Feeding value of whole raw soya beans as a protein supplement for beef cattle consuming low‐quality forages

Experiments (Exp) I and II were conducted to compare raw whole soya beans (WSB), roasted (rWSB) or other protein sources as supplements of low‐quality forages fed ad libitum to beef cattle, upon DM intake (DMI), ruminal and blood parameters, and animal performance. Exp I: treatments for wheat straw fed to four ruminally cannulated steers were (i) Control‐WS: no supplement; (ii) WSB‐WS: whole soya beans; (iii) rWSB‐WS: roasted WSB; and (iv) SBM‐WS: soybean meal–wheat midds mixture; all fed at 1.4 kg DM/day. Exp II: 12 steers grazed deferred grain sorghum (DS) receiving these treatments: (i) Control‐DS: no supplement; (ii) WSB‐DS: 1.26 kg DM/day whole soya beans; and (iii) SFM‐DS: 1.35 kg DM/day of sunflower meal. In Exp I, WS DMI resulted 47, 52 and 41% greater for WSB‐WS, rWSB‐WS and SBM‐WS, respectively, than Control‐WS (p < .05). In Exp II, the DMI of DS was unaffected by supplementation; a substitution of DS by supplement was found for WSB‐DS (p < .05); however, total diet and digestible DMI increased with supplementation (p < .05). Rumen pH in Exp I remained unaffected by supplementation, but N‐NH₃ as well as blood urea‐N in Exp II increased (p < .05). In Exp II, average daily weight gains improved similarly with both supplements compared with Control‐DS. Additionally, feed‐to‐gain ratio decreased (p < .05), being lower for WSB‐DS (8.3) vs. SFM‐DS (9.9). Roasting effects of WSB as a supplement for low‐quality forages were not detected, and all protein sources increased total diet DMI and forage utilization. Only moderate cattle weight gains could be expected for unsupplemented DS.     

Grape pomace improves antioxidant capacity and faecal microflora of lambs

Grape pomace is a by‐product of winemaking process and rich in bioactive compounds such as plant polyphenols having antioxidant and antimicrobial activities. As known, oxidative stress may cause a number of pathological conditions in farm animals and thus affecting animal welfare and production. Moreover, pathogenic bacteria affect animals’ health status. Thus, the objective of this study was to investigate whether lambs’ feed supplemented with grape pomace enhances the antioxidant mechanisms and reduces the growth of pathogenic bacteria. For this purpose, redox status was assessed in blood and tissues using oxidative stress markers in lambs fed with diet supplemented with grape pomace. Moreover, the effect on bacterial growth was assessed by examining microbial populations in lambs’ faecal microflora. The following oxidative stress markers were assessed: reduced glutathione (GSH), catalase activity (CAT), total antioxidant capacity (TAC), thiobarbituric acid‐reactive substances (TBARS) and protein carbonyls (CARB). Twenty‐four lambs were assigned to two experimental groups receiving standard or experimental diet for 55 days. Blood and tissues (liver, quadriceps muscle, spleen, heart and brain) were collected at two different time‐points, 42 and 70 days post‐birth, after ration administration. The results showed that lambs fed with experimental diet had significantly increased antioxidants mechanisms in blood and tissues as shown by increases in CAT and GSH compared to control. Moreover, lambs fed with the experimental diet exhibited decreased oxidative stress‐induced damage to lipids and proteins as shown by decreases in TBARS and CARB respectively. In addition, the experimental diet enhanced the growth of facultative probiotic bacteria and inhibited the growth of pathogen populations such as Enterobacteriacae and E. coli. This is the first study investigating the effect of diet supplemented with grape pomace on the redox status and microbiota of lambs.     

