Effects of replacing dietary maize grains with increasing levels of sugar beet pulp on rumen fermentation constituents and performance of growing buffalo calves

Rumen fermentation of meal-fed sheep in response to diets formulated to vary in fiber and protein degradability

The concentration of volatile fatty acid (VFA) provides an imprecise view of VFA dynamics due to the confounding effects of fluid pool size and dynamics. Determination of VFA flux using isotope is expensive and a complex methodology. Therefore, a rapid and affordable approach to explore VFA dynamics may allow comprehensive characterization of VFA availability. The objective of this study was to explore the use of VFA dynamics generated by meal feeding to derive time-series rates of VFA apparent appearance and disappearance driven by different protein and fiber sources. Six ruminally cannulated wethers were fed diets containing timothy hay or beet pulp (TH and BP) and soybean meal (SBM) or heated soybean meal (HSBM). Diets were, TH + HSBM; TH + SBM; BP + HSBM; and BP + SBM and the experimental design was a partially replicated 4 × 4 Latin Square. Concentrations of VFA and polyethylene glycol (PEG) in rumen fluid samples were estimated. Concentrations of PEG were used to estimate fluid passage and volume to calculate VFA mass, and fluid-mediated exit. Maximum apparent appearance rate (mmol/h), the rate of apparent appearance decline (mmol/mmol/h), mean apparent appearance flux (mmol/h), mean apparent disappearance (mmol/h), and apparent disappearance rate (mmol/mmol/h) were estimated by deriving a 1 pool model for each VFA on a mass basis where appearance was assumed to follow an exponential decay pattern and disappearance followed mass-action kinetics. Statistical analyses were conducted using a linear mixed effect regression with fixed effects for fiber source, protein source, and their interaction, as well as random effects for animal and period. Rumen fluid volume (L) was greater in HSBM diets (P = 0.033) and fluid passage (%/h) was greater in SBM diets (P = 0.048). Concentrations (higher acetate and butyrate, P = 0.002 and 0.004, respectively) and molar proportions (higher valerate, P = 0.035) of VFA were affected only by fiber source; however, protein source and fiber source interacted to significantly influence apparent appearance rates and absorption rates of many major VFA. On a flux basis, HSBM supported significantly elevated mean disappearance of propionate (P = 0.033). This data demonstrates that time-series evaluation of fermentation dynamics, including fluid dynamics and VFA concentrations can be used to estimate apparent appearance and disappearance of VFA. Although further work is needed to confirm the alignment of these estimates with measurements of VFA supplies to the animal, this modeling approach may provide a simpler way to better understand the kinetics of rumen.

The feasibility of partial replacement of berseem hay by spent mushroom (Pleurotus osteratus) substrate in rabbit diets on growth performance, digestibility, caecum fermentation, and economic efficiency

Nowadays, agricultural by-product disposal is a major concern. The mushroom by-products could be used as an alternative feed source in rabbit diets. Therefore, partial replacement of berseem hay (BH) with spent mushroom substrate (SMS) was conducted in four experimental groups as follows: 0, 20, 40, and 60% of SMS. Forty weaned New Zealand White (NZW) rabbits at 6th weeks of age with an initial body weight of 520.25 ± 70.01 g were fed the experimental diet for 8 weeks. The results showed that ash content and cell wall constituents in SMS were higher than in BH, while the other nutrient compounds in SMS were lower than in BH. Dietary SMS at a level of 60% increased the final body weight (p = 0.05) and feed conversion ratio (p ≤ 0.05). However, average daily gain and total feed intake were not affected by treatments. The replacement of SMS at levels of 40 and 60% significantly improved nutrient digestibility and total digestible nutrient value. SMS 60% decreased (p = 0.040) faecal N and improved (p = 0.006) retained nitrogen. The SMS replacement increased caecum length (p = 0.001), and full and empty caecum weight (p = 0.001 and 0.021, respectively) compared to the control. The SMS inclusion caused a decrease (p = 0.021 and 0.007) in the pH and NH3-N concentrations, respectively. Total VFA, acetic acid, butyric acid, and propionic acid proportions increased with the dietary inclusion of SMS in a level-dependent manner. Using SMS as a replacement for BH in growing rabbit diets reduced the total feed cost, and consequently improved net revenue, economic efficiency, and relative economic efficiency.

