Effects of Chinese herbal ultra-fine powder as a dietary additive on growth performance, serum metabolites and intestinal health in early-weaned piglets

This study was conducted to determine the effects of dietary supplementation with a Chinese herbal ultra-fine powder on growth performance, serum metabolites and intestinal health in early-weaned piglets. Sixty piglets weaned at 21 days of age were randomly assigned to one of the 3 treatment groups, representing supplementation with 0 or 2 g/kg of the powder, or 0.2 g/kg of colistin to maize- and soybean meal-based diets (n = 20 per group). Dietary supplementation with the powder increased ADFI and ADG, improved the gain/feed ratio, and reduced the incidence of diarrhea in the weaned piglets (P < 0.05), compared with the non-additive group. In contrast to colistin, the Chinese herbs decreased (P < 0.05) serum levels of triglycerides and glucose and increased (P < 0.05) serum concentrations of ferrum and phosphorus. Collectively, these findings indicate that the Chinese herbal powder is safe and effective in preventing the weaning-associated intestinal dysfunction and improving the growth performance in piglets.     

The effect of dietary crude protein concentration and inulin supplementation on nitrogen excretion and intestinal microflora from finisher pigs

A 2 × 2 factorial experiment was used to investigate the interaction between dietary crude protein (CP) concentration (200 vs 140 g/kg) and inulin supplementation (0 vs 12.5 g/kg) on nitrogen (N) excretion and intestinal microflora from 16 boars (n = 4, 74.0 kg live weight). The diets were formulated to contain similar concentrations of digestible energy and lysine. Pigs offered the high CP diets had a higher excretion of urinary N (P < 0.01), faecal N (P < 0.01) and total N (P < 0.001) than the pigs offered the low CP diets. Inulin supplementation increased faecal N excretion (P < 0.05) and decreased urine: faeces N ratio (P < 0.05) compared to the inulin free diets. There was no significant effect (P > 0.05) of dietary treatment on N retention. There was an interaction (P < 0.05) between dietary CP concentration and inulin supplementation on caecal E.coli. Pigs offered the diet containing 200 g/kg CP plus inulin decreased the population of E.coli compared to the inulin supplemented 140 g/kg protein diet. However, CP concentration had no significant effect on the population of E.coli in the unsupplemented diets. Inulin supplementation increased caecal bifidobacteria (P < 0.01) compared to the inulin free diets. In conclusion, inulin supplementation favourably altered N excretion and lowered the population of E.coli at high CP concentrations.     

Effect of cereal type and exogenous enzyme supplementation in pig diets on odour and ammonia emissions

A 2 × 2 factorial experiment was conducted to investigate the interaction between cereal type (wheat vs. barley) and exogenous enzyme supplementation (with or without) on odour concentration and ammonia emissions in grower–finisher pigs. The enzyme supplement used contained Endo-1, 3 (4)-β-glucanase (EC 3.2.1.6) and Endo-1, 4-β-xylanase (E.C 3.2.1.8). The diets were formulated to contain similar levels of digestible energy and lysine. The experimental treatments were as follows: (1) wheat-based diet, (2) wheat-based diet containing a β-glucanase and β-xylanase mixed enzyme supplement, (3) barley-based diet and (4) barley-based diet containing a β-glucanase and β-xylanase mixed enzyme supplement. The diets were offered to the pigs for 4 weeks and this was repeated 4 times (n = 4). Odour and ammonia emissions were measured on days 9, 11, 14, 16, 21 and 23 of each experimental period. Odour samples were collected in 20-litre Nalophan bags and analysed for odour concentration using an ECOMA Yes/No Olfactometer. Ammonia concentrations were measured using Dräger tubes. There was a cereal × enzyme interaction in odour emission rates (P < 0.05) and in ammonia emissions (P < 0.01). The addition of an enzyme supplement increased odour emissions and had no effect on ammonia emissions in the barley-based diet. The enzyme supplementation had no effect on odour but decreased ammonia emissions in the wheat based diet.     

Microbial activity in the gut of piglets: II. Effect of fibre source and enzyme supplementation

Twenty four Duroc × Landrace male piglets, aged 21 days, were assigned to 1 of 4 experimental diets. Diets 1 and 2 contained 150 g kg^− 1 wheat bran and diets 3 and 4 contained 90 g kg^− 1 maize cobs as the major fibre source. All diets contained 480 g kg^− 1 wheat and 200 g kg^− 1 soybean meal. Diets 2 and 4 were supplemented with the following enzyme complex: 800 U/kg cellulase, 1800 U/kg glucanase and 2600 U/kg xylanase.

The replacement of wheat bran by maize cobs increased the acetic (P < 0.05) and decreased the butyric acid production (P < 0.05) in the cecum. Piglets fed diets with maize cobs had lower (P < 0.05) levels of butyric acid in the colon than those fed wheat bran.

