In vitro fermentative characteristics of ruminant diets supplemented with fibrolytic enzymes and ranges of optimal endo-beta-1,4-glucanase activity.

Effectiveness of fibrolytic enzymes supplementing a range of forage to concentrate (F:C) diets was assessed with goat (G) or cow (C) inoculum using the gas production (GP) technique. Four F:C diets were evaluated: forage (1:0), high forage (0.7:0.3), medium forage (0.5:0.5) and low forage (0.3:0.7) diets, supplemented or not with Promote(TM) (PRO) at 1 or 2 ml/kg dry matter (DM). The GP kinetic was different between F:C (1:0 < 0.7:0.3 < 0.5:0.5 < 0.3:0.7) and inoculum. Responses to enzyme were positively related to forage level and differed with inoculum. The neutral detergent fibre and acid detergent fibre degradation were depressed by the concentrate in the substrates fermented with C and were not altered or even enhanced in G sets. Results confirm that increasing starch proportion modified the pattern of microbial fermentation, while no influences were detected in the improvement of cell wall degradation with fibrolytic enzymes. Another in vitro experiment was conducted to investigate factors by which endo-beta-1,4-glucanase activity (EA) of PRO is compromised in a factorial design (3 x 4 x 3) for three pH (4.0, 5.5 and 6.5), four temperatures (30, 40, 50 and 70 degrees C) and three doses (1, 2 and 3 ml/kg DM of substrate). Maximum EA were obtained for pH 4.0, 50 degrees C and 3 ml/kg DM. Optimal conditions for PRO proved to be outside the normal ranges in ruminal environment.

Cóndilos bifido y trífido en disfunción de la articulación témporo-mandibular: reporte de dos casos clínicos / Bifid or trifid condyles in temporomandibular joint disorder: report of 2 cases

Abstract: Bifid or trifid condyle is a rare morphological alteration of the temporomandibular joint (TMJ), of unknown etiology. The aim of this paper is to describe the imaging findings of two patients with bifid and trifid mandibular condyle associated with functional disorders. Material and Method: Two female patients, who over the last six months had presented with noise, click and unilateral TMJ pain radiated to the ear in addition to chronic progressive joint hypomobility underwent CTand MR I examinations. Results: A severe asymmetry of mandibular condyles regarding size and shape, along with irregular contours and presence of cracks or channels in condylar apex, were observed. The bone structure of cortical and trabecular bone of the condyles, as well as the condylar bone marrow, had a normal appearance. The morphology of both glenoid fossa and transverse apophysis of the temporal bone was normal. The articular disc presented a deformation adapted to the condylar shape, showing the biggest disc volume as related to the condylar groove; a case with an accumulation of fluid in the superior articular recess, and signs ofsynovitis in the anterior supradiscal recess. Both joint surfaces were covered with fibrocartilage of homogeneous appearance and regular thickness. Conclusions: Changes in condylar morphology deserve special attention in differential diagnosis of bone tumors. It is important for the radiologist to be aware of the extreme anatomic variability of the TMJ. Bifid condyles are affected by TMJ dysfunctions.

El cóndilo bífido o trífido es una rara alteración morfológica de las articulaciones témporo-mandibulares (ATM), de etiología desconocida. El objetivo del presente artículo es describirlos hallazgos imaginológicos de dos pacientes que presentan cóndilo mandibular bífido y trífido, asociado con patologías funcionales. Mediante tomografía computarizada y resonancia magnética se estudiaron dos mujeres que clínicamente presentaban ruidos, resalte y dolor de ATM unilateral irradiado al oído, además de hipomo-vilidad crónica progresiva de la articulación, durante los últimos 6 meses. Se observó severa asimetría de tamaño y forma de los cóndilos mandibulares, con irregularidad de contornos, aparición de hendiduras o canales en ápex condilar. La estructura ósea del hueso cortical y trabecular de los cóndilos mostró aspecto normal, así como también la médula ósea. La morfología glenoidea y de las apófisis transversas del temporal se observaron normales. El disco articular presentó una deformación adaptativa a la forma condilar, observándose el mayor volumen discal en relación a la hendidura condilar, un caso con acumulación de líquido en el receso articular superior y signos de sinovitis en el receso supradiscal anterior. Ambas superficies articulares se observaronn cubiertas de fibrocartílago de aspecto homogéneo y espesor regular. Conclusiones: Las alteraciones de la morfología condilar merecen especial atención para el diagnóstico diferencial con tumores óseos. Es importante para el radiólogo estar atento a la existencia de extrema variabilidad anatómica de la ATM. Los cóndilos bífidos son afectados por disfunciones de la ATM.

