Effects of supplementation of Farta sheep fed hay with sole or mixtures of noug seed meal and wheat bran on feed intake,digestibility and body weight change

Digestibility and feeding trials for 10 and 90 days were conducted using 25 yearling Farta rams with a mean body weight (BW) of 16.8 ± 0.17 kg (mean ± SD) to study the effects of supplementation with sole or mixtures of noug seed meal (NSM) and wheat bran (WB) on feed intake, digestibility and BW change in Farta sheep fed hay. The experimental design was a randomized complete block design. The sheep were arranged in five blocks based on initial BW, and the five treatments were assigned randomly to each animal in a block. The five treatments comprised of ad libitum hay (control, T1) and ad libitum hay plus daily supplementation of 300 g dry matter (DM) sole WB (T2), 2WB:1NSM (T3), 1WB:2NSM (T4) and sole NSM (T5). Supplementation increased total DM (P < 0.01) and crude protein (CP) (P < 0.001) intake and promoted daily BW gain (P < 0.001). Non- supplemented sheep consumed more (P < 0.01) hay DM compared to the supplemented treatments, except T2. Among supplemented sheep, T5 had higher (P < 0.001) CP intake than the other treatments. Supplementation improved (P < 0.001) the digestibility of CP. Lack of statistical differences in daily BW gain between the different supplements used in this study suggests that sheep producers can use the different feed supplements considered in this study depending on their availability in the order of T4, T5, T3 and T2, respectively.     

Supplementation of cottonseed meal on feed intake, digestibility, live weight and carcass parameters of Sidama goats

The experiment was conducted at Dilla Agricultural Technical Vocational Education and Training (ATVET) College in Ethiopia using twenty-four yearling intact male Sidama goats with a mean body weight (BW) of 16.8 ± 1.14 kg (mean ± SD). The objective of the experiment was to examine the effect of different levels of cottonseed meal (CSM) supplementation on the feed intake, digestibility, BW gain, and carcass parameters of Sidama goats. The experiment consisted of 90 days of feeding trial and 10 days of digestibility trial followed by evaluation of carcass parameters at the end of the experiment. The treatments included ad libitum feeding of hay (T1, control) and daily supplementation of CSM at 200 g (T2), 300 g (T3) and 400 g (T4) per head on dry matter (DM) basis. The experimental design was a completely randomized block design. The experimental goats were blocked on initial BW and six goats were randomly assigned to each treatment. Hay DM, crude protein (CP) and neutral detergent fiber (NDF) intake were higher (P < 0.001) in the non-supplemented than in the supplemented goats, however, the contrary was true for total CP intake. Total DM intake was higher (P < 0.001) for goats supplemented with the high level of CSM than those on the control treatment. Among CSM supplemented goats, the intake of CSM DM, CP, NDF (P < 0.001) and total CP (P < 0.01) were higher in the order of T4 > T3 > T2. The high level of supplementation with CSM resulted in better (P < 0.05) apparent digestibility coefficient (DC) of DM and organic matter (OM) compared to the non-supplemented goats. The apparent DC of CP was higher (P < 0.01) for supplemented than non-supplemented goats. The non-supplemented goats had lower daily BW gain, empty BW, dressing percentage on slaughter weight base, rib-eye muscle area (P < 0.01), BW change (P < 0.001), final BW (P < 0.05) and higher feed conversion ratio (P < 0.01) than the supplemented ones. The medium level of supplementation resulted in higher daily BW gain (P < 0.01), BW change (P < 0.001), final BW (P < 0.05) and lower feed conversion ratio (P < 0.01) than the lower level of supplementation, but with no differences (P > 0.05) in these parameters with the high level of supplementation. Therefore, it is concluded that supplementation of CSM at 300 g DM per head per day resulted in better animal performance parameters in Sidama goats.     

Feed intake,digestibility, body weight and carcass parameters of Afar rams fed tef (Eragrostis tef) straw supplemented with graded levels of concentrate mix