Effect of the type of silage on milk yield,intake and rumen metabolism of dairy cows grazing swards with low herbage mass

The aim of this study was to evaluate the effect of herbage allowance (HA) and type of silage supplemented (TS) on milk yield, dry matter intake (DMI) and metabolism of dairy cows in early lactation. Thirty‐six Holstein‐Friesian dairy cows were allocated to four treatments derived from an arrangement of two HA (LHA = 17 or HHA = 25 kg of DM/cow/day) and two TS (grass (GS) or maize (MS)). Herbage allowance had no effect on DMI or milk yield. Rumen pH and NH₃‐N concentration were not affected by HA. The efficiency of microbial protein synthesis in the rumen (microbial protein (MP)) was affected by HA with 21.5 and 23.9 g microbial nitrogen per kg ruminal digestible organic matter for LHA and HHA, respectively (P < 0.05). Supplementation with MS showed higher values of milk yield by 2.4 kg/cow/day (P < 0.001), milk protein content by 0.10 % (P < 0.023) and herbage DMI by 2.2 kg/cow/day, and showed lower values for milk urea compared to GS (P < 0.001). The former results suggest that TS had a greater effect on milk yield, total feed intake and energy intake than increase in herbage allowance; however, increase in HA had greater effects on MP than TS.     

The nutritive value of marula (Sclerocarya birrea) seed cake for broiler chickens: nutritional composition,performance, carcass characteristics and oxidative and mycotoxin status

This study was aimed at investigating the nutritive value of marula seed cake (MSC) as an alternative protein source for broilers. In a completely randomised design involving six replicate pens of five chickens assigned to each of five treatments, body weight gain (BWG), feed intake (FI), feed conversion efficiency (FCE) and carcass characteristics were measured in an experiment in which 150 28-day-old broilers were fed maize-based diets containing, respectively, 0, 5, 10, 15 and 20% MSC at finisher phase. The results showed MSC to be remarkably high in CP (470.0 g/kg DM) and EE (343.5 g/kg DM), with moderate CF (58.2 g/kg DM), ash (54.3 g/kg DM), Ca (1.1 g/kg DM) and P (11.0 g/kg DM). Whilst very poor in lysine, MSC was found to be rich in methionine, cyst(e)ine, arginine and glutamic acid; it also contains good levels of valine, glycine, threonine, isoleucine, leucine, histidine, phenylalanine, serine, proline and alanine. Also, it contained 85.24% oleic (OA), 9.65% palmitic and 5.11% stearic acids, with a high peroxide value and low levels of mycotoxins deoxynivalenol (DON) and T-2 toxin. BWG, FI and FCE of broiler chickens significantly decreased (P < 0.001) as the dietary level of MSC increased. Further, dietary MSC significantly decreased bird live weight at slaughter (P < 0.001), plucked weight (P < 0.001), dressed weight (P < 0.001) and weights of the liver (P < 0.001) and neck (P < 0.05). The results therefore demonstrate MSC to be a good source of CP, fat, Ca, P, amino acids (except lysine) and OA that can replace soya bean meal (SBM) in broiler diets. However, its use is currently limited by lipid peroxidation and presence of mycotoxins.

     

Supplementation of cottonseed,linseed, and noug seed cakes on feed intake,digestibility, body weight,and carcass parameters of Sidama goats

A digestibility, feed intake, and carcass evaluation experiment using 20 yearling intact male Sidama goats weighing 16.4 ± 0.63 kg (mean ± SD) was conducted in Ethiopia with the objectives to determine feed intake, digestibility, body weight (BW) gain, and carcass parameters. The treatments included feeding natural pasture hay (T1, control) and supplementation with cottonseed cake (284 g—T2), linseed cake (250 g—T3), and noug seed cake (296 g—T4) on dry matter (DM) basis to supply 85 g crude protein (CP) per head per day. Randomized complete block design for feed intake and BW parameters and complete randomized design for digestibility and carcass parameters were used. Hay DM intake was higher (P < 0.01) for T1 than for the other treatments. T3 promoted higher (P < 0.01) DM (29.3 g/kg W^0.75/day) and CP (14.1 g/kg W^0.75/day) intake than T4 (8.9 g/kg W^0.75/day DM and 4.1 g/kg W^0.75/day CP). T3 showed better (P < 0.05) organic matter and CP digestibility than T2. Goats in T3 had higher nitrogen intake (P < 0.01) and retention (P < 0.05) than those in T1. Goats in T2 and T3 showed higher (P < 0.05) daily BW gain and final BW than those in T4 and T1. Goats in T2 and T3 had higher (P < 0.05) slaughter weight, empty BW, hot carcass weight, rib-eye muscle area, and dressing percentage on slaughter weight basis than those in T1. The results showed that T2 and T3 had similar effect on CP intake, daily BW gain, and carcass parameters for growing Sidama goats fed natural pasture hay.     

