Effects of essential oils,yeast culture and malate on rumen fermentation,blood metabolites,growth performance and nutrient digestibility of Baluchi lambs fed high‐concentrate diets

The experiment was conducted to evaluate the effects of dietary supplementation with a mixture of essential oils (MEO), yeast culture (YC) and malate on performance, nutrient digestion, rumen fermentation and blood metabolites of lambs fed high‐concentrate growing diets. For this purpose, twenty Baluchi lambs (17.3 ± 0.5 kg body weight and 3 months old) were randomly assigned to four dietary treatments in a completely randomized design with five lambs per treatment. The treatment groups were as follows: (i) control: basal diet without any additive, (ii) basal diet plus 400 mg/day MEO (thymol, carvacrol, eugenol, limonene and cinnamaldehyde), (iii) basal diet with 4 g/day YC and (iv) basal diet plus 4 g/day malate. No differences between the dietary treatments were observed in dry matter intake, average daily gain or feed conversion ratio (p > 0.05). Compared with control and malate treatment, lambs fed MEO and YC had an improved crude protein digestibility (p < 0.05). Yeast culture significantly increased (p > 0.05) cell wall digestibility compared to the other treatments. No differences were observed between treatments with respect to nitrogen balance or ruminal pH and ammonia concentrations (p > 0.05). No differences were observed between treatments with respect to ruminal total volatile fatty acid concentration and molar proportions of acetate, butyrate and valerate. Molar proportion of propionate was higher (p < 0.05) for YC and malate compared to control and MEO. Plasma glucose concentration was higher (p < 0.05) in lambs fed YC and malate than in lambs fed the control or the MEO diet. Blood concentration of triglycerides significantly decreased when feeding the MEO and YC diets (p < 0.05). It was concluded that YC may be more useful as a feed additive for manipulation of rumen fermentation in lambs fed with high‐concentrate diets than MEO and malate, because YC enhanced crude protein and cell wall digestibility, ruminal molar proportion of propionate and plasma glucose concentration.     

Effects of pistachio by‐products on digestibility,milk production,milk fatty acid profile and blood metabolites in Saanen dairy goats

The objective of this study was to investigate the effects of pistachio by‐products (PBP) on nutrient digestibility, blood metabolites and milk fatty acid (FA) profile in Saanen dairy goats. Nine multiparous lactating Saanen goats (on day 90 post‐partum, 45 ± 2/kg BW) were randomly assigned to a 3 × 3 Latin square design with three treatment diets: 1) control diet (alfalfa hay based), 2) 32% PBP and 3) 32% PBP + polyethylene glycol (PEG‐4000; 1 g/kg dry matter). Each period lasted 21 days, including 14 day for treatment adaptation and 7 day for data collection. Pistachio by‐products significantly decreased (p < 0.01) crude protein (CP) digestibility compared with the control diet (64.4% vs. 58.7%), but PEG addition did not differ for CP digestibility of goats fed 32% PBP + PEG and those fed the two other diets. The digestibility of NDF tended (p = 0.06) to decrease for goats fed PBP compared with those fed the control diet. Yields of milk and 4% fat‐corrected milk were not affected by dietary treatments. Compared with the control diet, PBP supplementation appreciably changed the proportions of almost all the milk FA measured; the main effects were decreases (p < 0.01) in FA from 8:0 to 16:0 and increases (p < 0.01) proportions of cis‐9, trans‐11 18:2 and trans‐11 18:1, monounsaturated FA, polyunsaturated FA and long‐chain FA. The saturated FA, short‐chain FA and medium‐chain FA proportions were lower (p < 0.01) in goats fed the two PBP supplemented diet than in those fed the control diet and PEG addition led to intermediate proportions of saturated FA, unsaturated and monounsaturated FA. Inclusion of PBP in the diet decreased (p < 0.01) plasma concentrations of glucose and urea nitrogen compared with the control diet. It was concluded that PBP can be used as forage in the diet of dairy goats without interfering with milk yield. Inclusion of 32% PBP in the diet of dairy goats had beneficial effects on milk FA profile but PEG addition to PBP did not contribute to enhance further milk FA profile.     