The experiment was conducted at Alamata Agricultural Research Center, Ethiopia using 20 Afar rams with an initial body weight (BW) of 18.2 ± 1.76 (mean ± SD) kg. The objectives were to study the effect of supplementation with concentrate mix consisting of wheat bran (WB), noug seed cake (NSC) and sesame seed cake (SSC) at the ratio of 2:1:1 on dry matter (DM) basis, respectively on feed intake, digestibility, BW gain and carcass parameters of Afar rams fed tef (Eragrostis tef) straw basal diet. The experiment was arranged with four treatments and five replications in a randomized complete block design. The treatments included feeding sole tef straw (T1, control), and daily supplementation with the concentrate mix offered at 150 (T2, low), 250 (T3, medium) and 350 (T4, high) g DM per head. Total DM intake, crude protein (CP) digestibility, daily BW gain (P < 0.001), DM and organic matter (OM) digestibility, and carcass parameters (P < 0.05) were higher in the supplemented than in the control treatment. Intake of tef straw reduced as the level of supplementation increased, whereas the contrary was true for CP intake. Performance in carcass parameters was better for the medium compared to the low level of concentrate mix supplementation. Moreover, the medium level of supplementation did not substitute tef straw intake. Therefore, it is concluded that the medium level of concentrate mix supplement maintained the utilization of the roughage feed and resulted in better carcass parameters.     

Feed intake,digestibility and body weight change in Farta sheep fed hay supplemented with rice bran and/or noug seed (<Emphasis Type="Italic">Guizotia abyssinica</Emphasis>) meal

The study was conducted to determine the effect of supplementation with rice bran (RB) and /or noug seed (Guizotia abyssinica) meal (NSM) on feed intake, digestibility, and body weight (BW) change in hay based feeding of Farta sheep. Twenty five yearling Farta rams with a mean initial BW of 19.23 ± 0.28 kg were used in randomized complete block design arranged into five blocks of five animals. The five dietary treatments that consisted of hay alone (T₁), hay + RB (T₂), hay + mixture of RB and NSM at a ratio of 1:2 (T₃), hay + mixture of RB and NSM at a ratio of 2:1 (T₄) and hay + NSM (T₅) were randomly assigned to each sheep within a block. The supplements were daily offered at 300 g dry matter (DM) head⁻¹ in two equal parts at 800 and 1600 h. Supplementation improved the total DM and acid detergent fiber (ADF) intake (P < 0.05), organic matter (OM) intake (P < 0.01), crude protein (CP) intake (P < 0.001). The apparent digestibility of DM in T₅ was higher (P < 0.05) than in T₁ and T₂ and that of T₄ was also higher (P < 0.05) than in T₁. The apparent digestibility of CP in T₅ and T₄ were higher (P < 0.001) than in T₁ and T₂ and that of T₃ and T₂ were also higher (P < 0.001) than for T₁. The BW gain of experimental sheep was improved (P < 0.01) by supplementation with NSC (T₅) and/or its mixtures with RB (T₃ and T₄). The results of the study showed that supplementation with either of both mixtures of NSM and RB at 43% of total DM intake promoted better feed intake, digestibility and BW gain in Farta sheep.     

Effect of enset (Ensete ventricosum) leaf supplementation on feed intake, digestibility, nitrogen utilization and body weight gain of sheep fed untreated or urea and calcium oxide-treated wheat straw

The study was carried out to evaluate the effect of supplementing leaves of enset (Ensete ventricosum) to straw-based diets on the performance of sheep. In a growth experiment, which lasted for 76 days, 36 male sheep (average body weight of 17.3 ± 0.58 kg) were allotted to six treatments. A digestibility trial was conducted using three of the six sheep from each treatment. The treatments were untreated or 2% urea- and 3% calcium oxide-treated wheat straw as a basal diet supplemented with three levels of chopped fresh enset leaf: low (215 g), medium (417 g) and high (594 g dry matter [DM] per day). The mean total DM intake tended to be higher (p < 0.1) at medium and high levels of supplementation than at the low level. The intake of total DM and nitrogen (N) was higher in treated than untreated straw. There was no significant difference in organic matter (OM) intake among treatments. Sheep fed medium and high levels of enset leaf supplements had similar weight gain but higher than those supplemented at low level. The digestibility of DM was not significantly different among treatments whereas the digestibility of OM tended to be higher at medium than other levels of supplementation. The digestibility of N was lower (p < 0.001) for treated than untreated straw whereas the digestibility of neutral detergent fibre was higher (p < 0.001) in treated straw. The highest mean N retention was at medium level of supplementation. There were no significant differences in total purine derivatives excretion, absorbed microbial purines and microbial N supply among treatments. It could be concluded that there is no major beneficial effect beyond medium level of enset leaf supplementation in both treated and untreated straw. For efficient utilization of enset leaf, sources of fermentable energy are necessary.     

