed processing did not affect blood cell counts, serum biochemistry or radiographic examinations. In conclusion, parrots preferred the extruded diet and did not require an extensive SG to properly digest the feed. Consuming the processed diets improved the birds’ metabolism and health.     

Digestibility,ruminal fermentation,blood metabolites and antioxidant status in ewes supplemented with DL‐methionine or hydroxy‐4 (methylthio) butanoic acid isopropyl ester

The effects of supplementing ewe diets with either DL‐methionine (DL‐Met) or 2‐hydroxy‐4 (methylthio) butanoic acid isopropyl ester (HMBi) were investigated on ruminal in situ degradability of grain and forage diets, in vivo digestibility, rumen fermentation, blood metabolites and antioxidant status. Six ruminally cannulated ewes were used in a replicated 3 × 3 Latin square design with 28‐day periods. The dietary treatments were as follows: (i) no supplemental Met (control; CON), (ii) DL‐Met at 1.2 g/kg DM intake and (iii) HMBi at 1.8 g/kg dry matter (DM) intake. Corn grain, barley grain and alfalfa hay were evaluated for their ruminal degradability by both in situ incubation and effective degradability measurements of DM, neutral detergent fibre (NDF) and acid detergent fibre (ADF). Compared to other treatments, HMBi supplementation increased (p < 0.05) the digestibility of organic matter, crude protein and NDF and also tended (p = 0.08) to increase the digestibility of DM and ADF. Moreover, HMBi supplementation increased (p < 0.01) total VFA concentrations, the molar proportions of valerate and iso‐butyrate in the rumen. Compared to the CON treatment, DL‐Met and HMBi treatments tended (p = 0.08) to increase the molar proportion of acetate but decreased (p < 0.05) ruminal ammonia‐N concentration. Ewes supplemented with HMBi and DL‐Met recorded greater (p < 0.05) serum concentrations of glutathione peroxidase, total antioxidant capacity and superoxide dismutase than the CON treatment. Serum concentrations of glucose, total protein, albumin, high‐density lipoprotein and very low‐density lipoprotein were greater (p < 0.01) and serum urea nitrogen (p < 0.05), malonyl dialdehyde and triglyceride were lower (p < 0.02) in the HMBi and DL‐Met animals than in the CON ewes. The results concluded that HMBi is a very effective form of dietary Met supplementation for ewes with a positive effect on digestion, rumen fermentation and serum antioxidant function.     

Effect of feeding wood kraft pulp on the growth performance,feed digestibility,blood components,and rumen fermentation in Japanese Black fattening steers

This study aimed to examine the effects of feeding kraft pulp (KP) on the growth performance, feed digestibility, and rumen fermentation of Japanese Black fattening steers. Ten Japanese Black fattening steers (aged 26 months) were randomly divided into control and KP groups. The control group (n = 5) was fed concentrate feed without KP, and the KP group (n = 5) was fed concentrate feed containing 10% KP. Both the groups were provided rice straw as roughage. The experiment was conducted over a period of 12 weeks. There was no significant difference in dry matter intake, daily body weight gain, and nutrient digestibility between both groups. No difference was observed in the ruminal concentrations of volatile fatty acids among the groups. At weeks 8 and 12 after the onset of the experiment, the acetate‐to‐propionate ratio in the ruminal fluid of the KP group was significantly higher than that of the control group. The average daily pH of ruminal fluid and activity of ruminal lipopolysaccharide did not differ between the groups. Our results suggested that the growth performance and feed digestibility in the Japanese Black fattening steers were not influenced by replacing concentrate feed with KP.     

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.     