Can a blend of integrated feed additives modulate ruminal fermentation patterns and performance of growing lambs? In vitro and in vivo assessments

Two in vitro and in vivo experiments were accomplished to investigate the impacts of integrated feed additives (IFA, combination of protected fat, lysine, and methionine plus yucca extract, eucalyptus essential oil, and direct-fed microbial) on gas production (GP), ruminal fermentation and degradability parameters and lamb performance, digestibility, and nitrogen balance. In the in vitro experiment, responses of graded doses (0, 25, 50, 75, 100, and 125 g IFA/kg DM) were evaluated. In the in vivo experiment, 15 Barki male lambs (30.43 ± 0.74 kg BW ± SE) were individually allotted in complete randomized design into three treatments (five animal/treatment) as control (basal diet without additive), low dose (50 g/kg DM) and high dose (100 g/kg DM) for 120 days. In vitro results showed that both doses (100 and 125 g/kg DM) quadratically decreased (p < 0.001) GP and ammonia nitrogen (NH-3N) concentration. In vivo experiment revealed that dry matter intake was increased (p = 0.016) with low dose compared to high dose. Inclusion of high dose decreased blood serum glucose concentrations (p > 0.05) and ruminal protozoal populations (p = 0.094) compared with low dose and control diet. Both doses of IFA increased (p < 0.05) serum urea, creatinine, and triglyceride concentrations, while decreased (p < 0.001) ruminal NH3-N concentrations. These results suggested that, although IFA was effective to modify in vitro ruminal fermentation process and feed degradability, such aspects did not improve in vivo performance of growing lambs.

- Invited Review - Factors affecting beef quality and nutrigenomics of intramuscular adipose tissue deposition

Beef quality is characterized by marbling (marbling degree and marbling fineness), physiochemical (shear force, meat color, fat color, texture, and maturity), and sensory (tenderness, flavor, juiciness, taste, odor, and appearance) traits. This paper summarizes and addresses beef-quality characteristics and the beef-grading systems in Korea, Japan, the USA, and Australia. This paper summarizes recent research progresses on the genetic and nutritional factors that affect beef quality. Intramuscular (i.m.) adipose tissue deposition or marbling is a major determinant of beef quality. This paper addresses the mechanisms of i.m. adipose tissue deposition focused on adipogenesis and lipogenesis. We also address selected signaling pathways associated with i.m. adipose tissue deposition. Nutrients contribute to the cellular response and phenotypes through gene expression and metabolism. This paper addresses control of gene expression through several nutrients (carbohydrates, fat/fatty acids, vitamins, etc.) for i.m. adipose tissue deposition. Several transcription factors responsible for gene expression via nutrients are addressed. We introduce the concept of genome-based precision feeding in Korean cattle.

Effects of maize silage substitution with sugarbeet or citrus pulp ensiled with corncobs on growth performance, digestibility, and economic benefits in buffalo calves

Ensiling of high-moisture agro-industrial wastes with dry roughage as animal feeds may be a secure way to reduce the feeding cost. The objective of this study was to investigate the effects of either sugarbeet or citrus pulp ensiled with ground corncobs and used as a replacement of maize silage or maize fodder in total mixed ration (TMR) for fattening of buffalo calves. Twenty male calves of Nili-Ravi buffalo (aged 14 ± 2 months weighing 133 ± 5 kg) were randomly assigned to one of four iso-nutritious (12% CP and 69% TDN) experimental diets with 50:50 forage to concentrate ratio (dry matter basis) as: (1) TMR maize silage, (2) TMR sugarbeet pulp ensiled with corncobs, (3) TMR citrus pulp ensiled with corncobs, and (4) TMR green maize fodder with wheat straw. All calves received TMRs for ad libitum intake twice daily for 80-day period. Daily feed intake, fortnightly body weights, and digestibility and N balance study during last 15 days were recorded of individual animals. The calves fed TMR sugarbeet pulp silage got highest daily gain (856 g/d, P < 0.05) than citrus pulp silage (776 g/d) or green maize fodder (704 g/d). Average intake of nutrients was same among all the calves. Feed conversion ratio and digestibility of DM, NDF, and ADF were higher (P < 0.05) with TMR sugarbeet pulp silage compared to other TMRs. Economic benefit (output/input) with TMR sugarbeet pulp silage had 15.46, 34.27, and 37.36% higher effect for fattening of buffalo calves compared to citrus pulp silage, green maize fodder, and maize silage-based TMRs, respectively. In conclusion, sugarbeet pulp ensiled with ground corncobs is simple and appropriate method for silage making and its inclusion up to 50% of DM in TMR had pronounced economic impact to the production of buffalo calves.