Effects of feeding different levels of corn steep liquor on the performance of fattening lambs

This study was conducted to assess the effect of feeding corn steep liquor (CSL) on in vivo digestibility, ruminal pH, ammonia and hydrolytic enzyme activities, blood metabolites, feed intake (FI) and growth performance in fattening lambs. The CSL is a by‐product of wet milling process of maize starch industry. The crude protein (CP), rumen‐degradable protein (RDP), lactic acid and metabolisable energy contents of this by‐product were 420, 324, 200 g/kg dry matter (DM) and 12.6 MJ/kg DM respectively. Twenty‐seven male Moghani lambs were assigned randomly into three groups of nine lambs each in a completely randomised design. Three iso‐energetic and iso‐nitrogenous diets containing different levels (0, 50 or 100 g/kg dry matter) of CSL were offered ad libitum three times a day. Forage to concentrate ratio of the diets was 30:70. With inclusion of CSL in diet, the contents of canola meal, fish meal, wheat bran, corn grain and sugar beet pulp were decreased. The contents of DM, ash‐free neutral detergent fibre (NDFom), ether extract, starch, Ca and S were numerically lower, but soluble protein, RDP and non‐fibre carbohydrates were greater in the diets containing CSL in comparison with the control diet. The lambs fed with the diets containing CSL had lower [linear (L), p < 0.06] digestibility coefficients of DM and NDFom as compared to those fed with the diet free of CSL. Ruminal ammonia‐N concentration increased (L, p < 0.05), but pH decreased (L, p < 0.05) with raising CSL level in diet. Carboxymethyl cellulase and filter paper‐degrading activities decreased (L, p < 0.05), while proteases activity increased (L, p < 0.05) as dietary rates of CSL increased. Microcrystalline cellulase and ɑ‐amylase activities were similar among the treatments. Within blood metabolites, only urea‐N concentration increased (L, p < 0.05) in the lambs receiving CSL as compared to those fed with diet without CSL. Dietary inclusion of CSL resulted in linear decreases (L, p < 0.05) in the intakes of DM, organic matter, CP, NDFom and ash‐free acid detergent fibre, and average daily gain. However, the feed conversion ratio was similar among the experimental animals. Overall, feeding CSL up to 100 g/kg diet DM in lamb resulted in reductions of rumen fibrolytic microbial enzyme activities, in vivo digestibility, FI and growth performance, but rumen proteases activity increased.     

Effects of the natural sweetener rebaudioside A on intake,nutrient digestion,rumen fermentation,and blood biochemical parameters in adult goats during summer

The effects of dietary rebaudioside A inclusion on feed intake, digestion of nutrients, rumen fermentation, and blood biochemical parameters of goats were evaluated in a replicated 3 × 3 Latin square study. Nine adult goats during summer were fed a basal forage/concentrate-based diet and the forage was chopped rice straw. The three dietary treatments were 0, 350, and 700 mg rebaudioside A per kg chopped rice straw on a DM basis. No significant improvement was observed in dry matter intake (DMI) of forage and diet among treatments. Nutrient digestibility of DM and organic matter (OM) showed a significant trend (p < .10) across groups. Rebaudioside A inclusion significantly (p < .01) increased the concentration of total volatile fatty acids in the rumen, however, there were no differences in concentration of ruminal ammonia, and molar proportions of acetate, propionate, and butyrate. About blood metabolites, increasing rebaudioside A in the diet caused a quadratic response in glucose and total protein, and albumin concentrations. Under the conditions of this study, supplementation with rebaudioside A at 350 and 700 mg/kg forage did not improve consumption of rice straw-based diet in adult goats in summer. However, the responses in digestibility, rumen fermentation, and blood metabolites appear to indicate the potential of rebaudioside A as a bio-active substance in goats.     

The effect of grapeseed oil on performance,rumen fermentation,antioxidant status and subcutaneous adipose fatty acid profile in lambs