Long- and short-term effects of omitting two weekend milkings on the lactational performance and mammary tight junction permeability of dairy ewes.

The long- and the short-term effects of omitting 2 milkings weekly in early (wk 8 to 14) and mid lactation (wk 15 to 22) were investigated in an experiment conducted with a total of 58 dairy ewes (40 Manchega and 18 Lacaune). Ewes submitted to 2 milking omissions were milked twice daily from Monday to Friday (0800 and 1800 h), and once daily on Saturday and Sunday (1600 and 1400 h, respectively). Individual data were collected for milk yield (weekly), milk composition (biweekly), and somatic cell count (SCC; monthly). Omitting 2 milkings per week in early lactation tended to decrease milk yield in Manchega ewes (-15%), whereas no effects were observed in Lacaune ewes. Averaged milk composition was not modified by milking omissions in either breed. Milking omissions in late lactation did not affect milk yield and milk composition in either breed. The SCC were unaffected by milking omissions in both breeds and in both stages of lactation. A sample of 22 Manchega and 11 Lacaune ewes were used to evaluate the short-term (daily) effects of the 2 milking omissions per week on milk yield and composition, udder health, and tight junction permeability, both in early lactation (wk 12) and in mid lactation (wk 20). Milking omission decreased milk yield, milk fat, and milk lactose contents on the first omission day in both breeds, with losses being more noticeable in early lactation than in mid lactation. Milk protein content and SCC did not vary by effect of the weekend milking omissions. After restoring the twice-daily milking routine on Monday, milk yield showed a compensatory increase that was greater in the large-cisterned than in the small-cisterned ewes, which allowed milk yield to return to Friday values in both breeds. Milk fat content increased during Sunday and Monday, reestablishing Friday values thereafter in both breeds. Weekend milking omissions in early lactation caused tight junction leakiness in both breeds, but mammary epithelia adapted to extended milking intervals when applied successively, recovering their tight state after milking. In mid lactation, the mammary tight junction showed leakiness only in Manchega ewes. In conclusion, 2 milkings per week could be omitted with no negative effects on milk yield, milk composition, and milk SCC values in large-cisterned dairy ewes, as observed in Lacaune and large-cisterned Manchega ewes. Losses in milk yield could be reduced if milking omissions were done from mid lactation in small-cisterned ewes.

Changes in alveolar and cisternal compartments induced by milking interval in the udder of dairy ewes.