葡萄渣对羔羊生产性能、屠宰性能和养分消化代谢的影响

本试验采用单因子完全随机试验设计,选择60只3月龄左右杜寒F₁代公羔进行试验,测定不同水平葡萄渣对羔羊生产性能、屠宰性能和养分消化代谢的影响。本试验设4个饲粮处理组,每个处理15个重复,每个重复一只羊,Ⅰ为基础饲粮,Ⅱ、Ⅲ和Ⅳ处理组为饲粮中分别含有8%,16%和24%的葡萄渣,缩合单宁(condensed tannins,CT)含量分别为0,1.5,3.0和4.5 g/kg。结果表明,Ⅱ、Ⅲ、Ⅳ组羔羊日采食量、日增重、胴体重、屠宰率和胴体脂肪含量都显著高于Ⅰ组(P＜0.05),N表观存留率极显著高于Ⅰ组(P＜0.01),但Ⅰ组羔羊的酸性洗涤纤维和N表观消化率显著高于Ⅳ组(P＜0.05);Ⅱ组羔羊的饲料转化率显著高于Ⅰ组(P＜0.05),净肉率极显著高于Ⅰ组(P＜0.01)。随着CT含量的增加,羔羊的N、中性洗涤纤维和酸性洗涤纤维表观消化率逐渐降低,N的表观存留率逐渐升高,综合考虑羔羊日增重、饲料转化率、屠宰性能和养分利用率等指标,饲粮中葡萄渣以8%~16%为宜。     

Effects of fermented garlic powder supplementation on growth performance,nutrient digestibility,blood characteristics and meat quality in growing‐finishing pigs

One hundred pigs (BW = 50.7 ± 1.89 kg) were used to investigate the effects of fermented garlic powder (FGP) in growing‐finishing pigs. Pigs were allotted to one of five treatments, included: (i) NC (basal diet); (ii) PC (NC + 44 mg/kg of Tylosin); (iii) FGP1 (NC + 1 g/kg FGP); (iv) FGP2 (NC + 2 g/kg FGP); and (v) FGP4 (NC + 4 g/kg FGP). Supplemental FGP increased average daily gain (ADG) and gain/feed ratio compared with those fed NC diet throughout the experiment (P < 0.05, linearly). Dietary PC treatment increased the ADG and average daily feed intake during the first 6 weeks (P < 0.05). The inclusion of FGP2 and FGP4 treatments had higher apparent total tract digestibility of dry matter and nitrogen (P < 0.05) than those in the NC treatment. Dietary NC treatment exhibited lower (P < 0.05) lymphocyte count (6 and 12 weeks) and immunoglobulin G (12 weeks) than those in the other treatments. Marbling scores were higher (P < 0.05) in FGP treatment groups than the NC treatments. Pigs fed on FGP2 and FGP4 diets evidenced lower 2‐thiobarbituric acid reactive substances value (P < 0.05) than those in the NC and PC treatments. Collectively, our findings demonstrated that the administration of FGP at a level of 2 or 4 g/kg improved growth performance, nutrient digestibility and meat quality in growing‐finishing pigs.     

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.     

Effects of inoculants on the fermentation characteristics and in vitro digestibility of reed canary grass (Phalaris arundinacea L.) silage on the Qinghai‐Tibetan Plateau

