Fiber digestibility and protein value of pulp silage for lactating dairy cows: Effects of wet fractionation by screw pressing of perennial ryegrass.

The aim of the study was to investigate the effects of substituting silage of chopped grass with pulp silage of grass fractionated once or twice in a biorefinery using a screw press on fiber kinetics, protein value, and production of CH4 in dairy cows. Six lactating multiparous Holstein cows in mid-lactation (176 ± 93 d in milk), cannulated in the rumen, duodenum, and ileum, were used in an incomplete 6 × 4 Latin square design with a 2 × 3 factorial arrangement of treatments. Perennial ryegrass was harvested in third regrowth from the same field at early and late developmental stage (35 and 44 d of regrowth, respectively) and subjected to 1 of 3 types of processing within each developmental stage. Grass was either harvested for normal silage making (mowed, wilted, chopped, and ensiled), or harvested fresh and fractionated using a screw press. Half of the pulp from the first fractionation was ensiled, whereas the other half of the pulp was rehydrated, fractionated a second time, and pulp hereof was ensiled. The grass and pulp silages were used with concentrates (65:35 forage to concentrate ratio) to make total mixed rations (TMR) based on either silage of chopped grass (GS), pulp silage of grass fractionated once (1×P), or pulp silage of grass fractionated twice (2×P), harvested either at early (E) or late (L) developmental stage resulting in 6 different TMR treatments (EGS, E1×P, E2×P, LGS, L1×P, L2×P). The TMR were fed for ad libitum intake and samples of intestinal digesta and feces were collected for determination of digestibility. The effect of processing on ash-free neutral detergent fiber (aNDFom) concentration in silages depended on developmental stage, but showed that within each developmental stage, pulp silage of grass fractionated twice had higher aNDFom concentration than pulp silage of grass fractionated once and silage of chopped grass. The 2×P resulted in lower (14.9 ± 0.55 vs. 17.5 ± 0.54 kg/d) dry matter intake (DMI) compared with GS. The effects of processing and developmental stage interacted such that apparent total-tract aNDFom digestibility was higher (784 ± 13 vs. 715 ± 13 g/kg) for L2×P compared with LGS, whereas no difference was found between E2×P and EGS. Moreover, the protein value was higher (106 ± 5 vs. 92 ± 5 g AA digested in the small intestine/kg of DMI) for 2×P compared with GS. Unexpectedly, processing had no effect on fractional rate of digestion of digestible aNDFom or CH4 yield (L/kg of DMI), whereas feeding forages harvested at early compared with late developmental stage resulted in lower CH4 yield. Feeding pulp silage of grass fractionated once generally yielded results intermediate to cows fed silage of chopped grass and pulp silage of grass fractionated twice. This study showed that pulp silage of fractionated grass could serve as feed for dairy cows because the fiber digestibility and protein value improved, but further research investigating effects of physical processing of forage on fiber kinetics is required.

Effects on feed intake, milk production, and methane emission in dairy cows fed silage or fresh grass with concentrate or fresh grass harvested at early or late maturity stage without concentrate.