The aim of this work was to evaluate the effects of milking interval (4, 8, 12, 16, 20, and 24 h) on cisternal size and milk partitioning (cisternal and alveolar) in the udders of dairy ewes. Twenty-four dairy ewes (Manchega, n = 12; Lacaune, n = 12) were used in a 2-wk experiment during mid-lactation. Cisternal and alveolar milk yields were measured and milk samples from each udder fraction were collected for analysis. Cisternal milk was obtained after i.v. injection of an oxytocin receptor antagonist, and alveolar milk was obtained after i.v. injection of oxytocin. Enlargement of the cisternal compartment due to milking intervals was measured by ultrasonography for each half udder. Volumes of cisternal and alveolar milk differed according to breed, being greater in Lacaune (888 +/- 43 and 338 +/- 25 mL, respectively) than in Manchega ewes (316 +/- 43 and 218 +/- 25 mL, respectively). Alveolar milk increased linearly to 16 h in Manchega and 20 h in Lacaune and remained constant thereafter. Cisternal milk accumulated linearly to 24-h milking intervals in both breeds. Cisternal area (values per udder half) increased as milking interval increased, reaching a plateau at 20 h in Manchega (21 +/- 1 cm(2)) and 16 h in Lacaune (37 +/- 1 cm(2)). Correlation between cisternal area and cisternal milk was the greatest at 8 h (Manchega: r = 0.70 and Lacaune: r = 0.56). Cisternal area correlated with total milk (r = 0.80). Milk fat content varied markedly with milking intervals, increasing in alveolar milk (until 12 h in Manchega, 8.90 +/- 0.18%; and 20 h in Lacaune, 8.67 +/- 0.19%) and decreasing until 24 h in cisternal milk (5.74 +/- 0.29% and 4.85 +/- 0.29%, respectively). Milk protein content increased in alveolar milk until 24 h (Manchega, 6.46 +/- 0.11%; Lacaune, 5.95 +/- 0.11%), but did not vary in cisternal milk. Milk lactose content only decreased at the 24-h milking interval in the cisternal milk of Manchega ewes (4.60 +/- 0.04%). In conclusion, our results suggest that cisterns play an important role in accommodating secreted milk during extended milking intervals. Thus, long milking intervals could be a recommended strategy for large-cisterned dairy sheep. Evidence indicates that ultrasonography provides accurate estimations of udder cistern size and could be used as an indicator for selecting large-cisterned dairy ewes.

Effect of milking interval on milk secretion and mammary tight junction permeability in dairy ewes.

Twenty-four lactating ewes (Manchega, n = 12; Lacaune, n = 12) in mid lactation were used to assess the short-term effects of different machine milking intervals (4, 8, 12, 16, 20, and 24 h) on milk yield, milk composition, and tight junction (TJ) permeability of mammary epithelia. Milk samples were analyzed for chemical composition, somatic cell count (SCC), and plasmin activity. Plasma lactose, and milk Na and K concentrations were used as indicators of TJ permeability. Milk accumulated linearly for up to 24 h, showing a different rate according to the milk yield of the breed (Manchega, 38 mL/h; Lacaune, 87 mL/h). Milking interval affected milk fat content, which decreased markedly from 4 to 24 h in both breeds, but no differences were observed in milk protein content. The milk contents of casein, true protein, lactose, and total solids also varied according to milking interval. Values of SCC did not vary by breed (175 x 10(3) cells/mL, on average), showing the lowest log(10) values for the 4-and 24-h milking intervals in both breeds. Plasmin activity in milk increased with milking interval until 20 h of udder filling in both breeds, and was poorly but positively correlated with SCC content (r = 0.39). Plasma lactose increased dramatically after 20 h of milk accumulation, indicating enhanced permeability of mammary TJ. As a result, an increase in Na concentration and in the Na:K ratio, and a decrease in K concentration, were observed in the milk of Manchega ewes. On the contrary, no differences in Na and K concentrations in milk were detected in Lacaune ewes. In conclusion, our results proved that Manchega and Lacaune dairy sheep could maintain high rates of milk secretion during extended milking intervals in the short term, with no effects on udder health and few negative effects on milk yield. Increased TJ permeability, caused by the effect of udder filling, induced changes in milk composition that were more marked in Manchega than in Lacaune ewes.

Feeding soybean oil to dairy goats increases conjugated linoleic acid in milk.