To effectively use local available grass resources to cover the winter feed shortage on the Qinghai‐Tibetan Plateau, direct‐cut and wilted reed canary grass (RCG) silages were prepared by using a rolled‐bale system, and their ensiling characteristics and in vitro digestibility were studied. Silages were treated without (control) or with inoculants including LP (Lactobacillus plantarum), LPLB (L. plantarum, L. buchneri), and LPLBc (L. plantarum, L. buchneri, and cellulase), and were stored at ambient temperature (5.7–14.6°C) for 90 days. Compared with control, the inoculated silages increased (p < .05) lactic acid and acetic acid contents, and reduced (p < .05) final pH value and ammonia‐N ratio of total N. The highest WSC content (41.2 g/kg DM) occurred for LPLB‐inoculated silage, whereas LPLBc‐treated silage displayed the lowest contents of NDF (522.9 g/kg DM) and ADF (275.5 g/kg DM). In addition, LPLBc‐inoculated silage had the highest in vitro gas production (51.0 ml/g DM), in vitro DM digestibility (619.3 g/kg DM), and metabolic energy (9.6 kJ/kg DM). These results confirmed that treatments with inoculants at ensiling could improve silage fermentation and in vitro digestibility of RCG, and this could be a potential winter feed for animals on the Qinghai‐Tibetan Plateau.     

Effects of Rosmarinus officinalis L. essential oils supplementation on digestion,colostrum production of dairy ewes and lamb mortality and growth

The aim of this study was to evaluate the effect of rosemary essential oils (REO) and the forage nature on ewes' performances, immune response and lambs' growth and mortality. Forty‐eight dairy ewes (Sicilo‐Sarde) were fed oat‐hay or oat‐silage supplemented with 400 g of concentrate during pregnancy and 600 g during postpartum. The experimental concentrate contained the same mixture as the control (barley, soybean meal and mineral vitamin supplement) more 0.6 g/kg of REO. Two groups were obtained with each forage (Hay groups: H‐C and H‐REO; Silage groups: S‐C and S‐REO). REO increased the dry matter (DM) intake, the nitrogen intake and retention being higher with the silage groups (P < 0.05). REO increased solid non‐fat (P = 0.004) and fat contents of colostrum which was higher with hay (P = 0.002). REO decreased lamb mortality (P < 0.05) which averaged 21% for control groups and 6% for H‐REO, while no mortality was recorded with S‐REO. REO dietary supply improved forage intake and tended to ameliorate colostrum production; it could be a natural additive to improve ewes' performances.     

Improving ruminal degradability and energetic values of bamboo shoot shell using chemical treatments

This study evaluated effects of different treatments on nutritive value of bamboo shoot shell (BSS). Five treatments were sun‐drying (control), ammoniation (5%/dry matter (DM) urea), Ca(OH)₂ (4%/DM calcium hydroxide), NaOH (4%/DM sodium hydroxide), and AHP (4%/DM sodium hydroxide plus 1%/DM hydrogen peroxide). The results showed that chemical composition of BSS was greatly changed by chemicals (P < 0.01) except acid‐detergent lignin. All chemical treatments significantly reduced neutral detergent fiber (NDF) content except AHP (P < 0.01), and obviously increased acid detergent fiber (ADF) content (P < 0.01) except ammoniation. The predicted organic matter digestibility, metabolizable energy and net energy for lactation of BSS were greatly increased by chemical treatments (P < 0.01), the highest for ammoniation, followed by Ca(OH)₂, NaOH and AHP. Ammoniation had higher (P = 0.03) ammonia‐N concentration than the other four treatments. There were significant differences among all treatments on total volatile fatty acids (P = 0.03), propionate (P = 0.01), butyrate concentration (P < 0.01) and C₂/C₃ ratio (P = 0.02). Chemical treatments greatly improved effective degradability (ED) of DM (P < 0.01) and ED of NDF (P = 0.06) and ADF (P = 0.07) numerically. Ammoniation got a higher ED of crude protein than control. In conclusion, all chemical treatments greatly improved nutritive value of BSS with highest value obtained from ammoniation, followed by strong alkalization, alkaline hydrogen peroxide and modest alkalization.     