Supplementations of <Emphasis Type="Italic">Hyparrhenia rufa</Emphasis> -dominated hay with groundnut cake- wheat bran mix: effects on feed intake,digestibility and nitrogen balance of Somali goats

A digestibility and nitrogen (N) balance experiment was conducted using twenty yearling male Somali goats weighing 23.4 ± 2.02 (mean±SD). The objectives of the study were to evaluate the effects of supplementation with graded levels of mixture of groundnut cake and wheat bran at a ratio of 3:1 on DM basis on feed intake, apparent digestibility and N balance in Somali goats. The experimental design was a completely randomized design consisting of five animals in each treatment. The dietary treatments included ad libitum feeding of hay (T1, control), and daily supplementation with 200 (T2, low) 300 (T3, medium) and 400 g DM (T4, high) of the concentrate mix. Increased level of supplementation reduced (P < 0.001) daily hay DM intake. Digestibility of crude protein (CP) was higher (P < 0.001) for the supplemented goats. Urinary nitrogen, total nitrogen excretion and retention increased (P < 0.01) with the level of supplementation. It was concluded that supplementation with groundnut -wheat bran mixture promoted feed intake and digestibility of DM, CP, and N retention in Somali goats fed hay. However, supplementation at the medium level appeared to be more effective since it promoted similar N balance with the high level of supplementation.     

Effects of treating rice straw with urea or urea and calcium hydroxide upon intake, digestibility, rumen fermentation and milk yield of dairy cows

Three, multiparous Holstein crossbred dairy cows with initial body weight of 385 ± 19 kg were randomly allocated to 3 treatments of rice straw (T1 = untreated rice straw; T2 = 5.5% urea-treated rice straw (5 g urea in 100 ml water to 100 g air-dry (91% DM) straw); T3 = 2.2% urea + 2.2% calcium hydroxide treated rice straw (2.0 g urea and 2.0 g Ca(OH)₂ in 100 ml to 100 g air-dry (91% DM) straw) according to a 3 × 3 Latin square design. Each period lasted for 21 days in which feed, feces and rumen fluid were collected during the last 7 days for chemical analyses. The findings revealed significant improvements in dry matter intake and digestibility by using 5.5% urea-treated rice straw and 2.2% urea + 2.2% calcium hydroxide treated rice straw. Ruminal pH and NH₃-N were found higher (P < 0.05) as compared with urea-treated rice straw fed group, while blood urea nitrogen and milk urea nitrogen were in normal ranges. Volatile fatty acid concentrations especially those of acetic acid were decreased (P < 0.05) and those of propionic acid were increased (P < 0.05), thus acetic acid:propionic acid was subsequently lowered (P < 0.05) in cows fed with 5.5% urea-treated rice straw and 2.2% urea + 2.2% calcium hydroxide treated rice straw, respectively. Moreover, ruminal viable and cellulolytic bacterial counts were enhanced by urea and calcium hydroxide treatments. Milk protein and fat concentrations were additionally increased by respective treatments while 3.5% fat-corrected milk was highest; ranking from 2.2% urea + 2.2% calcium hydroxide treated rice straw, 5.5% urea-treated rice straw and urea-treated rice straw fed groups. Based on this study, implications could be made that using 2.2% urea + 2.2% calcium hydroxide treated rice straw for straw treatment could be an alternative treatment to 5.5% urea treatment with regards to its effectiveness and treatment cost for lactating dairy cows.     

甘油代替大麦对泌乳中后期奶牛采食量、产奶量和乳质量的影响

文章旨在确定在不影响牛奶产量、牛奶成分、乳脂肪酸组成和牛奶感官质量的情况下,用不同水平甘油代替大麦对泌乳中后期奶牛的影响。试验选择了40头荷斯坦奶牛,采用4×4拉丁方试验设计。在部分混合日粮中,粗甘油替代大麦的含量分别为日粮干物质的0、6%、12%和18%。每天记录个体产奶量、采食量和挤奶频率,每周分析牛奶成分。对新鲜牛奶和贮藏7 d的牛奶样品进行感官分析。部分混合日粮的摄入量随甘油添加水平由0升高至12%,增加近1 kg,甘油由12%升高至18%,减少约1 kg。甘油水平由0升高至6%时,精料摄入量下降0.5 kg。随着日粮中甘油比例的增加,牛奶产量呈线性下降(P<0.05),而牛奶中的脂肪和蛋白质含量呈上升趋势(P=0.08),导致能量校正乳水平随甘油水平的升高表现为二次曲线效应,其中6%甘油组产量最高,18%甘油组产量最低。蛋白质和乳糖产量随日粮中甘油比例的增加线性下降(P<0.05)。随着日粮甘油比例的增加,牛奶中棕榈酸、油酸、亚油酸、亚麻酸和共轭亚油酸的比例线性下降(P<0.05),而短链和中链脂肪酸的比例大部分呈上升趋势。综上所述,甘油作为一种能量饲料可以在不影响牛奶品质的前提下,在泌乳中后期奶牛日粮中替代大麦的水平高达18%。但日粮甘油水平超过12%时可能会降低能量校正乳的产量。     

