Comparison of immunosuppression in dry and lactating Awassi ewes due to water deprivation stress.

In seminomadic farming practice, dry and lactating ewes are exposed to different degrees of water deprivation, leading to stress followed by various disease outbreaks. This study compares quantitatively the immunosuppression to Salmonella Enteritidis (SE) fimbriae (14 and 21 kDa) and other major polypeptides (28.9, 37.7, 42.9, 68.0, 92.6 and 96.8 kDa) in water-deprived dry and lactating ewes. Sixteen dry and lactating multiparous Awassi ewes were divided into four treatment groups (A, A', B and B'). Ewes in groups A and B were lactating, whereas ewes in groups A' and B' were dry. All ewes were administered a killed SE vaccine, subcutaneously in the neck, at the initiation of the experiment. The water availability for ewes in groups B (lactating) and B' (dry) was ad libitum, while that for ewes in groups A (lactating) and A' (dry) was once every 4 days. A serum sample was collected from the jugular vein of each ewe at zero time (initiation of the experiment, when SE bacterin was delivered) and at 2, 9, 12, 15 and 18 days post SE vaccination. The percentage reduction in the level of humoral antibody response to polypeptides of > or = 21 kDa was more apparent in water-deprived lactating ewes of group A between 9 and 18 days post initiation of thirst. In this period, immunosuppression to polypeptides > or = 21 kDa was present in 14 out of 16 observations in group A (water-deprived lactating), with significant immunosuppression in 9 observations in relation to the respective control (p<0.05), while it was present in only 4 out of 16 observations in group A' (water-deprived dry), with significant immunosuppression in 2 observations (p <0.05). In conclusion, immunosuppression to polypeptides of > or =21 kDa is more significant in lactating water-deprived ewes in the period 9-18 days post initiation of thirst, a result that will influence our future sheep welfare awareness programmes targeting an elimination of the practice of water deprivation in seminomadic sheep farming.

Effects of feeding ervil (Vicia ervilia) seeds soaked in water or acetic acid on performance and internal organ size of broilers and production and egg quality of laying hens.

Experiment 1 was conducted to study the effects of feeding 60% untreated ervil seeds (UE) or ervil soaked in water at room temperature (RTWE) or at 40 degrees C (40WE) for 72 h with water change every 12 h on the performance and internal organ size of broilers. Isocaloric and isonitrogenous corn-soybean meal diet (control) and diets containing 60% UE, RTWE, or 40WE were fed to battery caged broilers in 4 replicates with 8 birds per replicate, from 8 to 49 d. Broilers consuming UE from 8 to 28 d gained less weight, used feed less efficiently, and had heavier liver, pancreas, and gall bladder weights (%BW) than the other treatments (P < 0.05). Compared with control birds, broilers on 40WE had similar relative organ weights, except for kidney, but lower BW gain at 49 d (P < 0.05). In experiment 2, ervil seeds were soaked in 1% acetic acid at room temperature (RTAAE) or at 40 degrees C (40AAE) for 24 h. A conventional diet and diets containing 60% UE, 40WE, RTAAE, or 40AAE were fed to individually caged laying hens in 4 replicates per treatment with 5 hens per replicate for 42 d. Hens on UE had the poorest performance followed by RTAAE, 40WE, and then 40AAE (P < 0.05). Compared with the control, all treated ervil diets resulted in lower shell thickness values but higher Haugh unit scores (P < 0.05). In experiment 3, 30% dietary UE and 40AAE at 10, 20, and 30% were fed to layers for 56 d. The general performance of hens on 30% 40AAE was comparable with that of the control except for BW and feed conversion (P < 0.05). Compared with UE, the performance of broilers and layers was improved by 40WE and that of hens was further enhanced by 40AAE. In addition, diets containing up to 20% 40AAE had no adverse effects on feed conversion, egg production, or quality of hens.

Vicine and convicine in common vetch (Vicia sativa) seeds enhance beta-cyanoalanine toxicity in male broiler chicks.