Evaluation of three popular diets fed to pet sugar gliders (Petaurus breviceps): Intake,digestion and nutrient balance

Three diets fed to 12 pair‐housed sugar gliders, Petaurus breviceps, were evaluated through 5‐day intake and digestion trials following 10‐day transitions. Diets 1 and 2 comprised liquid formula mixes with added vegetables and fruit, and Diet 3 comprised extruded pellets and a liquid formula. Diets eaten contained 16 —19% crude protein, 3%–15% crude fat, 10%–11% neutral detergent fibre, 4%–20% starch and 8%–49% sugar (dry basis). Calculated individual dry matter intakes (DMI) ranged from 3.9 to 5.1 g/day, representing 58.2–78.4 kJ/day. DMI was greater for Diet 2 (7.2% BW) vs. Diet 1 (5.6; p = .006) and Diet 3 (4.2% BW; p = .003). Although these differences were no longer detectable on a MBW basis, animals were shown to have gained BW (+14.2 g; p = .03) on Diet 2. In addition to nutrient composition differing widely among diets, DM digestibility (DMD) was higher in Diet 1 (91.2%) compared to Diet 2 (87.3%; p = .03), but DMD for Diet 3 (88.9%) did not differ from other diets. Gliders demonstrated ability to digest a variety of energy substrates, including simple sugars (96%–99%), fats (81%–96%) and starches (79%–98%), as well as substantial insoluble dietary fibre (58%–75%), with significant difference among diets demonstrated for some nutrients. Animals displayed selective feeding behaviours, rejecting insoluble fibre in produce and preferring the lipid‐coated exterior of pellets. The diets used appeared to be balanced with respect to energy, protein and macromineral content, but may predispose to iron excess, other mineral imbalances (especially Ca deficiency) and obesity—clinical health issues described for pet gliders. Future focus on concentrations, types and utilization of dietary fibre in natural and captive diets, vitamin D metabolism and trace mineral interactions in sugar gliders would assist diet optimization for this highly gummivorous species.     

The effects of increasing garlic powder and monensin supplementation on feed intake,nutrient digestibility,growth performance and blood parameters of growing calves

The objective of this study was to evaluate the effects of increasing garlic powder and monensin supplementation on feed intake, nutrient digestibility, growth performance and blood metabolites of growing calves. Forty Holstein calves (BW = 100 ± 11 kg) were randomly assigned to four dietary treatments (n = 10) in a complete randomized design. Experimental treatments consisted of the following: (i) basal diet (control), (ii) basal diet supplemented with 0.0003% of dietary dry matter (DM) sodium monensin, (iii) low level of garlic powder (Low‐GAR; 0.5% of dietary DM) and (iv) high level of garlic powder (High‐GAR; 1% of dietary DM). DM intake (DMI) and DM digestibility were (p < 0.05) decreased by High‐GAR. However, calves supplemented with Low‐GAR had a similar DMI to the control calves and similar DM digestibility to the control and monensin groups. The digestibility of other nutrients were not affected by the treatments. Although supplementing monensin relative to Low‐GAR increased the DMI (p < 0.05), average daily gain was similar between Low‐GAR and monensin supplemented calves, which were higher than the control and High‐GAR groups (p < 0.05). As a result, feed conversion ratio was improved in the Low‐GAR group versus other treatment groups (p < 0.05). Administrating garlic powder decreased the blood low‐density lipoprotein (LDL) and non‐esterified fatty acids (p < 0.05) without affecting the blood triglyceride, high‐density lipoprotein and beta‐hydroxybutyric acid concentrations. In conclusion, the calves fed the Low‐GAR showed an improved FCR and blood metabolites without changing the DMI and nutrient digestibility. It suggests that garlic powder could be used as an alternative to monensin for growing calves under the current feeding conditions.     

Does the level of forage neutral detergent fiber affect the ruminal fermentation,digestibility and feeding behavior of goats fed cactus pear?

This study aimed to evaluate the effects of forage neutral detergent fiber (fNDF) levels on the voluntary feed intake, digestibility, ruminal fermentation and feeding behavior of goats fed diets with cactus pear. Five non‐lactating ruminally cannulated goats fed ad libitum were randomly assigned to a 5 × 5 Latin square design. Treatments consisted of levels of fNDF at 0, 109, 222, 339 and 463 g/kg of dry matter (DM) in cactus pear‐based diets. The intakes of DM and NDF were quadratically affected (p ≦ .045) by fNDF levels. Voluntary water intake (VWI) increased linearly as the fNDF levels increased in the diet. The digestibility coefficients of organic matter, NDF and ether extract and total digestible nutrients concentration were quadratically affected (p ≦ .048) by fNDF levels. The ruminal pH linearly increased (p = .001) with fNDF levels, ranging from 5.44 to 5.81 for diets containing 0 and 463 g fNDF/kg DM, respectively. The fNDF levels promoted a linear increase (p = .006) in chewing time, linearly decreased (p = .007) resting time and quadratically affected (p = .033) rumination time. The inclusion of fNDF in the diets provided favorable conditions for ruminal function, digestibility and feeding behavior in goats fed diets containing cactus pear.     