Partial Substitution of Corn Grain in the Diet with Beet Pulp Reveals Increased Ruminal Acetate Proportion and Circulating Insulin Levels in Korean Cattle Steers

We investigated the effects of the partial substitution of corn grain in the diet with beet pulp on growth performance, ruminal fermentation characteristics, microbial profiles, and blood lipogenic parameters in fattening steers. Twelve Korean cattle steers (body weight, 485 ± 19.32 kg; age, 18.0 ± 0.17 months) were equally divided into corn grain (CG) and beet pulp (BP) groups. Approximately 75% of dry matter of the requirement was offered as a concentrate portion, and the remaining 25% was offered as oat straw. Eighty percent of the concentrate portion was provided by a pelleted basal concentrate, and the remaining 20% with corn grain for the CG group, or 18% beet pulp plus 2.0% rumen-protected fat for the BP group, respectively, by top dressing. The experiment was conducted for 14 weeks, including a 2-week acclimation period. Growth rate was not affected by beet pulp feeding (p = 0.55). The molar proportions of ruminal acetate (p < 0.05) on wk 4, the relative abundances of ruminal cellulolytic bacteria, including Fibrobacter succinogenes (p = 0.01) and Ruminococcus albus (p = 0.04) on wk 12, and serum insulin concentrations (p < 0.05) on wk 12 were higher in the BP group than in the CG group, whereas the molar proportions of propionate (p < 0.05) on wks 8 and 12 and serum nonesterified fatty acids (p < 0.05) on wk 12 were lower in the BP group. Beet pulp could be used as a lipogenic energy source without affecting growth performance during the fattening period of cattle.

Influence of Replacement Levels of Orange Waste Silage on Intake, Nutrient Digestion, Ruminal Fermentation and Milk Yield in Barki Goats

Exploring new alternative sources of feedstuffs can contribute to animal production sustainability in some Mediterranean regions in order to overcome the rising food demand. The influence of dietary replacement of wheat straw (WS) with orange waste silage (OWS) on nutrient intakes, apparent digestibility, ruminal fermentation and blood biochemical constituents and milk production of dairy goats were evaluated. Forty pregnant goats (46.30±1.6 kg BW) were housed in individual pens in a completely randomized design and fed (ad libitum) a TMR for 75 days period. Goats were assigned to four experimental diets with the forage amounts consisting of either WS as a control diet (1000 g WS/kg DM in the TMR), a 50:50 mixture of both WS and OWS (500 g WS and 500 g OWS/kg DM in the TMR), an orange waste silage (1000 g OWS/kg DM in the TMR) or corn silage as a positive control (1000 g CS/kg DM in the TMR). The DMI increased linearly (P<0.01), while fiber fractions intake decreased linearly (P<0.01) with increasing of OWS in the diet. Ruminal pH was increased quadratically (P<0.01), whereas NH3-N concentration and total protozoa abundance decreased quadratically (P<0.01) with increasing OWS in the diet. Ruminal acetate content was increased linearly (P = 0.012) by diet; whereas linear effects were observed on propionate and butyrate proportions (P<0.01) as OWS amount increased. Blood urea nitrogen (BUN), non-esterified free fatty acids (NEFA) and β-hydroxybutyrate (BHBA) levels decreased linearly (P<0.01) with ascending amounts of OWS. Serum glucose, BUN, NEFA and BHBA levels were lower (P<0.01) for goats fed the OWS diet than those fed the CS diet. Milk yield and milk nitrogen efficiency were linearly increased (P<0.01), whereas quadratic effects (P = 0.049) were observed on milk urea nitrogen content with increasing dietary OWS. In conclusion, the replacement of WS with OWS enhanced rumen fermentation and milk yield of late pregnant and early lactation Barki goats.