This experiment was carried out to examine the effect of grapeseed oil (GSO) on performance, rumen fermentation, antioxidant status and subcutaneous adipose fatty acid (FA) profile in lambs. Eighteen Baluchi lambs, 196 ± 14 days of age and 39.8 ± 1.7 kg body weight, were randomly assigned to three experimental diets: (i) diet without GSO (control), (ii) diet containing 2% of GSO (GSO2) and (iii) diet containing 4% of GSO (GSO4) for 42 days. Results showed that the experimental diets had no significant effect on dry matter intake and performance (p > 0.05). The supplemented diets with GSO had no effect on pH and NH₃‐N of rumen fluid (p > 0.05), but GSO4 increased (p = 0.003) the concentration of propionic acid and reduced (p = 0.002) the concentration of acetate acid compared to the control. Inclusion 4% of GSO to the diet increased total antioxidant activity and decreased malondialdehyde in serum and muscle (p < 0.001). The level of blood glutathione peroxidase in diets containing GSO was higher than control diet (p = 0.02), but diets had no effect on superoxide dismutase in blood and muscle tissues (p > 0.05). The concentration of vaccenic acid, rumenic acid and linoleic acid and thus polyunsaturated fatty acid in subcutaneous fat was affected by experimental diets (p < 0.001), as control had the lowest amount of these FAs and GSO4 had the highest amount of them. Therefore, it can be concluded that the use of GSO up to 4% improves the antioxidant status and adipose fatty acid profile in lambs without effects on performance.     

Effects of forage offering method on performance,rumen fermentation,nutrient digestibility and nutritional behaviour in Holstein dairy calves

The potential effect of dietary forage supplementation on the performance and rumen development in dairy calves is well established. However, limited research has been directed to the comparative effects of forage offering methods on calf performance. The objective of the present study was to determine the effects of forage provision methods (total mixed ration or free choice) on the performance, nutrient digestibility, rumen fermentation and nutritional behaviour in newborn calves. Forty‐five Holstein dairy calves (3 days of age and 41 ± 2 kg of body weight) were assigned to the following three groups (n = 15): (i) starter without forage provision (CON), (ii) starter supplemented with 10% alfalfa hay (AH) as a total mixed ration (AH‐TMR) and (iii) starter and AH as a free‐choice provision (AH‐FC) for a period of 70 days. All the calves were offered 5 l of milk/day from day 3 to 50, and 2.5 l/day from day 50 until weaning on day 56. Dry matter intake (DMI) was greater (p < 0.01) in the AH‐TMR and AH‐FC treatments than in the CON during the pre‐ and post‐weaning periods. Calves fed the AH‐FC diet showed the highest post‐weaning DMI among the treatments. The calves receiving ad libitum forage tended (p = 0.08) to increase crude protein digestibility and overall volatile fatty acids (VFA) concentrations in the rumen. No differences were observed among the treatments at the time spent on standing, lying, eating and performing non‐nutritive oral behaviours. Compared to CON calves, animals in the AH‐TMR treatment spent more time (p < 0.05) ruminating. In conclusion, our data suggest that forage supplementation in both forage offering methods increased total DMI, ruminal pH and ruminating time in dairy calves. Hence, there is no benefit in the free‐choice provision of AH in dairy calves.     

Effects of supplementary desalted mother liquor as replacement of commercial salt in diet for Thai native cattle on digestibility,energy and nitrogen balance,and rumen conditions

Four Thai native cattle were used in a 4 × 4 Latin square design experiment to evaluate the availability of desalted mother liquor (DML) as replacement of salt in concentrate. Each cattle was assigned to one of the following concentrate feeding treatments: C1, 1% NaCl was added as salt; C2, 2% NaCl was added as salt; D1, 1% NaCl was replaced by DML; D2, 2% NaCl was replaced by DML, on a dry matter (DM) basis. The animals were fed rice straw and experimental concentrates (40:60) at 1.9% of body weight on a DM basis, daily. Acid detergent fiber expressed exclusive of residual ash (ADFom) digestibility in DML treatment was higher than salt treatment (p < .05) and D2 feeding showed the highest value (60.8%). There were no significant differences in blood metabolites, nitrogen retention, ruminal ammonia nitrogen, methane emission or energy efficiency among treatments. Molar percent of acetate on volatile fatty acids in rumen fluid 4 hr post‐feeding tended to be higher in DML treatment than salt treatment (p = .08). The results indicated that adding DML could improve ADFom digestibility and salt could be replaced by DML up to 2% as NaCl in concentrate without adverse effects on nitrogen balance, rumen conditions, blood metabolites and methane emission.     