Effect of Supplementation with Leguminous Crop Residues or Concentrates on the Voluntary Intake and Performance of Kirdi Sheep

Twenty young Kirdi (West African Dwarf) rams, averaging 22 kg live weight and 15 months of age, were randomly assigned to four feeding groups of 5 animals each. The groups were subjected to an 8-week feeding trial to determine the effect of different protein supplements on their voluntary intake of rice straw and on their performance. The animals in one of the groups were maintained on a daily basal diet of rice straw given ad libitum and 250 g of rice bran per animal (control). Other groups were fed the basal diet, supplemented with 300 g of groundnut haulms (GH diet), 45 g of cotton seed cake (CSC diet) or 210 g of chopped cowpea vines (CPV diet) per animal per day. The average daily weight gains of the animals feeding on the control, GH, CSC and CPV diets were 20.00, 48.93, 52.14 and 49.29 g, respectively. The gains in live weight of the supplemented groups did not differ significantly (p>0.05), but there was a difference (p<0.05) in live weight gain between the supplemented groups and the control. The differences in intake of rice straw among the groups were highly significant (p<0.01). Cotton seed cake increased (p<0.01) the intake, while feeding crop residues tended to depress the intake of rice straw. Variations in the height at withers, heart girth and scapulo-ischial length did not differ significantly (p>0.05) among the groups. In terms of live weight gain and intake of rice straw, cotton seed cake was the most effective supplement, but, since the crop residues are more readily available to farmers in this area of the country, they merit more attention.     

The effect of replacing brewers' grains with barley tea grounds in total mixed ration silage on feed intake, digestibility and ruminal fermentation in wethers

Four wethers were used in a 4 × 4 Latin square to study the feed intake, apparent digestibility, nitrogen balance and ruminal fermentation characteristics when fed total mixed ration (TMR) silages which included wet barley tea grounds (WBTG). The TMR silages were prepared using compound feed including wet brewers' grains (WBG), corn, oat hay, alfalfa hay, dried beet pulp, salt and vitamin-mineral supplement in a ratio of 30.7:15:8:24:10:12:0.15:0.15, respectively, on a dry matter (DM) basis. The WBTG and soybean meal mixture (7:3 on DM basis) were substituted for WBG at ratio of 0% (Control), 5% (LTG), 10% (MTG), and 15% (HTG) on DM of TMR. WBTG addition to the TMR silages increased lactic acid concentration, decreased pH, acetic acid and ammonia-N ( P  < 0.001). Feed intakes and digestibilities for LTG and MTG (except ether extract (EE) digestibility) treatments were not different from the control ( P  > 0.05). However, EE and neutral detergent fiber (NDF) intake, crude protein, EE and NDF digestibility was lower, but the DM and gross energy digestibility was higher for the HTG treatment compared to control ( P  < 0.01). With progressive increases in WBTG concentrations, nitrogen intake, fecal nitrogen and retention nitrogen did not differ, but the urinary nitrogen for MTG and HTG treatments were lower than that of the control ( P  = 0.001). The ruminal total volatile fatty acid concentration and the molar ratios of propionate and butyrate were higher, but the acetate, ratio of acetate to propionate and ammonia-N content were lower for the HTG treatment compared with the control ( P  < 0.05). Therefore, the possible proportion of replacing WBG with WBTG for TMR silage can be 10% or less of the diet DM.     

The effects of protein sources supplemented with urea-treated potato pulp (PP) silage and feeding levels of the PP silage-based concentrate on feed intake, digestibility and ruminal fermentation in beef steers