Nutrient intake, digestibility, growth performance, and carcass of sheep fed urea-based diet supplemented with natural clinoptilolite

Forty-five male Barki lambs (30.62 ± 4.54 kg BW) were allocated into three treatments designed to evaluate the effect of replacing soybean meal nitrogen with urea supplemented with natural clinoptilolite on performance and carcass characteristics. Lambs were randomly assigned to nine pens blocked according to age and initial BW into three blocks of three pens each assigned to one of three treatments: Control diet: animals received only a basal diet ad libitum, UR diet: urea replaced 68% of SBM nitrogen in the control diet or UR-Z diet: UR diet supplemented with 20-g zeolite for 141 days. Lambs fed on UR-Z diet increased (p < 0.05) total intakes of DM, crude protein digestibility, ADG, FCR, blood glucose and cholesterol concentration. Lambs fed on UR-Z diet decreased (p < 0.05) ruminal NH3 -N concentration compared to the UR diet. Carcasses from lambs fed on UR diet had greater (p < 0.05) ether extract content, fat thickness, meat yellowness and saturation attributes than those fed on UR-Z and control diets. Sheep fed on UR-Z diet made higher economic profit than UR and control diets. Partial replacement of soybean meal with urea supplemented with zeolite seemed to be economically efficient, with comparable performance and carcass attributes in growing lambs diet.

Comparison of the effect of sodium bicarbonate, sodium sesquicarbonate, and zeolite as rumen buffers on apparent digestibility, growth performance, and rumen fermentation parameters of Arabi lambs

The current research was conducted to compare the effect of various buffers or alkalizers in Arabi lambs and find new and less expensive buffering resources. Forty-five Arabi lambs with an average weight of 29.37 ± 3.63 kg were used in a completely randomized design with five treatments and nine replicates. Treatments included 1 - control diet (no buffer); 2 - base diet + 0.75% sodium sesquicarbonate, 0.75% sodium bicarbonate; 3 - base diet + 2% zeolite; 4 - base diet + 1.5% sodium bicarbonate; and 5 - base diet + 1.5% sodium sesquicarbonate. Results showed that rumen pH increased and ammonia nitrogen concentration decreased in diets containing buffer in comparison to control diet (P < 0.05). Rumen concentration of acetate and acetate to propionate ratio showed reduction in experimental diets compared to control (P < 0.05). The concentration of propionate in control diet increased significantly compared to diets receiving buffer (P < 0.05). Using 1.5% sodium bicarbonate in the diet causes a significant increase in rumen protozoa population compared to the control group (P < 0.05). There was no significant difference in dry matter intake and growth performance of lambs. Generally, the effects of using 2% of zeolite were competitive with the effects of other buffers, and caused an increase in the rumen pH and concentration of the acetate. Therefore, the use of buffer in fattening lambs ration fed moderate concentrate diets is beneficial, and it is possible to use low-cost zeolite buffer in the ration of livestock as an alternative to sodium bicarbonate and/or sodium sesquicarbonate.

Effects of substituting sweet potato flour for ground corn on performance, feeding behavior, and metabolism of dairy cows