The objective of the study was to quantify the effects on dry matter intake (DMI), nutrient digestibility, gas exchange, milk production, and milk quality in dairy cows fed fresh grass harvested at different maturity stages. Sixteen Danish Holstein cows in mid-lactation were divided into 4 blocks and used in 4 incomplete 4 × 2 Latin squares with 2 periods of 21 d. The cows received 1 of 4 treatments in each period, resulting in 8 cows per treatment, as follows: grass-clover silage supplemented with 6 kg/d concentrate pellets (SILc), fresh grass harvested at late maturity stage supplemented with 6 kg/d concentrate pellets (LATc), fresh grass harvested at late maturity stage (LAT), and fresh grass harvested at early maturity stage (ERL). The cows were housed in tiestalls and milked twice daily. The cows had ad libitum access to the forage, and concentrate pellets were divided into equal amounts and fed separately in the morning and afternoon. Fecal samples were collected to determine apparent total-tract digestibility, and samples of rumen fluid were collected for determination of short chain fatty acid composition. Halters were used for measuring eating and rumination time. Gas exchange was measured in open-circuit respiration chambers. Total DMI was higher in LATc and ERL (16.9 ± 0.45 and 15.5 ± 0.39 kg/d, respectively) compared with LAT (14.1 ± 0.42 kg/d). Relative to SILc, cows fed fresh grass experienced a convex pattern in DMI during the experiment. The changes in DMI were related to changes in leaf to stem ratio, fiber concentration, and organic matter digestibility determined in vitro in samples of the fresh grass harvested throughout the experiment. The apparent total-tract digestibility of organic matter was higher in SILc and LAT compared with LATc. Methane yield was lower for LATc compared with LAT (19.5 ± 0.61 vs. 22.6 ± 0.55 g of CH4/kg of DMI), and was not different between LAT and ERL. Compared with LAT, milk yield was higher for ERL (21.1 ± 1.14 vs. 23.4 ± 1.11 kg/d) and energy-corrected milk (ECM) yield was higher for LATc (21.5 ± 0.99 vs. 25.3 ± 1.03 kg/d). We detected no differences in milk or ECM yield between SILc and LATc. Milk protein yield was higher and milk fat concentration was lower in LATc compared with LAT. The fatty acid percentages of ∑C4-C14:1 and ∑C16 in milk were higher for SILc compared with LATc, signifying pronounced de novo synthesis. The n-6:n-3 ratio in milk fatty acids was lower for SILc and LAT compared with LATc, indicating improved nutritional quality for SILc and LAT. However, retinol concentration in milk was lower in SILc compared with all other treatments. The study implies that feeding silage instead of fresh grass has no effect on DMI, ECM yield, or CH4 yield, and that concentrate supplementation can increase milk production, affects milk quality, and reduces the effect on climate, whereas feeding less mature grass increases DMI and milk yield, but has no effect on CH4 yield.

Fava beans can substitute soybean meal and rapeseed meal as protein source in diets for lactating dairy cows.

The effect of replacing mixtures of wheat and soybean meal and wheat and rapeseed meal by toasted fava beans, and the effect of toasting fava beans on feed intake, milk yield, and composition of milk and feces were investigated using 40 Holstein cows in each of two 4 × 4 Latin square design trials conducted simultaneously. In trial 1, the 4 treatment concentrates were untreated fava beans, toasted fava beans, 42% soybean meal + 58% rolled wheat, and a 21, 29, and 50% mix of soybean meal, rolled wheat, and toasted fava beans, respectively [on dry matter (DM) basis]. In trial 2, the 4 experimental treatments were untreated fava beans, toasted fava beans, 64% rapeseed meal + 36% rolled wheat, and a 32, 18, and 50% mix of rapeseed meal, rolled wheat, and toasted fava beans, respectively (on DM basis). In each trial, 16 primiparous and 24 multiparous cows were fed the treatment concentrates as part of a partial mixed ration, of which the forage consisted of 50% corn silage and 50% grass-clover silage. Substitution of soybean meal and wheat or rapeseed meal and wheat with toasted fava beans did not affect total DM intake, and no linear effects were observed on milk yield or energy-corrected milk (ECM) yield. However, in trial 2, a quadratic effect was observed on milk yield when substituting rapeseed meal and wheat with toasted fava beans. In both trials, substitution of soybean meal and wheat or rapeseed meal and wheat with toasted fava beans increased milk lactose concentration and decreased milk protein yield and concentration of protein in milk. In both trials, fecal concentration of starch increased linearly when substituting soybean meal and wheat or rapeseed meal and wheat with toasted fava beans. In trial 2, fecal concentration of P decreased when substituting rapeseed meal and wheat with toasted fava beans. In situ investigations showed increased rumen undegradable protein concentration and thereby increased estimated metabolizable protein supply when toasting fava beans. However, in both trials, milk protein yield and concentration decreased when cows were fed toasted compared with untreated fava beans. Furthermore, when cows were fed toasted compared with untreated fava beans in trial 1, milk yield, ECM yield, and nitrogen efficiency decreased. We conclude that toasted fava beans could substitute soybean meal and wheat or rapeseed meal and wheat with regard to ECM yield. However, milk protein yield decreased when substituting soybean meal and wheat or rapeseed meal and wheat with toasted fava beans. Compared with untreated fava beans, toasting had no positive effect on milk production and nitrogen efficiency.