The xylanolytic, pectinolytic and cellulolytic enzyme activities were higher (P < 0.05) in the cecum and colon of piglets fed the wheat bran based diets. The supplementation of the diet with the enzyme complex did not significantly affect the levels of short chain fatty acids formed in the small intestine and there was a non significant increase of the levels of acetic, propionic and butyric acids in the cecum and colon of piglets (P < 0.10). No interactions were present between fibre sources and enzyme addition.

The results suggest that the enzyme supplementation of the diet did not bring significant benefits to the animals and that when maize cobs replaces wheat bran in diets it negatively affects butyric acid production and fibre-degrading enzyme activity in the hindgut of piglets.     

The effect of dietary lysine restriction during the grower phase and subsequent dietary lysine concentration during the realimentation phase on the performance, carcass characteristics and nitrogen balance of growing–finishing pigs

Two experiments (exp.) were conducted to determine the effect of dietary lysine restriction during the grower phase and subsequent dietary lysine concentration during realimentation on the performance, carcass characteristics and nitrogen (N) balance of growing–finishing pigs. Seventy-two pairs of crossbred [meatline sires × (Large White × Landrace) dams] pigs (36 pairs entire male, 36 pairs female) were used in a 2 × 4 factorial performance study (exp. 1, 35 to 96 kg). The two factors were Diet1 (two lysine levels: LO or HI, day (d) 0 to 35) and Diet2 (four lysine levels: LO, M1, M2 and HI, d36 to slaughter). A further 30 boars were used in a 2 × 3 factorial N-balance study (exp. 2, 31 to 42 kg; Diet1: LO or HI; Diet2: LO, M3 and HI). The crude protein (CP) and lysine contents of the five isoenergetic (14.0 MJ DE/kg) diets were: LO (139 g/kg CP, 8.1 g lysine/kg), M1 (162 g/kg CP, 9.7 g lysine/kg), M2 (190 g/kg CP, 11.4 g lysine/kg), M3 (180 g/kg CP, 10.7 g lysine/kg) and HI (217 g/kg CP, 13.1 g lysine/kg). Diets were based on barley, wheat and soyabean meal with added vitamins, minerals and amino acids. Ratios of amino acids relative to lysine were similar for all diets. From d0 to 35 in exp. 1, pigs fed LO had lower daily gains (ADG: 785 vs. 939 g/day; P < 0.001), daily lysine intakes (DLYIN: 14.4 vs. 22.6 g/day; P < 0.001) and poorer feed conversion ratios (FCR: 2.28 vs. 1.84 kg/kg; P < 0.001) than pigs fed HI. From d36 to slaughter, pigs initially fed LO had higher ADG than those initially fed HI (948 vs. 879 g/day; P < 0.01). However, from d0 to slaughter, pigs initially fed LO had lower ADG (868 g/day; P < 0.01) and DLYIN (19.1 g/day; P < 0.001) than those fed HI (913 g/day and 23.3 g/day respectively). There was a Diet1 × Diet2 interaction for FCR from d36 to slaughter and d0 to slaughter (P < 0.05). FCR of pigs previously fed LO improved with each increase in dietary lysine concentration up to 13.1 g/kg (HI), but improvement was only evident for lysine concentrations up to 11.4 g/kg (M2) for pigs previously fed HI. In exp. 2, Diet1 was fed for an initial 5-day collection period (after adjustment to crate; C1). Diet2 was then fed and immediately there were 2 successive 5-day collection periods (C2 and C3). A Diet1 × Time interaction (P < 0.001) indicated that although N retention (NRET) during C1 was lower for pigs fed LO, there was no difference during C2 and C3 in NRET of pigs initially fed either LO or HI (14.5 vs. 25.0 g/day; 23.2 vs. 23.0 g/day; 26.0 vs. 26.6 g/day, for C1, C2 and C3, respectively). However, a similar interaction indicates that although N excretion (NEX) was 23% lower for LO compared with HI pigs during C1, there was no residual reduction in NEX of pigs initially fed LO (P < 0.01: 8.9 vs. 11.6 g/day; 12.3 vs. 12.7 g/day; 13.8 vs. 14.0 g/day, for C1, C2 and C3, respectively). Exp. 1 indicated improved performance and an ability to respond positively to higher lysine concentrations during realimentation for previously restricted compared with unrestricted pigs, however, overall performance was reduced. However, exp. 2 indicated that although NRET of initially restricted pigs increased during realimentation, it did not surpass that of unrestricted pigs. This apparent discrepancy may have been due to the time period of the N balance study.     