Effects of dietary supplementing tannic acid in the ration of beef cattle on rumen fermentation,methane emission,microbial flora and nutrient digestibility

Four adult Simmental male cattle (376 ± 9.0 kg initial BW), fitted with permanent rumen cannulas, were used in a 4 × 4 Latin square design to investigate the effects of dietary supplementing tannic acid (TA) on rumen fermentation, methane (CH₄) production, rumen microbes, nutrient digestibility and plasma biochemical parameters. Four levels of TA, that is 0, 6.5, 13.0 or 26.0 g/kg dry matter (DM), were added to the basal ration (composed of corn silage and concentrate mixture) as experimental treatments respectively. Each experimental period consisted of a 12‐day adaptation phase followed by a 3‐day sampling phase. The results showed that supplementing TA at 26.0 g/kg DM decreased the relative abundance of protozoa, methanogens and Ruminococcus albus to the total ruminal bacterial 16S rDNA in beef cattle (p < 0.05). The results also showed that supplementing TA at 6.5, 13.0 or 26.0 g/kg DM decreased (p < 0.01) the CH₄ production (l/kg DM intake) by 11.1%, 14.7% and 33.6% respectively. Supplementing TA at 13.0 or 26.0 g/kg DM decreased the ratio of acetate to propionate and ammonia nitrogen (NH₃–N) (p < 0.05) and tended to decrease the total volatile fatty acid (VFA) concentration of rumen fluid (p = 0.07). Supplementing TA at 26.0 g/kg DM decreased DM and organic matter (OM) digestibility (p < 0.05), supplementing TA at 6.5, 13.0 or 26.0 g/kg DM decreased (p < 0.01) crude protein (CP) digestibility by 5.0%, 8.6% and 15.7%, respectively, and supplementing TA at 6.5, 13.0 or 26.0 g/kg DM increased (p < 0.05) the plasma total antioxidant capability. It was concluded that supplementing TA in the ration of beef cattle decreased the CH₄ production and digestibility of CP of beef cattle. Supplementing TA could be an effective option to mitigate CH₄ emission form cattle, further research is necessary to study the effects of TA on the performance of cattle.     

Effects of supplementing galacto-oligosaccharides, Yucca schidigera or nisin on rumen methanogenesis, nitrogen and energy metabolism in sheep

The effects of galacto-oligosaccharides (GOS), Yucca schidigera (YS) or nisin (NS), as additives to a basal diet of grass silage and concentrate, on rumen methanogenesis, nitrogen and energy metabolism were conducted using four rumen cannulated wethers in a 4×4 Latin square design. Four treatments comprised basal diet (control), basal diet+20 g GOS, basal diet+120 ppm YS, basal diet+3 mg/kg BW^0.75 of NS. Apparent digestibility of DM, OM, CP, NDF and ADF were similar in all treatment diets. Animals fed YS had lower N losses in urine and total N losses resulting in a higher retained N. Ruminal pH values ranged from 6.33 to 6.47 and was significantly (P<0.05) altered by treatment. Sheep given YS had the lowest NH₃-N concentration, moderate in control and GOS, and the highest in NS. The GOS supplemented sheep had lower (P<0.01) proportion of acetic acid and higher (P<0.01) proportion of propionic acid compared to those fed the control diet. Microbial nitrogen supply was higher (P<0.05) in GOS supplemented sheep than those given control, YS and NS diets. Relative to control, YS and NS treatments, GOS reduced (P<0.05) methane production (l/kg BW^0.75). These results indicated that natural products have the potential to be used as manipulators of rumen fermentation.     

Effect of tannins and saponins in Samanea saman on rumen environment,milk yield and milk composition in lactating dairy cows