Parasites in cross-bred pigs in the Upper East region of Ghana.

A cross-sectional study was carried out in the Upper East Region (UER) of Ghana in order to estimate the prevalence of parasitic infections in local cross-bred pigs. Out of 60 villages with a human population of 200-1000 inhabitants, 10 villages were randomly selected for the study. The number of pigs varied from 50 to 200 pigs per village. In total 259 faecal samples from growers were collected and examined. Ninety-one percent of the animals excreted parasite eggs. Among these the prevalence of Eimeria spp. was 77.2%, Isospora suis (27%) and Balantidium coli (19.3%).The following helminth eggs were identified: Metastrongylus salmi (19.3%); Physocephalus sexalatus (17.4%); Oesophagostomum spp./Hyostrongylus rubidus (60.6%); Trichuris suis (4.6%); Ascaris suum (12.7%); Ascarops strongylina (8.1%); Brachylaemus suis (1.9%); Paragonimus suis (0.8%); Globocephalus urosubulatus (2.7%); and Schistosoma suis (0.4%). Furthermore, six growers were selected from each village for clinical and postmortem examinations, i.e. 60 in total. The clinical examinations revealed ectoparasites on 98.3% of the animals. The ectoparasites were: Haematopinus suis (66.7%); Boophilus spp. (58.3%); Amblyomma spp (45.0%); Sarcoptes suis (38.3%); and Rhipicephalus spp. (8.3%). All pigs were examined for the presence of haemoparasites. It was found that 23.3% of the animals had haemoparasites. These were: Babesia perroncitoi (23.3%); Babesia trautmanni (13.3%); and Eperytrozoon suis (1.7%). Based on postmortem examinations the following adult worms were identified: Metastrongylus salmi (83.3%); Oesophagostomum dentatum (63.3%); Oesophagostomum quadrispinulatum (38.3%); Hyostrongylus rubidus (23.3%); Ascarops strongylina (76.7%); Globocephalus urosubulatus (20.0%); Strongyloides spp. (1.7%); and Physocephalus sexalatus (65.0%). Cysts of the human tapeworm Taenia solium, Cysticercus cellulosae, were present in 11.7% of the animals. Small pieces of the diaphragm were examined for the presence of Sarcocystis spp.. The prevalence was 28.3%, but no larvae of Trichinella spp. were found. Furthermore, four of the animals (6.7%) had Taenia hydatigena cysts.

Experimental hybridization between Oesophagostomum dentatum and O. quadrispinulatum in pigs.

To investigate eventual hybridization between two nodular worm species of pigs, Oesophagostomum dentatum and O. quadrispinulatum, we used either mature, adult worms or 10-day-old fourth-stage larvae (L4) as starting material, employing a nonsurgical transplantation technique. Following the transfer of adult worms the ensuing first generation of larvae gave rise to adult worms that were found by morphological examination to be purely O. dentatum. Therefore, we decided to use the immature L4 as starting material. After the transfer of L4 to recipient pigs, fecal cultures were established and the L3 derived from the O. dentatum male O. quadrispinulatum female cross gave rise to adult but infertile worms, which morphologically had the sexual characters of their parent generation, whereas other characteristics were intermediate between the two species. Attempts to reproduce the hybrid worms or the reciprocal cross were unsuccessful, indicating that hybridization between the two species is a rarely occurring phenomenon.