Six Japanese Black (Wagyu) steers (average initial weight 467 ± 45 kg) fitted with a ruminal cannula were used in a split‐plot design experiment comprising a 3 × 3 Latin square design (whole‐plot) and a randomized block design (subplot). The whole‐plot treatments were three different feeding levels of urea‐treated potato pulp (PP) silage‐based concentrate: 1.00%, 1.75% and 2.50% of body weight (BW) (on a dry matter (DM) basis). The subplot treatments consisted of the concentrate formulated to contain either soybean meal (SBM) as a rapidly rumen‐degraded protein source or corn gluten meal (CGM) as a slowly degraded protein source. Dry matter intake tended to be lower (P = 0.071) for CGM (8.9 kg/day) than for SBM (9.4 kg/day). Protein sources had no significant effect on digestibility and in situ degradation. Ruminal ammonia nitrogen (NH₃‐N) was lower (P = 0.033) for CGM (7.5 mg/dL) than for SBM (9.5 mg/dL). Protein sources did not affect ruminal pH and the total volatile fatty acids (VFA) concentrations. The molar proportions of ruminal acetate and valerate were higher (P = 0.032) for CGM than for SBM. The maximum daily intake of the PP silage‐based concentrate expressed as a percentage of BW was approximately 1.4% of BW. Dry matter intake was higher (P = 0.046) for steers fed at 1.0% of BW of the PP silage‐based concentrate than for steers fed at 1.75% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate had no effect on DM and nutrients digestibility, except for crude protein (CP) digestibility. CP digestibility tended to be lower (P = 0.071) for steers fed at 1.75% of BW of the PP silage‐based concentrate than for steers fed at 1.0% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate also did not affect the in situ degradation parameter of hay and PP silage. The feeding levels of the PP silage‐based concentrate did not affect ruminal pH, NH₃‐N and total VFA concentrations. The molar proportion of acetate was highest for steers fed at 1.0% of BW of the concentrate. In conclusion, in the urea‐treated PP silage‐based concentrate, CGM seems to be more effective than SBM for stabilizing the ruminal NH₃‐N concentration and to be advantageous for fiber digestion in the rumen. The feeding levels of the PP silage‐based concentrate did not change the amount of VFA production in the rumen and the DM digestibility.     

Effect of inclusion of HMBi in the ration of goats on feed intake,nutrient digestibility,rumen bacteria community and blood serum parameters

The objective of this experiment was to test the effect of supplementation of analogues of methionine 2-hydroxy-4-methylthio butanoic acid isopropyl ester (HMBi) on growth, digestibility, antioxidant index, abundance and composition of rumen bacterial community in Xiangdong Black Goats. Thirty-six growing Xiangdong Black Goats were divided into four groups in such a way that each group had three replicate and each replicate had three animals. Experimental groups were assigned four levels of HMBi in basal diet: 0% HMBi (on dietary DM basis); 0.05% HMBi; 0.10% HMBi and 0.20% HMBi. Goats fed 0.10% HMBi in basal diet had higher average daily weight gain (p < .05). Goats fed 0.05% HMBi had higher apparent digestibility of gross energy (p < .01). The group 0% HMBi supplementation had a higher level of superoxide dismutase and malondialdehyde (p < .01). The goats fed 0.20% HMBi in basal diet had a higher level of insulin and leptin (p < .01) than 0% HMBi supplementation goats. 16S rRNA high-throughput sequencing analysis revealed similarities in the community composition, species diversity and relative abundance of dominant bacteria at the phylum and genus levels among the four groups. In conclusion, HMBi supplementation has no negative effect on apparent digestibility, antioxidant index and the ruminal bacteria composition. Therefore, 0.10% supplementation of HMBi is recommended in the diet of goats to improve the growth performance.     

Effects of supplementation on voluntary dry matter intake, growth and nutrient digestibility of the Fiji Fantastic sheep on a basal diet of Guinea grass (Panicum maximum)

Eighteen growing Fiji Fantastic (FF) sheep (nine ram lambs and nine ewe lambs), 5–6 months old, pre-experimental average body weight of 25.6 ± 0.82 kg were randomly divided into three groups of six and allotted to the treatments designated as A: Guinea grass (Panicum maximum); B: Guinea grass + concentrate mixture; and C: Guinea grass + crushed wheat grain in a completely randomized design experiment that lasted for 92 days. Total DM intake of sheep on forage + concentrate mixture were significantly higher (P < 0.001) than those on forage + crushed wheat grain and forage alone. Average daily gains (ADG) were 30, 75 and 42 g/day for forage, forage + concentrate mixture and forage + crushed wheat grain, respectively. ADG was significantly (P < 0.001) higher in sheep on forage + concentrate mixture. Daily protein intakes and BUN concentration were 3.59, 10.39 and 5.60 g/kg^0.75/day; and 6.0, 9.7 and 6.0 mmol/l for sheep on forage alone, forage + concentrate mixture and forage + crushed wheat grain, respectively. BUN and glucose concentrations at the post-experimental period were significantly (P < 0.001) higher in sheep on forage + concentrate mixture. DM, organic matter (OM), crude protein (CP), acid detergent lignin (ADL), hemicellulose and energy digestibility were significantly (P < 0.001) higher in sheep on the concentrate mixture while neutral detergent fibre (NDF) digestibility was significantly (P < 0.001) higher in sheep fed crushed wheat grain. Sheep on the concentrate mixture were also significantly (P < 0.002) higher in metabolizable energy intake (MEI). Sheep on concentrate mixture had higher organic matter (OM) and crude protein (CP) digestibility, high DMI and ADG. In conclusion this experiment has provided some relevant lacking information on the average DMI and ADG of the FF sheep and a concentrate mixture of 16.5% CP plus 19.0 MJ GE/kg BW seems ideal to meet the protein and energy requirements of the FF sheep for growth in the tropical environment of Fiji. Finally data obtained also demonstrated the influence of supplementary concentrate feeding on DMI and ADG of the FF sheep.     