The objective of this study was to investigate the effects of tannins and saponins in Samanea saman on rumen fermentation, milk yield and milk composition in lactating dairy cows. Four multiparous early‐lactating dairy cows (Holstein‐Friesian cross‐bred, 75%) with an initial body weight (BW) of 405 ± 40 kg and 36 ± 8 day in milk were randomly assigned to receive dietary treatments according to a 4 × 4 Latin square design. The four dietary treatments were unsupplemented (control), supplemented with rain tree pod (S. saman) meal (RPM) at 60 g/kg, supplemented with palm oil (PO) at 20 g/kg, and supplemented with RPM at 60 g/kg and PO at 20 g/kg (RPO), of total dry matter (DM) intake. Cows were fed with concentrate diets at a ratio of concentrate to milk yield of 1:2, and chopped 30 g/kg of urea‐treated rice straw was fed ad libitum. The RPM contained condensed tannins and crude saponins at 88 and 141 g/kg of DM respectively. It was found that s upplementation with RPM and/or PO to dairy cows diets did not show negative effect on ruminal pH, blood urea nitrogen and milk urea nitrogen concentration (p > 0.05). However, supplementation with RPM resulted in lower ammonia nitrogen (NH₃‐N) concentration (p < 0.05). In addition, propionic acid and milk production increased while acetic acid, acetic to propionic ratio, methane production, methanogens and protozoal population decreased with RPM and/or PO supplementation. Furthermore, addition of PO and RPO in the diets increased milk fat while supplementation of RPM resulted in greater milk protein and Fibrobacter succinogenes numbers (p < 0.05). The population of Ruminococcus flavefaciens and Ruminococcus albus were not affected by any treatments. The findings on the present study showed that supplementation with RPM and RPO to diets of cows improved the rumen environment and increased milk yield, content of milk protein and milk fat.     

Effect of forage inclusion and particle size in diets of neonatal lambs on performance and rumen development

A slaughter experiment was conducted to determine the effects of alfalfa particle size on rumen morphology and performance of lambs. Twenty‐four Balouchi lambs aged 21 days (9.1 ± 1.1 kg) were randomly fed control (diet without alfalfa hay; CON) and mixed rations containing 15% finely ground (FINE; 2 mm) and 15% coarsely chopped alfalfa hay (LONG; 3 to 4 cm). After a 63 days feeding period, nine animals (three per treatment) were slaughtered to obtain ruminal tissue samples for morphological analyses. Alfalfa particle size did not affect (p > 0.05) papillae density, height, width, epithelium depth and surface area. Coarse alfalfa decreased the stratum corneum and increased (p < 0.05) muscle depth compared with fine and control diets. Neither DNA content and nor RNA concentration of rumen tissue was affected by feeding different diets. Forage particle size did not affect the blood concentration of glucose, urea nitrogen (BUN), beta‐hydroxybutyric acid (BHBA) and non‐esterified fatty acids (NEFA). Dry matter intake and feed conversion ratio were higher for control diet; however, there were no significant differences between treatments for average daily gain. These data suggest that coarse alfalfa significantly reduces the stratum corneum and increases muscularity of rumen wall and tended to better feed conversion ratio.     

Effect of increasing levels of white mulberry leaves (<Emphasis Type="Italic">Morus alba</Emphasis>) on ruminal dry matter degradability in lambs

A study was conducted to estimate dry matter (DM) degradability in the rumen of lambs offered a basal soybean meal and sorghum grain diet with three levels of white mulberry (WM) leaves (Morus alba). Diets consisted of 90% concentrate and 10% sorghum straw, which was incrementally replaced by WM leaves at 0% (control diet, T1), 2.5% (T2), and 5% (T3) of the total ration. Crude protein (CP) in WM was 21.8% (DM basis). Diets had equal CP (14% DM basis) and metabolizable energy (10.8 MJ/kg DM) content. Three non-castrated Pelibuey male lambs fitted with permanent rumen cannula were utilized in a 3 × 3 Latin square design. Each experimental period consisted of 10 days of adaptation followed by sampling. DM degradability was determined using the nylon bag technique. Bags contained the experimental diets offered in each period and were incubated in rumen in pairs for 4, 8, 12, 24, and 48 h. The potential degradation was higher (P < 0.05) for T2, followed by T3 and T1. WM level did not influence the degradation rate or the effective degradation at the three passage rates modeled. It was concluded that WM forage may have useful application in feedlot diets for growing lambs, as this forage increases potential degradation of high-grain diets. The incorporation of WM in diets for feedlot lambs in tropics may reduce the use of expensive conventional protein supplements.     