Effects of dietary supplementation of selenium and iodine on growth performance,carcass characteristics and histology of thyroid gland in goats

This study assessed the effects of dietary selenium (Se), iodine (I) and a combination of both on growth performance, thyroid gland activity, carcass characteristics and the concentration of iodine and selenium in Longissimus lumborum (LL) muscle in goats. Twenty‐four bucks were randomly assigned to four dietary treatments: control (CON), basal diet without supplementation, basal diet + 0.6 mg Se/kg dry matter (DM) (SS), 0.6 mg I/kg DM (IP), or combination of 0.6 mg/kg DM Se and 0.6 mg/kg DM I (SSIP) and fed for 100 days. Animals fed diet SSIP exhibited higher (P < 0.05) body weight and better feed conversion ratio (FCR) than those fed other diets. Dressing percentage of goats fed the supplemented diets was higher (P < 0.05) than that of the control. Carcasses from the IP group had higher (P < 0.05) total fat proportion than the SSIP group. The levels of both elements were significantly elevated (P < 0.05) in LL muscle in supplemented goats. Thyroid follicular epithelial cells of IP and SSIP animals were significantly higher than those of CON and SS groups. The study demonstrated that the combined Se and I dietary supplementation improves growth performance, carcass dressing percentage and increases the retention of Se and I in goat meat.     

Effects of dietary water‐soaked barley on amino acid digestibility,growth performance,pork quality and Longissimus dorsi muscle fatty acid profiles in pigs

Two experiments were conducted to assess the feeding value of water‐soaked barley (WB) as a replacement for dehulled barley (DB) in pigs. In experiment (Exp.) 1, eight barrows (body weight = 30.56 ± 0.78 kg) were fitted with a T‐cannula and allotted to a duplicated 4 × 4 Latin square design: WB10, 100g/kg WB; WB20, 200 g/kg WB; DB10, 100 g/kg DB; and DB20, 200 g/kg DB. In Exp. 2, 80 barrows (body weight = 70.56 ± 1.29 kg) were used in a 56‐day experiment: (i) WB15, 150 g/kg WB; (ii) WBD10, 100 g/kg WB and 50 g/kg DB; (iii) WBD5, 50 g/kg WB and 100 g/kg DB; and (iv) DB15, 150 g/kg DB. In Exp. 1, the apparent ileal digestibilities of total essential amino acids were higher (P < 0.05) in WB10 treatment than DB20. For Exp.2, the WB15 and WBD10 had higher pH and lower cooking loss (P < 0.05) than other two treatments. The WB15 treatment decreased (P < 0.05) the contents of palmitic acid (C16:0) in Longissimus dorsi muscle than WBD5 and DB15 treatments. In conclusion, it is suggested that water‐soaked barley improved some amino acid digestibility and the cooking loss and moderate fatty acid profiles in Longissimus dorsi muscle.     

Changes in blood profile in sheep receiving raw garlic,garlic oil or monensin

This study aimed to evaluate the effects of supplementing a basal diet (CTR) with raw garlic (GAR) or garlic oil (GAO) on blood profile in sheep. Monensin (MON, 33 mg/kg DM) was used as positive control. Four ruminally fistulated rams were used in three experiments each arranged in a 4 × 4 Latin square design with 28‐day periods. Experiments 1 and 2 differed in the dose of GAR (75 vs. 100 g/kg DM) and GAO (500 vs. 750 mg/kg DM), while experiment 3 was designed to compare the two doses of each additive (GAR and GAO). The animals were fed a basal diet as TMR consisting of 77.83% forage (alfalfa hay and corn silage) and 22.17% concentrate, providing 10.50 MJ/kg DM (metabolizable energy) and 16.5% crude protein to cover maintenance energy and protein requirements. Supplementation of monensin decreased (P < 0.05) β‐hydroxybutyrate (BHB) and non‐esterified fatty acid (NEFA) concentrations in the blood compared with other treatments. There was no significant effect of additives on serum concentration of glucose, total triglycerides, cholesterol, total protein, albumin and blood urea nitrogen (BUN). Although the serum insulin concentration was elevated in sheep receiving MON and GAO (P < 0.01), no change was observed in blood glucose concentration. No significant effect of GAO and GAR was observed in key energy and protein‐related blood metabolites. However, administration of monensin had a positive influence on energy indices. In conclusion, whereas parameters characterizing the energy balance did not show a significant effect of GAR supplementation, a higher insulin concentration in GAO‐treated animals was observed.     