A total of 24 Murciano-Granadina dairy goats milked once daily throughout lactation were used to study the effects of including soybean oil (SBO) in the diet on lactational performance and milk fatty acid (FA) content, particularly conjugated linoleic acid (CLA) and trans-vaccenic acid (trans-11 C18:1, TVA). Three weeks after parturition, goats were allocated to 2 balanced groups according to lactation number, body weight, and daily milk yield, and were kept in separate pens. The experiment consisted of a 2-period (28 d each) crossover with 2 dietary treatments: control and SBO (6% as fed in the concentrate). Goats were fed dehydrated fescue (ad libitum), alfalfa pellets (0.5 kg/d), and concentrate (1 kg/d) to which the SBO was or was not added. Forage was fed in the pens, and concentrate was fed individually in 2 equal portions at milking (0900 h) and in the afternoon (1700 h). Final SBO content in the consumed SBO diet was 2.5% (dry matter basis). Diets were isonitrogenous (17.4% crude protein), but their total FA content varied from 2.2% (control) to 4.6% (SBO). There was no effect of SBO on dry matter intake, milk yield, energy-corrected milk, body weight, or body condition score. Compared with the control diet, feeding SBO increased milk fat content (4.57 vs. 5.24%) and yield as well as total solids content. Soybean oil had no effect on milk crude and true protein contents, but it reduced milk casein content (2.48 vs. 2.34%). Short- and medium-chain FA decreased by feeding SBO, whereas long-chain FA increased. Feeding preformed linoleic acid through SBO increased milk concentrations of linoleic, oleic, and stearic FA but reduced levels of linolenic and palmitic FA. As a consequence, feeding SBO decreased the saturated-to-unsaturated FA ratio and the atherogenicity index. Compared with the control treatment, milk contents of cis-9, trans-11 CLA (0.68 vs. 2.03%) and TVA (2.04 vs. 6.41%) in the SBO treatment increased by approximately 200%. In conclusion, feeding a moderate dose of SBO to dairy goats was a useful way to increase milk fat, CLA, and TVA contents in milk and to reduce the atherogenicity index without negative effects on intake, milk yield, and protein content.

Performance of dairy ewes fed diets with a fibrolytic enzyme product included in the concentrate during the suckling period.

Seventy-two multiparous ewes from two dairy breeds (Manchega, n = 36 and Lacaune, n = 36) were used in a replicated 2 × 2 factorial design to evaluate the effects of diet supplementation with an exogenous fibrolytic enzyme product on lactation performance and feed intake during the suckling period (weeks 1 to 4) according to breed. Ewes were blocked in groups of nine and fed ad libitum after lambing a diet based on 70% forage and 30% concentrate to which the enzyme was added after pelleting. Experimental concentrates were: control (without enzyme) and enzyme (fibrolytic enzyme complex, included at 0.47% volume to weight of concentrate). Twenty-four dry and open ewes (Manchega, n = 12 and Lacaune, n = 12) were also grouped by breed and used to measure the fill value of the ration used. During the suckling period, milk yield, milk composition, dry matter intake, lamb growth, as well as body weight change and body condition score change were not affected by enzyme supplementation. Breed effect was significant for milk yield, the Manchega ewes yielding less milk with a higher content of milk components than the Lacaune ewes. The opposite was observed for dry matter intake. Enzyme supplementation reduced intake by 9% in the dry ewes, resulting in a greater fill value of the diet. In conclusion, no lactational effects were detected when the fibrolytic enzyme product was added to the concentrate fed to dairy ewes.

Mammogenesis and induced lactation with or without reserpine in nulliparous dairy goats.

Nulliparous goats were used to evaluate the effects of a standard protocol for inducing lactation with or without using a prolactin-releasing agent (reserpine). Estrus was synchronized and goats were submitted to daily s.c. injections of estradiol-17beta and progesterone (0.5 and 1.25 mg/kg of body weight, respectively) for 7 d. The goats were divided into 2 groups and injected i.m. with 1 mg/d of reserpine (n = 7) or the vehicle (n = 7) on d 12, 14, 16, 18, and 20. Lactation was initiated by i.m. injections of dexamethasone (10 mg/d) from d 18 to 20. Goats were machine milked once daily from d 21 to 120, at which time they were mated with herd sires. Milk was measured and sampled daily during wk 1 of lactation and weekly thereafter. Udder traits were measured in all goats at d -2 (before the induction treatment) and on d 35 and 100 (during lactation). Goats initiated lactation on d 21 (100%) and milk yield increased thereafter. The milk yield of control and reserpine-treated goats increased as lactation advanced, peaking at wk 10 of lactation, when reserpine-treated goats yielded 1,079 +/- 89 mL/d of milk compared with 850 +/- 96 mL/d for control goats. Yet milk yield at the peak was only 55% of the peak milk yield observed in contemporary primiparous goats. The composition of initial milk (d 21) was different from that expected for colostrum. Milk composition stabilized after d 3 of lactation. There were no differences among groups for milk fat, protein, casein, or whey protein, but milk from control goats contained greater nonprotein nitrogen than that from reserpine-treated goats (0.48 +/- 0.02 vs. 0.41 +/- 0.02%). Teat length increased from 24.7 +/- 1.1 to 34.5 +/- 2.4 mm in control goats during mammogenesis (d -2 to 35), but stabilized in reserpine goats (25.2 +/- 2.2 mm). The distance between teats (11.5 +/- 0.4 cm), and the volume (922 +/- 63 mL) and depth (15.6 +/- 0.60 cm) of the udder increased similarly in both groups during mammogenesis and lactation. After mating, 82% of herdmates became pregnant, whereas only 21% of the lactation-induced goats conceived (1 reserpine-treated and 2 control goats). In conclusion, lactation induction was effective in nulliparous goats, but neither milk yield nor the side effects on fertility seem to support its recommendation.