Effect of sex and feeding system on feed intake, growth, and meat and carcass characteristics of fattening Assaf lambs

The effect of feeding system and sex on intake, growth and carcass and meat characteristics of Assaf fattening lambs was studied. Twenty four weaned Assaf lambs, half males and half females were used. After an adaptation period, lambs were randomly assigned to one of the two feeding systems studied. Control lambs received ad libitum commercial concentrate (70% barley, 22% soybean meal, 4.8% wheat, 0.5% bicarbonate, 2.7% mineral–vitamin premix) and barley straw. Free Choice lambs had ad libitum and separate access to whole barley grain and a protein supplement (73.3% soyabean meal, 16% wheat, 1.7% bicarbonate, 9% mineral–vitamin premix). Lambs were slaughtered at 25 kg LBW. Feed intake was not significantly affected by sex (P > 0.05) but Free Choice lambs showed higher dry mater intake than the Control lambs. Nevertheless, only males from the Free Choice group showed an improvement in feed efficiency rate (P < 0.05) and average daily gain (P < 0.01) relating to the Control lambs. Neither feeding system nor feeding system × sex interaction significantly affected non-carcass weight, fat depots, cold carcass weight, dressing percentage, main proportions of commercial cuts and meat characteristics (P < 0.05). As it was expected, female lambs showed a lower average daily gain and a higher feed conversion efficiency than male lambs (P < 0.001) which was related to a greater fat deposition. Meat characteristics were unaffected by sex, with the exception of longissimus lumborum fat content, which was higher in female lambs.The present results suggest that Free Choice feeding system might be suitable for intensively reared male lambs since improvements in daily weight gain and feed conversion rate were achieved, with no adverse effect on carcass and meat quality. Despite the selected diet of both, males and females, did not differ in the crude protein content, the use of Free Choice feeding system for female lambs did not improve performance compared to the Control group.     

Effect of magnesium sulphate and l-tryptophan and genotype on the feed intake, behaviour and meat quality of pigs

Sixty-nine entire male pigs with different halothane genotype (homozygous halothane positive — nn-, n = 36; and homozygous halothane negative — NN-, n = 33) were fed with a supplementation of magnesium sulphate (Mg) and/or l-tryptophan (Trp) in the diet for 5 days before slaughter. Animals were housed individually and were submitted to stressful ante mortem conditions (mixed in the lorry according to treatments and transported 1 h on rough roads). Individual feed intake was recorded during the 5-d treatment. At the abattoir, pig behaviour was assessed in the raceway to the stunning system and during the stunning period by exposure to CO₂. Muscle pH, colour, water holding capacity, texture and cathepsin activities were determined to assess meat quality. The number of pigs with an individual feed intake lower than 2 kg/day was significantly different among diets (P < 0.05; Control: 8.7%; Mg&Trp: 43.5%; Trp: 17.4%) and they were considered to have inadequate supplement intake. During the ante mortem period, 15.2% of pigs included in the experiment died, and this percentage decreased to 8.7% in those pigs with a feed intake > 2 kg/day, all of them from the stress-sensitive pigs (nn). In general, no differences were observed in the behaviour of pigs along the corridor leading to the stunning system and inside the CO₂ stunning system. During the stunning procedure, Trp diet showed shorter periods of muscular excitation than control and Mg&Trp diets. The combination of a stressful ante mortem treatment and Mg&Trp supplementation led to carcasses with high incidence of severe skin lesions. Different meat quality results were found when considering all pigs or considering only those with adequate supplement intake. In this later case, Trp increased pH₄₅ (6.15) vs Control diet (5.96) in the Longissimus thoracis (LT) muscle (P < 0.05) and pH at 24 h (Trp: 5.59 vs C: 5.47) led to a higher incidence of dark, firm and exudative (DFD) traits in SM muscle (P < 0.05). Genotype affected negatively all the meat quality traits. Seventy-five percent of LT and 60.0% of the SM muscles from nn pigs were classified as pale, soft and exudative (PSE), while none of the NN pigs showed these traits (P < 0.0001). No significant differences were found between genotypes on the incidence of DFD meat.Due to the negative effects observed in the Mg&Trp group in feed intake and carcass quality, the utilization of a mixture of magnesium sulphate and tryptophan is not recommended.     