钴和铜对肉用绵羊维生素B_(12)合成、瘤胃发酵及造血机能的影响

为研究不同水平的钴和铜对肉用绵羊维生素B12合成、瘤胃发酵及造血机能的影响,试验选20只体重相近(28.9±1.1)kg、装有永久瘤胃瘘管的杂交一代羯羊,随机均分为5组,定量饲喂对照组日粮,4种不同水平的钴铜(0.3:10、0.3:20、0.6:10和0.6:20)日粮。结果表明:瘤胃维生素B12合成主要取决于钴的摄入量,日粮中同时添加钴、铜及其不同的配比对维生素B12合成未显协同效应和影响。钴与铜合用可增加瘤胃挥发性脂肪酸的浓度,并改变乙酸、丙酸和丁酸比例,用量越多其影响越大。随肉羊日粮中钴与铜合用及其用量增加,可更有效地促进铁的吸收和利用,从而更加明显地改善机体的造血机能。     

Effects of juniper essential oil on growth performance,some rumen protozoa,rumen fermentation and antioxidant blood enzyme parameters of growing Saanen kids

This study aimed to evaluate the effects of juniper essential oil on the growth performance, rumen fermentation parameters, rumen protozoa population, blood antioxidant enzyme parameters and faecal content in growing Saanen kids. Thirty‐six male Saanen kids (36 ± 14 days of age) were used in the study. Each group consisted of 9 kids. The control group (G1) was fed with a diet that consisted of the above concentrated feed and oat hay, whereas the experimental groups consumed the same diet but with the concentrated feed uniformly sprayed with juniper essential oil 0.4 ml/kg (G2), 0.8 ml/kg (G3) or 2 ml/kg (G4). There were no differences (p > 0.05) in live weight, live weight gain or feed consumption between the control and experimental groups. There was a significant improvement (p < 0.05) in feed efficiency in the G3 group. There were no differences in the rumen pH, rumen volatile fatty acid (VFA) profile or faecal pH of the control and experimental groups. The rumen NH₃N values were similar at the middle and end of the experiment, but at the start of the experiment, the rumen NH₃N values differed between the control and experimental groups (p < 0.05). The faecal score value was significantly (p < 0.05) decreased in the experimental groups. The addition of juniper essential oil supplementation to the rations caused significant effects on the kids’ antioxidant blood parameters. Although the superoxide dismutase (SOD) activity, total antioxidant capacity (TAC) and catalase values were significantly (p < 0.05) increased in the experimental groups (G2, G3 and G4), especially group G4, the blood glutathione peroxidase (GPX) value significantly decreased in the experimental groups. The results of this study suggest that supplementation of juniper oil is more effective on antioxidant parameters than on performance parameters and may be used as a natural antioxidant product.     

Effect of changing forage on the dynamic variation in rumen fermentation in sheep

To better understand rumen adaptation during dietary transitions between high‐ and low‐quality forages, 10 rumen‐cannulated Hu sheep were randomly allocated to two dietary treatments (five sheep each) with the same concentrate‐to‐forage ratio and concentration mixture, but different forage sequences: (i) alfalfa hay (AH) to corn stover (CS) and back to AH; and (ii) CS to AH and back to CS. A significant decrease in the rumen microbial protein concentration was observed on day 6 after dietary transition whether the transition was from AH to CS or from CS to AH, and this was accompanied by an increase in the ammonia nitrogen concentration as well as a decrease in the total volatile fatty acids concentration and pH. However, after transitioning back to the original forage, the rumen fermentation parameters returned to their initial levels within 2 weeks. Our findings suggest that abrupt substitutions of forages with large nutrient differences could influence rumen function to some extent, but recovery can occur within 2 weeks without detrimental effects. Furthermore, we speculate that the variation of fermentation in the first 6 days may indicate an important rumen transition stage that requires further study.     

Net energy of oat bran,wheat bran,and palm kernel expellers fed to growing pigs using indirect calorimetry

The objectives of this experiment were to (a) determine the effects of fiber increase in diets on heat production (HP), (b) determine the net energy (NE) of oat bran (OB), wheat bran (WB), and palm kernel expellers (PKE) fed to growing pigs using indirect calorimetry (IC). Twenty‐four growing barrows (29.2 ± 2.6 kg) were randomly allotted to one of four diets with six replicate pigs per diet. Diets included a corn‐soybean meal basal diet and three test diets containing 30% OB, WB or PKE, respectively. During each period, pigs were individually housed in metabolism crates for 20 days, including 14 days to adapt to the diets. On day (d) 15, pigs were transferred to the open‐circuit respiration chambers for determination of daily total HP and were fed one of the four diets at 2.3MJ ME/kg body weight (BW)^0.6/day. Total feces and urine were collected for the determination of digestible energy (DE) and metabolizable energy (ME) and daily total HP was measured from d 15 to d 19 and fasted on day 20 for the measurement of fasting heat production (FHP). The apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), and organic matter (OM) were greater (p < 0.01) in pigs fed the basal diet compared with those fed the test diets. The ATTD of neutral detergent fiber (NDF) was lower (p < 0.01) in pigs fed the WB diet compared with those fed the basal, OB, or PKE diets. The ATTD of ether extract (EE) in pigs fed the PKE diet was greater (p < 0.01) compared with those fed the other diets. The average total HP and FHP in pigs fed the four diets were 1261 and 787 kJ/kg BW^0.6/d, respectively, and were not significantly affected by diet characteristics. The NE:ME ratio for diets ranged from 78.1 to 80.9%. The NE contents of OB, WB, and PKE were 10.93, 7.47, and 8.71 MJ/kg DM, respectively.     