Sward characteristics, grass dry matter intake and milk production performance is affected by timing of spring grazing and subsequent stocking rate

The objective of this study is to investigate the effect of contrasting spring grazing dates (GD) and stocking rate (SR) on sward characteristics, grass dry matter intake and milk production performance of autumn calving dairy cows during the spring period. Two swards were created by grazing in March (early grazing; E) or by delaying first grazing until mid-April (late grazing; L). Two stocking rates, high (H; 5.5) and medium (M; 4.5) were applied across each sward. Forty eight autumn calving Holstein cows (160 ± 35 days in milk) were assigned to one of four (n = 12) different grazing treatments. The experiment began on April 17th and finished after 2 grazing rotations on June 20th. Later spring grazing significantly increased herbage mass (kg DM/ha) above ground level (+ 933, P < 0.05) and > 50 mm (+ 738, P < 0.05). Compressed sward height (+ 22.1 mm, P < 0.05), extended tiller height (+ 73 mm, P < 0.001) and pseudostem height (+ 35 mm, P < 0.001) were also significantly higher for later grazed swards. In the grazing horizon (> 80 mm— extended tiller height), later grazed swards had significantly lower leaf proportion (− 0.09, P < 0.05) and higher dead material (+ 0.05, P < 0.001). Daily herbage allowance (> 50 mm) was on average 12.7, 15.9, 18.2 and 21.9 kg DM/cow for EH, EM, LH and LM, respectively. Daily leaf allowance (> 80 mm) was 10.1, 12.3, 13.3 and 14.5 kg DM/cow for EH, EM, LH and LM, respectively. The EM (16.2 kg DM/cow), LH (+ 0.1 kg) and LM (0.8 kg) treatments all had similar grass DM intake, however there was evidence of an interaction (P < 0.10) between GD and SR, this was due to the low grass DM intake of the EH (13.9 kg DM/cow) treatment. When expressed as UFL (Fill unit) intake the EM treatment recorded the highest value. There was a significant interaction between GD and SR (P < 0.01) for milk, protein yield, 4% fat corrected milk yield (P < 0.05) and protein concentration (P < 0.001). Cows grazing the EM treatment produced 23.9 kg of milk, 876 and 685 g of fat and protein yield. The difference in milk production (cow/day) between EM and EH treatments was + 3.6 kg milk, + 98 g fat and + 107 g protein. The production yield difference between LM and LH treatments was + 1.1 kg milk, + 27 g fat and + 29 g protein in favour of the LM treatment (23.9 kg of milk, 877 and 687 g fat and protein yield). Herbage quality and morphological characteristics are clearly improved with early spring grazing as herbage mass is reduced on subsequent rotations. Swards grazed in early spring allow higher grass utilisation and high milk production performance when grazed at a medium stocking rate. Improved milk production from herbage can be achieved provided herbage mass and allowance are maintained at levels where herbage quality decreases are minimised.     

Effect of fibrolytic enzyme inclusion in high concentrate fattening diets on nutrient digestibility and growth performance of Awassi lambs

The objective of this study was to study the effect of fibrolytic enzyme (FE) inclusion on nutrient digestibility and growth performance of Awassi lamb fed on a high concentrate diet. Thirty weaned Awassi lambs (initial body weight = 20.4 ± 3.0 kg) were fed a high concentrate diet (with or without the addition of FE (15 lambs/treatment)) for 60 d in a completely randomized design. The diet contained 17, 7, 58.5, 15, and 2.5% wheat straw, wheat bran, barley grain, soybean meal and minerals, respectively. Lambs were fed ad libitum twice daily at 08:00 and 15:00 h. Dry matter, OM, CP, and NDF intakes were all similar (P > 0.05) for lambs fed diet with or without the FE and averaged 1078, 941, 171, and 432 g/d, respectively. Metabolizable energy intake was also not affected (P > 0.05) by the enzyme supplementation and averaged 2.87 Mcal/d. Dry matter, OM, CP, and NDF digestibilities were all unaffected (P > 0.05) by the enzyme inclusion and averaged 64.8, 67, 65.7 and 60.4%. Final body weight, average daily gain, and feed to gain ratio were all unaffected (P > 0.05) by the FE inclusion and averaged 34.9 kg, 222 g/d, and 5.4, respectively. In summary, FE treatment of high concentrate diet for lambs had no effect on nutrient intake or any of the growth performance parameters. Therefore, supplementing such diets with FE for fatting Awassi lambs is not recommended.     