Effect of pregnancy and extended lactation on milk production in dairy goats milked once daily.

Thirty multiparous Murciano-Granadina dairy goats milked once daily were used to study the lactational effects of an extended 24-mo kidding interval (K24; n = 14) compared with the traditional 12-mo kidding interval (K12; n = 16). Goats were divided into 2 groups at wk 29 of lactation balanced with respect to parity, milk yield, and somatic cell count. Over a period of 92 wk, K12 goats were mated twice, at wk 29 during the first lactation and at wk 79 during the second lactation, whereas K24 goats were mated once, at wk 79 of extended first lactation. The K12 goats were dried off from wk 14 to 21 of pregnancy (wk 43 to 50 of lactation). Milk yield was recorded from wk 2 to 92, and milk composition was studied from wk 29 to 92. Milk fatty acids were analyzed in milk samples taken at wk 39 (wk 10 of pregnancy) and 55 (wk 5 of subsequent lactation), when milk in udder compartments (cisternal and alveolar) was also evaluated. Average milk yield during the first 29 wk was 2.23 +/- 0.13 L/d. Pregnancy reduced milk yield in K12 goats from wk 39 to 42 of lactation compared with K24 goats. During the dry period for K12 goats, milk yield of K24 goats averaged 1.53 +/- 0.10 L/d. From wk 51 to 79, K12 goats produced 32% more milk than did K24 goats, but their milk contained lower fat and protein than that of K24 goats. No changes were detected for milk lactose and somatic cell count from wk 51 to 79. From wk 80 to 92, differences in milk yield and milk composition between groups were not significant. Milk of pregnant K12 goats contained higher C16:1 and conjugated C18:2 fatty acids, and had a higher desaturase index than milk of open K24 goats at wk 39. In the following lactation (wk 55), milk of K12 goats contained higher C18:2 and C18:3, and lower C16:0 fatty acids, resulting in a lower atherogenicity index compared with K24 goats. Cisternal milk at wk 39 was lower for K12 than K24 goats, whereas alveolar milk did not differ. In K12 goats, values of cisternal milk tripled, but alveolar milk only doubled at wk 55 (wk 5 of subsequent lactation) compared with wk 39, indicating the importance of the cistern in accommodating high milk yield in early lactation. Values of cisternal and alveolar milk did not differ between wk 39 and 55 for K24 goats. Fat content was higher for alveolar milk than cisternal milk for K12 goats at wk 55 and for K24 goats at wk 39 and 55. No differences in milk protein or lactose were detected between cisternal and alveolar milk. In conclusion, pregnancy reduced milk yield from wk 10 after conceiving onwards. Extended lactation did not significantly decrease milk yield (-8.2%), but increased milk components that may contribute to cheese yield, and may be a useful strategy for reducing metabolic stress in early lactation and for simplifying herd management in dairy goats.

Effects of once versus twice daily milking throughout lactation on milk yield and milk composition in dairy goats.