Effects of supplementing rare earth element cerium on rumen fermentation,nutrient digestibility,nitrogen balance and plasma biochemical parameters in beef cattle

The objectives of the trial were to investigate the effects of supplementing rare earth element (REE) cerium (Ce) on rumen fermentation, nutrient digestibility, methane (CH₄) production, nitrogen (N) balance and plasma biochemical parameters in beef cattle. Four Simmental male cattle, aged at 14 months, with initial liveweight of 355 ± 8 kg and fitted with permanent rumen cannulas, were used as experimental animals. The cattle were fed with a total mixed ration (TMR) composed of concentrate mixture and corn silage. Four levels of cerium chloride (CeCl₃·7H₂O, purity 99.9%), that is 0, 80, 160 and 240 mg CeCl₃/kg DM, were added to basal ration in a 4 × 4 Latin square design. Each experimental period lasted 15 days, of which the first 12 days were for pre‐treatment and the last 3 days were for sampling. The results showed that supplementing CeCl₃ at 160 or 240 mg/kg DM increased neutral detergent fibre (NDF) digestibility (p < 0.05) and tended to increased acid detergent fibre (ADF) digestibility (p = 0.083). Supplementing CeCl₃ at 80, 160 or 240 mg/kg DM decreased the molar ratio of rumen acetate to propionate linearly (p < 0.05). Supplementing CeCl₃ at 160 or 240 mg/kg DM decreased total N excretion, urinary N excretion and increased N retention (p < 0.05), increased excretion of total urinary purine derivatives (PD) (p < 0.05) and decreased CH₄/kg DMI (p < 0.05). In conclusion, supplementing CeCl₃ at 160 or 240 mg/kg DM in the ration of beef cattle increased the digestibility of NDF, decreased the molar ratio of rumen acetate to propionate, increased N retention and microbial N flow and decreased CH₄/kg DMI.     

Effect of supplementation of calf starter with fennel powder on performance,weaning age and fermentation characteristics in Holstein dairy calves

The objective of this experiment was to investigate the effects on performance, weaning age and rumen fermentation characteristics in Holstein calves when fennel powder was added to their starter diets. Thirty Holstein calves with a mean birth weight 40 kg (SD = 0.5) were allocated randomly to one of the following experimental diets: (i) control (starter diet without fennel powder), (ii) starter diet containing 0.4% of fennel powder and (iii) starter diet containing 0.8% of fennel powder (DM basis). The effect of treatments on mean dry matter intake was significant (p < 0.05) in the post‐weaning and total experimental periods. Average daily weight gain before (0.38, 0.49 and 0.47 kg/day) and after (0.6, 1.01 and 0.83 kg/day) weaning and during the entire study (0.45, 0.7 and 0.58 kg/day) was influenced by diets of 1, 2 and 3, respectively (p < 0.05). Maximum daily weight gain and the best feed conversion ratio were achieved with 0.4% fennel powder. Mean weaning age of the calves supplemented with fennel powder was lower (p < 0.05) than that of the control group. Ruminal fluid pH in calves offered starter containing 0.8% fennel powder was lower (p < 0.05) compared to calves fed the other diets. Ammonia nitrogen content increased (p < 0.05) in the third week of feeding fennel powder. The mean concentration of total short‐chain fatty acids (SCFA) and propionate molar percentage in the ruminal fluid of the calves fed with the fennel powder were higher (p < 0.05) at 6 weeks and 2 weeks after weaning than control group; however, acetate‐to‐propionate molar ratio was lower (p < 0.05). The results showed that adding 0.4% fennel powder to the starter increased the propionate molar percentage in the rumen and improved the calf performance, allowing the calves to be weaned at an earlier age.     