The objective of this study was to evaluate the effect of substituting sweet potato flour for ground corn in rations fed to lactating dairy on milk yield and composition, blood metabolites, and feeding behavior. Twenty lactating Holstein cows from 30 to 60 days postpartum were randomly assigned to one of two groups (n = 10 each) and used in a cross-over design trial with two treatments: a standard concentrate with ground corn as an energy source or experimental concentrate with sweet potato flour (SPF) replacing all of the ground corn. Each of the 35-day periods consisted of 14 days for adaptation to diet and 21 days for data and sample collection. Milk yield, dry matter intake (DMI), and feeding behavior were evaluated daily throughout the trial. Milk samples were collected weekly and blood samples were collected every 3 days. Milk was analyzed for fat, protein, lactose, and total solid constituents. Blood was analyzed for glucose, non-esterified fatty acid (NEFA), gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), total protein (TP), albumin, and urea concentrations. Milk yield (P = 0.62) and composition (fat: P = 0.71; protein: P = 0.12; lactose: P = 0.82; total solids: P = 0.56) were not affected by dietary treatments. There were no differences between treatments in DMI or meal frequency, but total eating time (P = 0.001), feeding time (P = 0.001), and meal duration (P = 0.001) was higher for control compared with SPF. However, feeding rate (P = 0.001) and serum urea concentration (P = 0.001) were higher for SPF compared with control. No differences were observed in serum metabolites and enzymes measured among treatments. The results of this trial indicate that SPF can be substituted for ground corn without impairing the performance, feeding behavior, and metabolism in dairy cows.

Effects of supplementation of nonforage fiber source in diets with different starch levels on growth performance, rumen fermentation, nutrient digestion, and microbial flora of Hu lambs

The objectives were to evaluate the effects of fiber source and dietary starch level on growth performance, nutrient digestion, rumen parameters, and rumen bacteria in fattening Hu lambs. A total of 360 Hu lambs (BW = 24.72 ± 0.14 kg, 2 months old) were subjected to a 2 × 3 factorial arrangement. Lambs randomly assigned 6 treatments with 6 repetitions (10 lambs per repetition) of each treatment. Six treatments were formulated to include the fiber sources with three starch levels. The experiment lasted a 63 d. The amount of feed, orts, and total feces were sampled on the 42nd day of the experiment. Rumen fluid samples were collected after 2 h of morning feeding on day 56. Rumen contents were collected last day after the selected lambs were slaughtered. Increasing the starch content decreased the digestibility of neutral detergent fiber (NDF, P = 0.005). Increasing the starch level increased the proportions of propionate (P = 0.002) and valerate (P = 0.001) and decreased the proportion of acetate (P < 0.001) and the ratio of acetate to propionate (P = 0.005). The abundance of Fibrobacter succinogenes was affected by an interaction between the fiber source and the starch level (P < 0.001). Fibrobacter succinogenes tended to be greater in lambs fed SH than in lambs fed BP (P = 0.091), which was greater in lambs fed high starch levels than in lambs fed low starch levels (P = 0.014). Increasing the starch level increased Streptococcus bovis abundance (P = 0.029) and decreased total bacteria (P = 0.025). At the genus level, increasing the starch level reduced the abundance of Butyrivibrio_2 (P = 0.020). Nevertheless, the final body weight (BW) and acid detergent fiber (ADF) digestibility were greater (P < 0.01) in lambs fed soybean hull (SH) than in lambs fed BP. The proportion of butyrate was greater (P = 0.005), while the rumen pH was lower (P = 0.001) in lambs fed beet pulp (BP) than in those fed SH. The abundances of Succiniclasticum, Candidatus_Saccharimonas, Ruminococcus_1, and Christensenellaceae_R-7 were greater in lambs fed SH than in those fed BP (P < 0.050), whereas the abundance of Fibrobacter was lower (P = 0.011). The predominant microbial phyla in all of the groups were Firmicutes, Bacteroidetes, and Fibrobacteres. Changing the starch level for fiber sources mainly changed the rumen community in terms of the phylum and genus abundances. Lambs fed SH with low starch level increased the final BW without affecting total volatile fatty acids (TVFA) concentrations.

Effect of Prickly Pear Cactus Peel Supplementation on Milk Production, Nutrient Digestibility and Rumen Fermentation of Sheep and the Maternal Effects on Growth and Physiological Performance of Suckling Offspring

Simple Summary

The agricultural byproducts commonly used as a feedstuff depend on their high abundance and the nutritional composition. Moreover, several agricultural byproducts are a valuable source of active ingredients, which could be used as feed supplements to improve the quality of formulated diets and animal performance. The present study evaluated the use of prickly pear cactus peels (Opuntia ficus-indica, PPCP) as an agricultural byproduct rich with phytochemicals in the diet of lactating Barki ewes at two doses (5 and 10 g/head/day). Supplementation with 5 g PPCP improves the milk production and composition of ewes. The maternal effect of supplementation of both doses of PPCP in the diets of lactating Barki ewes has been successful to improve the serum lipid profile, kidney function, hormonal and antioxidant status of their suckling lambs. Moreover, supplementation with 5 g PPCP improves the nutrient digestibility and rumen fermentation parameters in the sheep.