Growth performance and metabolic responses in barrows fed low-protein diets supplemented with essential amino acids

This study was conducted to determine the effect of supplementation with Lys, Met, Thr to low-protein diets on growth performance and metabolic responses in growing barrows. Seventy crossbred barrows (Duroc × Yorkshine), with an average initial body weight of 16 kg, were fed diets containing five crude protein (CP) levels (18.2, 16.5, 15.5, 14.5, and 13.6%) and 0.83% true ileal digestible lysine. On d 17 of the trial, all pigs were fitted with an indwelling jugular catheter for blood collection. On d 18 and 53, blood samples were obtained at 4 h post feeding. Reducing dietary CP concentration linearly decreased (P < 0.05) ADG, ADFI, feed efficiency, longissimus muscle area (LMA), and plasma concentrations of urea N and protein, while increasing backfat thickness linearly (P < 0.05). Pigs fed the 13.6% CP diet exhibited the poorest growth performance. On d 53, dietary CP affected plasma IGF-I (quadratic, P < 0.01) and leptin (linear, P < 0.01) concentrations. Plasma leptin levels were correlated positively with backfat thickness (r = 0.76, P < 0.05) and negatively with LMA (r = − 0.64, P < 0.01). There was a positive correlation between ADG and plasma IGF-I concentrations (r = 0.91, P < 0.05). Our results suggest that adequate provision of nonessential AA and all EAA is required for achieving maximum growth performance and reducing fat accretion in growing pigs fed low-CP diets.     

Influences of lipopolysaccharide-induced immune challenge on performance and whole-body protein turnover in weanling pigs

The objective of this study is to characterize the influence of immune stress induced by lipopolysaccharide (LPS) on protein utilization and turnover for early-weaned pigs. A total of 15, crossbred weanling pigs (initial body weight 10.15 ± 0.39 kg) were assigned to one of three treatments. Pigs were injected with LPS and fed ad libitum (LPS-challenge), or injected with endotoxin-free physiological salt solution (PSS) and fed ad libitum (control), or injected with PSS and fed the same amount of feed as LPS-challenged pigs (pair-feed). All pigs received a 4-d nitrogen balance trial. On d 1 and 3 of the trial, LPS-challenged pigs were injected intramuscularly with 200 μg/kg BW of LPS dissolved in 1 ml PSS. Pigs in other treatments were injected with 1 ml PSS. ¹⁵N-Glycine (5 mg/kg BW) was gastrically infused after the second injection. Feces and urine were collected daily to determine the N output throughout the duration of the trial. Lymphocyte blastogenesis (LB) and serum immunoglobulins (IgA, IgG, IgM) were also detected to illustrate the LPS-induced immune responses. Results indicated that the injection of LPS significantly (P < 0.01) elevated the LB and resulted in lower average daily gain (ADG), feed intake (ADFI) and efficiency of feed utilization than control pigs. Pair-fed pigs had higher performance than LPS-challenged pig but poorer than control pigs. Injection of LPS also resulted in significantly (P < 0.01) lower nitrogen intake and efficiency of utilization than controls, and more fecal N excretion than Pair-fed pigs (3.19 ± 0.85 vs. 2.19 ± 0.67 g/d, P < 0.05). The whole-body nitrogen flux (4.34 ± 0.19 vs. 11.35 ± 0.12 g N/kg BW^0.75/d) and N accretion (5.57 ± 0.59 vs. 10.17 ± 1.12 g Pr/kg BW^0.75/d) were acutely (P < 0.01) reduced as the feed intake decreased, but there was no significant difference between LPS-challenged and pair-fed pigs. Injection of LPS markedly (P < 0.05) increased the protein degradation (16.76 ± 1.09 vs. 14.53 ± 1.24 g N/kg BW^0.75/d). It is concluded that LPS-induced immune challenge depresses growth performance and feed utilization efficiency by enhancing protein degradation rate and decreasing protein utilization for body protein retention.     

Performance and nitrogen metabolism of calves fed conventionally or following an enhanced-growth feeding program during the preweaning period

Thirty-seven Holstein and seven crossbred female calves (16.1 ± 4.60 days, and an initial BW of 36.5 ± 3.19) were used to study the effects of conventional (CF) vs enhanced-growth feeding programs (EF) on performance, plasma amino acid (AA) concentrations, and rumen microbial development. After 1 week of adaptation to milk replacer (MR), the CF calves received 4 l/day of MR at 12.5% DM throughout the preweaning period, and the EF calves were offered MR at 18% DM: 6 l/day from 1 to 6 days, 8 l/day from 7 to 26 days, and 4 l/day from 27 days to weaning day (38 days). Calf starter and water were offered ad libitum throughout the study (87 days). Calves fed EF were heavier (P < 0.05) than CF calves at the end of the study (111.7 vs 102.6 ± 1.72 kg, respectively). Until the 27 days, average daily gain (ADG) was greater (P < 0.001) for EF than for CF calves (1.00 vs 0.49 ± 0.061 kg/day, respectively), but it was lower (P < 0.001) from days 27 to 45 of the study (0.32 vs 0.71 ± 0.061 kg/day, respectively), coinciding with the days around weaning. Starter intake was greater (P < 0.001) for CF than for EF calves during the first 45 days of the study (0.60 vs 0.27 ± 0.061 kg/day, respectively) but similar afterwards. As a consequence, EF treatment may have delayed rumen function as suggested by total daily purine derivatives urinary excretion (49.52 vs 33.27 ± 3.095 mmol/day, in CF and EF calves, respectively). Linear regression analyses showed a positive relationship between plasma Trp and Phe concentrations and ADG, and a negative relationship between these two AA and plasma urea concentrations, suggesting that Trp and Phe could be limiting growth in calves fed conventional feeding programs.     