Effects of inclusion of graded amounts of soya bean hulls on feed intake,chewing activity and nutrient digestibility in dairy cows

Twelve multiparous Holstein dairy cows were used in a replicated 4 × 4 Latin square changeover design to evaluate the effects of graded inclusion of soya bean hulls (SHs) in replacement of diet forages at 0%, 10%, 20% and 30% of dietary dry matter (DM) basis on peNDF > 8 and peNDF > 1.18 contents of diets and their resulting effects on chewing activity, nutrient digestibility and milk production of dairy cattle. The control diet contained 50% forage, 50% concentrate and no SH. In the other three diets, SH was substituted for alfalfa hay, corn silage and wheat bran to supply 10%, 20% and 30% of the dietary DM. Increasing SH concentration in the diets resulted in decreasing concentrations of forage neutral detergent fibre (NDF), physically effective NDF (peNDF) and mean particle size (p < 0.01). Chewing activity per kilogram of daily dry matter intake (DMI) was not affected by the different diets tested. However, chewing activity significantly decreased for kilogram intake of NDF, but increased for peNDF > 1.18 when SH was included in the diets (p < 0.01). Total tract apparent digestibility of nutrients significantly increased for DM, organic matter (p < 0.05) and NDF (p < 0.01) but decreased for crude protein (p < 0.05) as the proportion of SH was increased in the diets. Rumen pH value of cattle was not influenced by the diets. Including medium and high amounts of SH in the diets decreased DMI of the animals (p < 0.05) without any significant effect on their daily milk or 4% fat‐corrected milk production. In conclusion, the results of this study showed that the NDF from a non‐forage fibre source like SH had a lower potential for stimulating chewing activity than did forage NDF. Despite this, the small size of dietary particles increased not only the chewing activity per kilogram of peNDF intake but also saliva secretion as well as the potential for rumen to neutralize acids. The findings of this study demonstrate the greater differences in peNDF > 8 among the diets and that these differences are better reflected in terms of DMI, chewing activity and nutrient digestibility, but not in rumen pH.     

Influence of different dietary zinc levels on cashmere growth,plasma testosterone level and zinc status in male Liaoning Cashmere goats

The experiment was conducted to investigate the influence of different levels of zinc (Zn) on cashmere growth, plasma testosterone and Zn profile in male Cashmere goats. Twenty‐eight male Liaoning Cashmere goats, 3 years old and body weight at 56.2 ± 2.45 kg, were assigned to four groups. The animals were fed a basal diet containing of 45.9 mg Zn/kg dry matter (DM) basis and supplemented with 0, 20, 40 or 80 mg Zn (reagent grade ZnSO₄·7H₂O) per kg DM for 90 days. There was no significant effect on growth and diameter of cashmere fibre for Zn supplemented in diets. However, the length and growth rate of wool were improved (p < 0.05) with dietary Zn. The length and growth rate of wool were higher (p < 0.05) for the groups supplemented with 40 or 80 mg Zn/kg DM compared with that of 20 mg Zn/kg DM treatment group. Plasma testosterone concentration was increased for Zn supplemented in diets, and the testosterone concentration was higher (p < 0.05) in goats fed on the diet supplemented with 40 or 80 mg Zn/kg DM compared with those fed on basal diet. Plasma Zn concentrations increased (p < 0.05) with increasing dietary Zn and supplemented with 40 and 80 mg Zn/kg DM groups improved plasma Zn concentration (p < 0.05) more than 20 mg Zn/kg DM group. Fibre Zn content was higher (p < 0.05) in groups supplemented with 40 or 80 mg Zn/kg DM compared with control group, but no difference between Zn‐supplemented groups (p > 0.05). The activity of plasma alkaline phosphatase was increased (p < 0.05) due to dietary Zn supplementation; however, no difference was found between supplemented treatment groups (p > 0.05). In conclusion, Zn content (45.9 mg Zn/kg DM) in control diet was insufficient for optimal wool growth performance, and we recommended the level of dietary Zn for such goats is 86 mg/kg DM during the breeding season and cashmere fibre growing period.