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 different levels of dried sweet potato (<Emphasis Type="Italic">Ipomoea batatas</Emphasis>) leaves inclusion in finisher ration on feed intake,growth, and carcass yield performance of Ross broiler chicks

The effect of supplementation with increasing levels of dried leaves of sweet potato (Ipomoea batatas) on feed intake, body weight gain, and carcass yield characteristics of finisher Ross broiler chicks was studied at Haramaya University, Ethiopia. Three hundred Ross broiler chicks aging 29 days and weighing 540 ± 5.28 g (mean ± SD) were randomly distributed to 15 pens, each with 20 chicks, representing five treatment rations each with three replications. Dietary treatments consisted of inclusions of dried leaves of sweet potato at levels of 0, 50, 100, 150, and 200 g/kg DM for treatments T1, T2, T3, T4, and T5, respectively. The experiment lasted for 28 days, during which, dry matter intake (DMI), body weight gain, and feed conversion efficiency; carcass yield characteristics; and weights and lengths of different parts of gastrointestinal tract were measured. Data were subjected to statistical analysis using SAS (1998). Inclusion of dried leaves of sweet potato at the level of 200 g/kg DM resulted in lower (P < 0.01) daily DMI as compared to chicks in control diet (T1). The daily body weight gain declined (P < 0.01) when the level of dried leaves of sweet potato in the diet was 150 and 200 g/kg DM. Inclusion of dried leaves of sweet potato up to 100 g/kg DM did not affect (P > 0.05) eviscerated carcass weight, and weights of drumstick with thigh and breast meat were not affected (P > 0.05) by inclusion of dried leaves of sweet potato up to 150 g/kg DM. The results of this study revealed that inclusion of dried leaves of sweet potato up to 100 g/kg DM in the finisher ration might be considered as the optimum level of supplementation when chickens are sold on live weight basis, but if birds are sold on eviscerated carcass weight basis, inclusion up to 150 g/kg DM might be economically feasible as it produced higher carcass yield components.     

Using a complex non-TDN based model (the DVE/OEB system) to predict microbial protein synthesis, endogenous protein, degradation balance, and total truly absorbed protein supply of different varieties of cereal oats for ruminants

Recently a new super‐genotype of oat has been developed in the Crop Development Center called CDC SO‐I (‘SuperOat’: low lignin and high fat). In a previous study, we evaluated total metabolizable protein using a TDN‐based model‐NRC‐2001 which is popular in North America. However, the TDN‐based NRC model is not accepted universally. The objectives of this study were to use a complex non‐TDN based model, the DVE/OEB system, to evaluate potential nutrient supply to ruminants from the SuperOat in comparison with two normal varieties of oats (CDC Dancer and Derby) in western Canada. The quantitative predictions were made in terms of: (i) truly absorbed rumen synthesized microbial proteins in the small intestine; (ii) truly absorbed rumen undegraded feed protein in the small intestine; (iii) endogenous protein in the digestive tract; (iv) total truly absorbed protein in the small intestine; and (v) protein degraded balance. Results showed that using the DVE/OEB system to predict the potential nutrient supply, it was found that the SuperOat had similar truly absorbed rumen synthesized microbial protein levels (61, 63, 59 g/kg DM, P > 0.05, for SuperOat, CDC Dancer and Derby, respectively), higher truly absorbed rumen undegraded feed protein than CDC Dancer (22 vs. 17 g/kg DM P < 0.05, for SuperOat, CDC Dancer, respectively), but similar to Derby (22 vs. 21 g/kg DM; P > 0.05), and similar endogenous protein (16, 16, 18 g/kg DM; P > 0.05). Total truly absorbed protein in the small intestine is only numerically higher in the SuperOat (67 vs. 65, 62 g/kg DM, P > 0.05, for CDC Dancer and Derby, respectively). However, the protein degraded balance was significantly different (P < 0.05) with a positive value for the SuperOat (7.0 g/kg DM) and negative values for two normal varieties (?1.5, ?6.8 g/kg DM for CDC Dancer and Derby, respectively). In conclusion, the model predicted significantly different protein degradation balance. The SuperOat had positive degradation balance but other two normal varieties had negative protein degraded balance However, the SuperOat had similar total absorbed protein value to the two normal varieties of oats.     