Effect of an enzyme complex derived from Trichoderma longibrachiatum on ileal digestibility of amino acids and non-starch polysaccharides in piglets

A digestibility trial on piglets was conducted to study the effect of an enzyme complex derived from Trichoderma longibrachiatum (Roxazyme G2) supplemented to a rye-based diet on apparent ileal digestibility of amino acids and NSP-constituting sugars. Enzyme supplementation at 200 mg kg^− 1 increased (P < 0.05) the digestibility of total amino acids from 67.1 to 70.8. As the dietary concentration of Roxazyme G2 increased from 0 to 100 mg/kg, the ileal digestibility of the NSP constituents gradually increased. No further increase was observed with the supplementation level of 200 mg/kg. The improvement in the digestibility of arabinose + xylose (685%, P < 0.05) was much higher than that of the remaining sugars (110%, P < 0.05). The apparent ileal digestibility of galactose was positively influenced by Roxazyme G2 but it remained negative in all dietary treatments, presumably due to the high concentration of galactose in endogenous secretions. It is concluded that Roxazyme G2 effectively degrades non-starch polysaccharides in upper digestive tract and marginally improves amino acid availability in young pigs.     

Performance and grazing behaviour of Churra Tensina sheep stocked under different management systems during lactation on Spanish mountain pastures

Thirty-six adult ewes rearing single male lambs were randomly allocated to three paddocks (n = 12) grazing permanent Pyrenean pastures in spring (0.5 ha/lot). Treatments were rationed grazing (Rat-Gr) in which lambs remained indoors and ewes grazed during 8 h/day (08:00–16:00 h) and were supplemented 0.5 kg/day of barley meal; continuously grazing ewes rearing non-supplemented lambs (Gr) and continuously grazing ewes rearing supplemented lambs in creep feeders at pasture (Gr + S). Grazing behaviour was registered at weekly intervals by direct observation during the outdoor time in Rat-Gr and from dawn to dusk in Gr and Gr + S.

Sward height of Rat-Gr became higher than the rest (P < 0.05), resulting in a greater dry matter and a lower crude protein content of this pasture (P < 0.05). Ewe live-weight, body condition score and lumbar fat thickness were similar across treatments (P > 0.05), while milk yield was higher in Gr + S (P < 0.05). Lambs from Rat-Gr and Gr + S presented a higher average daily gain than Gr treatment (P < 0.05). Grazing behaviour records showed that all treatments spent grazing similar percentages of daylight time at pasture (average 52%; P > 0.05). Ewes biting rate was greater in Gr (P < 0.05) and it was higher after noon in all treatments (P < 0.001). Gr and Gr + S showed an extended peak of grazing (min/h) in the evening. Lambs followed the grazing pattern of dams since 3 weeks old. It was concluded that in contrast with the traditional indoor system of managing production of light lambs both spring continuous grazing systems allowed producing Ternasco lambs (18–24 kg LW, younger than 90 days old). Lambs supplemented suckling their mothers and grazing until slaughter showed similar performance to those obtained in indoor system. Dietary supplementation of lambs at pasture did not impair ewes milk yield and grazing time but reduced their biting rate and the offspring grazing time.     

Reproductive and productivity traits of goats grazing Acacia cyanophylla Lindl. with and without daily PEG supplementation

A grazing experiment, conducted for 90 days compared the effect of polyethylene glycol (PEG) supplementation on postpartum reproductive traits and productivity of suckling goats grazing Acacia cyanophylla Lindl. A total of 54 native adult goats (34.4 ± 5.49 kg) were randomly allocated, 24 h after kidding, to 2 treatment groups balanced for age and the number of reared kids. Goats in both treatment groups designed C and PEG grazed in acacia for approximately 5 h every day and received each on daily basis 0.3 and 0.4 kg of hay and concentrate respectively. In addition, goats in treatment PEG were initially supplemented with 10 g/day of PEG and this supplement was then increased to 20 g /goat/day over the last 60 days of the trial. Goats receiving PEG tended (P > 0.05) to spend more time browsing acacia than those in treatment C. There were no treatment effects on live weight change of the goats, growth of their kids until 90 days of age or composition of their milk in terms of fat, protein and urea contents. Similar proportions of 74.1 and 77.8% of goats resumed postpartum ovulation with a mean ovulation rate of 1.50 ± 0.61 and 1.67 ± 0.47 (P > 0.05) in respectively the PEG and C treatments. PEG supplementation was associated with an increase (P < 0.05) in ovulation rate at the second postpartum ovulation occurring approximately 27 days after the application of the nutritional treatments (1.76 ± 0.60 versus 1.25 ± 0.45); 9 of the 13 goats ovulating in the PEG treatment were bearing more than one corpus lutuem in comparison to only 3 out of 12 females in the C group (P < 0.05). The likely increased availability of proteins in the PEG receiving goats could explain their higher ovulation rate.     