Wheat particle size,insoluble fibre sources and whole wheat feeding influence gizzard musculature and nutrient utilisation to different extents in broiler chickens

A 21‐day experiment was conducted to investigate the effects of wheat particle size, insoluble fibre source and whole wheat (WW) inclusion on the gizzard musculature, intestinal architecture and nutrient utilisation of broiler chickens. The following seven treatments, all in mash form, were tested: control diet using finely ground wheat (Fine); control diet using medium‐ground wheat (Medium); control diet using coarsely ground wheat (Coarse); fine diet diluted with 10 g/kg lignocellulose (LC); fine diet diluted with 30 g/kg oat hulls (OH); fine diet diluted with 30 g/kg wood shavings (WS); and ground wheat in the fine diet replaced with 50 and 100 g/kg WW during the second (day 8–14) and third (day 15–21) weeks of the study respectively. Except for the LC diet, all treatments increased (p < 0.05) the thickness of the caudodorsal thick muscle of gizzard compared to the fine diet. The highest (p < 0.05) caudoventral thin and cranioventral thick muscle diameters in the gizzard walls were achieved with the OH and WS diets. Feeding OH, WS and WW diets improved (p < 0.05) starch digestibility compared with the fine diet, while medium, coarse and LC diets had no effect (p > 0.05). All diets containing fibre sources (LC, OH and WS) reduced (p < 0.05) the energy digestibility compared to the fine diet. Birds fed OH and WS diets gained the lowest (p < 0.05) weights. Feeding LC, OH, WS and WW diets increased (p < 0.05) the feed per gain compared with the fine diet. The current results suggest that there is a potential for coarse particles, insoluble fibre sources and WW feeding to improve the gizzard musculature and digestibility of some nutrients, with the effect being more pronounced with the inclusion of structural fibre sources.     

Low-tannin sorghum grain could be used as an alternative to corn in diet for nursery pigs

This study was conducted to test the hypothesis that low-tannin sorghum grain produced in China as a potential substitute for corn in diets could not impair the performance of nursery pigs. A total of 60 pigs (7.2 ± 1.2 kg) were randomly assigned to 2 diets with 5 replicate pens per treatment. Corn-based diet (CBD) included 60% corn grain during the overall experimental period, and sorghum-based diet (SBD) consisted of 30% (d 1 to 14) or 60.55% (d 15 to 28) sorghum grain in partial or total replacement of corn grain. Both diets were formulated to contain the same amount of digestible energy and indispensable amino acids. The results demonstrated no differences in growth performance or apparent digestibility of gross energy between treatments over the whole period. However, the substitution of corn by sorghum reduced (p < 0.05) or tended to reduce (p = 0.09) apparent digestibility of crude protein associated with an increased faecal nitrogen excretion per weight gain (p < 0.05). Pigs fed SBD had higher contents of urea nitrogen, total triglyceride and insulin in serum than those fed CBD (p < 0.05). Visceral organ weights or antioxidant enzyme activities in serum or liver were not different between treatments. Compared with CBD, SBD increased or tended to increase amylase activity in jejunal mucosa (p < 0.05) or trypsin activity in duodenal mucosa (p = 0.08). Replacement of corn by the low-tannin sorghum in diets did not influence the microbiota community based on alpha and beta diversity in caecal and colonal digesta. Overall, the home-grown low-tannin sorghum could be an alternative energy source in diets for pigs without adverse effects on growth performance.     