Abstract

Prickly pear cactus peels (Opuntia ficus-indica, PPCP) are sustainable byproducts available in arid regions and a rich source of antioxidants. Fifteen multiparous Barki ewes (2–3 years old, 46.94 ± 0.59 kg body weight, BW) at postpartum were individually distributed in three equal groups and fed diets supplemented with PPCP at doses of 0, 5 and 10 g/head/day. Lambs were individually distributed into three equal groups according to their mothers’ groups to investigate the maternal effect on lambs’ growth performance, hematology and serum metabolites. This trial lasted for 56 days from birth to weaning. Moreover, nine adult male Barki sheep with a live BW of 65.76 ± 0.54 kg were randomly allocated into three equal groups to determine the effect of PPCP on the nutrient digestibility of the experimental diets. The results indicate that supplementing PPCP at low levels (5 g/head/day) increased milk yield (p = 0.050), fat-corrected milk (p = 0.022), energy-corrected milk (p = 0.015) and the yield of milk constituents compared to 10 g PPCP and the control group. In addition, lambs suckling from ewes fed the diet supplemented with 5 g PPCP had a higher (p = 0.001) weaning BW compared to other groups. Serum total protein, globulin, superoxide dismutase, glutathione peroxidase enzyme activities and the triiodothyronine hormone improved significantly in lambs suckling from ewes fed diets supplemented with 5 g PPCP compared to the control group. Serum cholesterol profile and kidney activities were enhanced significantly in lambs suckling from ewes fed diets supplemented with 5 and 10 g of PPCP compared to the control group. The dietary supplementation of 5 g PPCP improved the crude protein digestibility, digestible crude protein value, nitrogen balance and rumen fermentation characteristics of male sheep compared to the control group. In conclusion, supplementation with 5 g PPCP improved ewes’ milk production, offspring growth and physiological status. Furthermore, it improved the crude protein digestibility and rumen fermentation characteristics of Barki sheep.

Effects of substitution of beet pulp for barley or corn in the diet of high-producing dairy cows on feeding behavior, performance, and ruminal fermentation

This study investigated the effects of substituting beet pulp (BP) for different grains (barley or corn) in the diet of high-producing dairy cows on intake, feeding behavior, nutrient digestibility, ruminal fermentation, milk production, and feed conversion efficiency. Eight second-parity Holstein cows (62 ± 2 d in milk; milk yield = 54 ± 1.2 kg/d; body weight = 624 ± 26; all mean ± SE) were used in a replicated 4 × 4 Latin square design during 4 periods of 21 d. Cows were randomly assigned to 1 of 4 treatments that were a 2 × 2 factorial arrangement of 2 grain sources (corn or barley) and 2 levels of BP inclusion [5 or 15% of dry matter (DM)] in the diet: (1) barley-based diet with BP at 5% of dietary DM; (2) barley-based diet with BP at 15% of dietary DM; (3) corn-based diet with BP at 5% of dietary DM; and (4) corn-based diet with BP at 15% of dietary DM. The increasing amount of BP in the diet was at the expense of decreasing an equal proportion of grain (barley or corn). All diets were high in concentrates (65% of diet DM) and formulated to have similar concentrations of energy and protein. The portion of feedstuffs that is potentially able to be consumed by humans is known as human edible. Accordingly, human-edible protein (HEP) and human-edible energy (HEE) inputs were calculated according to the recommended potential human-edible fraction of each dietary ingredient, and HEP and HEE outputs were determined as the amount of gross energy and true protein in the milk. Feed conversion efficiency (FCE) for HEP and HEE were expressed as output per input of each variable, whereas FCE for the production of fat-corrected milk (FCM) and energy-corrected milk (ECM) were expressed as the amount of each variable per DM intake. Results showed that substituting BP for grain did not affect DM intake, crude protein intake, or nutrient digestibility, whereas starch intake (5.70 vs. 7.43 kg/d for the low-BP vs. high-BP diets, respectively), HEP (2.34 and 1.92 kg/d), and HEE (186 and 147 MJ of gross energy/d) decreased. Treatments did not affect sorting and chewing activities, but increasing BP in the diet increased ruminal pH at 4 h after feeding (6.20 vs. 6.39) and milk fat content (2.92 vs. 3.15%). Similarly, FCE for ECM production (1.44 vs. 1.54) as well as FCE for HEE (0.653 vs. 0.851) and HEP (0.629 vs. 0.702) were greater in high-BP diets compared with low-BP diets. The interaction of BP and grain sources significantly affected FCE for ECM production, where improvements were more evident when BP was substituted for barley than for corn. The improvement in FCE for HEE was greater when BP was substituted for barley (0.236) rather than corn (0.161). In conclusion, the substitution of BP for barley or corn grains in high-concentrate diets of high-producing cows decreased starch intake, increased ruminal pH at 4 h after feeding, and improved FCE for FCM production. Substitution for barley, rather than for corn, promoted greater FCE for ECM production and HEE.