Dietary nucleotide supplementation reduces occurrence of diarrhoea in early weaned pigs

In the weaning period, transition from sow's milk to the post-weaning diet causes the withdrawal of important nutrients as milk nucleotides, which are known to be determinant for the development of the gastrointestinal tract and immune function. The objective of these investigations was to study the effect of including these nucleotides in solid diets for piglets. Nucleotide composition of sow's milk was analyzed using 5 sows at 21 days of lactation. The average free nucleotide concentration was 102.8 ± 9.16 μmol/100 mL. Two experiments were performed to assess the effect of a product based on this composition (Nucleoforce Piglets®) on digestive adaptation and incidence of diarrhoea of nursery piglets. In Exp. 1, three groups of 6 piglets were weaned at 21 days of age and fed with a diet supplemented with 0 (control), 1000 or 2000 ppm of nucleotides, and a fourth group of 6 piglets was maintained in lactation. Seven days after weaning, piglets were euthanized and samples of jejunal mucosa were processed for histological measurements. Villus height decreased from 448 μm in un-weaned pigs to 275 μm in the control group 7 days after weaning. Although there were no differences in feed intake among groups, the reduction in villous height was less pronounced (P < 0.001) in nucleotide supplemented groups showing a villous height of 351 and 378 μm with the doses of 1000 or 2000 ppm respectively. In Exp. 2, 384 early weaned pigs were fed during 14 days with a diet supplemented with 0 (control), 750 and 1000 ppm of nucleotides. ADG and ADFI were not modified by the treatment, but nucleotide supplementation reduced the number of pigs treated with antibiotic as a result of diarrhoea (15.63% vs 3.13% and 1.56%; for control, 750 and 1000 ppm; P < 0.001). These results suggest that dietary supplementation with nucleotides from yeast might help to prevent post-weaning diarrhoea in piglets.     

Xylanase supplementation improves energy digestibility of wheat by-products in grower pigs

Value-added processing of cereals produces high-value fractions for food and bio-processing application and by-products that are used in animal nutrition to reduce feed costs. Wheat by-products contain arabinoxylans that might limit nutrient digestibility. Effects of xylanase supplementation (0 or 4375 U/kg feed) on energy digestibility were studied in a wheat control and by-product diets (30% millrun, middlings, shorts, screenings, and bran) in a 2 × 6 factorial arrangement. The wheat control diet was formulated to contain 3.34 Mcal digestible energy (DE)/kg and 2.8 g apparent digestible lysine/Mcal DE, and included 0.4% chromic oxide as a marker for digestibility. Twelve ileal-cannulated pigs (32.5 ± 2.5 kg) were each fed seven of 12 diets. Faeces and then digesta were each collected for 2 d, and diet digestibility values are reported. Wheat had higher ileal and total-tract energy digestibility than by-products (P < 0.01). Xylanase improved energy digestibilities for by-products (P < 0.001) but not for wheat. Among by-products, ileal energy digestibility was lowest for middlings (62%), then bran < screenings < millrun, and highest for shorts (66%). Xylanase improved (P < 0.05) ileal energy digestibility of millrun by 19% to 76%. Total-tract energy digestibility of millrun improved from 72 to 79% (similar to wheat) with xylanase (P < 0.05). In summary, xylanase improved energy digestibility in the selected wheat by-product diets, indicating that arabinoxylans in wheat by-products limit nutrient digestibility.     

The effects of feeding level upon protein and fat deposition in Iberian heavy pigs

