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Forty-four merino lambs (6 to 8 wk old; BW 15.6 ± 0.21 kg) were used to study the effect of adding different proportions of sunflower soap stock (SS) to pelleted total mixed ration (TMR) for fattening lambs on feed intake, animal growth and dressing percentage, ruminal fluid characteristics, and blood acid-base parameters. Lambs were assigned to 1 of 4 experimental groups (11 lambs per group), each randomly assigned to 1 dietary treatment: 00SS (0 g SS/kg TMR pellet), 15SS (15 g SS/kg TMR pellet), 30SS (30 g SS/kg TMR pellet), and 60SS (60 g SS/kg TMR pellet). Lambs were individually fed the corresponding diet ad libitum. On d 19 to 23, total feces were collected and sampled from 4 lambs per group. When lambs reached 27 kg BW, they were slaughtered. Dry matter intake, ADG, and length of fattening period were not affected by the dietary treatment (P0.10). Animals in the 30SS group tended to show the best G:F values (P0.10). Dressing percentage tended to linearly decrease as SS increased (P0.10). Animals in the 60SS groups showed the lowest DM and fiber digestibility values (P0.05). Total VFA contents in ruminal fluid were not affected (P0.10), but the propionate proportion linearly increased (P0.05), and the acetate to propionate ratio tended to decrease with SS supplementation. Increasing dietary content of SS linearly decreased the cold carcass weight (P0.05) but did not affect other measured carcass characteristics. Ruminal fluid pH tended to decrease (P0.10) and mucosa color decreased as SS increased in the TMR (P0.05). Blood pH and Na concentration increased (P0.05), whereas the anion gap, CO2 pressure, and K concentration linearly decreased (P0.05) as SS increased. Including more than 30 g SS/kg TMR in the diet for fattening lambs reduces DM and fiber digestibility without affecting feed intake and ADG. The acidotic rumen conditions that induced a darkening of rumen mucosa were counteracted by blood acid-base parameters. The optimum level of inclusion seems to be 30 g SS/kg TMR.

The aim of this study was to investigate the effects of milking frequency reduction and dietary lipid supplementation on intake, BW, and milk yield and composition in high yielding dairy ewes. Ten lactating Assaf ewes were allocated into 2 experimental groups (n=5). Ewes were fed alfalfa hay ad libitum and 34 g·kg(-1) of BW of a concentrate feed with either 0 (Control group) or 43 g of sunflower oil·kg(-1) of DM (SO group). The experiment lasted 63 d and consisted of 3 periods. During Period 1 (from d 1 to 21), ewes were milked twice a day. During Period 2 (from d 22 to 49), ewes were unilaterally milked, so that each gland of each ewe was milked either once or twice daily. During Period 3 (from d 50 to the end of the experiment), both udder halves were again milked twice daily. Intake, BW, and milk composition were controlled weekly and milk production from each half udder was recorded twice a week. Total DM intake, BW, and milk yield in Period 1 were not significantly (P0.10) affected by dietary treatments. Milk yield tended to be increased in the ewes fed the SO diet in periods 2 (P=0.093) and 3 (P=0.067). Oil supplementation (SO diet) significantly (P0.05) decreased milk protein and total solids concentrations in the 3 experimental periods and fat content in Period 3, and tended (P=0.077) to decline fat content in Period 2. Lactose content and somatic cell count (SCC) were unaffected (P0.10) by dietary lipid supplementation in any of the experimental periods. There were no significant (P0.10) differences between half udders in milk yield and composition in Period 1, and in SCC in any of the experimental periods. Fat and total solids contents were unaffected (P0.10) by reducing milking frequency. Nevertheless, milk protein content was increased (P0.001) when glands were milked only once daily whereas milk yield and lactose content were decreased (P=0.001). The interaction between gland and diet was significant for lactose in Period 2, suggesting a greater effect of milking frequency reduction on tight junctions in Control ewes. In fact, the ratio between glands for milk yield was significantly (P0.05) greater in SO (0.82) than in Control (0.72) ewes. In Period 3, this ratio increased but it was still lower in Control ewes (0.92 vs. 0.78, P0.05). Thus, milking frequency reduction and SO supplementation seem to have counteracting effects on milk production and composition. Our results suggest that SO-supplemented ewes have a better capacity of adaptation to changes in milking frequency, probably due to processes induced in the mammary gland.