Chemical Composition, In Vitro Digestibility and Rumen Fermentation Kinetics of Agro-Industrial By-Products

The nutritive value of 26 agro-industrial by-products was assessed from their chemical composition, in vitro digestibility and rumen fermentation kinetics. By-products from sugar beet, grape, olive tree, almond, broccoli, lettuce, asparagus, green bean, artichoke, peas, broad beans, tomato, pepper, apple pomace and citrus were evaluated. Chemical composition, in vitro digestibility and fermentation kinetics varied largely across the by-products. Data were subjected to multivariate and principal component analyses (PCA). According to a multivariate cluster analysis chart, samples formed four distinctive groups (A-D). Less degradable by-products were olive tree leaves, pepper skins and grape seeds (group A); whereas the more degradable ones were sugar beet, orange, lemon and clementine pulps (group D). In the PCA plot, component 1 segregated samples of groups A and B from those of groups C and D. Considering the large variability among by-products, most of them can be regarded as potential ingredients in ruminant rations. Depending on the characteristic nutritive value of each by-product, these feedstuffs can provide alternative sources of energy (e.g., citrus pulps), protein (e.g., asparagus rinds), soluble fibre (e.g., sugar beet pulp) or less digestible roughage (e.g., grape seeds or pepper skin).

Utilization of blue panic (Panicum antidotale) as an alternative feed resource for feeding Barky sheep in arid regions

This study aimed at elucidating effects of replacing sorghum with blue panic (BP) on total dry matter intake (TDMI), average daily gain (ADG), feed conversion ratio (FCR), apparent nutrient digestibility, blood biochemical constituents, rumen fermentation patterns and economic feasibility of Barky male lambs. Fifteen lambs (av. BW, 22.5 ± 1.6 kg) were randomly allotted into 3 treatments (n = 5/group). Control lambs were given a diet of concentrate mixture (CM) plus sorghum (S), BP_50% lambs were given a diet of CM plus (S: PB 1:1) and BP_100% lambs were given CM plus PB. The experiment lasted for 54 days. At the last week of the experiment, the apparent nutrient digestibility coefficients were determined using lignin contents of feeds and faeces as an internal marker. Blood samples were collected at weeks 3, 5 and 7 to determine serum biochemical parameters. Results showed that TDMI significantly (P < 0.05) influenced by diet, whereas ADG was not affected. Mean FCR values were 5.67, 5.46 and 5.86 for control, BP_50% and BP_100%, respectively. Neither nutrients digestibility nor ruminal fermentation parameters were affected (P > 0.05) by total replacement of sorghum with BP. Likewise, none of the serum biochemical constituents were different in BP than in control lambs. This study concluded that BP grass would be considered as one of the promising tropical green forages in the arid regions as an alternative feedstuff in case of shortage of green fodders.