Effect of Mediterranean saltbush (Atriplex halimus) ensilaging with two developed enzyme cocktails on feed intake,nutrient digestibility and ruminal fermentation in sheep

The aim of this study was to assess the effects of feeding Atriplex halimus (AH) silage treated with two developed enzyme cocktails to sheep on feed intake, nutrient digestibility and ruminal fermentation. The AH silage was treated without or with 2 L of ZAD1^® or ZAD2^®/1000 kg with 5% molasses and ensiled for 30 days. Barley grain (300 g/head/day) was fed as an energy supplement once daily at 10.00 hours and AH silage with or without enzyme treatment was offered ad libitum to animals twice daily at 09.00 and 16.00 hours. Sheep were fed on four experimental forage diets comprised of AH silage and barley (D1), AH silage treated with ZAD1^® and barley (D2), AH silage treated with ZAD2^® and barley (D3) and AH silage treated with a combination of ZAD1^® and ZAD2^® (1:1) and barley (D4). Ensiling AH with enzymes reduced its contents of neutral detergent fiber and acid detergent fiber. The dry matter intake of AH of D2, D3 and D4 decreased (P < 0.001) as compared to D1. However, enzyme‐treated diets had greater total digestible nutrients intake (P < 0.001) as compared to D1. The nutrients digestibility for D2, D3 and D4 were higher than those for D1 (P < 0.001), and were higher for D3 as compared to both D2 and D4. Sheep fed on D3 had highest (P < 0.001) ruminal total volatile fatty acids concentration, ammonia nitrogen concentration and microbial protein yield. It could be concluded that AH silage treated with ZAD1^® or ZAD2^® improved digestibility and rumen fermentation in sheep.     

日粮中添加不同水平紫苏籽对湖羊生长性能、瘤胃发酵及养分表观消化率的影响

本试验旨在研究日粮中添加不同水平紫苏籽(Perilla frutescens seed,PFS)对湖羊生长性能、血清生化指标、养分表观消化率及瘤胃发酵的影响。选取2月龄、平均初始体重为(23.02±1.36) kg的湖羊公羔60只,依据日粮中PFS含量随机分成为:对照组(Control)、5%紫苏籽组(5%PFS)、10%紫苏籽组(10%PFS)和15%紫苏籽组(15%PFS)。预试期14 d,正试期70 d。饲喂试验结束前21 d,从各组随机挑选4只羊进行7 d的消化代谢试验。试验结束后称重,计算平均日增重(ADG),并采集瘤胃液和血液分别用气相色谱法、比色法、全自动生化分析仪和酶联免疫分析法测定瘤胃液挥发性脂肪酸(VFA)、氨态氮(NH₃-N)、血清中总蛋白(TP)、尿素氮(UN)、葡萄糖(Glu)和血清中生长激素(GH)、胰岛素样生长因子-1(IGF-1)等。结果表明,日粮中PFS水平对湖羊生长性能(干物质采食量、平均日增重和料重比)、血清生化指标(TP、UN、Glu、GH和IGF-1)、瘤胃pH和瘤胃液乙酸、丙酸及总挥发性脂肪酸(TVFA)等含量的影响不显著(P>0.05),但随着PFS添加水平的升高,乙酸、丁酸和TVFA的含量呈降低趋势,丙酸呈上升趋势;与对照组相比,15% PFS组中NH₃-N和乙酸/丙酸极显著降低(P<0.01);添加PFS不影响日粮中粗脂肪(EE)和酸性洗涤纤维(ADF)的表观消化率(P>0.05),但干物质(DM)、有机物(OM)和中性洗涤纤维(NDF)的表观消化率随着PFS添加水平升高而下降,且15% PFS 组的DM和OM的表观消化率均极显著低于对照组(P<0.01);与对照组相比,10% PFS组的粗蛋白(CP)表观消化率极显著提高(P<0.01),而15% PFS组的极显著降低(P<0.01)。综上所述,湖羊日粮中添加PFS水平为10%时,饲喂效果较好。     