Twenty-four Merino lambs (mean BW 15.4 ± 0.13 kg, 6 to 7 wk old) were used to study the effects of the addition of 0 (control), 100 (V10), and 200 (V20) g of vinasse per kilgram of concentrate on intake, animal performance, biochemical blood profile, and carcass and meat characteristics. Lambs were assigned to 1 of 3 experimental diets and fed barley straw and the corresponding concentrate ad libitum. When the animals reached 25 kg of BW, a sample of blood was taken and the lambs were slaughtered. Feed intake, growth rate, biochemical blood profile, and carcass and meat characteristics were assessed. Lambs that received the concentrates with vinasse showed a reduced concentrate intake (linear contrast, P = 0.029) and ADG (linear contrast, P = 0.004) and an increased length of fattening period (linear contrast, P = 0.002) as well as feed:gain ratio (linear contrast P = 0.011). Vinasse enhanced ruminal pH (orthogonal contrast control vs. V10 + V20; P = 0.007). Plasma glucose concentrations declined in lambs fed vinasse (linear contrast, P = 0.003), whereas plasma urea concentration increased in animals fed vinasse (linear contrast, P = 0.036). The plasma concentrations of creatinine, triglycerides, and lactate and the enzyme profile studied (alkaline phosphate, alanine transaminase, glutamate oxal-acetate transaminase, γ-glutamyl transpeptidase, and lactate dehydrogenase) were not modified in response to vinasse inclusion. Lambs in the vinasse groups had less Na(+) and nitrate and greater K(+) and nitrite plasma concentrations (linear contrasts, P0.05). None of the carcass characteristics studied was affected by vinasse (P0.10). Meat chemical composition and characteristics were unaffected (P0.10), but shear force was greater for lambs that received vinasse (orthogonal contrast, control vs. V10 + V20, P = 0.007). The addition of 100 or 200 g vinasse/kg of concentrate for fattening lambs reduced feed intake and growth rate and increased the feed:gain ratio and meat toughness without affecting any other carcass and meat characteristics.

Three experiments were performed to study the nutritional characteristics of sugar beet pulp (SBP) according to the concentration of vinasse (condensed molasses solubles) added. Eighteen Merino ewes were used to study preference in Exp. 1, and 18 Merino ewes were used in Exp. 2 to study voluntary intake of SBP with different amounts of vinasse inclusion (0, 7, and 13% on a DM basis; SBP0, SBP7, and SPB13, respectively). Sheep showed a marked preference for SBP with vinasse, regardless of the amount of addition, whereas voluntary feed intake was not affected (P0.34). Eight ruminally cannulated Merino ewes were used in Exp. 3 to study rumen fermentation of SBP0 and SBP13. Regardless of the diet fed to the animals (SBP0 or SBP13), disappearance rates of DM, NDF, and CP were greater when SBP13, compared with SBP0, was incubated in sacco (P0.05), and NDF and CP disappearance rates were increased when animals were fed the SBP13 diet. No significant differences were observed for pH, ammonia concentration, or total or individual VFA in the ruminal liquor of sheep at different sampling times after feeding (P0.23) in response to vinasse addition. Experiment 4 was designed to study digestibility, solid passage rate, and excretion of purine derivatives from 12 Merino ewes fed SBP0 and SBP13. Digestibility of NDF tended to be greater (P0.10) for the SBP13 group compared with the SBP0 group; digestibilities of DM, OM, CP, and ADF were not affected (P0.11). Digesta flow kinetics and urinary excretion of purine derivatives were not significantly affected by the presence (SBP13) or absence (SBP0) of vinasse in the diet (P0.21). In conclusion, sheep showed a clear preference for SBP with vinasse. However, the lack of significant differences in most of the in vivo variables measured indicates that ewes can be satisfactorily fed with any of the amounts of vinasse inclusion studied.

The objective of this study was to evaluate the effects of malate supplementation on growth rate, feed efficiency, and diet digestibility in growing lambs. Twenty-four Merino lambs with a mean BW of 15.3 +/- 0.22 kg were divided into 3 homogenous groups. Each group was randomly allocated to 1 of 3 malate (16% disodium malate:84% calcium malate) levels: 0 (control), 4 (MAL-4), or 8 (MAL-8) g/kg of concentrate. Lambs were fed concentrate and barley straw ad libitum for 35 d. After a 20-d period, diet digestibility was determined, and microbial N flow at the duodenum was estimated from the urinary excretion of purine derivatives. Blood samples were taken on d 0, 20, and 35. On d 35, lambs were slaughtered and ruminal fluid samples were collected. There were no effects (P = 0.18 to P = 0.95) of malate on concentrate or straw intake, ADG, carcass yield, and apparent digestibility of OM, CP, NDF, or ADF. Malate supplementation did not influence (P = 0.80) the daily urinary excretion of total purine derivatives, and therefore there were no treatment effects (P = 0.77) on estimated microbial N flow at the duodenum. No differences (P0.05) among treatments were observed for plasma concentrations of glucose, cholesterol, triglycerides, urea-N, lactate, or VFA, but malate addition increased (P = 0.003) the molar proportion of butyrate in ruminal fluid (4.29, 6.14, and 5.45% of total VFA for control, MAL-4 and MAL-8, respectively). The use of malate as a feed additive under the conditions of the current study did not influence diet intake or digestion, and consequently did not improve lamb performance.