Eighteen Iberian barrows of 100 kg initial BW were used in a comparative slaughter experiment to investigate the effects of feeding level (FL; 0.70 and 0.95 × ad libitum) on growth, protein- and fat-deposition rates and body composition. They were fed on a diet supplying the optimum level of digestible ideal protein:ME ratio (4.82 g/MJ) and slaughtered at 150 kg BW. The apparent digestibility of DM, OM, total N and GE, and the ME:GE and ME:DE ratios were not affected by FL. The average daily gain increased with the increase in FL (691 and 918 g/day respectively). Neither the gain:feed (g/g DM) nor the gain:ME intake (g/MJ) ratios were significantly affected however. An energy cost of 59.9 kJ ME/g gain was calculated. The rate of whole-body protein deposition was not significantly altered by FL. On average it reached 80 g/day. The pigs fed at the lowest level exhibited lower fat deposition (P < 0.01) and total energy retention (P < 0.01) than those in the group subjected to only a slight feed restriction. The overall efficiency of utilization of ME for energy gain (ER:ME intake) remained at 0.363 on average, irrespective of the FL imposed. Relative proportions of energy retained as protein and fat were not statistically altered by changes in FL. Mean values for ERP:ER and ERF:ER were 0.100 and 0.903 respectively. No differences between treatments were observed in fat, ash, water or energy content of the whole-body (g/kg) at 150 kg empty BW, the mean values (n = 12) being 512 ± 8.5, 27.6 ± 0.63 and 353 ± 6.7 g/kg for fat, ash and water respectively and 22.90 ± 0.31 MJ/kg for energy. Nevertheless, the proportion of protein tended to decline with the increase in FL (111 vs 104; P = 0.069). At 150 kg the Iberian pigs contained more fat and energy and less ash and water than at 100 kg. Whilst the percentage of lean tissue decreased significantly (P < 0.05) and protein content in the carcass showed a strong tendency to decline in the pigs fed close to ad libitum (104 vs 96; P = 0.056), the proportions of fat, ash, water and energy remained constant at 564 ± 9.0, 22.2 ± 0.91, 312 ± 6.6 g/kg, and 24.82 ± 0.32 MJ/kg, respectively. It was concluded that a degree of feed restriction may result in a discernible improvement in carcass quality.     

Gut growth and glucose tolerance in newborn pigs subjected to prenatal protein restriction and postnatal Glucagon-like Peptides

Fetal protein restriction is potentially associated with organ dysfunctions after birth (e.g. impaired gut growth, glucose tolerance and pancreatic β-cell function). Just after birth, gut growth and maturation is stimulated by enteral food intake, and inhibited by total parenteral nutrition (TPN), in part mediated via differential release of insulino- and intestino-tropic hormones like the Glucagon-Like Peptides 1 and 2 (GLP-1, GLP-2). We hypothesized that short-term co-infusion of GLP-1 and GLP-2 would stimulate pancreatic and intestinal growth in newborn TPN-fed pigs subjected to prenatal protein restriction. Two sows were fed a protein-restricted diet (PR: 8% crude protein during last 50% of gestation) while a third sow was fed a control diet (C: 15% crude protein). PR pigs were killed either at birth (n = 7) or after 3 days TPN with (n = 6) or without (n = 4) intravenous infusion of a mixture of synthetic human GLP-1_7–37 and GLP-2_1–33 (each 50 μg/kg/d). At birth, PR piglets did not show reduced body weight, relative to controls (1.45 vs. 1.50 kg), but significantly reduced weight of the small intestine (18.0 ± 0.6 vs. 21.9 ± 0.5 g/kg, P < 0.001) and a marginally reduced pancreas weight (0.85 ± 0.02 vs. 0.93 ± 0.04 g/kg, P = 0.10). Co-infusion GLP-1 and GLP-2 into PR pigs resulted in increased basal glucose levels (5.3 vs. 4.0 mM), and glucose-stimulated insulin release, but did not have any significant effect on body weight, or weight of internal organs (heart, lungs, spleen, kidneys, adrenals, stomach, colon, liver, intestine, pancreas). We conclude that short-term (3 days) infusion of native GLP-1 and GLP-2 does not stimulate gut growth or glucose tolerance in TPN-fed piglets born from protein-restricted mothers. Moderate maternal protein restriction does however cause significant reduction in intestinal growth in newborn piglets which may decrease the neonatal digestive capacity.     

Effect of photoperiod on milk yield and quality, and reproduction in dairy goats

The objective of this study was to examine the effect of long day photoperiod (LDPP) on milk production and reproduction in milk goats. A total of 79 goats were randomly assigned to three treatment groups blocked by day of kidding. Group 1 (Gr1, n = 26) was subjected to natural photoperiod from January 6 to December 5. Group 2 (Gr2, n = 24) was subjected to LDPP (20 h light, 4 h dark) from June 22 to December 5. Group 3 (Gr3, n = 29) was subjected to LDPP from January 6 to December 6. Weekly milk weights and samples were collected for fat, protein and somatic cell count (SCC) determinations. Blood serum was harvested for progesterone (P4) determination. Results indicated a significant effect (p < 0.001) between treatments for body weight changes, feed intake and milk yield. Both light treated groups had a significantly higher (p < 0.001) average daily milk output for the entire lactation period than the control group (G1, 2.193 kg/day; G2, 2.517 kg/day; G3, 2.305 kg/day). Milk fat for the overall lactation was significantly higher in Gr3 (+ 0.19 g/100 ml) than for Gr2 (+ 0.06 g/100 ml) when compared to the control group (x g/100 ml) under natural photoperiod. Somatic cell counts throughout lactation were significantly (p < 0.001) lower for Gr2 (1.70 million/ml) and higher for Gr3 (2.03 million/ml), with the control group (Gr1) having an intermediate level (1.96 million/ml). Progesterone levels between June 9 and August 30 indicated that 27%, 48% and 63% of the animals had P4 levels in excess of 1.0 ng/ml serum for Gr1, Gr2 and Gr3, respectively. Pregnancy diagnosis by ultrasound in December revealed that a high number of does in the light treated groups (10 of 37) were pseudo-pregnant when compared with the control group (1 of 21). Although light appeared to be effective in increasing milk production, further investigations are needed to evaluate the effect of LDPP on pseudo-pregnancy in dairy goats.     