Effect of partly replacing cottonseed cake with Mucuna spp. (var. Ghana) hay on feed intake and digestibility, milk yield and milk composition of zebu cows

The effect of partly replacing cottonseed cake with Mucuna hay (Mucuna spp. var. Ghana) on feed intake, digestibility and milk production of dairy cows was studied using six Zebu cows randomly assigned to three dietary treatments in a replicated Latin square design. All cows were fed hay from natural pastures ad libitum and 1.1 kg molasses as a basal diet, which was supplemented with: (1) 2 kg cottonseed cake (control diet), (2) 1.5 kg cottonseed cake and 1.2 kg Mucuna hay (low Mucuna, LM), and (3) 1.0 kg cottonseed cake and 3.3 kg Mucuna hay (high Mucuna, HM). Dry matter (DM) and crude protein (CP) intake were similar for all the diets. The addition of Mucuna significantly increased DM and organic matter digestibility, whereas CP, acid detergent fibre and neutral detergent fibre digestibility were similar among the diets. The treatments had no effect on daily milk yield (3.38, 3.43 and 3.38 kg milk) or milk composition (41.1, 43.7 and 42.7 g fat/kg milk; 35.1, 36.4 and 35.9 g protein/kg milk; and 46.1, 45.8 and 45.3 g lactose/kg milk, respectively, for cows fed control, LM and HM diets). The treatments had no significant effect on live weight changes. The results showed that replacing 50% of the cottonseed cake with Mucuna hay had no negative effects on feed intake and digestibility, milk yield or milk composition.     

Effect of selection for growth on normal and reduced protein diets on weight gain, feed intake, feed efficiency and body composition in mice

Mice selected for weight gain from 3 to 9 weeks of age on a normal (N) protein diet containing 19.3% protein and a reduced (R) protein diet with 5.1% protein were reared on both diets in generations 7 and 9. The lines NH, NC, NL, RH, RC and RL (H, high; C, control; L, low) were tested for weight gain on diet N and R and for feed intake and feed efficiency on diet N in generation 7. In generation 9, the lines were tested for body composition traits (fat, protein and water percentage) at 3, 6, 9 and 12 weeks of age on both diets. A significant (p < 0.0001) genotype × environment interaction for growth rate was observed in generation 7. Weight gain at both the protein levels was best improved by selection at the protein level itself. Furthermore, the ranking of the lines on diet N was similar for weight gain, feed intake and feed efficiency. In generation 9 at 9 weeks of age, the ranking of the lines for fat percentage was equal to the ranking for weight gain in generation 7 on both test‐diets. The association between weight gain and protein or water percentage was less pronounced, particularly on diet R. These results suggest that the largest genetic improvement in growth rate is obtained when the protein content of the feed is the same in selection and production. However, when selection is carried out in one environment while the animals have to perform under conditions with varying nutrient protein contents, selection in an inferior environment may be advantageous.     

Associative effects of supplementing rice straw‐based diet with cornstarch on intake,digestion, rumen microbes and growth performance of Huzhou lambs

Thirty‐six male Hu lambs consuming a rice straw‐based diet were used in a 60‐day trial to study the associative effects of cornstarch supplementation on intake, digestion, ruminal microbial population and growth performance. All animals were fed rice straw ad libitum together with 160 g/day of rapeseed meal and supplemented with cornstarch at levels of 0 (control), 60, 120 or 180 g/day, respectively. Increment of supplementary cornstarch showed little influence on rice straw intake. Optimal growth performance and highest apparent digestibility of organic matter was achieved in the 120 g/day cornstarch group (P < 0.05), while the digestibilities of neutral detergent fiber and crude protein were significantly decreased by 180 g/day cornstarch (P < 0.05). Similar results were observed for carboxymethyl cellulose activity and relative populations of cellulolytic bacteria (Ruminococcus albus, Ruminococcus flavefaciens and Fibrobacter succinogene). Blood urea nitrogen was reduced by supplementary cornstarch, indicating enhanced protein utilization efficiency. Carcass traits were all significantly improved by supplementary cornstarch. These results suggested that proper amounts of starch supplementation (within 0.5% BW) has little adverse effect on forage utilization, but could effectively improve growth performance. High levels of cornstarch, however, would decrease cellulase activity and populations of cellulolytic bacteria, and hence the digestibility of forage.