Two studies were conducted to investigate the effects of feeding raw and water-soaked vetch seeds to male broiler chicks on performance, organ weights, and blood parameters. Intact and ground vetch seeds were soaked in water (1:5) at room temperature for 24 hours (study 1), and (1:10) at 40 degrees C for 24, 48, and 72 hours, with water change every 12 hours (study 2). In study 1, untreated vetch contained, on dry matter basis, 0.530%, 0.731%, and 0.081% total beta-cyanoalanine (BCA), vicine, and convicine, respectively. Toxins were not appreciably reduced in soaked intact and ground vetch. Diets containing untreated, soaked intact, and soaked ground vetch, each at 0%, 20%, 40%, and 60%, were fed to 7-day-old male broilers until onset of neurotoxicity symptoms. Survival time was not only decreased by BCA level but also by those of vicine and convicine (p <.05). In study 2, 60% of untreated or treated vetch seeds were incorporated in chick diets. Although untreated vetch used in this study contained 32% less BCA but 8% and 81% more vicine and convicine, respectively, yet, the chicks on 60% untreated vetch showed toxicity symptoms earlier than those of study 1. Soaking ground vetch for 48 hours or more reduced BCA and totally removed vicine and convicine. Consequently, birds on 60% ground vetch soaked for 48 and 72 hours survived through the starter period and had mean corpuscular hemoglobin concentration and organ weights comparable to those of control at 4 days post trial. The results indicated that "high levels" of vicine or convicine or both might have shortened the birds' survival time by enhancing the neurotoxicity induced by "lower levels" of BCA.

Performance of broilers and production and egg quality parameters of laying hens fed 60% raw or treated common vetch (Vicia sativa) seeds.

Two experiments were conducted to study the effect of feeding 60% untreated (U) or coarsely ground treated vetch (V) seeds on performance of broilers and laying hens. In Experiment 1, the V seeds were soaked in 1% NaHCO3 (1:10) or in 1% acetic acid (1:5) at room temperature for 24 h (RTAA). Birds on the NaHCO3-treated V diet had 100% mortality rate but had significantly longer survival time than those on UV (14.9 vs 5.1 d). Birds on RTAA-V survived and had similar BW and feed conversion but greater kidney size than those of the controls at 7 wk of age (P < 0.05). In Experiment 2, control, UV, V soaked in water at 40 C (40WV), RTAA-V, and V soaked in acetic acid at 40 C (40AAV) diets were fed to laying hens for 84 d. The ground seeds in RTAA-V and 40AAV were soaked in acetic acid (1:10) at room temperature or at 40 C, respectively, for 24 h. For 40WV, the seeds were soaked in water (1:10) at 40 C for 72 h with a water change every 12 h. The UV-fed hens ceased egg production within 14 d and had the highest BW loss and the lowest feed intake among all treatments (P < 0.05). The 40WV and 40AAV significantly improved these criteria. Moreover, the RTAA-V resulted in performance comparable to that of the controls. Eggs produced by hens on treated V diets had similar weight but higher Haugh unit score (11 points), thinner shell, and lower yolk color score than those of the controls (P < 0.05). Results indicated that RTAA-V at 60% dietary level was not detrimental to broilers and laying hens.

Effect of feeding raw and treated common vetch seed (Vicia sativa) on the performance and egg quality parameters of laying hens.

Two experiments were conducted to study the effect of feeding raw or treated common vetch seeds (V) on BW, feed intake (FI), egg production (EP), feed conversion (FC), egg weight (EW), shell thickness (ST), yolk color score (YC), and Haugh unit score (HU) of Single Comb White Leghorn hens for 56 d. In Experiment 1, diets contained 0, 7.5, 15, and 22.5% raw V. Compared with the control, the 22.5% V diet decreased (P < .05) BW, FI, and EP. In Experiment 2, intact or ground (G) V were either soaked (S) in water (1:5) for 24 h or autoclaved (A) at 103.5 x 10(3) Pa for 8 h, and then dried (D) at 55 C for 24 h. Eight diets were used, a corn soybean (control) and seven others, each containing 25% V, previously subjected to the forementioned treatments as follows: untreated V (UV), SDV, GSDV, ADV, GADV, SADV, and GSADV. Compared with the control, the UV diet decreased (P < .05) FI (75 vs 98 g) and EP (47.3 vs 88.7%), increased FC (1.99 vs 1.4 kg feed per dozen eggs), and induced BW loss (-63 vs 49 g). Soaking intact V improved (P < .05) FI (85 g) and EP (69%). Remaining treatments resulted in further improvement. Hens fed all V diets produced eggs with HU score 13 points better than that of the control (P < .05). In both experiments, EW, YC, and ST were not different among treatments. Results indicated that autoclaved V at 25% level was not detrimental to layers' performance.