The effect of leucaena hay as a source of effective fibre and nutrients in diets with forage palm for finishing sheep in semi-arid regions

The present study was conducted to evaluate the intake, digestibility and nitrogen balance of diets for finishing sheep, containing leucaena hay as a source of effective fibre and forage palm. Twenty-one male sheep were used in a randomized block design with three treatments, represented by total diets, where the forage was leucaena hay and forage palm in natura in proportions 350:650, 450:550 and 550:450 g/kg respectively. For the pH and NH₃-N in the ruminal fluid, and urea in the blood serum, plots split in time were adopted. Dry matter and nutrient digestibility, and the nitrogen balance were not influenced (p > .05) by the diets. The neutral detergent fibre digestibility decreased (p < .05) as the proportions of leucaena hay in the diets increased. The pH and NH₃-N were suitable for ruminal fermentation, and blood urea was maintained under normal physiological conditions for sheep. Combining 350 to 550 g/kg of leucaena hay with 450 to 650 g/kg of forage palm in total diets with a forage:concentrate ratio of 60:40 in late-maturing sheep meets the nutritional requirements for daily gain 200 g, characterizing leucaena hay as important source of effective fibre and nutrients in diets.     

Effects of different forage sources as a free‐choice provision on the performance,nutrient digestibility,selected blood metabolites and structural growth of Holstein dairy calves

The objective of this study was to determine the effects of different forage sources on the growth performance, nutrient digestibility and blood metabolites of dairy calves. Individually housed calves (n = 40; body weight = 41.2 ± 3.5 kg) were randomly allocated (n = 10 calves per treatment: five males and five females) to one of the following four treatments: (i) starter without forage provision (CON), (ii) starter plus chopped alfalfa hay (AH), (iii) starter plus chopped wheat straw (WS) and 4) starter plus dried sugar beet pulp (BP) flakes. Calves fed AH diets had lowest (p < 0.05) starter intake than those fed other diets, and WS promoted a significant increase (p < 0.01) in starter intake during 43–80 days. Forage intake was greatest (p < 0.01) for calves fed AH than those fed WS and BP. Calves in the AH treatment consumed less (p < 0.01) total dry matter intake than those offered other forage treatments. Final body weight was greatest (p < 0.05), and age of weaning was lowest for calves fed BP than other treatments. Calves in the BP treatment had greater (p < 0.05) average daily gain (ADG) than CON and WS treatments, but similar to AH calves. Digestibility of NDF and ADF was greater (p < 0.05) in BP treatment than other treatments. Calves fed BP had greater (p < 0.05) digestibility of DM and OM than those fed CON diets and similar to those fed AH and WS diets. Calves in the AH treatment had greater (p < 0.05) CP digestibility than CON, but similar to WS and BP calves. Blood beta‐hydroxybutyrate concentration was lower in forage‐offered calves than CON one. Body measurements (with the exception of body barrel) did not differ across treatments. It was concluded that BP improves final body weight, ADG and nutrient digestibility of calves than starter without forage provision during weaning transition.     

Nitrogen digestion and urea recycling in Hokkaido native horses fed hay‐based diets

Nitrogen (N) digestion and urea‐N metabolism in Hokkaido native horses fed roughage‐based diets containing different types and levels of protein sources were studied. Horses (173 ± 4.8 kg) fitted with an ileum cannula were fed four diets consisting of 100% timothy hay (TH), 88% TH and 12% soybean meal (SBM), 79% TH and 21% SBM, and 51% TH and 49% alfalfa hay at 2.2% of body weight. Dietary protein content varied from 5% to 15% of dry matter. Apparent N digestibilities in the pre‐cecum and total tract for the TH diet were lower than those for other diets. However, the proportion of post‐ileum N digestion to N intake was not affected by the diets. Urea‐N production was linearly related to N intake, but gut urea‐N entry was not affected by the diets. The proportion of gut urea‐N entry to urea‐N production tended to be higher for the TH diet (57%) than the two SBM diets (39%). Anabolic use of urea‐N entering the gut was not affected by the diets (20–36% of gut urea‐N entry). These results indicate that urea‐N recycling provides additional N sources for microbial fermentation in the hindgut of Hokkaido native horses fed low‐quality roughages.