Effects of pregelatinized vs. native potato starch on intestinal weight and stomach lesions of pigs housed in barren pens or on straw bedding

In a 2 × 2 factorial arrangement, 16 groups of 12 pigs (approximately 25 kg) were assigned to either barren or straw housing and to native or pregelatinized potato starch included in the diet (35%) to investigate effects on intestinal weight and gastric lesions. Pigs were fed restrictedly (2.5 × MEm) for 5 weeks. At slaughter, weights of empty small intestine and stomach were determined. Stomachs were inspected for incidence of lesions in the pars oesophagea. No starch type × housing interactions were found. In pigs fed pregelatinized starch, weight of the small intestine (26.8 ± 0.4 g/kg BW) and stomach (7.6 ± 0.1 g/kg BW) were higher than in pigs fed native starch (24.9 ± 0.4; 7.1 ± 0.1 g/kg BW, respectively; P < 0.01). Straw bedding increased empty stomach weight (7.9 ± 0.1 vs. 6.8 ± 0.1 g/kg BW; P < 0.001), but not small intestine weight. Starch type did not affect stomach scores, but straw bedding reduced the incidence of gastric lesions to a very low level (scores 0.5 and 3.0 for straw and barren housing, P < 0.001). In conclusion, straw bedding reduced gastric lesions, reflecting either reduced environmental stress or a positive effect of physical stimulation. Pregelatinization of starch increased the empty weight of the proximal GI tract, possibly reflecting increased nutrient uptake.     

Concentrate supplementation responses of the pasture-fed dairy cow

The aim of this study was to investigate the effects of increasing amounts of cereal-based concentrate on milk production. The study consisted of a series of three separate experiments in which cows were grazed in intensive rotation on timothy-meadow fescue pasture. In Experiment 1, 28 multiparous Holstein–Friesian cows received 0, 3, 6 and 9 kg concentrate in a cross-over designed trial with a fixed daily herbage allowance of 21 kg DM/cow. The energy-corrected milk yield increased linearly 0.84 kg/kg DM (P < 0.001), up to the 9 kg concentrate level. The milk fat (P < 0.001) and urea (P < 0.001) content decreased linearly (0.41 g/kg DM and 0.15 mmol/kg DM, respectively). The milk protein content tended (P = 0.08) to increase 0.10 g/kg DM with increasing supplementation.

In Experiment 2, 17 primiparous cows and 28 multiparous cows were used in a randomized-block designed trial with 3, 6 and 9 kg concentrate supplementation and a fixed 25 kg DM herbage allowance. The energy corrected milk yield increased linearly (P < 0.01) 0.67 kg/kg DM, whereas the milk urea content decreased linearly (P < 0.001) 0.27 mmol/kg DM. The milk protein content increased and the fat content decreased, but these differences were not significant.

In Experiment 3, a cross-over design was used to assess the response to concentrate supplementation of 24 multiparous cows (treatments: 6, 9 and 12 kg; fixed herbage allowance 25 kg DM) and 12 primiparous cows (treatments: 4, 7 and 10 kg; herbage allowance > 25 kg DM). The energy-corrected milk yield of the multiparous cows varied quadratically (P_quad < 0.001; 30.0, 32.5 and 32.2 kg for 6, 9 and 12 kg supplementation, respectively). Supplementation linearly decreased the urea (P < 0.001) 0.13 mmol/kg DM and fat (P < 0.001) 0.46 g/kg DM contents. The milk fat content also varied quadratically, showing the lowest content with the 12 kg level (P_quad < 0.05; 37.3, 37.3 and 34.9 g/kg for 6, 9 and 12 kg supplementation, respectively). The energy-corrected milk yield of the primiparous cows increased linearly (P < 0.001) 0.54 kg/kg DM up to 10 kg supplementation, whereas the milk urea (P < 0.001) and fat contents decreased linearly (P < 0.01) by 0.19 mmol/kg DM and 0.61 g/kg DM, respectively.

The results showed that the milk response remained linear up to the 9 kg supplementation level, but the highest level of supplementation resulted in only a marginal increase in milk yield. There was no interaction between season and milk or milk protein yield, which indicates that it is possible to maintain stable grazing conditions during the main grazing season in Nordic latitudes. The results support to some extent the hypothesis that the marginal milk response to supplementation increases with increasing milk production.