Effect of isocaloric infusion of glucose in the rumen or propionate in the duodenum.

This study was undertaken to understand better the mechanisms causing increased milk protein. Cows fed steam-flaked sorghum have increased milk protein compared with that of cows fed dry-rolled sorghum because of a large shift of starch digestion from the intestine to the rumen. Five cannulated lactating cows were infused with glucose in the rumen or with propionate in the duodenum in two trials. The experimental design was a 2 x 2 Latin square with 7 d of adjustment and 7 d of infusion. During the experiment, cows received a TMR containing 19.3% CP and 1.56 Mcal/kg of NEL (on a DM basis); alfalfa hay and dry-rolled sorghum grain were the principal ingredients. Similar concentrations in feces of cows among propionate treatments suggested complete absorption of infused propionate. Milk yield did not differ, but protein percentage of milk was higher (2.88 versus 2.72%) for cows infused ruminally with glucose than for those infused in the duodenum with propionate. For the respective treatments, duodenal flows were 2.11 and 1.76 kg/d for microbial protein and 3.44 and 2.73 kg/d for total CP (or 85 and 74% of CP intake). These data demonstrate that increased propionate availability for gluconeogenesis and a possible sparing of essential AA did not result in increased milk protein content, but ruminal infusion of glucose, which tended to increase microbial protein synthesis, did increase the protein percentage of milk.

Influence of yucca extract on ruminal metabolism in cows.

Two trials were conducted to determine the influence of yucca extract on ruminal digestion, fermentation, and ammonia patterns using ruminally and duodenally cannulated dairy cows. In Trial 1, urea at 0 or 1% of the diet and yucca extract at 0 or 4 g/d formed four dietary treatments in a 2 x 2 factorial arrangement. The experimental design was a 4 x 4 Latin square with 15-d periods. Duodenal digesta were sampled every 6 h during the last 4 d of each period to determine OM and ADF digestibilities and bacterial protein synthesis in the rumen using Cr2O3 and 15N markers. Ruminal digestibilities were (percentage): OM 46.3 vs 43.0%, and ADF 35.9 vs 41.4%, with or without Deodorase. Microbial protein entering the duodenum averaged 2.7 vs 3.1 kg/d for the respective treatments. Ruminal measurements were not affected by treatment (P > .10). In Trial 2, five cows were used in a 5 x 5 Latin square with 7-d periods. Treatments were 0, 2, 4, 6, and 8 g/d of yucca extract administered via ruminal cannulas. Ruminal fluid was sampled 0, 1, 2, 4, 7, 11, 16, and 22 h after feeding during the last 2 d of each period. Average ruminal NH3 N ranged from 31.4 to 35.4 mg/dL, pH 5.99 to 6.18, and total VFA from 120 to 129 mM, and all did not differ among treatments (P > .10). Yucca extract administered at 4 g/d did not significantly affect ruminal digestibilities of OM and ADF, and up to 8 g/d did not affect ruminal NH3, pH, or VFA.

Effect of three supplemental fat sources on lactation and digestion in dairy cows.

Tallow, Ca salts of palm fatty acids, or prilled fatty acids were added at 2.5% to a control diet (3.7% fatty acids) containing 7.2% ammoniated whole cottonseed. Diets were fed to midlactation cows (6 cows per treatment) for 72 d to determine effects of fat supplementation and fat source on lactation performance and nutrient digestibilities. Dry matter intake did not differ among treatments. Milk yield was 31.6 kg/d for the control and increased an average of 2.1 kg/d with fat supplementation. Source of supplemental fat did not significantly affect lactation performance. Added fat decreased milk protein content but did not affect protein yield. Milk fat, lactose, and SNF contents did not differ among treatments. Overall fat supplementation did not affect digestibilities of DM, ADF, or NDF but decreased digestibility of fatty acids. Contribution of de novo fatty acids to milk fat was decreased with fat supplementation. Addition of 2.5% fat to a diet containing a medium amount of fat from whole cottonseed increased milk yield. Tallow, Ca salt of palm fatty acids, and prilled fatty acids did not differ in milk yield response.