葡萄渣单宁对绵羊养分消化代谢及瘤胃发酵的影响

选用4只体重28 kg左右且安装永久瘤胃瘘管羯羊[萨福克(Suffolk)♂×小尾寒羊(small tail Han-yang)♀],采用4×4拉丁方试验设计,通过消化代谢试验,研究饲料中不同含量葡萄渣单宁对绵羊养分消化代谢及瘤胃发酵的影响。试验共设4个处理,葡萄渣缩合单宁含量分别为0.00,0.85,1.70和2.25 g/kg DM。结果表明,葡萄渣单宁对绵羊干物质、有机物、中性洗涤纤维、酸性洗涤纤维、钙和磷的表观消化率没有产生显著影响(P>0.05),但显著提高绵羊氮表观消化率和存留率(P<0.05);显著降低绵羊瘤胃液总氮和蛋白氮浓度而显著提高尿素氮浓度(P<0.05),对绵羊瘤胃液氨氮浓度没有产生显著的影响(P>0.05);显著提高绵羊瘤胃液丙酸摩尔比而显著降低丁酸摩尔比和乙丙比(P<0.05),对绵羊瘤胃液pH、总挥发性脂肪酸浓度和乙酸及其他酸摩尔比没有产生显著的影响(P>0.05)。此外,试验结果表明饲料中添加2.25 g/kg DM含量的葡萄渣单宁,能够提高绵羊对饲料蛋白质的利用率。     

Effects of apple pomace proportion levels on the fermentation quality of total mixed ration silage and its digestibility,preference and ruminal fermentation in beef cows

Four Japanese black beef cows were used in a 4 × 4 Latin square to evaluate the fermentation quality, digestibility, ruminal fermentation and preference of total mixed ration (TMR) silages prepared with differing proportions of apple pomace (AP). Experimental treatments were the control (no AP added, CAP), 5% (low, LAP), 10% (medium, MAP) and 20% (high, HAP) of TMR dry matter (DM) as AP. All TMR silages were well preserved. Ethanol was produced in silages containing AP and the amount increased with the proportion of AP (P < 0.05). Nutrient digestibility with LAP, MAP and HAP treatment was lower than that with CAP treatment (P < 0.05). The ruminal molar proportion of acetic acid increased (P < 0.05), but the ruminal ammonia‐N concentration decreased (P < 0.05) as the proportion of AP increased. The preference of the animals was highest for HAP, followed by MAP, CAP and LAP. This study demonstrates that decrease in nutrient digestibility might be related to the ethanol produced naturally from AP. Therefore, the proportion of AP in TMR silages should be less than 5% of dietary DM.     

Effects of dietary crude protein and tannic acid on nitrogen excretion,urinary nitrogenous composition and urine nitrous oxide emissions in beef cattle

Two consecutive trials were carried out to study the effects of dietary crude protein (CP) and tannic acid (TA) on nitrogen (N) metabolism of beef cattle and consequently, the N₂O emissions from the urine of cattle. In Trial I, eight growing castrated cattle were used as the experimental animals. Two levels of dietary CP (110.6 and 135.7 g/kg dry matter [DM]) and two levels of TA (0 and 16.9 g/kg DM) were allocated in a replicated 2 × 2 crossover design. In Trial II, the N₂O emissions from the urine of cattle collected from Trial I were determined using the static incubation technique. An interaction between dietary CP and TA on the urinary N excretion (p < .05) was found but not on the N₂O‐N emission of cattle urine. Increasing dietary CP level from 110.6 g/kg DM to 135.7 g/kg DM increased the total N excretion (p < .001), the N retention (p < .05) and the ratio of urinary urea‐N/urinary N (p < .01), did not affect the N use efficiency (NUE; p > .05) and shifted the N excretion from faeces to urine. Increasing the dietary CP level increased the N₂O‐N emission of cattle urine. Dietary addition of TA decreased the urinary excretions of urea (p < .001) and shifted the N excretion from urine to faeces, did not affect the NUE of beef cattle (p > .10), and decreased the N₂O‐N emission of cattle urine. Pyrogallol and resorcinol of the TA metabolites were detected in urine with dietary addition of TA. Feeding beef cattle with relatively low CP level and adding TA in rations are effective approaches to mitigate the N₂O‐N emissions from cattle urine.