The effects of once (1X) vs. twice (2X) daily milking throughout lactation on milk yield, milk composition, somatic cell count (SCC), and udder health were studied in 32 Murciano-Granadina dairy goats. Goats were assigned at wk 2 of lactation to two treatment groups; once daily milking at 0900 (1X, n = 17), or twice daily milking at 0900 and 1700 (2X, n = 15). Milk yield was recorded weekly until wk 28, and milk composition and SCC were evaluated for each individual udder half at each milking at wk 2 and 4 of lactation and then, monthly until the end of the experiment. Once daily milking resulted in an 18% reduction in the yield of 4% fat-corrected milk compared to twice daily milking (1.61 vs. 1.95 L/d, respectively). This reduction was more marked from wk 2 to 12 than in mid and late lactation. Response to milking frequency also varied according to parity number where goats of less than four parities suffered more milk yield losses during 1X than older goats. Milk of 1X goats contained higher percentages of total solids (13.6 vs. 12.9%), fat (5.10 vs. 4.62%) and casein (2.57 vs. 2.35%) than milk of 2X goats, but milk protein percentage did not differ between treatments (3.28 vs. 3.20%). Yields of total solids, fat, protein and casein tended to be higher for 2X than 1X. Milk SCC did not differ between treatments. We conclude that application of once daily milking in Murciano-Granadina dairy goats moderately reduced milk yield without negative effects on milk composition and udder health. Losses in milk yield would be reduced if 1X is practiced during mid- or late lactation and in older goats. An increase in labor productivity and a higher farmer's standard of living is also expected.

Effect of nitrogen source in high-concentrate, low-protein beef cattle diets on microbial fermentation studied in vivo and in vitro.

In Exp. 1, four Holstein heifers (112+/-5.5 kg BW) fitted with ruminal cannulas were used in a 4 x 4 Latin square to evaluate the effects of N source on ruminal fermentation and urinary excretion of purine derivatives. A 2 x 2 factorial arrangement of treatments was used; the factors were the type of protein source (soybean meal, SBM, vs a 50:50 mixture of fish meal and corn gluten meal, FMCGM) and the partial substitution of protein source by urea (with vs without). Heifers were allowed to consume concentrate and barley straw on an ad libitum basis. Barley straw:concentrate ratio (12:88) and average ruminal pH (6.25) were not affected (P > 0.05) by treatment. Ruminal NH3 N concentration and urinary excretion of purine derivatives were not affected (P > 0.05) by supplemental N source. In situ CP degradability of supplemented SBM was very low (50%). In Exp. 2, eight dual-flow continuous-culture fermenters were used to study diet effects on microbial fermentation and nutrient flow, using forage:concentrate ratio, solid and liquid passage rates, and pH fluctuation to simulate in vivo conditions. The treatment containing SBM without urea reached the greatest total VFA concentration (P < 0.01), molar percentage of acetate (P < 0.05), and NH3 N concentration (P < 0.05), followed by treatments with partial substitution of protein source by urea, and finally by the treatment containing FMCGM. True OM digestion tended to increase (P = 0.13) in treatments containing SBM. These results suggest that amino N from SBM and NH3 N concentration stimulated nutrient digestion. Microbial protein synthesis was lowest in treatments with FMCGM and without urea, indicating that rapidly available N limited microbial growth. The low CP degradability of SBM observed may have contributed to the limitation in N supply for microbial growth. Efficiency of microbial protein synthesis increased in treatments containing urea (P < 0.05). Protein source affected total (P < 0.05) and essential AA (P < 0.10) flows, which were greater in treatments containing FMCGM. Partial replacement of protein supplements by urea did not affect total and essential AA flows. Because mean dietary protein contribution to total N effluent was 46%, the AA profile of supplemental protein sources had a great impact on total AA flow and its profile.

Effects of protein concentration and degradability on performance, ruminal fermentation, and nitrogen metabolism in rapidly growing heifers fed high-concentrate diets from 100 to 230 kg body weight.

Twenty crossbred heifers (101 +/- 4.5 kg BW) were used to examine the effects of protein concentration and degradability on performance, ruminal fermentation, nutrient digestion, N balance, and urinary excretion of purine derivatives. Heifers were offered concentrate and barley straw for ad libitum consumption. Two protein concentrations (17 vs 14%, DM basis) and two protein sources differing in ruminal degradability (58 vs 42% of CP for soybean meal and treated soybean meal, respectively) were tested. The experiment was divided into four consecutive 28-d periods to evaluate the age (period) effect. Increasing protein concentration and degradability did not improve ADG or intake (P > .05). The increase in urinary N excretion (P < .001) in heifers fed 17% CP suggests that N was in excess of requirements. When the low-degradable protein source was supplemented and(or) CP concentration was low, ruminal NH3 N concentrations fell below 5 mg/100 mL. Urinary excretion of purine derivatives was not affected (P > .05) by protein concentration and degradability, suggesting that in high-concentrate diets NH3 N concentration was not limiting microbial growth. Total VFA concentration decreased (P < .001) and the acetate:propionate ratio increased (P < .01) with advancing period, suggesting an increase in ruminal absorption capacity and an increase in fiber fermentation. The decrease in ruminal NH3 N concentration in the last period suggests a greater use of NH3 N by microorganisms. This hypothesis is supported by the increase (P < .001) in urinary excretion of allantoin and estimated duodenal flows of purine bases and microbial protein with advancing period. Reducing CP concentration and increasing ruminal undegradable protein supply did not affect animal performance or estimated duodenal flow of microbial protein in rapidly growing heifers fed high-concentrate diets.

Effects of calcium soaps and rumen undegradable protein on the milk production and composition of dairy ewes.

Forty-eight Manchega dairy ewes were used during a complete lactation in a 2 x 2 factorial design to determine the effects of supplementing diets with fat (calcium soaps of palm oil fatty acids, CSFA) and rumen undegradable protein (RUP) on milk production and composition. Factors tested were amounts of CSFA (0 or 200 g/kg) and RUP (300 or 450 g/kg crude protein) in the concentrate. RUP was altered by adding a mixture of maize gluten meal and blood meal. Lactation was divided into one nursing period (period 1, weeks 1-4), and three milking periods (periods 2-4, weeks 5-8, 9-14 and 15-21). Concentrates were given at 0.8 kg/d during periods 1 and 2, and at 0.6 kg/d in periods 3 and 4. Ewes grazed rotationally in an Italian rye-grass pasture and received a daily supplement of 0.8 kg vetch-oat hay during period 1, and 0.3 kg lucerne hay during periods 2-4. For the whole lactation, supplemental fat markedly increased milk fat content (+23%) and yield (+16%), and decreased milk protein content (-9%). The positive effect of feeding CSFA on milk fat content was more evident at the beginning of lactation; however, its negative effect on milk protein was more pronounced in late lactation. Supplementary RUP had little effect, increasing milk protein content only in period 3, when the crude protein content of pasture was lower. Milk yield and lamb growth were not affected by dietary treatments. The results indicated that CSFA can be useful for increasing the milk fat content of dairy ewes at pasture, which may help farmers to produce milk reaching the minimum requirements of fat content for the cheese industry.

Influence of kid rearing systems on milk composition and yield of Murciano-Granadina dairy goats.

One-hundred eight lactations of Murciano-Granadina goats from different years were used to compare two kid rearing systems. Goats were separated into two groups: suckling and milking. Dams in the suckling group were milked once daily until kids were weaned (wk 0 to 7) and then were milked twice daily. Dams in the milking group were separated from their kids at 48 h after birth; then, kids were raised artificially, and goats were milked twice daily. Total milk yield was estimated according to the oxytocin method during suckling. Stage of lactation, parity, prolificacy, and year effects on milk yield and composition were also studied. As expected, during the first 7 wk of lactation, marketable milk was higher for dams that were milked than for dams that were suckled. Neither milk yield nor milk composition throughout the entire lactation was affected by group or prolificacy with the exception of the percentage of milk CP. The lactation curve peaked at wk 4 or 5 and declined slowly afterward. First parity goats had the lowest milk yield but the highest fat and protein percentages. Third parity goats had the highest milk yield. The separation of kids from their dams after birth did not affect total lactation performance because of the minimal importance of the neuroendocrine milk ejection reflex in goats compared with that of other ruminants.